Chapter 3: “These are the Voyages”
NEWS at TEN
The IRA man wins the ballot; Poland’s prime minister gives an ultimatum; and President Reagan may go home tomorrow.
NEWS ANCHOR: Good evening. The Space Shuttle Enterprise, which was supposed to be orbiting the Earth tonight, is still on its launch pad at Cape Canaveral…one of the five computers on board is not in touch with the others. Now, maybe it’s not properly synchronised, but they’re not sure. Officials admitted later that they have not run a full test program in trials with the computer on board.
……
INTERVIEWER: What does a stop like this do to morale?
DAVID SCOTT: Well, of course it has been very disappointing for him [the astronauts] today, having been geared up and ready to go on this precise day and everything going so well…but we’ll fall back, find out, and get their enthusiasm up again. And tomorrow morning, they’ll be ready to go, just as they had been today…
INTERVIEWER: Now, hasn’t the whole Shuttle program been dogged by disappointment over the years?
DAVID SCOTT: Well again, I’d like to emphasise the fact that this is an experimental program, and that the things that happen are publicised widely. If we were doing this in secret, you’d never hear of anything until it launched. It hasn’t been dogged by problems more than any other experimental program. As a matter of fact, I’d say that Apollo’s lessons have made its development more successful.
INTERVIEWER: Thank you very much, David.
– Extract from Independent Television News (UK), News at 10.
¶
It took two days for engineers to discover and rectify the problem hiding in Enterprise's flight computers. It turned out that an innocuous and unrelated fix a year ago introduced a short timespan, within which powering up the primary computers caused some processing to be carried out one computing cycle later than expected. This was exactly what happened on that occasion; the backup computer interpreted this as a fault, and refused to process all data from the primary computer that it now perceived as flawed. The backup then waited in loops for the crew to switch to it, a command that never came due to the apparent nominal operation of the primary computers.
As the countdown was recycled for a launch on April 12, 1981, the anniversary of Gagarin's flight, many wondered if more such malicious interactions hid between the systems they and others had built. There were certainly an uncountable multitude of these aboard OV-102 and S-1D-601 combined, some of which would not have stopped the show before delivering a lethal blow.
The day slowly rolled by, and the astronauts found themselves thinking the same as they had their comforting ritualistic breakfast of fillet mignon and eggs, washed down with orange juice and coffee. They tried pivoting their mind to the procedures that could save them, contained within muscle memory and 22 thick volumes onboard.
While they ate, then suited up, Enterprise was also being prepared to play its part. The network of humans and machines that constituted the Launch Processing System (LPS) orchestrated this process precisely; monitoring, processing and recording every step. It interfaced with the Shuttle through the Launch Complex, modified from Apollo hardware to accommodate the new vehicle. Payloads, of which there was only the Development Flight Instrumentation (DFI) Package, have long since been loaded via the Mobile Service Structure (MSS), which was rolled to a safe distance 11 hours before launch. The MSS was created by cutting the Apollo-era MSS off its platform, and permanently fixing it onto rails that led to the launchpad.
Six hours before launch, swing arms began loading thousands of tons of propellant into the cavernous tanks. Unmodified Saturn hardware poured liquid oxygen into the booster, joining the RP-1 previously loaded in the wet dress rehearsal; further up, an umbilical connected to the orbiter’s tail filled both ETs with LOX and LH2. These cryogenic propellants boiled vigorously under the relative heat, producing vapours that were taken away by vent arms. These, and the slimmed down upper part of the launch tower, were placed mere centimetres or metres away from the Shuttle's fragile heat shield. Soon, the tanks were filled to the brim.
The backup crew, Joe Engle and Richard Truly, went into the cockpit to flick all 2000-odd switches into the proper configuration. The inertial guidance system was calibrated, and teams walked around the launch tower to make sure nothing was visibly wrong. Some time after they were done, Young and Crippen arrived in their bulky launch suits. They were strapped with their backs to the ground, in a backs to the ground position any other pilot would not have hoped to assume. Once in place, they talked through Enterprise’s radio for the first time. The hatch was then closed; there were no leaks. The White Room was partially retracted, followed by the last of the ground crew clearing the area. It was now T-2 hours.
While the busy wait continued, the sky began to lighten up. Atmosphere condensed by the cold tank skins rolled down the booster, wafting between the massive fins and engine bells. Fuel continued to trickle into the tanks to make up for any that boiled off.
All countdown clocks then stopped, frozen at T-20 minutes. This was a planned hold, for the guidance system to be checked again, fuel cells to be thermally conditioned, the cabin vent valves to close, and so on; from now on, Enterprise would possess its own atmosphere until the end of the mission. The backup computer synced perfectly this time, much to everyone’s relief.
The countdown resumed. Then it paused again as planned, this time at T-9 minutes. Chase planes took off, and weather at the landing strip was verified; it would be needed for some abort modes. Go/No-gos were given; everything was Go. The automatic launch sequencer kicked in, to choreograph the split-second steps that would occur very soon. The White Room also retracted fully, no longer required to be brought out rapidly for crew escape; from this moment on, they would do so with the most powerful ejection seats in the world. Hydrazine APUs were started to provide hydraulic pressure for the control surfaces and the J-2S’ gimbals. It was now T-5 minutes.
After that, everything seemed to happen more quickly; everything did happen more quickly. The aerodynamic surfaces wiggled, and so did the orbiter’s engines inside the conical interstage. The GOX vent caps, added in 1978 for fear of ice formation, retracted from the ETs’ tops. At T-3 minutes, Enterprise switched to internal reactants for its fuel cells, and the booster started using helium from onboard tanks for its pressurised systems; STS-1 was now completely on its own.
All fuel tanks rose to flight pressure by T-2 minutes. The GH2 vent arms successfully moved out of the wings’ way; unlike the other arms, they would not be left to chance seconds before the orbiter began to rise. Over the onboard intercom, Young briefly advised the rookie pilot on the experience a Saturn V could give.
T-30 seconds. The final auto sequence started; it would check for any debilitating faults before launch, and could react quickly enough to abort it even after engine ignition. Pyrotechnics were armed, ranging from the orbiter main engines’ starter charges, to linear explosives that would tear the fuel tanks apart for range safety. Data recording devices began to roll. Far below the astronauts, the gimbal actuators for five F-1As were activated. They were now guided by modern instruments, instead of the obsolete IU of the Saturns.
T-15 seconds. As gyros in the guidance system were released, a torrent of water poured around the booster’s engines; it would dampen the destructive acoustic power generated by their operation.
“Ignition sequence start.”
T-9 seconds; electric sparklers in the F-1As burn, ready to receive fuel now slowly churning through the impellers. In the gas generator, the small amount of RP-1 and LOX diverted from the inlet mainfolds mixed and ignited; the resulting hot gas shot through the turbine, generating a rising whine as the pumps generated increasingly absurd propellant pressures. This pressure forced the partially open ball valves wide open, for the fuels to pour into the main combustion chamber. At the baffled copper injector, some of the RP-1 was held behind cartridges filled with trimethylaluminum and triethylborane; these burst open, unleashing fuel laced with those fluids that ignited upon contact with the LOX.
“We have booster engine start. All five F-1A engines ramping up to 9 million pounds of thrust.”
Robust hold down arms on ML-2 waited as the rocket got powerful enough to lift itself.
“Five, four, three, two, one…”
They let go. Enterprise began to rise.
“Liftoff of Space Shuttle Enterprise, the first flight of the Space Transportation System, beginning a new age of American Space Exploration!”
Using hydraulics driven by pressurised RP-1, the engines yawed hard to the left. Enterprise's right wingtip lurched correspondingly, distancing from the tower. With more thrust and less weight than a Moon-bound Saturn, the Shuttle rose faster than most crewed spacecraft to date, bursting out of the clouds of smoke, steam, ice and flames it created.
From Crippen's side, the grey tower still seemed too close when it slipped beneath the right ET.
"Roger, yaw program complete. Commencing roll program."
"And the Space Shuttle has cleared the tower!"
The open-loop sequences manoeuvred the stack through time-critical steps crucial for a successful launch. With a twist of the booster engines, the Shuttle rolled to the optimal azimuth for inserting into a circular 40.3° orbit at 280 km.
Miles away, the beaches of Florida were now struck by the soundwaves of rocket engines from LC-39 for the first time in six years. Everything continued to perform normally as the trail of kerosene flame carried over 2500 tons of vehicle into the clear sky. It all had to; if not, the crew would face a bailout via the ejection seats, or ride out a Mode 1 Return to Launch Site (RTLS) abort. This involved flying a crippled but still functioning booster on a steeper trajectory, separating the orbiter and completely full ETs in a more tenuous atmosphere, then diving down while making an aerodynamic dogleg to the KSC. It was not a very survivable proposition.
As the vehicle accelerated, air began to flow faster over the vehicle, and laminar flow soon separated from the ET ogives; the resulting shock waves created severe drag, which tried to turn the stack nose down. This was mainly counteracted by the four large fins at the bottom of the booster; the rest of the deviations were cancelled out by automatically twitching the F-1As faster than a human could, to keep the vehicle flying true. Simultaneously, the orbiter control surfaces did the same, but for the sake of reducing aerodynamic loads instead.
Just like the simulations and tests showed, this fine balance held as dynamic pressure (Q) rose. Enterprise soon breached Mach 1; the F-1As began throttling back to curb the highest value Q could reach. At T+1 min 15 s, Max Q abated as soon as it came; despite continuously increasing velocity, there was less air for the Shuttle to crash against.
"Enterprise, Houston, you're go at throttle up."
"Roger, go at throttle up."
Soon, the Shuttle outflew the T-38 chase planes' performance. Only ground tracking cameras would be able to keep an eye on its progress, capturing footage in which the Shuttle’s approximate attitude can be discerned using checkerboard patterns on the booster. Around this time, the ejection seats also lost their functionality.
"Booster engine limits to enable."
With the Shuttle now high and fast enough, it would no longer crash back quickly or lose control if power was lost. Hence, the booster was now allowed to shut down all its engines if a destructive cascade of problems was detected. Shortly thereafter, any abort would also necessitate Mode 2 RTLS, where the Shuttle would start its engines for a boost back to the Cape, as wing lift was no longer sufficient to reverse Enterprise's horizontal motion in the time it fell.
Booster 601 was rapidly emptied as the ascent continued, leaving huge voids in the tanks; gaseous oxygen and helium kept the LOX and RP-1 tanks respectively at pressure. With the vehicle losing mass, the engines throttled back once more to limit acceleration to 3g.
Those who had also designed the Saturn V began to hold their breath as the T+2min mark approached, for it was a vehicle that historically suffered from longitudinal resonance (POGO). Some feared that the new vehicle configuration’s acoustics were not completely accounted for; that the frequencies of fuel surges, thrust increases and structure rebounds would be resonant, until it became unbearable for the crew or worse, structure. Thankfully, the accumulators added to the LOX ducts sufficiently disrupted the surge frequencies, proving to be more effective than all the incremental mitigations employed on Apollo.
With the tanks almost dry, the F-1As could no longer throttle down enough to keep acceleration in check. Thus, the centre engine shut down 2 minutes into the flight. This was followed 30 seconds later by two outboard engines. With the bulk of the atmosphere now behind it, Enterprise now flew mostly horizontal, building up orbital speed with the last two engines at near full power.
At T+2 minutes and 43 seconds, the LOX low level sensor was tripped. For a split second, Young and Crippen were thrown against their straps as all thrust disappeared. Mission control uttered a phrase not heard since Gordon Cooper's Atlas ride.
"BECO."
Mechanical latches silently released in Enterprise's tail. Simultaneously, eight solid fuel retrorockets backed the S-1D away, sending mushrooms of flame shooting up to the ETs. Guide rails allowed the booster and orbiter to slide apart with centimetres to spare.
"Roger on the sep, Enterprise."
The starter cartridges fired all at once; the four J-2S engines ignited, first in "idle mode" to settle the ETs' propellants. A second later, they roared towards full thrust.
"We have SES. All four."
Upon staging, Enterprise switched to a closed-loop guidance algorithm: it would now be actively steered towards the intended final orbit. In this mode, the computer repeatedly calculates current motion, and determines the corrections needed to converge with the intended trajectory at a certain stage. These reevaluations were done at a much higher frequency than the Saturns' algorithms, and would continue once per computing cycle for the remainder of ascent.
“You have negative return, Enterprise.”
Trailing far behind and below was the S-1D, now arcing towards apogee. Shaped explosive charges cleanly sliced the ten flanges connecting the LOX tank to the forward skirt, releasing it and the conical interstage. Preloaded springs then pushed the conjoined parts away; the forward dome was left exposed. Then, self-contained nitrogen gas thruster modules fired to keep the stage nose forward. Latches in the gigantic fins released, allowing a spring-loaded tab on the end of each fin to deploy perpendicular to the airflow.
Booster 601 would not meet the same fate of its -500 series predecessors, all of which either disintegrated due to aerodynamic forces or upon impact. While gravity accelerated the stage back to the high supersonic speeds it was propelled to, the thickening atmosphere pushed against its immense drag, slowing it down. The forces only slammed the drag brakes tighter in the perpendicular position, thanks to an ingenious organisation of load bearing paths. With this drag, the stage remained passively stable in the opposite direction, despite being tail heavy from the engines.
The aluminium skin began to heat up from friction. However, there was more than enough of the material to keep the overall temperature below what it took to weaken it. Even better, reentry warmed the chilly oxygen tank sufficiently, so that its temperature would be similar to the tropical Atlantic waters’ when it all ended.
Cameras onboard recorded the sights they saw on ascent in reverse: dark blue gave way to cerulean, then teal. Condensation formed around appendages as the stage penetrated deep into the stratosphere. Battery-powered beacons onboard allowed tracking antennas to determine the stage's location over the Atlantic. This was then projected into the future; the recovery ship SS Catamount then started proceeding towards the expected landing area.
At a preset barometric threshold, the pilot chute gun fired; a laughably tiny canopy dragged out a pair of drogue chutes, which then extracted four main parachutes. These were initially reefed to reduce the shock of full deployment, lest the fabric be torn. Reefing lines were then cut, allowing the canopies of reassurance to expand to nearly an acre of total area. Booster 601 descended through cloud cover, its red-white chutes easily spotted using binoculars.
Tensioning lines were cut, allowing one of the chutes to be dragged across a rail over the kerosene tank. That chute’s attachment point latched onto fittings on the interstage, and the booster was now held at a 15° angle to vertical.
Now less than half a kilometre from splashdown, the booster began preparing itself for the sea. Floatation bags attached to the kerosene tank inflated using residual helium from RP-1 tank pressurisation; very little time passed between complete inflation and water impact.
Spading hundreds of cubic metres of water aside, the LOX dome slowed the booster to a stop. It heaved like a sea dragon, before falling over to the expected side thanks to the slanted impact. The forwardmost flotation bags cushioned this second fall by controllably deflating, with each subsequent one absorbing less and less force, until the aftmost bags settled into the water relatively gently and retained all of their gas. Once the spray subsided, the only noise came from the waves and the slow venting of boiling oxygen.
It took less than an hour for the Catamount to approach. Divers ferried over on Rigid Inflatable Boats (RIBs) removed the drenched parachutes, and detached the two lower fins; those fins were brought aboard the Catamount first. The RIBs were then hooked up to the booster, and guided the stage into the well deck. Hoisted by winches aboard Catamount, Booster 601 went in tail first, with the missing lower fins allowing it to fit. The doors were then closed, and water was pumped out of the ship; workers noted that the foil-covered engines were still sooty from launch, without as much as a drop of water on them. The stage was tied down by its two remaining fins. Pyrotechnics were safed, and residual kerosene was offloaded to holding tanks on Catamount. Plastic covers were placed over the engines and other orifices. A distilled water wash then began as Catamount began the journey back to the Cape.
But long before the recovery action commenced, and hundreds of kilometres overhead, Enterprise's engines shut down on schedule. The J-2S engines have been ramping down since a few minutes ago, to decrease g-forces as the ETs ran dry.
“We have SECO. 25670.20 feet per second.”
“Roger, Enterprise, SECO.”
Despite the main engines breathing their last, Young and Crippen were not yet in orbit; the perigee remained well inside the atmosphere, for a good reason. The two astronauts looked out of their respective side’s windows. There was a light clunk, and the two white objects obscuring the view backwards drifted upwards as Enterprise thrusted downwards with its RCS. ETs 1 and 2 would meet fiery ends over the Indian ocean.
To avoid following the same trajectory, Enterprise reoriented prograde for a planned burn, OMS-1. This impulse would be delivered using the twin self-contained hypergolic engine pods, which were the Shuttle’s only means of main propulsion once alone. The decision to omit retrorockets on the ETs and stage on a suborbital trajectory made the associated fuel tanks much larger. The OMS pods used AJ-10-190s, simple pressure-fed engines that were distant descendants of the Aerobee’s. Both operated for the required duration on this crucial first burn, continuing their reputation of being trouble-free during development.
Now travelling at 25 times the speed of sound at sea level, at 280 kilometres above Earth, Enterprise was flying higher and faster than any winged machine had ever gone.
Young and Crippen would stay in orbit for two days, testing out the vehicle’s systems comprehensively. One by one, the fearful what-if scenarios came and went with execution; payload bay door opening, fuel cell operation, altitude determination and control, three major orbital manoeuvres, resource management, and many more went almost as intended. The only persistent issue was chilliness in the spacious 65m³ cabin, which was resolved on Flight Day 2. There was also no shortage of both camaraderie and formality.
At the start of Flight Day 3, the crew closed the payload bay doors, sealing the radiator panels and the DFI pallet from space, and the expected heat of reentry. Up to this point, the most worrisome system remained untested: the heat shield. When the payload bay was still open, aft-facing windows allowed the crew to confirm that the wingtip RCC panels were intact; that was about all that could be definitively checked. Remote imaging using the USAF’s new KH-11 reconnaissance satellites showed no issues with the underbelly, where the heating would be the most severe. But ultimately, centimetre-scale defects mattered, and those were beyond the spysats’ resolution.
Weather issues forced the mission to conclude at Edwards AFB, instead of the purpose-built Shuttle Landing Facility at Kennedy. Enterprise made its final OMS burn for the mission, bleeding off the modicum of speed that would drop it back into the atmosphere. Half an orbit later, plasma began to form around the blunt underside.
From this point, it should take 20 minutes for the ionisation to subside, and radio contact to be reestablished.
Within the radio silence, Enterprise should be making S-turns, dipping one wing after the other to bleed off speed; Young would fly the latter half of the descent manually, something that wouldn’t ever be attempted in the program again. The vehicle should be streaking across the Pacific, but nobody knew for sure if it actually was still doing so controllably, as aerodynamic models may not have represented real aerodynamics.
“Standby for mark on 9700 feet per second…”
“...”
“Hello, Houston, Enterprise’s here!”
A few quick checks using live information verified that the Shuttle was right on track, having bled off and conserved just the right amount of energy for a spiralling descent path. All vital systems continued to hold, and would have to hold as Mach 3 controllably decreased to 0. Twin sonic booms were soon heard over the desert, signalling its approach to the runway.
At subsonic speeds, Enterprise fell four units of vertical distance per unit of horizontal distance travelled; T-38 chase planes struggled to stay behind even with landing gear deployed. It was by all means a terrible, but graceful flying machine. The two astronauts would have to stick the landing on the first try, for the jet engines that would have made it a powered aircraft have long since been deleted in development.
Young called out vertical distances as the landing gear was irretrievably deployed; just like all the planes he piloted throughout his career, he eased the nose up, and planted the main tires into the sandy landing strip, where Constitution made the ALT landings five years ago. The nose then pivoted to the ground, kicking up a third trail of dust with the nose gear. High-tech brakes converted the last of the Shuttle’s kinetic energy to heat.
A convoy of vehicles adorned by NASA’s new 'Worm' logo raced across the sand, to tend to the almost stationary orbiter. They would safe all remaining pyrotechnics and drain toxic chemicals, as well as help the crew egress.
“Wheels stop, Enterprise. Wheels stop!”
The dust slowly settled, and Enterprise sat still in one piece. The crew would soon be walking around the ship that took them to orbit and back; doing a postflight inspection, while visibly tired but exhilarated from the experience.
But for Enterprise and its future siblings to live up to the promise of a Space Transportation System, OV-102 would have to prove that it could fly again.
¶
Even before Enterprise was moved from the runway, the astronauts and ground crew noted a number of issues with the orbiter. Alarmingly, some of these were not cosmetic.
It was discovered that a subtly small part of the curved engine shroud, which protected the main engines from reentry heating, had melted and warped. Cracks on neighbouring tiles suggested that staging had bent the shroud sufficiently for tiles to pop off, exposing the underlying aluminium to searing 1500°C heat. It was through blind luck that the shroud was not structurally compromised. Moreover, several non-densified tiles disappeared from the OMS pods, likely blown off by ascent turbulence between the ETs and the orbiter. While the latter issue can be solved by using the improved tiles, the tiles in the interstage area would have to be diced to permit more flexing, until a more permanent fix was found.
The booster faced a similar issue of fluids getting where they weren’t supposed to. As STS-1 was a demonstration flight, Booster 601 was thoroughly disassembled for analysis at Michoud; seawater was found in the GOX vent, although none thankfully made it into the tank. A drop-down cover that latched shut upon umbilical disconnect would be added.
These corrections would be kept in mind during preparations for the next mission, STS-2. As Booster 601 was thoroughly gutted for analysis, the brand-new Booster 602 was shipped via barge to propel the next flight. In hopes of expediting preparations for future flights, STS-2 preparations also tried flying in ETs via Super Guppy; the bulbous aeroplanes have been out of a job since S-IVB stages stopped being produced. However, this method of transporting the ETs would soon be abandoned in favour of more cost-effective barging.
Inside the OPF, Enterprise was fitted with some of the payloads it would carry. Besides a series of Earth-observation experiments, and the familiar DFI package, STS-2 would fly the first Canadarm, a robotic manipulator system designed to handle all future payloads. This Canada-built component replaced free-flying propulsive cargo tugs envisaged in the past.
Reprocessing for STS-2 was taken relatively slowly and methodically, resulting in an atrociously long (but acceptable for FMOF) turnaround duration of 103 days. Again, Enterprise was mounted onto the launch stack, and after sorting out a hydrazine spill and another computer failure, launched in November 1981 with ALT pilots Joe Engle and Richard Truly at the controls. Booster 602 was recovered intact after launch, with minor wrinkling on the LOX tank dome. As for the orbiter’s planned 5-day mission, it was forcefully cut short when one fuel cell failed, a rule put in place since the Apollo days. The failed fuel cell also resulted in the water supply being saturated with gaseous hydrogen; the crew would become somewhat dehydrated as they refrained from drinking, to avoid flatulence.
While the truncated mission would have resulted in the Canadarm not being tested, the crew decided to defy orders and test it during rest periods devoid of ground contact. The arm was put through its paces, testing handling and reach (such as by using a camera mounted on its end to reveal a ‘Hi Mom’ sign Truly brought, through the aft windows). The de jure mutiny was somewhat welcomed, as it contributed to most mission objectives being achieved when Enterprise touched down at Edwards again. Remarkably fewer tiles were also lost, rendering the tile repair kit they brought along redundant.
The third FMOF flight, STS-3, brought about a dramatic change in the stack’s appearance: the previous flights allowed many to identify where mass can be safely removed, which would enhance the Shuttle’s payload capabilities for operational flights. The 300 kg of white paint on the ETs was an easy target, especially after it was determined that the foam was more robust than initially thought. As a result, the spray-on insulation (SOFI) would be laid bare to ultraviolet rays from the sun, which turned it an increasingly deeper orange with exposure. In the very near future, the ET would be further lightened by shaving off excess metal and deleting some components.
STS-3 launched in early 1982, with Enterprise boosted by Booster 603, commanded by Skylab veteran Jack Lousma and ALT pilot Gordon Fullerton. The increasing flight experience meant that very few issues were encountered, the worst onboard being a failure of the toilet and some communications losses. When the time came to land, however, Edwards AFB experienced unacceptable flooding. The orbiter was thus diverted to Northrop Field in New Mexico, a decision that gave one extra flight day to the astronauts.
The alternate landing spot also dragged out preparations for the next mission. Northrop Field’s strip had thrown absurd amounts of gypsum into nooks and crannies of the orbiter, which needed cleaning. It was joked that Enterprise forever remained at least a kilogram heavier despite the subsequent decontamination.
The penultimate FMOF flight, STS-4, followed on a record-setting 2 months after the last. Ken Mattingly and Hank Hartsfield flew Enterprise on an almost picture-perfect orbital mission. However, the mission would have been completely perfect had the booster survived the program’s first attempt at reflying a booster.
After staging, Booster 601 successfully reoriented into a nose-forward altitude. But when the drag tabs deployed, one of them failed to receive any commands owing to an improperly connected cable between the stage and the corresponding fin. As the atmosphere thickened with the descent, the forces acting on the three deployed tabs became ever stronger and asymmetrical; the nitrogen thrusters rapidly exhausted their fuel fighting the resulting rotation. The roll-tumble continuously accelerated, with only the fins’ broadside area limiting it from tearing the stage apart with centrifugal forces. Yet for all intents and purposes, Booster 601 was doomed. The parachutes deployed, and were wrapped around its circumference; the floatation bags tried to inflate, but were bound back by the chute risers. Wrapped in a mass of fluttering fabric and plastic, it impacted the ocean more than ten times faster than what was survivable. Catamount arrived on the scene to find a kerosene oil slick, dotted by bits of shredded flotsam; ROVs tilled through the underwater debris to find the cause, and nothing was recovered once the reason behind the program’s first major loss became apparent.
With Booster 604 still some time from completion, a short scramble to procure another replacement ensued. With the boosters and their parts being potentially less resilient than thought, the operational booster fleet size was changed from five to six, to provide a schedule buffer against similar booster losses or severe damage.
Aside from the booster recovery failure, STS-4’s mission received comparatively little press coverage than its predecessors. This was partly because the Shuttle’s novelty was beginning to wear off, and also due to the DoD payload being carried onboard; Mattingly disclosed that it was a “rinky-dink collection of minor stuff they wanted to fly”, and that it failed to function. The civilian payloads were much more successful; the student-contributed experiments in “Get-Away Special” (GAS) containers, as well as a McDonnell Douglas instrument that tested methods of producing medicines in microgravity, all delivered results. The GAS cans are part of NASA’s attempt to garner more payloads for the Shuttle while being more relevant to civilian life; they would be a constant fixture of nearly all future Shuttle flights.
When Enterprise concluded STS-4 at Edwards AFB, again due to inclement weather at the KSC, the FMOF program officially came to an end, and the Shuttle marched into operational status.
In view of this new status, August 1982 saw a reassessment of Shuttle capabilities. The program was certain to be jointly managed by both NASA and the DoD; variables only remained in the transition from expendable launch vehicles (ELVs) to the Shuttle, which would depend on the demonstrated flight rate and capabilities of the latter. It was concluded that all ELVs should be phased out by 1986, leaving the Shuttle to satisfy all of the United States' space access needs by flying 40 missions a year. Achieving a high flight rate was thus paramount to justify the Shuttle’s stated purpose of increasing access to space, as well as its economy.
These were big plans for the Shuttle’s capabilities, complementing an entire market that arose around it in the intervening decade between the Shuttle's gestation and first flight. For NASA of the 80s, it was an international business machine; for the government now vying for national defence against a revitalised enemy, it was the perfect tool to deliver space-based national security assets, and create new national solidarity by invoking patriotic sentiments with.
¶
“Through our history, we've never shrunk before a challenge. The conquest of new frontiers for the betterment of our homes and families is a crucial part of our national character, something which you so ably represent today. The space program in general and the Shuttle program in particular have gone a long way to help our country recapture its spirit of vitality and confidence. The pioneering and pathfinding spirit still flourishes in America. In the future, as in the past, our freedom, independence, and national well-being will be tied to new achievements, new discoveries, and pushing back new frontiers in this great American enterprise.”
“The fourth landing of the Enterprise is the historical equivalent to the driving of the golden spike which completed the first transcontinental railroad. It marks our entrance into a new era. The test flights are over. The groundwork has been laid. And now we will move forward to capitalise on the tremendous potential offered by the ultimate frontier of space. Beginning with the next flight, the Enterprise and her sister ships will be fully operational, ready to provide economical and routine access to space for scientific exploration, commercial ventures, and for tasks related to the [sic] national security.”
……
“Before I introduce you [Hartsfield and Mattingly], if you'll all just look -- well, I'm sure down in front maybe you can't see -- but way out there on the end of the runway, the Space Shuttle Independence, affixed atop a 747, is about to start on the first leg of a journey that will eventually put it into space in November. It's headed for Florida now.”
– Extracts from a speech by President Reagan after STS-4’s landing
End of Act 1
) say aircraft. Turn around times of "24 hours" are highly unlikely, a couple of days are "in theory" possible but still unlikely, probably the 'best' assumption is a couple of weeks at a minimum so to achieve a high fight rate you need more vehicles which costs more money in every aspect. Which actually runs into the 'reusable' versus 'expendable' problem because what we've learned is that if you need more reusable vehicles to achieve a certain flight rate then it's been shown that simply making 'cheaper' expendable vehicles is still actually economically comparable.
