My understanding was that they tried parachutes on several flights, but gave up on them once they realized the parachutes were tearing their boosters apart in the upper atmosphere. Although, Falcon 9 v1.0 is a lot less structurally sound than the K-1 LAP since the former wasn't designed with parachute recovery explicitly in mind. Propulsive landing is "hard mode" for an entirely new vehicle, but I think in the case of Falcon 9 it was the option that required the minimum booster re-design.
Kistling a Different Tune: Commercial Space in an Alternate Key
The major difference here is that both the LAP and the OV of the K-1 have attitude control systems that are active prior to parachute deployment. The need for such systems was indicated in the 1970s by Bellcomm as noted in this AMERICAN ROCKET NEWS EXCLUSIVE REPORT: Propulsive Landing of Ballistic Vehicles. This was a feature that SpaceX had not implemented into their recovery plans. I would also note that less than 20 main parachutes out of over 810 possible (135 flights, each with two boosters, each with three mains) had issues with either failures to deploy, or collapses after inflation over the shuttle program. Of these, only two boosters in the program were not recovered - the ones on STS-4, where they hit the water hard and fast after the 'chutes were cut prematurely.
Kistler has a pretty good handle on this, and ATK is the main integration contractor. Furthermore, Kistler isn't like SpaceX - they only have plans for two LAPs, three OVs, and a handful of payload modules. They can't afford to loose a third of their fleet hardware on the first launch.
It's worth comparing SpaceX's original recovery plans and the K-1 strategy in detail. SpaceX on Falcon 1 and the early Falcon 9 flights was attempting to orient the stage passively in the upper atmosphere and then decelerate to safe velocities for parachutes entirely aerodynamically with passive control. Their issue was that they were entering so fast and with so little control that the stages were breaking up. Once they decided to use the engines for orientation and boostback, having nine engines made landing propulsively make more sense than continuing to develop the parachutes and ocean landing. By contrast, the K-1 from day one was using a "boostback" and entry burn to slow the stage, and it only would reach a peak altitude of about 95 km even with some additional loft to help RTLS. They were less aggressive in their design, and thus they can probably get by with parachutes. That's not to say I don't think they'll have a few things to learn, but the sorts of things that mostly don't blow up stages...
IncongruousGoat wrote:
E of pi wrote:
IncongruousGoat wrote:
E of Pi is correct and as far as I can find SpaceX’s boosters never got to the point of deploying their chutes at all since they broke up due to tumbling and instability before that point. Parachutes would have actually stabilized the stages during reentry, (the short time they would have lasted) but SpaceX made some serious stability and balance assumptions that were unfounded. SpaceX had to experiment and find a way to stabilize the booster for proper reentry before they could even attempt propulsive landing and it took quite a while.
Kistler has already wind-tunneled and modeled the reentry stability and flight characteristics of their booster and orbiter and know that the ‘boost-back’ and lighter aerodynamic loading for the booster is within structural parameters. They are assuming that the booster will arrive at parachute deployment in a stable position from that modeling and are likely vastly closer to right than SpaceX was since the booster stage was made “shorter and squatter” specifically to ensure those dynamics.
(The more compact ‘squat’ shape of the K1 booster at 18.3m/60ft tall and 6.7m/22ft wide means it is less likely to tumble whereas the tall, thin F9 at 40.9m/143ft tall and only 3.7m/12ft wide pretty much ensures that without active stability control intact entry and landing is impossible. As noted it also included a reaction control stabilization system to keep it stable for reentry and parachute deployment. SpaceX didn't bother)
You REALLY want an even more ‘squat’ but aerodynamic shape for a stable reentry and landing booster, (SERVE/Apollo for example) but the “difficulty” of constructing is often the most cited reason for not using such a shape. In reality the main issue is transportation of such a shape any distance easily. Arguably building on or near the launch site and shipping by barge or ‘floating’ would be quite feasible for larger booster designs.
Maybe at some point when/if “I” have a couple billion to play with I’ll toss my hat in the ring too
Randy
E of pi wrote:
IncongruousGoat wrote:
E of Pi is correct and as far as I can find SpaceX’s boosters never got to the point of deploying their chutes at all since they broke up due to tumbling and instability before that point. Parachutes would have actually stabilized the stages during reentry, (the short time they would have lasted) but SpaceX made some serious stability and balance assumptions that were unfounded. SpaceX had to experiment and find a way to stabilize the booster for proper reentry before they could even attempt propulsive landing and it took quite a while.
Kistler has already wind-tunneled and modeled the reentry stability and flight characteristics of their booster and orbiter and know that the ‘boost-back’ and lighter aerodynamic loading for the booster is within structural parameters. They are assuming that the booster will arrive at parachute deployment in a stable position from that modeling and are likely vastly closer to right than SpaceX was since the booster stage was made “shorter and squatter” specifically to ensure those dynamics.
(The more compact ‘squat’ shape of the K1 booster at 18.3m/60ft tall and 6.7m/22ft wide means it is less likely to tumble whereas the tall, thin F9 at 40.9m/143ft tall and only 3.7m/12ft wide pretty much ensures that without active stability control intact entry and landing is impossible. As noted it also included a reaction control stabilization system to keep it stable for reentry and parachute deployment. SpaceX didn't bother)
You REALLY want an even more ‘squat’ but aerodynamic shape for a stable reentry and landing booster, (SERVE/Apollo for example) but the “difficulty” of constructing is often the most cited reason for not using such a shape. In reality the main issue is transportation of such a shape any distance easily. Arguably building on or near the launch site and shipping by barge or ‘floating’ would be quite feasible for larger booster designs.
Maybe at some point when/if “I” have a couple billion to play with I’ll toss my hat in the ring too
Randy
IncongrouousGoat wrote:
Probably not unjustified but probably also not for the ‘reason’ you might think SpaceX caused a ‘revolution’ not for re-usability or stage recovery thought they did manage those quite rapidly if not very efficiently. What they did was show that the overall cost of space access could be dropped significaintly which is something the ‘main’ players have been denying it possible without a vast and expensive “new” RLV program for the last couple of decades. This is going to remain a SpaceX strength TTL because one thing Kistler/RPK was NOT was “innovative” in either the manufacturing or business model sense. They were a lot of ex-NASA and ‘big’ Aerospace people who had no problems nor expectations of dropping the costs of access OUTSIDE having a reusable launch vehicle.
Outside of having an RLV their business and operations model was straight NASA/Aerospace so massive cost savings (and reduced launch prices) are extremely unlikely. The fact that the K1 is LEO capable only is another issue and the lack of crew carrying ability. (Though the latter isn’t “fixed” and since I’m not sure I posted it before: http://www.hobbyspace.com/AAdmin/archive/RLV/PR/AAS_Briefing_Edited.pdf, note the CTV “all-up” mass is right around the maximum of the K1 to lift to a 200km orbit or 4,400kg/9,900lbs)
Recently I've gotten to wondering "what-if" Beal and Kistler had gotten together or Beal at least had not gone down the "big-dumb-booster" route but instead went towards a reusable booster?
Randy
Probably not unjustified but probably also not for the ‘reason’ you might think
SpaceX caused a ‘revolution’ not for re-usability or stage recovery thought they did manage those quite rapidly if not very efficiently. What they did was show that the overall cost of space access could be dropped significaintly which is something the ‘main’ players have been denying it possible without a vast and expensive “new” RLV program for the last couple of decades. This is going to remain a SpaceX strength TTL because one thing Kistler/RPK was NOT was “innovative” in either the manufacturing or business model sense. They were a lot of ex-NASA and ‘big’ Aerospace people who had no problems nor expectations of dropping the costs of access OUTSIDE having a reusable launch vehicle.Outside of having an RLV their business and operations model was straight NASA/Aerospace so massive cost savings (and reduced launch prices) are extremely unlikely. The fact that the K1 is LEO capable only is another issue and the lack of crew carrying ability. (Though the latter isn’t “fixed” and since I’m not sure I posted it before: http://www.hobbyspace.com/AAdmin/archive/RLV/PR/AAS_Briefing_Edited.pdf, note the CTV “all-up” mass is right around the maximum of the K1 to lift to a 200km orbit or 4,400kg/9,900lbs)
Recently I've gotten to wondering "what-if" Beal and Kistler had gotten together or Beal at least had not gone down the "big-dumb-booster" route but instead went towards a reusable booster?
Randy
December 21, 2009--K-1 Risk Reduction Demo Attempt 1
Digsby Log: December 21, 2009 5:40 PM
rwdavidoff: Hello!mmeowl: Hi!
rwdavidoff: Hows the first day of break going?
mmeowl: Awesomely! Done with finals, nervous about grades but they won't be out for weeks
rwdavidoff: Yeah...grades.
rwdavidoff: I'm still nervous about calc.
rwdavidoff: Mom and I went out to Home Depot and got an ax yesterday, so I was taking out my nerves on that with the firewood pile all of today.
mmeowl: Nice! I should try that sometime.
rwdavidoff: Yeah, it was fun once I started to get the hang of it. I've got a nice little fire going in the fireplace.
rwdavidoff: Watching a fire waiting for a fire is pretty nice.
rwdavidoff: Not like Woomera or Oklahoma need the heat, but I'm enjoying it.
mmeowl: Heh. It's cold here too.
mmeowl: Woomera is where the rocket launch is?
rwdavidoff: Yeah. Woomera, Australia.
rwdavidoff: I was reading a bunch about it today.
mmeowl: Yeah? Any fun facts in particular?
mmeowl: Also what time is the launch? With that many time zones we'll be lucky if it isn't 3 AM
rwdavidoff: Fortunately, the orbital control team are over here. RPK's headquarters are in Oklahoma City. So they scheduled it for...an hour or so from now. T-43 minutes and counting.
rwdavidoff: The timezone's actually one of the interesting things. They're 15 and a half hours ahead of us.
mmeowl: Why would they do that.
mmeowl: That's bizarre.
rwdavidoff: I dunno. Maybe that's what happens when your clocks are all upside down?
mmeowl: LOL
rwdavidoff:
rwdavidoff: But Woomera's interesting. Historic, in a sense. The British had their missile test range out there for a long time back in the 50s and 60s.
rwdavidoff: And they even launched a few rockets to orbit.
rwdavidoff: Well, one rocket to orbit successfully.
rwdavidoff: Black Arrow's 4th flight, which took place after the program was cancelled.
rwdavidoff: They flew once to orbit, and they've never launched anything of their own since.
mmeowl: They launched it after the program was canceled? Did they not get the memo?
rwdavidoff: The stuff was already over there, and so the engineers who wanted to fly it argued it was cheaper to launch it than ship it back. You might approve of the name origin--they renamed the satellite from "Puck" to "Prospero" in that subtle British way of throwing shade.
rwdavidoff: Shakespeare allusions, eh?
mmeowl: "How do we get rid of this thing we don't want anymore? Let's THROW IT INTO SPACE."
mmeowl: Also that is an excellent Shakespeare allusion for a thing that got abandoned and then did well anyway.
rwdavidoff: Yeah. Woomera's sort of got a history of that. It was also the launch site for the early European space program rockets, before Britain bailed.
rwdavidoff: https://en.wikipedia.org/wiki/Europa_(rocket)#Operational_history
rwdavidoff: They flew the first few Europa launches from there.
rwdavidoff: All of which failed, on the German and French parts.
rwdavidoff: So then britain decides they'll go it alone, builds Black Arrow, and then cancels that too.
rwdavidoff: France and Germany put their heads together, decide to start over from scratch, and build Ariane.
mmeowl: Let's hope this one breaks the curse then lol
rwdavidoff: And that leads to the modern ESA and Ariane 5.
rwdavidoff: Yeah, right?
rwdavidoff: It's not even stuff like that...this rocket's engines, the AJ-26-58, 59, and 60?
rwdavidoff: They're really NK-33s.
rwdavidoff: The rocket engines from the Russian moon program.
mmeowl: Mmm, tasty alphabet soup.
mmeowl: But anyway how did an American rocket wind up with Russian engines?
rwdavidoff: Another round of cancellations and hilarious coincidence, basically.
rwdavidoff: The N1, the Russian moon rocket, had the same stellar record as everything else Kistler's reusing. Four straight failures. They were going to introduce the NK-33 engines on the fifth flight, replacing the (worse) NK-15 engines that had given them so much trouble.
rwdavidoff: They'd built enough for 5 launches or something.
mmeowl: And then they didn't? Did they stick with the NK-15s or cancel the whole thing?
rwdavidoff: Cancelled it. The new program head didn't like the old program head, so he cancelled the rocket and ordered all the engines destroyed. The basically hid them in a warehouse instead and said they had.
rwdavidoff: And then after the Soviet Union fell, American engineers heard about them.
mmeowl: And I thought high school grudges got weird.
rwdavidoff: They're staged combustion, which basically means they use insanely high pressures and get much better performance than anything we've built using kerosene and LOX.
mmeowl: Cool!
rwdavidoff: Like, SpaceX's Merlin engines run on about the same engine pressure as the Saturn V's F-1s back in the 60s.
rwdavidoff: The NK-33 is about 50% higher.
mmeowl: Nice.
rwdavidoff: They use similar engines with the same cycle on their current rockets, but the Nk-33s were just kind of sitting around. Kistler, back in the mid-90s before they were bought by rocketplane, found out and designed their vehicle around them since they were cheap.
mmeowl: That's sensible. Is the rest of it new, then?
rwdavidoff: Yeah. Hang on, there's a video...
rwdavidoff:
rwdavidoff: It's a two stage reusable vehicle, like the Shuttle was going to be originally.
mmeowl: Cool. Watching the video . . .
rwdavidoff: Hopefully, we'll set to see something like this in half an hour or so.
mmeowl: The flat top is weird. Put a nose cone on, there are children watching.
rwdavidoff: I hope so!
rwdavidoff: They just confirmed propellant loading is complete. The webstream should start in another ten minutes.
rwdavidoff: The kind of cool thing about it is that the front part is swappable.
rwdavidoff: They're flying it with that first version today--the "Expandable Payload Module," the nose fairing for launching satellites.
mmeowl: What are the other options?
rwdavidoff: They'll use another pair for servicing the International Space Station, like they show afterward i nthe video.
mmeowl: Neat.
rwdavidoff: They both have a space station docking port on the front behind the nosecone. One has a pressurized module for carrying cargo, and the other has a side door and an unpressurized area for sticking stuff that goes on the outside of the station.
mmeowl: And that first one is the one they use to launch satellites?
rwdavidoff: So you pull that section off and swap it around, nad you can make one Orbital Vehicle do triple duty.
rwdavidoff: Yeah.
mmeowl: Clever.
rwdavidoff: Well, if anyone buys from them...
rwdavidoff: I hope they get some contracts soon.
mmeowl: Knock on wood.
rwdavidoff: Some of the people on ARN say it's too small or it won't be cheap enough. I guess we'll see.
rwdavidoff: The company is so old and full of 90s strangeness. Like, you were saying this one looks funny? Look at this:
rwdavidoff:
rwdavidoff: Yeah, I know. It's the reason they call their first stage a "Launch Assistance Platform"--the original design was that bedstead thing carrying something that was just barely shy of a single-stage-to-orbit.
rwdavidoff: And the middle part comes off...it's like a rocket in a to-go box made of rockets.
rwdavidoff: Propulsive landing on the LAP, instead of airbags. I think they got rid of that as too complex.
mmeowl: Does that change what sort of locations/surfaces they can land on?
rwdavidoff: Well, you need a pad for rocket landing, like the old Heinlein books. You can do parachutes and airbags on the water if you really need to.
rwdavidoff: But RPK don't want to--sea water's nasty enough they'd rather not deal with it.
rwdavidoff: It's part of why they're using Woomera--it's far enough inland that even if their boostback fails, the stages will just land downrange in the desert.
mmeowl: I can see that. I also prefer not to get dropped in the ocean.
mmeowl: Of course, I wouldn't like being dropped in the desert either.
rwdavidoff: I'll make a note of that for if we ever go to the beach together, dear.
mmeowl: Hee.
rwdavidoff: Oh, hey! They're starting the stream. Here: www.kistleraerospace.com/webcast
mmeowl: Nice!
rwdavidoff: So the launch control room we're seeing here is the one in Oklahoma.
rwdavidoff: I think the tiny one they cut to now and then is the one on-site at Woomera.
rwdavidoff: Rocketplane's basically two companies mashed together, so the division of responsibility is a little strange--yeah, they're talking about that. Woomera will control the vehicle during ascent and descent, but the flight will also be monitored from OK.
rwdavidoff: Oh, hey! Better version of that video we were just watching!
mmeowl: Oh neat, good resolution! I'm glad they seem to have their act together coordinating everything; it sounds pretty annoying.
rwdavidoff: If the half hour offset is annoying for us, I can't imagine for them...
mmeowl: Yup.
mmeowl: I like that they're going into the history of the launch site; maybe a lot of the people watching already know this stuff, but I don't and it's neat.
mmeowl: Oh hey it's that prospero rocket you mentioned.
rwdavidoff: I think it's nifty too, I didn't know a huge amount about Woomera until....basically, last night.
rwdavidoff: Stayed up way too late reading wikipedia.
rwdavidoff: Yeah, and there's Europa.
mmeowl: Fun video.
rwdavidoff: Oooh! Actually K-1 on the pad. That beats history videos.
mmeowl: Ah, wikipedia. Second only to TV tropes in ability to eat your night.
rwdavidoff: Look at the vapor plumes off the vehicle.
rwdavidoff: I think that's boiling LOX?
rwdavidoff: Yeah, ARn is saying it is.
mmeowl: It always seems like such a waste, but presumably it's more efficient than preventing boil-off would be or they'd do that.
rwdavidoff: It's 95 degrees over there right now, and they supercool the LOX so they can fit more in.
rwdavidoff: It increases the density.
rwdavidoff: So with that weather (summer, it's summer over there at the launch site. And half hour offsets. Australia is strange...) it'd be pretty hard to stop any boiloff at all.
rwdavidoff: So I guess they just let it happen.
mmeowl: Yeah.
mmeowl: Though really, the difference between summer and winter is pretty minor when you're at liquid-oxygen temperatures.
rwdavidoff: Yeah...
rwdavidoff: Ohh! Polling for the autosequences...
rwdavidoff: Come on...Go, GO, GO!
rwdavidoff: Yes, all good!
rwdavidoff: T-5 minutes and counting...
mmeowl: W00t!
rwdavidoff: Man, I'm wired.
mmeowl: I love the ritual aspect of it, when they poll everybody.
rwdavidoff: I need to walk around for a minute, I'm going to go grab my jacket and go grab some more wood from outside.
mmeowl: Have fun, I'll be inside where it's warm.
rwdavidoff: I've just about burnt everything I brought in earlier, and its that are start bouncing around like a lunatic.
rwdavidoff: *it's that or
rwdavidoff: brb
rwdavidoff: Back. Waht's the clock at?
mmeowl: T minus 2:15
rwdavidoff: All right. Still waiting for handoff to internal power then.
rwdavidoff: Every time the venting kicks up and the microphones catch the hiss it's making me jumpy.
mmeowl: Yeah.
rwdavidoff: T-90 seconds...
rwdavidoff: Okay, there. Internal power.
rwdavidoff: T-45 engines, should be in startup.
rwdavidoff: Yeah, they just confirmed that. I think that's the new plume at the base?
rwdavidoff: Oh! The water deluge just kicked in.
rwdavidoff: T-15...
rwdavidoff: 10.
rwdavidoff: 9
rwdavidoff: 8
rwdavidoff: 7
rwdavidoff: 6
rwdavidoff: 5
rwdavidoff: 4
rwdavidoff: 3
rwdavidoff: 2
rwdavidoff: 1...
rwdavidoff: ...liftoff?
"Liftoff?" Oh dear. That's concerning. Hopefully the first K-1 didn't just blow up on the pad.
Guys, Some research might be in order (look at page 23).
Yes, 'Kistler' is still a somewhat going concern even now in 2019. For all I can tell it's three guys in an office and a website, that happens to also be the server for Rocketplane Global
December 21, 2009--K-1 Risk Reduction Demo Ascent and LAP Landing
AUTHOR'S NOTE: Points to @TimothyC for seeing through my blatant attempt to stoke some tension in how I split up the launch coverage. As the payload guide confirms, the K-1 counts T-0 as ignition, not liftoff, and has a somewhat long hold-down time to verify the engines are running well before release. On a first launch, I'd imagine it'd be rather alarming...
Ever since the five minute mark, the K-1’s Draper-designed avionics had been in complete control of the vehicle and even commanding the ground infrastructure. For all intents and purposes, the human monitoring of the data was only a backup--and one all too likely to respond too slowly in an emergency. Thus, Draper and RPK had worked carefully to give the vehicle as much intelligence as it could use. If the flight was successful, the next time the vehicle would really require any input from the ground was ahead of the return of the OV from orbit. For the last fifteen minutes, 3 lbm/sec of supercooled LOX had been circulating through the vehicle’s engines to cool it down, which just within the last few minutes had doubled. For the last forty-five seconds, the vehicle had been busy. The engine controllers had performed an internal-self test, verified valve positions, and checked the sensor signals. Then, it had cycled the mixture ratio valves and thrust control valves in and out of flight nominal to confirm actuator function, first with the primary and then with the backup electronic command channels. With the settings controlled, the engine had queried tank pressures and temperatures, and confirmed it was ready to start. As all three LAP engines reported up the line to the vehicle’s main avionics, the signal had come back down to each controller: go for main engine start. The tightly calibrated dance that was starting a staged-combustion engine of a near 40-year old vintage began.
The fuel prevalves opened, the turbines were pre-spun by a solid propellant cartridge, and a series of pressure-actuated valves began the flow of liquid oxygen. Half a second before flight, the waves of propellants hit the proper levels. Three massive pyroigniters started the fires of the main chamber, while a splash of hypergolic TEA-TEB lit the preburner. A wave of flame leapt through the engine, and the deflagrating gasses lept out the throat of the engine until there wasn’t room in the throat. The flow choked, and the accumulating pressures slammed it supersonic. The gas flow stabilized at the startup throttle point of 55%, while the engine controllers each monitored the arrays of valves and sensors at their electronic fingertips. As the count-down hit zero, the vehicle hung, still held down to the pad by a delicate balance of thrust, hold-downs, and gravity. Two seconds passed while thousands of hearts leapt into throats before the steely-eyed computers gave their verdict from aboard the howling stack. All three engine controllers raised an electronic thumbs-up, and the main avionics issued two commands. One was to the engine controllers--full power! As the throttles answered electronic bells for 100% thrust, the K-1’s avionics commanded the ground support computers to fire the bolts and release the rocket. It was the last order the control line would carry--just moments later, as the vehicle lifted free of the pad, the expendable flyaway umbilical to the ground detached and fell away into the fire of the engines as the rocket rose above the pad. The K-1 was free, clear, and rising. With a thrust to weight ratio of 1.21, it took a ponderous six seconds to move its own height, but the vehicle was quickly gathering way as the avionics began to steer the vehicle down the pitch and roll programs for the LAP main ascent burn.
rwdavidoff: Yes, there it goes!
mmeowl: Woah
rwdavidoff: Man, it hung there for a second. I thought my feed had died.
mmeowl: For a second I thought it turned on and just . . . didn't go up. Like the engine only came on halfway.
rwdavidoff: Past the tower, they're tipping over.
mmeowl: But there it goes!!
rwdavidoff: Okay, so power and telemetry nominal...engines nominal?
rwdavidoff: Yes, propulsion nominal. Whatever that was, it’s over now.
rwdavidoff: Come on NK-33!
mmeowl: Look at that. The plume is so funky--all stretched out by the three engines in a line. It looks like Sauron...
rwdavidoff: Yeah that really does look like an eyeball.
mmeowl: At least from this angle. I guess from 90 degrees around it would look different.
mmeowl: How long until it's supposed to stage?
rwdavidoff: 2 minutes, 19 seconds.
rwdavidoff: Should pass through max-Q any moment now...
rwdavidoff: And it did!
rwdavidoff: Another minute, that's all...come on...
mmeowl: The plume looks bigger now; is that because it's high enough that there's less air pressure holding it together?
rwdavidoff: Yeah.
rwdavidoff: It's part of why they have to stage, the engines on the LAP aren't built for the higher altitudes.
rwdavidoff: Another fifteen seconds or so...dang, the plume's getting really wide.
rwdavidoff: The camera view down the rocket is interesting. Look at how red the outback looks.
rwdavidoff: Just...nothing down there.
rwdavidoff: Truly the middle of nowhere.
rwdavidoff: I think this is mounted on the LAP? I don't see the flare, so it's not mounted on the OV.
mmeowl: I wonder if they'll switch to another camera for the second stage.
rwdavidoff: Here comes staging!
mmeowl: Then we'll have two separate rockets to be nervous about!
rwdavidoff: Wow, that is a complex list of events they were just explaining.
mmeowl: I honestly think "explosive bolts" is one of the coolest phrases ever.
rwdavidoff: Staged engine shutdown, staging, OV engine ignition, first stage flip, and LAP relight...
rwdavidoff: Yeah, I know, right?
As the vehicle prepared for separation, the avionics switched relays, changing the image being broadcast to the ground from the camera mounted looking aft near the top of the LAP to one of the other two on the vehicle. Both were on the OV, one tucked inside the payload module, facing forward from the aft bulkhead of the payload bay, and this one, facing aft inside the confined compartment inside the flare, where the bell of the vacuum-optimized AJ-26-60 engine dominated the scene, dimly lit by a light on the camera. Mounted to the engine, that engine controller was stepping through the same sequence which the LAP engines had followed just two minutes earlier--indeed the two engine types were so identical that they were almost completely interchangeable, except for the oversized radiatively-cooled nozzle extension.
The backside of the flare was a maze of propellant tanks and avionics boxes. Intermixed were yet more engines. Flanking the camera on the frutum's sloping sides were two of the orbital vehicle's cold-gas thruster pods, each with three tiny nozzles, two for roll and one facing aft for pitch and yaw control. Another pair faced the other way from just a few centimeters below--the LAP’s own jets, facing up into the frustum for these last few moments before separation. Just in view on the other side of the frustum were two medium-sized bells--the exhausts of the LOX/ethanol maneuver engines which made the K-1’s OV not just a rocket stage, but a spacecraft. Mounted inside the flare’s frustum, the camera had the best view possible of the critical propulsion and control systems of the OV to beam back to ground-based receivers not just for the webcast but for engineering analysis, while being securely tucked away from the fires of entry.
As the thrust of the LAP cut away suddenly, hoses and insulation in the compartment jostled and leapt, then suddenly a bright light whited out the scene until the camera could compensate, the bright light of the earth entering as the bolts released the LAP and it was kicked clear of the OV and its precious engines by the pressure built up in the interstage. As the bells cleared, dozens of RPK employees caught a measured breath of relief, augmented as the engine belched smoke for a moment and then the flames of proper start and full throttle. Astern, the LAP fell away, already beginning to twist into the flip for its boostback. Behind it, the camera caught the brilliant blue glow of the Earth’s atmosphere, and the gorgeously vivid colors of the Australian Outback--inhospitable, terribly hot, but gorgeous seen from this far away.
mmeowl: ...Oh! New camera. Is this inside the second stage?
rwdavidoff: Looks like it!
mmeowl: I love the top-down angle on the plume.
mmeowl: Wow, the first stage gets left behind really fast.
rwdavidoff: No kidding! Wow, you can see it flipping over.
rwdavidoff: I'm looking at what we can see here in the flare. I think that's the OMS engines just visible on the other side of the main engine bell, the ones they use for orbital maneuvers.
rwdavidoff: And then the thruster clusters around the inside.
rwdavidoff: Ohh! You can see the LAP engine firing!
mmeowl: Cool. Are they likely to use either of those before the stream ends?
mmeowl: Nifty!
rwdavidoff: I don't know how much they're showing today.
rwdavidoff: Oh, I guess I'm wrong, you can see the thrusters jetting.
rwdavidoff: Roll control for the flight, I guess?
rwdavidoff: Fun. I'm not sure how long the first stage burn is going to be, I'll be glad when they confirm it's on a proper course back to Woomera.
rwdavidoff: That's got to be nerve-wracking. "The rocket stage is coming almost directly at us, but in exactly the right amount of 'almost'. "
mmeowl: Yeah, I actually feel more nervous about that than about the satellites.
mmeowl: Not like I'm worried it's going to land on the control building in particular--there are a lot of places for it to go and only one of them is the control building.
mmeowl: Just that it'll land in the wrong place, or too hard, or get really confused and land in the Pacific or something.
rwdavidoff: I am too. Not much to go wrong once stage two is firing. Just have to watch the upper stage version of the engine keep glowing and burning.
rwdavidoff: Wow, look at the curvature on the Earth. We were on the ground five minutes ago!
rwdavidoff: Heh, the webcast announcer mentioned that. A nice little plug for their suborbital tourism business.
mmeowl: Heh. If I ever win the lottery that I don't play . . .
rwdavidoff: They must be jealous Virgin Galactic beat them to rolling out their spaceplane.
rwdavidoff: First stage atmospheric entry coming up. I wonder if we'll get a camera view back?
mmeowl: I mean...that camera we were watching is still mounted to it ,right?
rwdavidoff: OV's just trucking along. I wish they'd give us a different camera angle, all the excitement's going on down near the ground…
rwdavidoff: OV should burn out any minute now…7.5 kms, we’re basically orbital.
rwdavidoff: And cutoff!
rwdavidoff: Now just have to see if they get the LAP back and ready to fly! Doesn’t look like we’re getting a picture. Entry coming up…
mmeowl: Sounds like the drogue chutes are out!
rwdavidoff: Yeah! Wish they’d show that, not just the OV sitting there.
rwdavidoff: Wait, are the OMS engines firing?
mmeowl: Well it doesn’t look like the mains
rwdavidoff: No, but that’s definitely the OMS engines. “Cleanup burn.” Funky. I think Shuttle does...something like that? Still! There, they just said good orbit! I’ll take it.
mmeowl: Nominal for best word.
rwdavidoff: Nominal nominated?
rwdavidoff: Oh! And ground tracking camera! Look at it twitching under the drogues.
rwdavidoff: Breathing fast, but I think they’ve got it…
mmeowl: I bet they do, I bet it works
rwdavidoff: They’ve tested this all...
rwdavidoff: Now just the mains...
rwdavidoff: Maybe?
mmeowl: Yes!
rwdavidoff: Yeah! There they are! Wow…
mmeowl: They kick in really fast, woah.
rwdavidoff: Wow, look at it slow down...
rwdavidoff: I wonder if they can make it to the ground okay even without the airbags? They can't end up going that fast. Shuttle SRbs use parachutes too, and they just splashdown.
mmeowl: Well, landing on the water is probably more forgiving?
mmeowl: Than landing on the ground, I mean.
rwdavidoff: True. Looks like it’s getting bigger. I think that’s not all zoom, right?
mmeowl: I think so. Makes you wish you were watching in person, though.
rwdavidoff: No kidding! Here it comes . . .
rwdavidoff: Come on, zoom INNNN.
rwdavidoff: Looks like the airbags are deploying!
mmeowl: Yeah, I can see them too!
rwdavidoff: Looks kind of silly, hanging off the side like that.
rwdavidoff: If it works, it works, though...
rwdavidoff: We'll know soon.
mmeowl: I keep thinking they're going to pop like balloons.
rwdavidoff: Me too...
mmeowl: Touchdown!
Left off the cameras, the LAP had been busy since separating. There wasn’t time to waste. Almost from the instant it had separated, its Draper avionics had been at work. First, it had to compute the required time to start the boostback burn and the right moment to shut it off to leave it on track for the launch site, then the time until entry. After a frantic minute or two, though, things had quieted down. The stage was in freefall, steady in entry attitude--engine nozzles and base thermal protection facing into the airstream, held in place by the intermittent bursts from the cold gas attitude jets at the top of the stage. Bottom-first, it rose towards the increased apogee created by boostback. The curvature of the Earth yawned below it, visible to the rocket-mounted camera which had carried the feed from launch. The view was only the camera’s to enjoy and record--it was no longer being broadcast to the ground, waiting to be retrieved from the camera’s onboard storage. If the stage survived, it would make amazing marketing footage for both RPK’s orbital and suborbital vehicles. Unlike its sister the OV or its cousin the Rocketplane XP, though, the K-1 LAP wasn’t quite a spaceship. It skimmed to 97 kilometers, missing the Karman line by bare kilometers, before beginning to gather velocity back towards the ground below.
The camera, pointed aft along the stage to capture ascent, was oriented wrong to capture the critical events of entry. The drogue’s deployment was just a jerk of the stage as the chutes yanked open and fought the airstream. The mains were more of the same, accompanied by a reassuring decrease in the rate of approach of the yawning earth below. For a long minute, it seemed as though the stage was hardly moving, the camera picture changing only barely as the stage drifted tail-first towards the ground. Finally, however, the ground began to come up, suddenly growing close remarkably fast. Just as a human pilot might have beginning to be alarmed, the deployment of the bridle and the attitude control thrusters began to tip the stage onto its side for final descent. The placement of the rocket camera had been hotly debated by the K-1 team. Some had wanted it on the top side, to better image the parachutes and bridle during this critical phase. Others had successfully argued for using it to directly image the deployment of the four airbags on the underside. While the camera’s field of view down the rocket would barely capture the parachutes, even drifting side-on towards the ground, the airbags were perfectly centered, the data on their deployment being collected for analysis after flight.
With the camera facing down between the airbags, the ground came up, closer every moment. Dots grew into the the minor terrain and rocks left in the carefully cleared square kilometers of desert Kistler and ATK technicians had spent months pulling every boulder and tree out of--a square of desert as carefully manicured as a croquet lawn. With little left on the ground, there was no scale until, suddenly, the stage’s shadow flashed into the view, mere seconds before the entire stage hit the ground. The airbags didn’t pop--they released air as they had been designed to, spreading the shock as they lowered the stage to the ground. The camera jolted, while ground cameras carried the good news to the controllers. With touchdown verified, the LAP avionics completed their last tasks to begin safing the vehicle for the trucks that would arrive soon to retrieve it. The airbags released their remaining pressure with a hiss and the tanks began to vent the remaining propellant pressure in tight clouds of vapor, like the stage was letting out its own sigh of relief.
rwdavidoff: IMPACT!
rwdavidoff: Looks like it's intact?
rwdavidoff: I didn't see any Earth shattering kaBOOM anyway.
mmeowl: It looks good! I hope it didn't get battered too much inside.
rwdavidoff: Me too. We'll get to find out.
mmeowl: The real test is will they fly it again.
mmeowl: OV is in space, too.
rwdavidoff: Not a bad 7 minutes, all told.
rwdavidoff: It turns out it's a spaceship.
mmeowl: The announcer sounds really happy.
rwdavidoff: I would be too!
mmeowl: Heck, I am happy and I'm not even involved.
mmeowl: Spaceships are awesome.
rwdavidoff: Yep!
rwdavidoff: I guess they're cutting the feed here. I guess that makes sense, but I wanted to see the nosecone deployment. Not for an hour, though.
mmeowl: It would be cool if they grabbed isolated bits of footage of later cool things happening and posted them.
rwdavidoff: Yeah, I hope they do.
rwdavidoff: Let me go throw another few logs on the fire, and then want to read some 1/0?
rwdavidoff: I'm really looking forward to seeing you after Christmas. It's nice talking, but it's been a while since Thanksgiving.
rwdavidoff: https://xkcd.com/352/
mmeowl: Yeah, I miss you too. Sure, 1/0 is good.
mmeowl: And having someone to talk about it with in real time only improves it.
mmeowl: I think I'm actually more excited for your visit than I am for actual Christmas.
rwdavidoff: Me too. I love you, geeky.
mmeowl: I love you too.
Ever since the five minute mark, the K-1’s Draper-designed avionics had been in complete control of the vehicle and even commanding the ground infrastructure. For all intents and purposes, the human monitoring of the data was only a backup--and one all too likely to respond too slowly in an emergency. Thus, Draper and RPK had worked carefully to give the vehicle as much intelligence as it could use. If the flight was successful, the next time the vehicle would really require any input from the ground was ahead of the return of the OV from orbit. For the last fifteen minutes, 3 lbm/sec of supercooled LOX had been circulating through the vehicle’s engines to cool it down, which just within the last few minutes had doubled. For the last forty-five seconds, the vehicle had been busy. The engine controllers had performed an internal-self test, verified valve positions, and checked the sensor signals. Then, it had cycled the mixture ratio valves and thrust control valves in and out of flight nominal to confirm actuator function, first with the primary and then with the backup electronic command channels. With the settings controlled, the engine had queried tank pressures and temperatures, and confirmed it was ready to start. As all three LAP engines reported up the line to the vehicle’s main avionics, the signal had come back down to each controller: go for main engine start. The tightly calibrated dance that was starting a staged-combustion engine of a near 40-year old vintage began.
The fuel prevalves opened, the turbines were pre-spun by a solid propellant cartridge, and a series of pressure-actuated valves began the flow of liquid oxygen. Half a second before flight, the waves of propellants hit the proper levels. Three massive pyroigniters started the fires of the main chamber, while a splash of hypergolic TEA-TEB lit the preburner. A wave of flame leapt through the engine, and the deflagrating gasses lept out the throat of the engine until there wasn’t room in the throat. The flow choked, and the accumulating pressures slammed it supersonic. The gas flow stabilized at the startup throttle point of 55%, while the engine controllers each monitored the arrays of valves and sensors at their electronic fingertips. As the count-down hit zero, the vehicle hung, still held down to the pad by a delicate balance of thrust, hold-downs, and gravity. Two seconds passed while thousands of hearts leapt into throats before the steely-eyed computers gave their verdict from aboard the howling stack. All three engine controllers raised an electronic thumbs-up, and the main avionics issued two commands. One was to the engine controllers--full power! As the throttles answered electronic bells for 100% thrust, the K-1’s avionics commanded the ground support computers to fire the bolts and release the rocket. It was the last order the control line would carry--just moments later, as the vehicle lifted free of the pad, the expendable flyaway umbilical to the ground detached and fell away into the fire of the engines as the rocket rose above the pad. The K-1 was free, clear, and rising. With a thrust to weight ratio of 1.21, it took a ponderous six seconds to move its own height, but the vehicle was quickly gathering way as the avionics began to steer the vehicle down the pitch and roll programs for the LAP main ascent burn.
rwdavidoff: Yes, there it goes!
mmeowl: Woah
rwdavidoff: Man, it hung there for a second. I thought my feed had died.
mmeowl: For a second I thought it turned on and just . . . didn't go up. Like the engine only came on halfway.
rwdavidoff: Past the tower, they're tipping over.
mmeowl: But there it goes!!
rwdavidoff: Okay, so power and telemetry nominal...engines nominal?
rwdavidoff: Yes, propulsion nominal. Whatever that was, it’s over now.
rwdavidoff: Come on NK-33!
mmeowl: Look at that. The plume is so funky--all stretched out by the three engines in a line. It looks like Sauron...
rwdavidoff: Yeah that really does look like an eyeball.
mmeowl: At least from this angle. I guess from 90 degrees around it would look different.
mmeowl: How long until it's supposed to stage?
rwdavidoff: 2 minutes, 19 seconds.
rwdavidoff: Should pass through max-Q any moment now...
rwdavidoff: And it did!
rwdavidoff: Another minute, that's all...come on...
mmeowl: The plume looks bigger now; is that because it's high enough that there's less air pressure holding it together?
rwdavidoff: Yeah.
rwdavidoff: It's part of why they have to stage, the engines on the LAP aren't built for the higher altitudes.
rwdavidoff: Another fifteen seconds or so...dang, the plume's getting really wide.
rwdavidoff: The camera view down the rocket is interesting. Look at how red the outback looks.
rwdavidoff: Just...nothing down there.
rwdavidoff: Truly the middle of nowhere.
rwdavidoff: I think this is mounted on the LAP? I don't see the flare, so it's not mounted on the OV.
mmeowl: I wonder if they'll switch to another camera for the second stage.
rwdavidoff: Here comes staging!
mmeowl: Then we'll have two separate rockets to be nervous about!
rwdavidoff: Wow, that is a complex list of events they were just explaining.
mmeowl: I honestly think "explosive bolts" is one of the coolest phrases ever.
rwdavidoff: Staged engine shutdown, staging, OV engine ignition, first stage flip, and LAP relight...
rwdavidoff: Yeah, I know, right?
As the vehicle prepared for separation, the avionics switched relays, changing the image being broadcast to the ground from the camera mounted looking aft near the top of the LAP to one of the other two on the vehicle. Both were on the OV, one tucked inside the payload module, facing forward from the aft bulkhead of the payload bay, and this one, facing aft inside the confined compartment inside the flare, where the bell of the vacuum-optimized AJ-26-60 engine dominated the scene, dimly lit by a light on the camera. Mounted to the engine, that engine controller was stepping through the same sequence which the LAP engines had followed just two minutes earlier--indeed the two engine types were so identical that they were almost completely interchangeable, except for the oversized radiatively-cooled nozzle extension.
The backside of the flare was a maze of propellant tanks and avionics boxes. Intermixed were yet more engines. Flanking the camera on the frutum's sloping sides were two of the orbital vehicle's cold-gas thruster pods, each with three tiny nozzles, two for roll and one facing aft for pitch and yaw control. Another pair faced the other way from just a few centimeters below--the LAP’s own jets, facing up into the frustum for these last few moments before separation. Just in view on the other side of the frustum were two medium-sized bells--the exhausts of the LOX/ethanol maneuver engines which made the K-1’s OV not just a rocket stage, but a spacecraft. Mounted inside the flare’s frustum, the camera had the best view possible of the critical propulsion and control systems of the OV to beam back to ground-based receivers not just for the webcast but for engineering analysis, while being securely tucked away from the fires of entry.
As the thrust of the LAP cut away suddenly, hoses and insulation in the compartment jostled and leapt, then suddenly a bright light whited out the scene until the camera could compensate, the bright light of the earth entering as the bolts released the LAP and it was kicked clear of the OV and its precious engines by the pressure built up in the interstage. As the bells cleared, dozens of RPK employees caught a measured breath of relief, augmented as the engine belched smoke for a moment and then the flames of proper start and full throttle. Astern, the LAP fell away, already beginning to twist into the flip for its boostback. Behind it, the camera caught the brilliant blue glow of the Earth’s atmosphere, and the gorgeously vivid colors of the Australian Outback--inhospitable, terribly hot, but gorgeous seen from this far away.
mmeowl: ...Oh! New camera. Is this inside the second stage?
rwdavidoff: Looks like it!
mmeowl: I love the top-down angle on the plume.
mmeowl: Wow, the first stage gets left behind really fast.
rwdavidoff: No kidding! Wow, you can see it flipping over.
rwdavidoff: I'm looking at what we can see here in the flare. I think that's the OMS engines just visible on the other side of the main engine bell, the ones they use for orbital maneuvers.
rwdavidoff: And then the thruster clusters around the inside.
rwdavidoff: Ohh! You can see the LAP engine firing!
mmeowl: Cool. Are they likely to use either of those before the stream ends?
mmeowl: Nifty!
rwdavidoff: I don't know how much they're showing today.
rwdavidoff: Oh, I guess I'm wrong, you can see the thrusters jetting.
rwdavidoff: Roll control for the flight, I guess?
rwdavidoff: Fun. I'm not sure how long the first stage burn is going to be, I'll be glad when they confirm it's on a proper course back to Woomera.
rwdavidoff: That's got to be nerve-wracking. "The rocket stage is coming almost directly at us, but in exactly the right amount of 'almost'. "
mmeowl: Yeah, I actually feel more nervous about that than about the satellites.
mmeowl: Not like I'm worried it's going to land on the control building in particular--there are a lot of places for it to go and only one of them is the control building.
mmeowl: Just that it'll land in the wrong place, or too hard, or get really confused and land in the Pacific or something.
rwdavidoff: I am too. Not much to go wrong once stage two is firing. Just have to watch the upper stage version of the engine keep glowing and burning.
rwdavidoff: Wow, look at the curvature on the Earth. We were on the ground five minutes ago!
rwdavidoff: Heh, the webcast announcer mentioned that. A nice little plug for their suborbital tourism business.
mmeowl: Heh. If I ever win the lottery that I don't play . . .
rwdavidoff: They must be jealous Virgin Galactic beat them to rolling out their spaceplane.
rwdavidoff: First stage atmospheric entry coming up. I wonder if we'll get a camera view back?
mmeowl: I mean...that camera we were watching is still mounted to it ,right?
rwdavidoff: OV's just trucking along. I wish they'd give us a different camera angle, all the excitement's going on down near the ground…
rwdavidoff: OV should burn out any minute now…7.5 kms, we’re basically orbital.
rwdavidoff: And cutoff!
rwdavidoff: Now just have to see if they get the LAP back and ready to fly! Doesn’t look like we’re getting a picture. Entry coming up…
mmeowl: Sounds like the drogue chutes are out!
rwdavidoff: Yeah! Wish they’d show that, not just the OV sitting there.
rwdavidoff: Wait, are the OMS engines firing?
mmeowl: Well it doesn’t look like the mains
rwdavidoff: No, but that’s definitely the OMS engines. “Cleanup burn.” Funky. I think Shuttle does...something like that? Still! There, they just said good orbit! I’ll take it.
mmeowl: Nominal for best word.
rwdavidoff: Nominal nominated?
rwdavidoff: Oh! And ground tracking camera! Look at it twitching under the drogues.
rwdavidoff: Breathing fast, but I think they’ve got it…
mmeowl: I bet they do, I bet it works
rwdavidoff: They’ve tested this all...
rwdavidoff: Now just the mains...
rwdavidoff: Maybe?
mmeowl: Yes!
rwdavidoff: Yeah! There they are! Wow…
mmeowl: They kick in really fast, woah.
rwdavidoff: Wow, look at it slow down...
rwdavidoff: I wonder if they can make it to the ground okay even without the airbags? They can't end up going that fast. Shuttle SRbs use parachutes too, and they just splashdown.
mmeowl: Well, landing on the water is probably more forgiving?
mmeowl: Than landing on the ground, I mean.
rwdavidoff: True. Looks like it’s getting bigger. I think that’s not all zoom, right?
mmeowl: I think so. Makes you wish you were watching in person, though.
rwdavidoff: No kidding! Here it comes . . .
rwdavidoff: Come on, zoom INNNN.
rwdavidoff: Looks like the airbags are deploying!
mmeowl: Yeah, I can see them too!
rwdavidoff: Looks kind of silly, hanging off the side like that.
rwdavidoff: If it works, it works, though...
rwdavidoff: We'll know soon.
mmeowl: I keep thinking they're going to pop like balloons.
rwdavidoff: Me too...
mmeowl: Touchdown!
Left off the cameras, the LAP had been busy since separating. There wasn’t time to waste. Almost from the instant it had separated, its Draper avionics had been at work. First, it had to compute the required time to start the boostback burn and the right moment to shut it off to leave it on track for the launch site, then the time until entry. After a frantic minute or two, though, things had quieted down. The stage was in freefall, steady in entry attitude--engine nozzles and base thermal protection facing into the airstream, held in place by the intermittent bursts from the cold gas attitude jets at the top of the stage. Bottom-first, it rose towards the increased apogee created by boostback. The curvature of the Earth yawned below it, visible to the rocket-mounted camera which had carried the feed from launch. The view was only the camera’s to enjoy and record--it was no longer being broadcast to the ground, waiting to be retrieved from the camera’s onboard storage. If the stage survived, it would make amazing marketing footage for both RPK’s orbital and suborbital vehicles. Unlike its sister the OV or its cousin the Rocketplane XP, though, the K-1 LAP wasn’t quite a spaceship. It skimmed to 97 kilometers, missing the Karman line by bare kilometers, before beginning to gather velocity back towards the ground below.
The camera, pointed aft along the stage to capture ascent, was oriented wrong to capture the critical events of entry. The drogue’s deployment was just a jerk of the stage as the chutes yanked open and fought the airstream. The mains were more of the same, accompanied by a reassuring decrease in the rate of approach of the yawning earth below. For a long minute, it seemed as though the stage was hardly moving, the camera picture changing only barely as the stage drifted tail-first towards the ground. Finally, however, the ground began to come up, suddenly growing close remarkably fast. Just as a human pilot might have beginning to be alarmed, the deployment of the bridle and the attitude control thrusters began to tip the stage onto its side for final descent. The placement of the rocket camera had been hotly debated by the K-1 team. Some had wanted it on the top side, to better image the parachutes and bridle during this critical phase. Others had successfully argued for using it to directly image the deployment of the four airbags on the underside. While the camera’s field of view down the rocket would barely capture the parachutes, even drifting side-on towards the ground, the airbags were perfectly centered, the data on their deployment being collected for analysis after flight.
With the camera facing down between the airbags, the ground came up, closer every moment. Dots grew into the the minor terrain and rocks left in the carefully cleared square kilometers of desert Kistler and ATK technicians had spent months pulling every boulder and tree out of--a square of desert as carefully manicured as a croquet lawn. With little left on the ground, there was no scale until, suddenly, the stage’s shadow flashed into the view, mere seconds before the entire stage hit the ground. The airbags didn’t pop--they released air as they had been designed to, spreading the shock as they lowered the stage to the ground. The camera jolted, while ground cameras carried the good news to the controllers. With touchdown verified, the LAP avionics completed their last tasks to begin safing the vehicle for the trucks that would arrive soon to retrieve it. The airbags released their remaining pressure with a hiss and the tanks began to vent the remaining propellant pressure in tight clouds of vapor, like the stage was letting out its own sigh of relief.
rwdavidoff: IMPACT!
rwdavidoff: Looks like it's intact?
rwdavidoff: I didn't see any Earth shattering kaBOOM anyway.
mmeowl: It looks good! I hope it didn't get battered too much inside.
rwdavidoff: Me too. We'll get to find out.
mmeowl: The real test is will they fly it again.
mmeowl: OV is in space, too.
rwdavidoff: Not a bad 7 minutes, all told.
rwdavidoff: It turns out it's a spaceship.
mmeowl: The announcer sounds really happy.
rwdavidoff: I would be too!
mmeowl: Heck, I am happy and I'm not even involved.
mmeowl: Spaceships are awesome.
rwdavidoff: Yep!
rwdavidoff: I guess they're cutting the feed here. I guess that makes sense, but I wanted to see the nosecone deployment. Not for an hour, though.
mmeowl: It would be cool if they grabbed isolated bits of footage of later cool things happening and posted them.
rwdavidoff: Yeah, I hope they do.
rwdavidoff: Let me go throw another few logs on the fire, and then want to read some 1/0?
rwdavidoff: I'm really looking forward to seeing you after Christmas. It's nice talking, but it's been a while since Thanksgiving.
rwdavidoff: https://xkcd.com/352/
mmeowl: Yeah, I miss you too. Sure, 1/0 is good.
mmeowl: And having someone to talk about it with in real time only improves it.
mmeowl: I think I'm actually more excited for your visit than I am for actual Christmas.
rwdavidoff: Me too. I love you, geeky.
mmeowl: I love you too.
With the Ariane 5 launches I've seen - where they ignite the Vulcain Engine at T+0 and liftoff occurs at T+7 - I should've suspected this was a possibility.
One thing's certain though, this will be having some major effects down the line.
Just what changes they'll be, is what's got my interest at this time.
One thing's certain though, this will be having some major effects down the line.
Just what changes they'll be, is what's got my interest at this time.
Yeah, there's some interesting philosophical differences in where different providers set T-0. In a sense, you could set it any time you wanted--it's just a time for everything else that needs to be coordinated to be set in relation to. You could make it autosequence start, and have liftoff at T+5 minutes! You could have it be staging! Most people don't go that far, but there does appear to be some variation as to whether it should be "main engine ignition," "SRB ignition," or "time of first motion from the pad". When I saw the RPK K-1 used the latter, I couldn't resist a cheap moment of drama to emphasize it, since I needed a point to break these chat logs anyway.
Also on the subject of timing, I'd like to point out a few interesting details I found while researching K-1 launch events:
1) Note that the OV actually reaches its initial parking orbit before the LAP returns to the ground--a contrast to our experience with SpaceX. The reason is that there's changes on both sides--the Falcon 9 second stage has slightly lower thrust-to-weight ratio and thus burns a little longer, while the K-1 LAP gets hung up for a few additional minutes under parachutes while the F9 is coming in for the hoverslam final touchdown.
2) Note that the K-1 uses an OMS burn to "clean up" its initial insertion, a little like the Space Shuttle did. This is sort of nifty--a point in how much of a true spacecraft it is, not just a stage. It has options for other precision burns than the kind of Mvac "burps" we've seen on Iridium circularization burns.
I'm working on getting the OV's orbital mission written up to finish off this "three-parter" covering the maiden risk reduction flight. I'm hoping to post that today, but we'll see. Once that's up, we get to kick into high gear with this--until now, RPK's basically just been doing what they planned to do historically, and others haven't had much reason to change their priorities. As we enter 2010, butterflies will really start flapping from RPK's actions...
Please feel free to speculate, I love seeing it and it helps get discussion flowing.
Speculation and conjecture? I can do that.Please feel free to speculate, I love seeing it and it helps get discussion flowing.
Well, I think it's safe to say that SpaceX will be pushing reuse as hard, or maybe harder than, OTL (if that's even possible). I think it's also safe to say that we're going to see a Falcon 9 v1.1 much like the one we got in OTL. There's no way SpaceX are going to change the tank diameter on Falcon 9, since common tank tooling and a common engine is part of what makes Falcon 9 so cheap. The question is, are SpaceX going to go for propulsive landing ITTL? On the one hand, they've got good evidence now that parachute recovery on land can be made to work. On the other hand, their experience with parachutes will be less than ideal (as per OTL), and the Falcon 9 booster is a very different beast than the K-1 LAP, aerodynamically and structurally speaking. Even if parachute landing looks like it might work for Falcon 9, Elon might decide to go for propulsive landing anyways, on the grounds that it'll scale much better. SpaceX are looking to colonize Mars, after all, and that process will require a vehicle a hell of a lot bigger than Falcon 9.
Also, by my math and what figures I can find, Falcon 9 v1.1 will beat Kistler for cost per kilo to orbit, even flying fully expendable. I've got a a price per launch of $23,000,000 for the K-1, which gives a cost of $5100/kg. Falcon 9 v1.1, meanwhile, cost $56,500,000, giving a cost of $4900/kg. Falcon 9 is a remarkably cheap, lean vehicle. So there's going to be some fun competition there, although one thing's for sure: the Delta II is going to die even ITTL even harder than it did OTL.
What's more interesting, I think, is what's going to happen with everyone else. ULA, Roscosmos, SeaLaunch, and ArianeSpace are all going to feel the bite of NewSpace even harder than OTL. ISRO is going to be in a bad way, since the K-1 can dominate PSLV's market much like Falcon 9 will dominate Ariane 5's market. Blue Origin... is still going to be a turtle, unfortunately. They have a constant cash flow in the form of Jeff Bezos's bank account, and no motivation to try and compete for launches while developing a vehicle. Constellation is getting canceled, as OTL, but all the talk of DIRECT has me thinking and hoping that it's going to be replaced with something better than SLS. RocketLab is probably dead on arrival, given how well K-1 can serve the microsat rideshare market, but they might still find a bit of business from people who really need their tiny bird in a weird orbit on a budget.
@IncongruousGoat I'll leave some of the rest for others to comment on, but you hit on one of the interesting points and challenges I've had in my research: the always-nebulous area of what, exactly, it costs to launch a rocket. Kistler's price for a launch seems to have hung out at about $17-25 million depending on service offered and the year. Ditto for Falcon 9: while it's $56.5 million for a base launch, Iridium has paid a total of $492 million for their seven-and-a-half launches totaling 75 satellites. Therefore, if you're Iridium, you're interested in flying on K-1 instead of Falcon 1 or Falcon 9 if RPK can price you a bulk deal on 24-25 launches each carrying 3 birds for less than $20 million or so. It definitely means SpaceX have to work hard to keep to the lower end of their launch cost promises. And, of course, this assumes that RPK's orbital offerings are a static target while SpaceX is taking 3-4 years to develop propulsive landing...
Regardless, it seems like RPK and SpaceX are close competition for each other, each driving the other to accelerate their offerings and development, and forcing the overall launch cost down--it's harder for Ariane, ULA, or others to rely on being the second-least-expensive option.
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Assuming Kistler can lock up the small LEO market (not a given, of course), might SpaceX ittl go with an optional high energy upper stage? I seem to remember them promising a LH2 upper stage early on.
Unlikely. OTL, SpaceX have been very opposed to multiple-propellant rockets, since they complicate manufacturing, fuel procurement and storage, and pad plumbing, and there's nothing ITTL that would make that reasoning unsound. Remember, SpaceX's whole business model at this point is based on building a dirt-cheap rocket, and a hydrolox upper stage, requiring its own engines, tooling, and pad infrastructure, would not be cheap.
As of 2010, there's a small team at SpaceX working on a hydrolox upper stage engine, but A: it's only a small team, and B: this is the engine that would eventually become Raptor. The switch to methalox OTL was made in 2012, because methalox is easy to make and store on Mars. Again, this reasoning is unlikely to change ITTL, since it wasn't made based on any particular market factors but on the resources available on Mars.
Kistler costs would likely be about 20m USD for a standard flight and ~25m if you need the expendable active dispenser (a biprop hypergolic third stage for missions beyond 1000km up). What the active dispenser brings to the table are things like 1600 kg to GTO or 800 kg to GSO. While the active dispenser is limited in being a small stage (it has to fit inside the payload volume of the K-1 with the payload itself), it can be useful for the smaller Mars missions. Some quick math shows that the Insight lander, which massed under 750 kg at launch, and had a backshell under three meters in diameter, would be a prime candidate for launch on a K-1. MAVEN was a bit too heavy and early for the use of the K-1, and LADEE might be a bit to early as well, but it is easy to see the K-1 taking over US launches that would otherwise fly on a Minotaur class lifter.
As I note above, there is a third stage proposed for the K-1, but it wasn't hydrolox. The fact is that with the very limited volume available in even the extended payload module (remember, not fairings, but a can with a big hatch on one end), a single launch mission with a hydrolox upper stage is not all that plausible. The smallest US proposed hydrolox stage that I know of was a high energy kick stage built using centaur parts (a centaur LOX tank as the hydrogen tank and a collection of small spherical lox tanks around the central RL-10). What is interesting is that this stage would fit inside the EPM on a Kistler vehicle, meaning that two-launch could see this vehicle put two metric tons to escape, or one metric ton anywhere from Venus to Vesta. Not sure there are a lot of missions that would need this capability over that of the active dispenser. What might work better is something denser, such as methalox (which RpK is working on for their plane).
As I finished typing this out, I realized you were talking about SpaceX, not RpK, but it was an interesting thought exercise, and it showed what you might be able to do with a distributed launch architecture and an otherwise limited launcher.
Something else is that Kistler is a full year ahead of SpaceX here, and if they can get their first risk reduction mission to the space station done in three months or so from first launch, they will be two years ahead of what SpaceX did historically. It is entirely possible that there will be an experiment delivered to the station on a K-1 OV, and returned on one of the last shuttle flights. RpK will be able to use their station missions before the shuttle program ends as marketing how they are 'continuing America's legacy of reusable space access." Another point is that the K-1 making it to the station this early give weight to those in the Obama administration who want (as of late 2009) to hand over ISS ops to commercial providers - as it is obvious that the program has worked with one company having already gotten their vehicle on orbit, and a second being close to doing so.
December 21, 2009--K-1 Risk Reduction Demo Orbital Operations: Circularization, Payload Deploy, and Phasing
It seemed like the entire town of Woomera had braved the heat to come watch the launch from bleachers moved over from the school and laid out near the combination integration building and control center. At least a hundred and people had crowded together, watching the K-1 lift off from the pad a few kilometers away and fly away into the stratosphere, holding hands over their eyes or placing binoculars to their face to help follow it and fight the glare from the noon sun. The school had even made a field trip out, the primary and high schoolers mixing with the festival atmosphere common from any children blessed with a Monday excuse to be out of classes. Much of the town had taken an early lunch break and come out to watch the first rocket to fly from Woomera in half a lifetime. Not everyone was a local though--in truth, only fifty or sixty, just half the town population of 150. The rest were RpK personnel, ATK contractors, NASA observers, international press, and Australian service members and Thales Australia contractors from the nearby test range. There were even a handful of dedicated tourists, a combination which had brought the ELDO Hotel to near capacity for the first time in years. The launch events, broadcast from speakers mounted on the side of the building, had brought cheers and shouts, contributing to the festival atmosphere. This launch meant a lot to the town, particularly as the first of many--this would hopefully be no fizzle like Black Arrow and Europa.
Once the LAP had fallen over the horizon to the landing area, drifting gently under parachutes, and the RpK announcers called the nominal orbit of the OV, the crowd began to break up. The school children boarded their bus, and villagers and base staff began to pack up as well. Other broke out grills, getting ready for an impromptu party. The roar of diesel engines sprouted, as RpK technicians and ATK contractors warmed up the big straddle truck which would be used to retrieve the LAP. Already, a few utes were bouncing along the access road to the landing ellipse, carrying technicians to begin the safing process while the truck made its way more slowly. They carried one of the major improvements in K-1 operations since the vehicle had originally been designed in 1999: a GPS tracker located on the stage which had begun sending its location as soon as the stage registered touchdown. The landing ellipse covered a circular area nearly two kilometer in diameter, and RpK wanted to waste no time in finding the stage in the area. They hoped to have the stage safed, the parachutes cut away for repacking, and the stage brought back to the barn by the end of the day. If all went well, the OV would be back tomorrow, and it was better to have the LAP already safely secured before the OV touched down and put them behind.
For its part, the K-1 Orbital Vehicle had left the coast of Australia behind as it finished its OMS-1 burn. Now, five minutes later, it was already over the Marshall Islands, the last ground it would see below it until it passed over the French Frigate Shoals of the Hawaiian chain in another ten minutes. If the K-1’s avionics had been human, they might have taken a moment to reflect on the path that had finally brought it here. Almost a decade after the original Kistler Aerospace team had tried to bring their rocket to Woomera and after several false starts--the challenge by SpaceX to the Space Launch Initiative contract which had lead to the original Kistler’s bankruptcy, the acquisition by Rocketplane which had brought the ability to exit bankruptcy and bid on NASA’s COTS contract, and the critical investments by ATK which had helped paper over the cracks and reassure enough investors to secure funding for everything up to the flight today. It had been a massive bet, a series of tragically close calls, but the K-1 rocket had finally seen space. A human astronaut would have found it hard not to give thanks for their luck, for the view of the Earth spread below, or simply to take a moment to think about the crazy paths of life.
The rocket wasn’t human, though. It was only digital, a Motorola PowerPC architecture. Its radiation-hardened 200 MHz processors had little time free for such reflections on the nature of life. Moreover, it had a major challenge ahead of itself, and as Robert Frost might have said, orbits to go before it slept. The K-1 Orbital Vehicle was no simple upper stage, suited to just get to the right orbit, separate a payload, and safe itself. It was a true spacecraft, with attitude control thrusters, an ethanol/LOX Orbital Maneuvering System, and the recovery systems to bring it home--and it had a tightly controlled window for how long it could stay in space, where it needed to land, and how much propellant it had to get there. It wasn’t even a simple matter of flight optimization--the rocket also had to ensure it didn’t have an excess of OMS propellant aboard which could cause it to be too heavy as it descended into the atmosphere. The PowerPC chips went to work executing the Draper-designed, RpK-polished algorithms which would steer it through the series of five burns which would bring it to payload deployment and back home to the ground safely.
The first was already behind it, the cleanup burn with the OMS which had resolved any uncertainty in how the decades-old engines might perform in vacuum. The use of the OMS burn, a single-engine burn a minute after the AJ-26-60 engine had seen MECO, meant that the stage could essentially burn to depletion, leaving minimal residuals of the un-needed kerosene and main stage liquid oxygen aboard, while still tracking to a precisely calculated initial trajectory. The initial orbit shape was a strange one compared to most rockets--it had essentially set its apogee to the initial parking altitude of 500 kilometers, then nosed over and burnt purely prograde to add velocity until the perigee cleared Earth’s atmosphere. As soon as the bare essentials of orbit were satisfied, the main engine had done its work. The second burn would finish the job of circularizing at the target orbit.
The stage played a waiting game, biding its time and working ahead on the tightly calculated autonomous guidance problems until its first apogee over Minnesota. Under the watchful eye of radar dishes outside the company’s headquarters in Oklahoma City, the K-1 OV fired its OMS again, circularizing on target for the deployment of today's demonstration payloads, both simulated and real. It didn’t really need the watching--though the ground could watch via radar, its only communications for telemetry down and override commands up if needed came over NASA’s TDRS satellite network, bouncing down from geostationary orbit whether the satellite was in line of a ground station or not. It was insufficient for the video footage which the stage had initially beamed home, but it was enough for the stage’s four minders in the control center at Woomera and their backup team of six working under the eyes of the rest of the team at the ceremonial launch control at Oklahoma City. The orbiter fired just one engine on the burn, reserving the other for backup--the K-1’s conservative design meant it had redundancies everywhere the weight could be justified, and the OMS was critical to mission success and a safe return home.
The stage and ground confirmed the second burn’s results: perfectly on target. Another twenty minutes passed before the stage proceeded to payload deployment--more than an hour since launch. The hatch opened up and flipped clear of the payload bay, giving the camera recording onboard inside the payload module a view of space as a “boresight” from its mounting spot on the aft end of the payload module. The stage reoriented, pointing itself sideways along the orbital track to give some clearance between the payload and itself as they went along their way. The K-1 was carrying three payloads on this mission. Two were inert. One would remain attached--a chunk of gold alloy to be cast into ceremonial coins after the recovery of the mission, bound for those who had contributed to the launch. The second was also a fake payload, though it at least would be cast loose of the vessel. A steel frame and sheet metal structure contained a tank of nearly three tons of water, sitting on top of the payload dispenser. The forward telescoping portion of the Expanded Payload Module retracted aft and the elevator inside the payload module shifted forward, pushing the watery simulated payload to the rim of the bay. Under the camera’s watchful eye, the deployment system pushed the “satellite” free and away as the signal came from the avionics on redundant pathways. After another half orbit, once the K-1 OV had a chance to move clear, the simulator was just smart enough to use a nitrogen thruster system to orient itself retrograde, then vent the rest of its nitrogen through the water tank like an overgrown bottle rocket. The sublimating cloud would provide a visible signal to be tracked by Australians of the deployment system’s precision, and the venting “propellants” would both lower the simulator’s perigee and the remaining structure and tanks light enough to quickly deorbit.
The third and final payloads--and the only real satellites being deployed on the maiden launch--weren’t in the bay at all, but instead mounted among the avionics boxes, tanks, and thruster systems inside the aft flare. A PPOD dispenser, carrying three cubesats, was mounted just inside the view of the flare’s camera. After a few minutes were allowed for the mass simulator forward to drift away, the three satellites were kicked loose, the small boxes covered in foil and surface-mounted solar panels tumbling away above the Earth. One was a project by students at Oklahoma State University, lead by a masters student in engineering who was a former RpK summer intern, the chance for a launch donated by RpK to their home state in a gesture of goodwill. Similar goodwill drove the second of the three satellites in the standard 3U dispenser, this one built by students at the University of Adelaide. The third was from cadets with the US Air Force Academy and would do minor science experiments for the weeks before the tiny satellite fell into the atmosphere. If the simulator’s venting and the OV’s return to Earth went well, within a week or so these three spacecraft, totalling less than five kilos, would be the only record of the mission’s success on orbit. As the tumbling trio of cube floated away from the OV, grad students and cadets worked over their arrangements for contacting their tiny satellites trying to beat the odds of cubesats which saw many fail without every signalling home.
That was the end of the easy activities, the primary mission. The old military pilot joke was that the trip out was for Uncle Sam, and the trip home was for yourself. The RpK team joked that the burns until payload separation were for the customer, and then the burns afterward were for themselves. These were the three burns which left the avionics the largest optimization challenge. In atmosphere, the OV flew like a brick. Even worse than the Space Shuttle, the K-1 OV had a cross range of barely 100 kilometers. In order to ensure the safe return to the tiny landing ellipse, the stage would have to make its fifth burn, the retro burn, precisely in the right place. To get it to the right place with the right amount of propellant remaining, the stage had two burns in its arsenal--the phasing burns. By burning to raise or lower one side of its circular orbit, the stage could adjust to the second its orbital period, and thus its ground track over Woomera 22 hours away. The main burn would happen two hours after launch, the second would serve as a cleanup of the phasing just a few orbits before entry. The stage’s task was to determine the right amount to raise or lower the orbit to ensure it used up the right amount of propellant. The 32-bit, 1990s grade radiation-hardened Motorola chips thought long and hard, looked at the internal guidance solution, compared the position to the projections and to tracking, and judged the right solution. It lined itself up with bursts from the attitude jets and waited for its calculated moment. The OMS flared to life.
Monitoring the phasing burn was among the last activities that RpK’s team in Oklahoma City would take before handing off to their relief. Jean-Pierre Boisvert nursed a cup of lukewarm coffee as they waited for TDRS to update telemetry and bring the news if the stage was coming home or not. In the lead-up to the launch, he’d lead the simulation teams through ground override responses any number of failures, each more unlikely than the rest. In a nominal mission, the control teams at Woomera and Oklahoma City were so much window dressing for a vehicle that literally flew itself. In an off-nominal mission, they’d have to be ready to leap into action to come to the aid of a wounded, confused spacecraft to recover the mission, get the payload away, and bring home a corporate asset with a value measured in the tens of millions. He took a sip of the coffee and winced. Soon enough, they’d know if they needed to do any of that, or if the scenarios he’d brainstormed over reams of printouts with his engineers and over beers with his old RCAF buddy William Anderchuk when his company’s oil business brought him to town were just so much waste of time. The moment the OV had signalled it calculated for the burn came and went, and the telemetry flashed its updates. The controllers on two sides of the planet leaned forward in unison, fingers flying across keyboards to update their own projections and to query details of the spacecraft’s health. The team was disciplined and professional--Jean-Pierre was proud of that. They called off by the numbers as he polled down the list, no wasted time as the men and women he’d trained snapped back their answers. He’d learned to read them, though, and he knew the answers they’d give from the set of their shoulders as they leaned over their consoles.
“Power?”
“Go flight.”
“Propulsion?”
“Nominal! No residuals.”
“Guidance?”
“Go flight! Good burn, we’re right on target. Might not need OMS-4, phasing accuracy looks within acceptable limits. Updating ground retro estimate, OV analysis in progress.”
The team sat back, all smiles, the relaxation and confidence their shoulders had shown filling the room. The hardest part of the flying home was already behind them. Their baby had done its job, and was coming home. Now, they could go home themselves and rest, to wait for the landing tomorrow. The Woomera team would take over monitoring while they worked on finishing getting the LAP onto the truck and back to the barn, with a relief overnight, and then they’d pick back up as primary here in Oklahoma City in the morning. Jean-Pierre smiled behind his coffee mug. A hell of a thing, he thought to himself. A hell of a team.
Once the LAP had fallen over the horizon to the landing area, drifting gently under parachutes, and the RpK announcers called the nominal orbit of the OV, the crowd began to break up. The school children boarded their bus, and villagers and base staff began to pack up as well. Other broke out grills, getting ready for an impromptu party. The roar of diesel engines sprouted, as RpK technicians and ATK contractors warmed up the big straddle truck which would be used to retrieve the LAP. Already, a few utes were bouncing along the access road to the landing ellipse, carrying technicians to begin the safing process while the truck made its way more slowly. They carried one of the major improvements in K-1 operations since the vehicle had originally been designed in 1999: a GPS tracker located on the stage which had begun sending its location as soon as the stage registered touchdown. The landing ellipse covered a circular area nearly two kilometer in diameter, and RpK wanted to waste no time in finding the stage in the area. They hoped to have the stage safed, the parachutes cut away for repacking, and the stage brought back to the barn by the end of the day. If all went well, the OV would be back tomorrow, and it was better to have the LAP already safely secured before the OV touched down and put them behind.
For its part, the K-1 Orbital Vehicle had left the coast of Australia behind as it finished its OMS-1 burn. Now, five minutes later, it was already over the Marshall Islands, the last ground it would see below it until it passed over the French Frigate Shoals of the Hawaiian chain in another ten minutes. If the K-1’s avionics had been human, they might have taken a moment to reflect on the path that had finally brought it here. Almost a decade after the original Kistler Aerospace team had tried to bring their rocket to Woomera and after several false starts--the challenge by SpaceX to the Space Launch Initiative contract which had lead to the original Kistler’s bankruptcy, the acquisition by Rocketplane which had brought the ability to exit bankruptcy and bid on NASA’s COTS contract, and the critical investments by ATK which had helped paper over the cracks and reassure enough investors to secure funding for everything up to the flight today. It had been a massive bet, a series of tragically close calls, but the K-1 rocket had finally seen space. A human astronaut would have found it hard not to give thanks for their luck, for the view of the Earth spread below, or simply to take a moment to think about the crazy paths of life.
The rocket wasn’t human, though. It was only digital, a Motorola PowerPC architecture. Its radiation-hardened 200 MHz processors had little time free for such reflections on the nature of life. Moreover, it had a major challenge ahead of itself, and as Robert Frost might have said, orbits to go before it slept. The K-1 Orbital Vehicle was no simple upper stage, suited to just get to the right orbit, separate a payload, and safe itself. It was a true spacecraft, with attitude control thrusters, an ethanol/LOX Orbital Maneuvering System, and the recovery systems to bring it home--and it had a tightly controlled window for how long it could stay in space, where it needed to land, and how much propellant it had to get there. It wasn’t even a simple matter of flight optimization--the rocket also had to ensure it didn’t have an excess of OMS propellant aboard which could cause it to be too heavy as it descended into the atmosphere. The PowerPC chips went to work executing the Draper-designed, RpK-polished algorithms which would steer it through the series of five burns which would bring it to payload deployment and back home to the ground safely.
The first was already behind it, the cleanup burn with the OMS which had resolved any uncertainty in how the decades-old engines might perform in vacuum. The use of the OMS burn, a single-engine burn a minute after the AJ-26-60 engine had seen MECO, meant that the stage could essentially burn to depletion, leaving minimal residuals of the un-needed kerosene and main stage liquid oxygen aboard, while still tracking to a precisely calculated initial trajectory. The initial orbit shape was a strange one compared to most rockets--it had essentially set its apogee to the initial parking altitude of 500 kilometers, then nosed over and burnt purely prograde to add velocity until the perigee cleared Earth’s atmosphere. As soon as the bare essentials of orbit were satisfied, the main engine had done its work. The second burn would finish the job of circularizing at the target orbit.
The stage played a waiting game, biding its time and working ahead on the tightly calculated autonomous guidance problems until its first apogee over Minnesota. Under the watchful eye of radar dishes outside the company’s headquarters in Oklahoma City, the K-1 OV fired its OMS again, circularizing on target for the deployment of today's demonstration payloads, both simulated and real. It didn’t really need the watching--though the ground could watch via radar, its only communications for telemetry down and override commands up if needed came over NASA’s TDRS satellite network, bouncing down from geostationary orbit whether the satellite was in line of a ground station or not. It was insufficient for the video footage which the stage had initially beamed home, but it was enough for the stage’s four minders in the control center at Woomera and their backup team of six working under the eyes of the rest of the team at the ceremonial launch control at Oklahoma City. The orbiter fired just one engine on the burn, reserving the other for backup--the K-1’s conservative design meant it had redundancies everywhere the weight could be justified, and the OMS was critical to mission success and a safe return home.
The stage and ground confirmed the second burn’s results: perfectly on target. Another twenty minutes passed before the stage proceeded to payload deployment--more than an hour since launch. The hatch opened up and flipped clear of the payload bay, giving the camera recording onboard inside the payload module a view of space as a “boresight” from its mounting spot on the aft end of the payload module. The stage reoriented, pointing itself sideways along the orbital track to give some clearance between the payload and itself as they went along their way. The K-1 was carrying three payloads on this mission. Two were inert. One would remain attached--a chunk of gold alloy to be cast into ceremonial coins after the recovery of the mission, bound for those who had contributed to the launch. The second was also a fake payload, though it at least would be cast loose of the vessel. A steel frame and sheet metal structure contained a tank of nearly three tons of water, sitting on top of the payload dispenser. The forward telescoping portion of the Expanded Payload Module retracted aft and the elevator inside the payload module shifted forward, pushing the watery simulated payload to the rim of the bay. Under the camera’s watchful eye, the deployment system pushed the “satellite” free and away as the signal came from the avionics on redundant pathways. After another half orbit, once the K-1 OV had a chance to move clear, the simulator was just smart enough to use a nitrogen thruster system to orient itself retrograde, then vent the rest of its nitrogen through the water tank like an overgrown bottle rocket. The sublimating cloud would provide a visible signal to be tracked by Australians of the deployment system’s precision, and the venting “propellants” would both lower the simulator’s perigee and the remaining structure and tanks light enough to quickly deorbit.
The third and final payloads--and the only real satellites being deployed on the maiden launch--weren’t in the bay at all, but instead mounted among the avionics boxes, tanks, and thruster systems inside the aft flare. A PPOD dispenser, carrying three cubesats, was mounted just inside the view of the flare’s camera. After a few minutes were allowed for the mass simulator forward to drift away, the three satellites were kicked loose, the small boxes covered in foil and surface-mounted solar panels tumbling away above the Earth. One was a project by students at Oklahoma State University, lead by a masters student in engineering who was a former RpK summer intern, the chance for a launch donated by RpK to their home state in a gesture of goodwill. Similar goodwill drove the second of the three satellites in the standard 3U dispenser, this one built by students at the University of Adelaide. The third was from cadets with the US Air Force Academy and would do minor science experiments for the weeks before the tiny satellite fell into the atmosphere. If the simulator’s venting and the OV’s return to Earth went well, within a week or so these three spacecraft, totalling less than five kilos, would be the only record of the mission’s success on orbit. As the tumbling trio of cube floated away from the OV, grad students and cadets worked over their arrangements for contacting their tiny satellites trying to beat the odds of cubesats which saw many fail without every signalling home.
That was the end of the easy activities, the primary mission. The old military pilot joke was that the trip out was for Uncle Sam, and the trip home was for yourself. The RpK team joked that the burns until payload separation were for the customer, and then the burns afterward were for themselves. These were the three burns which left the avionics the largest optimization challenge. In atmosphere, the OV flew like a brick. Even worse than the Space Shuttle, the K-1 OV had a cross range of barely 100 kilometers. In order to ensure the safe return to the tiny landing ellipse, the stage would have to make its fifth burn, the retro burn, precisely in the right place. To get it to the right place with the right amount of propellant remaining, the stage had two burns in its arsenal--the phasing burns. By burning to raise or lower one side of its circular orbit, the stage could adjust to the second its orbital period, and thus its ground track over Woomera 22 hours away. The main burn would happen two hours after launch, the second would serve as a cleanup of the phasing just a few orbits before entry. The stage’s task was to determine the right amount to raise or lower the orbit to ensure it used up the right amount of propellant. The 32-bit, 1990s grade radiation-hardened Motorola chips thought long and hard, looked at the internal guidance solution, compared the position to the projections and to tracking, and judged the right solution. It lined itself up with bursts from the attitude jets and waited for its calculated moment. The OMS flared to life.
Monitoring the phasing burn was among the last activities that RpK’s team in Oklahoma City would take before handing off to their relief. Jean-Pierre Boisvert nursed a cup of lukewarm coffee as they waited for TDRS to update telemetry and bring the news if the stage was coming home or not. In the lead-up to the launch, he’d lead the simulation teams through ground override responses any number of failures, each more unlikely than the rest. In a nominal mission, the control teams at Woomera and Oklahoma City were so much window dressing for a vehicle that literally flew itself. In an off-nominal mission, they’d have to be ready to leap into action to come to the aid of a wounded, confused spacecraft to recover the mission, get the payload away, and bring home a corporate asset with a value measured in the tens of millions. He took a sip of the coffee and winced. Soon enough, they’d know if they needed to do any of that, or if the scenarios he’d brainstormed over reams of printouts with his engineers and over beers with his old RCAF buddy William Anderchuk when his company’s oil business brought him to town were just so much waste of time. The moment the OV had signalled it calculated for the burn came and went, and the telemetry flashed its updates. The controllers on two sides of the planet leaned forward in unison, fingers flying across keyboards to update their own projections and to query details of the spacecraft’s health. The team was disciplined and professional--Jean-Pierre was proud of that. They called off by the numbers as he polled down the list, no wasted time as the men and women he’d trained snapped back their answers. He’d learned to read them, though, and he knew the answers they’d give from the set of their shoulders as they leaned over their consoles.
“Power?”
“Go flight.”
“Propulsion?”
“Nominal! No residuals.”
“Guidance?”
“Go flight! Good burn, we’re right on target. Might not need OMS-4, phasing accuracy looks within acceptable limits. Updating ground retro estimate, OV analysis in progress.”
The team sat back, all smiles, the relaxation and confidence their shoulders had shown filling the room. The hardest part of the flying home was already behind them. Their baby had done its job, and was coming home. Now, they could go home themselves and rest, to wait for the landing tomorrow. The Woomera team would take over monitoring while they worked on finishing getting the LAP onto the truck and back to the barn, with a relief overnight, and then they’d pick back up as primary here in Oklahoma City in the morning. Jean-Pierre smiled behind his coffee mug. A hell of a thing, he thought to himself. A hell of a team.
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@TimothyC From a technical standpoint, you're entirely correct. However, NASA isn't going to give Category 3 certification to the K-1 until it's flown at least 40 or 50 times, which is what it would need to launch a high-profile mission like InSight. Remember, it took until November 2018 for Falcon 9 to get Category 3 OTL. If it were really as easy as being capable of launching the mission, Falcon 9 would have launched InSight.
Also, as a general note, there's been a few mentions of SpaceX taking a few years to really get things going. While this is the case, Kistler are almost certainly going to run into snags of their own. They're going to be somewhat faster than SpaceX since they don't have to build quite as much hardware (even assuming they lose a few vehicles, which I'm almost certain they will), but they're still going to have to spend months stripping down the LAP and OV they just launched to evaluate in what shape they came back, not to mention time spent re-designing both based on things that they found out during and after the launch (and there will be things that need changing). It's going to be a while before either company really gets going.
Also also, I have a couple questions about the K-1 as a vehicle. First off, what kind of TPS material is being used on the OV? And secondly, where is the landing zone located with respect to Woomera, and how much does this affect the boostback burns for launches to polar orbit, compared to 45 or 30 degree orbit? Because it seems to me that, depending on where the landing ellipse is located, the boostback burn for a polar orbit might require a substantial lateral component, decreasing the K-1's payload capacity to polar or sun-synchronous orbit.
Also, as a general note, there's been a few mentions of SpaceX taking a few years to really get things going. While this is the case, Kistler are almost certainly going to run into snags of their own. They're going to be somewhat faster than SpaceX since they don't have to build quite as much hardware (even assuming they lose a few vehicles, which I'm almost certain they will), but they're still going to have to spend months stripping down the LAP and OV they just launched to evaluate in what shape they came back, not to mention time spent re-designing both based on things that they found out during and after the launch (and there will be things that need changing). It's going to be a while before either company really gets going.
Also also, I have a couple questions about the K-1 as a vehicle. First off, what kind of TPS material is being used on the OV? And secondly, where is the landing zone located with respect to Woomera, and how much does this affect the boostback burns for launches to polar orbit, compared to 45 or 30 degree orbit? Because it seems to me that, depending on where the landing ellipse is located, the boostback burn for a polar orbit might require a substantial lateral component, decreasing the K-1's payload capacity to polar or sun-synchronous orbit.