A very good question! We'll be getting into this more as we go through the next few posts! Any speculation?
Boldly Going: A History of an American Space Station
- Thread starter e of pi
- Start date
If this timeline doesn't end up with an orbital rotating gravity lab (ORGL? Original? Ogre?) at some point I shall be very
Oh, you meant short-term. Maybe they could get an early start on trying to actually cook food in microgravity instead of relying on reheating pre-packaged meals.
I hope you didn't take the comparison to the historical NASA propellant scavanging studies as an insult. I meant the comparison as a way to show that such schemes were seriously considered, part of explaining why we're not using them.
Your masses for the fuel cells and the residuals ae pretty close to accurate. In fact, typical reserves for Shuttle missions were figured about 3,000 lbs. You can more on this in Wayne Hale's blog post about STS-93. You'll see they intended to launch with about 3,900 lbs of reserve, and ended up with about 3,000 due to local conditions at time of filling the tanks (not a bad margin when loading, really - just 0.06% error!). The issue is that on that flight, engine problems lead them to consume their entire oxygen quantity. They hit low propellants warnings just as the engines burnt out...16 ft/s shy of the planned burn. If that were Enterprise on top of those engines, and they'd been depending on those reacts to power the station, they would have been out of luck.
There's also a pressure problem. If I'm doing my math right, boiling the residual LOX makes for higher gas pressure than the tank is designed for (about 2.7 atm, well above the design limit of 2.2 to 2.5 atm). Moreover, the fuel cells are expecting to be fed reactants at about 54 atm. Venting boiloff to a level of pressure in the tanks which is tolerable is doable, as likely is converting the fuel cells to run on far lower inputs or adding a storage tank and compressor to scavenge the low-pressure tank contents, compress the to the expected input pressure, and then open to feed the Shuttle fuel cells. The challenge is timing. Batteries are proven, and they have not one but two chances to automatically deploy solar arrays before they run into an issue which requires an accelerated STS-38R contingency launch. When the station is being originally designed, they don't have the time to take on additional challenges like modifying the reactant feeds to connect the fuel cells to the External Tanks and then conduct some kind of orbital testing on a previous Shuttle flight to resolve a relatively low-odds (though high-impact) contingency - though certainly one that weighs on the program.
The issues you mention with fuel cells not being regenerative (while batteries can also serve the required function of smoothing solar power generation over orbital periods) and their short life of only a few weeks means keeping the fuel cells does come at the expense of some other payload, probably 500-600 kg of it once the feed lines, existing Shuttle reactant tanks, and new ET scavenging equipment is added. It's not a terrible idea, it's a pretty decent one, and I'm sure in this timeline, somebody wrote a 110 page NASA report on "A Consideration for Propellant Scavenging as an Alternate Keep-Alive Power Source". However, under the time pressure, we don't think the Space Station Enterprise Program Office will have gone with it on top of the existing challenges. It's worth noting that the Space Station conversion study from Space Industries International @Expansive linked also envisions replacing the fuel cells in their entirety with batteries. If the program office ITTL had known they'd have until 1989, instead of 1986/87...perhaps they'd have tried it, but they didn't know and so they have not. You may recall this timeline's opening post specifically cites Enterprise as an example of both successful improvisation and of "technical debt". You can argue keeping the OMS engines instead of replacing the entire system in an example, and that not keeping the fuel cells is another, at least to reduce the risk of a contingency which fortunately turns out not to occur. That's sort of the nature of this entire timeline - if you've been convinced that anything about Space Station Enterprise is a particularly good idea, it's probably not.
By the way, @Shevek23 , I wanted to be clear: I appreciate you posting here and thinking deeply about all of this. It's good to have you aboard.
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It seems straightforward to add more solar wings to the tips of the existing ones, like the real Space Station, but my limited knowledge of the radiator system on the Shuttle suggests that hooking that up to a truss-system would be more difficult.
I wonder could something like project Babylon be used to deliver water,food and other cargo to the space station?
en.wikipedia.org
www.popsci.com
Project Babylon - Wikipedia
A Cannon for Shooting Supplies into Space
John Hunter wants to shoot stuff into space with a 3,600-foot gun. And he’s dead serious—he’s done the math. Making deliveries to an orbital outpost on a rocket costs $5,000 per pound, but using a space gun would cost just $250 per pound.
www.popsci.com
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Assuming no butterflies Bull's already working for Saddam by now (and scheduled for assassination by whoever did the deed OTL) so the technology is essentially dead (in both senses of the word).I wonder could something like project Babylon be used to deliver water,food and other cargo to the space station?
Project Babylon - Wikipedia
I sure some else could make it work and it would a much cheaper way to supply the space station.
How much if the stuff you want to send to the space station could survive a 100+ G acceleration down the barrel of a space gun? You’d basically be limited to water, fuel, and gases, so you would still need regular rocket launches, and you would also require the added expense of a space tug to go retrieve packages launched by the space gun. Considering the amount of material needed by a space station like this, I doubt the cost per kg to the space station for the development, construction, and operation of space gun would be lower than using an existing rocket.
The Space Gun also has a political dimension: it can hit anywhere on earth. Even if launching a nuclear weapon through it is impossible, will anyone believe that?
For an orbital launcher, it needs thrusters that can survive the launch. If they don't fire, that shell is in an orbit that intersects Earth's surface, and a cargo pod coming down at orbital velocity will make a big hole!
For an orbital launcher, it needs thrusters that can survive the launch. If they don't fire, that shell is in an orbit that intersects Earth's surface, and a cargo pod coming down at orbital velocity will make a big hole!
Part 9: STS-38R and the “Last of the Skylab Guys” complete Enterprise commissioning
Boldly Going Part 9
The crew woke on Flight Day 5 to the Beatles’ 1969 “Here Comes the Sun.” This marked not just the task of finishing the station’s solar array deployment, but a major shift in the mood of the crew and teams on the ground. With Enterprise’s entire starboard solar array wings deployed, the station could be made self-sufficient with no crew aboard. Even if Atlantis finished no further tasks over the remaining five days aboard the station, their major task of securing the station for the future was done. The Beatles’ hopeful melody marked the turning point in the program from securing Enterprise’s deployment to maximizing its success. With the deployment that day of the port solar array wings, Space Station Enterprise had the power to be considered fully operational, and Merbold and Engle continued work to activate the systems in the Enterprise mid-deck, the orbital operations center, the LeoLab, and the airlock. Late in the day, Engle’s crew had caught up to almost every mission milestone. After erasing the 24-hour deficit, the rookies were put to work on “get-ahead” tasks to prepare for Flight Day 6’s main activities: the much-anticipated “Intra-Vehicular Activity” inside ET-007. As the name suggested, this was something which wasn’t quite a spacewalk, but was still quite distinct from operating in a fully pressurized spacecraft. After all, even after days of venting and passivating, ET-007 still contained massive propellant feed and vent lines where ground conditioning systems had fed the tanks full of millions of kilograms of propellants only days prior, then hungry engines had sucked them dry in minutes. All represented potential leak points for the future station. Though there were no immediate plans to make use of the LOX tank’s 560 cubic meters, and even less planning for the massive 1,500 cubic meters of the hydrogen tank, one of STS-38R’s mission goals was to make sure ET-007’s tanks were sealed and pressure-tight, allowing them to be considered fully a part of the station’s volume for future expansion before any errant plans were made.
The crew had spent three days making Space Station Enterprise fit for human occupation, including two spent wrestling with the “hamster tubes” alone. Now, the crew would be confined to Atlantis again while the tubes were used as an impromptu airlock by the two-person team of Garriott and Thuot, with Sullivan suited up in the airlock on Atlantis in case of contingency needs. After checking the hatches to Atlantis and Enterprise proper were closed, the space-suited pair opened the inspection manhole into the LOX tank, their lights catching on the stringers and baffles of the tank. The images captured by each of the pair of the other working backlit against the faintly illuminated tank walls became famous, helping to drive home for those watching on the ground who had not yet grasped the true size of the external tank Enterprise could someday grow into. The pair worked for half an hour around the base of the tank, sealing the main propellant fill/drain line, a job complicated by the baffling designed to prevent sloshing during ascent or geysering during tank fill procedures. Next came another dramatic image, as Garriott (the most experienced of the pair in both EVA and the unusual situation of operating in vacuum in microgravity inside a large but constrained environment) leaped to the top of the tank trailing a tether. There, he jammed a sealant plug into the nose LOX vent where the “beanie cap” had made its usual pre-launch contact to capture boiling LOX and the smaller port where oxygen recirculated from the SSMEs provided tank pressurization. The sealant plugs formed a secondary backup against the valve actuators to ensure the valves would never pass crew breathing atmosphere the way they had once passed gaseous oxygen.
Completing their IVA into the LOX tank, Garriott and Thuot closed and sealed it, then repeated the performance inside the even-larger hydrogen tank, plugging the hydrogen vent valve and pressurization line near the top of the tank, then both made the leap more than 25 meters (nearly twelve stories) to the bottom of the tank to work on plugging the main fill/drain lines. After more than 6 hours of IVA time for the day, Garriott and Thuot finished their work in the hydrogen tank and closed it out as they had the oxygen tank before it. Their work was tested by bleeding a small amount of air into each tank after the intertank was repressurized, to be monitored over coming days and weeks. Still, the final results wouldn’t come until increases in the station’s onboard consumables could allow more precious breathing gasses to be wasted pressurizing unused volume. Nearly eight hundred kilograms (800 kg) of air would be required to fully fill the LOX tank, with just over two thousand kilograms (2,000 kg) required for the hydrogen tank. Even sparing 280 kg to reach 10% final pressure was enabled only by the consumables brought by Atlantis to help fully charge the station’s tanks. While the IVA team had worked in the tanks and Sullivan had stood by to come for assistance, the rest of the crew had worked in Atlantis to prepare for consumables transfer over the coming days.
On July 15th, NASA granted STS-38R a day of relative rest for Flight Day 6. The major activities of the mission lay behind them: the crew now had free run of Atlantis, her Spacelab cargo, the ET-007 tubes, the PCAM passage, the mid-deck and orbital operations center of Enterprise, and the LLM and airlock in OV-101’s payload bay. The day was spent in organizational tasks and cargo transfer, with the crew forming a “bucket brigade” to fling cargo bags and air canisters around the tight corners of the ET-007 access tubes where the day before Garriott and Thuot had struggled in their suits through the constrained manholes into the tanks. With the major work to activate the station complete, the time constraints on the STS-38R fell away. Over Flight Days 7, 8, and 9, the crew were able to gradually complete the process of unloading their cargo, stocking the station’s larders, then setting the station into a quiescent mode to wait out the time until its next visitors. As Atlantis drew away from the station on Flight Day 10, the crew was granted perspective on their accomplishments of the last week. The station now spread its massive solar wings and looked ready and waiting for the next crew. Enterprise’ STS-37R launch had been a massive risk for an agency still smarting from the loss of Discovery, but STS-38R’s experienced hands and capable rookies had made good on the wager.
The final statistics of Space Station Enterprise following the STS-38R deployment mission were staggering. Even discounting some of the primary structure of OV-101 and other systems only needed for launch, Enterprise’s single launch had carried more than 150,000 kilograms of useful payload to orbit, more than ten times that of typical Space Shuttle missions. The core modules of the station (OV-101 crew module, Leonardo Lab Module, airlock, and intertank tunnels) constituted two hundred cubic meters, already larger than the Soviet Mir, and had proven easily capable of supporting the visiting crew of seven from STS-38R. The LOX tank added another six hundred cubic meters, and when outfitted would eventually bring the station up to nearly three times the size of the Skylab station which had preceded it, though that would have to wait many more missions. The staggering volume of the fifteen hundred cubic meter liquid hydrogen tank remained a dream for another day, one which would once again nearly triple the size of the station. Even American planners still struggled with how to effectively convert such a large volume on orbit for operational use, and with how many crew such a large volume might require or justify.
With STS-38R concluded by Atlantis’ landing in Florida, the flags for both Enterprise and Atlantis were moved. Atlantis’ flag would continue to follow the orbiter as she made her way to the OPF to prepare for her next flight. Enterprise’ flag was moved to fly just outside the Launch Control Center, marking the orbiter’s continuing flight. To many on the ground, STS-37R and STS-38R solidified the new era in the space program: a dramatic accomplishment that pad workers and support teams could look to as a model of what could go right after Discovery’s loss. Enterprise was a model for what the program could aspire to as it moved on from the tragedy. In the future, the Enterprise flag would roll to the pad with each new mission to support the station, flying just below the orbiter’s own flag. However, while Enterprise waited on its next crew, the future of American spaceflight was being radically reshaped in a way inspired by Enterprises fantastically successful launch.
Artwork by: @nixonshead (AEB Digital on Twitter)
The crew woke on Flight Day 5 to the Beatles’ 1969 “Here Comes the Sun.” This marked not just the task of finishing the station’s solar array deployment, but a major shift in the mood of the crew and teams on the ground. With Enterprise’s entire starboard solar array wings deployed, the station could be made self-sufficient with no crew aboard. Even if Atlantis finished no further tasks over the remaining five days aboard the station, their major task of securing the station for the future was done. The Beatles’ hopeful melody marked the turning point in the program from securing Enterprise’s deployment to maximizing its success. With the deployment that day of the port solar array wings, Space Station Enterprise had the power to be considered fully operational, and Merbold and Engle continued work to activate the systems in the Enterprise mid-deck, the orbital operations center, the LeoLab, and the airlock. Late in the day, Engle’s crew had caught up to almost every mission milestone. After erasing the 24-hour deficit, the rookies were put to work on “get-ahead” tasks to prepare for Flight Day 6’s main activities: the much-anticipated “Intra-Vehicular Activity” inside ET-007. As the name suggested, this was something which wasn’t quite a spacewalk, but was still quite distinct from operating in a fully pressurized spacecraft. After all, even after days of venting and passivating, ET-007 still contained massive propellant feed and vent lines where ground conditioning systems had fed the tanks full of millions of kilograms of propellants only days prior, then hungry engines had sucked them dry in minutes. All represented potential leak points for the future station. Though there were no immediate plans to make use of the LOX tank’s 560 cubic meters, and even less planning for the massive 1,500 cubic meters of the hydrogen tank, one of STS-38R’s mission goals was to make sure ET-007’s tanks were sealed and pressure-tight, allowing them to be considered fully a part of the station’s volume for future expansion before any errant plans were made.
The crew had spent three days making Space Station Enterprise fit for human occupation, including two spent wrestling with the “hamster tubes” alone. Now, the crew would be confined to Atlantis again while the tubes were used as an impromptu airlock by the two-person team of Garriott and Thuot, with Sullivan suited up in the airlock on Atlantis in case of contingency needs. After checking the hatches to Atlantis and Enterprise proper were closed, the space-suited pair opened the inspection manhole into the LOX tank, their lights catching on the stringers and baffles of the tank. The images captured by each of the pair of the other working backlit against the faintly illuminated tank walls became famous, helping to drive home for those watching on the ground who had not yet grasped the true size of the external tank Enterprise could someday grow into. The pair worked for half an hour around the base of the tank, sealing the main propellant fill/drain line, a job complicated by the baffling designed to prevent sloshing during ascent or geysering during tank fill procedures. Next came another dramatic image, as Garriott (the most experienced of the pair in both EVA and the unusual situation of operating in vacuum in microgravity inside a large but constrained environment) leaped to the top of the tank trailing a tether. There, he jammed a sealant plug into the nose LOX vent where the “beanie cap” had made its usual pre-launch contact to capture boiling LOX and the smaller port where oxygen recirculated from the SSMEs provided tank pressurization. The sealant plugs formed a secondary backup against the valve actuators to ensure the valves would never pass crew breathing atmosphere the way they had once passed gaseous oxygen.
Completing their IVA into the LOX tank, Garriott and Thuot closed and sealed it, then repeated the performance inside the even-larger hydrogen tank, plugging the hydrogen vent valve and pressurization line near the top of the tank, then both made the leap more than 25 meters (nearly twelve stories) to the bottom of the tank to work on plugging the main fill/drain lines. After more than 6 hours of IVA time for the day, Garriott and Thuot finished their work in the hydrogen tank and closed it out as they had the oxygen tank before it. Their work was tested by bleeding a small amount of air into each tank after the intertank was repressurized, to be monitored over coming days and weeks. Still, the final results wouldn’t come until increases in the station’s onboard consumables could allow more precious breathing gasses to be wasted pressurizing unused volume. Nearly eight hundred kilograms (800 kg) of air would be required to fully fill the LOX tank, with just over two thousand kilograms (2,000 kg) required for the hydrogen tank. Even sparing 280 kg to reach 10% final pressure was enabled only by the consumables brought by Atlantis to help fully charge the station’s tanks. While the IVA team had worked in the tanks and Sullivan had stood by to come for assistance, the rest of the crew had worked in Atlantis to prepare for consumables transfer over the coming days.
On July 15th, NASA granted STS-38R a day of relative rest for Flight Day 6. The major activities of the mission lay behind them: the crew now had free run of Atlantis, her Spacelab cargo, the ET-007 tubes, the PCAM passage, the mid-deck and orbital operations center of Enterprise, and the LLM and airlock in OV-101’s payload bay. The day was spent in organizational tasks and cargo transfer, with the crew forming a “bucket brigade” to fling cargo bags and air canisters around the tight corners of the ET-007 access tubes where the day before Garriott and Thuot had struggled in their suits through the constrained manholes into the tanks. With the major work to activate the station complete, the time constraints on the STS-38R fell away. Over Flight Days 7, 8, and 9, the crew were able to gradually complete the process of unloading their cargo, stocking the station’s larders, then setting the station into a quiescent mode to wait out the time until its next visitors. As Atlantis drew away from the station on Flight Day 10, the crew was granted perspective on their accomplishments of the last week. The station now spread its massive solar wings and looked ready and waiting for the next crew. Enterprise’ STS-37R launch had been a massive risk for an agency still smarting from the loss of Discovery, but STS-38R’s experienced hands and capable rookies had made good on the wager.
The final statistics of Space Station Enterprise following the STS-38R deployment mission were staggering. Even discounting some of the primary structure of OV-101 and other systems only needed for launch, Enterprise’s single launch had carried more than 150,000 kilograms of useful payload to orbit, more than ten times that of typical Space Shuttle missions. The core modules of the station (OV-101 crew module, Leonardo Lab Module, airlock, and intertank tunnels) constituted two hundred cubic meters, already larger than the Soviet Mir, and had proven easily capable of supporting the visiting crew of seven from STS-38R. The LOX tank added another six hundred cubic meters, and when outfitted would eventually bring the station up to nearly three times the size of the Skylab station which had preceded it, though that would have to wait many more missions. The staggering volume of the fifteen hundred cubic meter liquid hydrogen tank remained a dream for another day, one which would once again nearly triple the size of the station. Even American planners still struggled with how to effectively convert such a large volume on orbit for operational use, and with how many crew such a large volume might require or justify.
With STS-38R concluded by Atlantis’ landing in Florida, the flags for both Enterprise and Atlantis were moved. Atlantis’ flag would continue to follow the orbiter as she made her way to the OPF to prepare for her next flight. Enterprise’ flag was moved to fly just outside the Launch Control Center, marking the orbiter’s continuing flight. To many on the ground, STS-37R and STS-38R solidified the new era in the space program: a dramatic accomplishment that pad workers and support teams could look to as a model of what could go right after Discovery’s loss. Enterprise was a model for what the program could aspire to as it moved on from the tragedy. In the future, the Enterprise flag would roll to the pad with each new mission to support the station, flying just below the orbiter’s own flag. However, while Enterprise waited on its next crew, the future of American spaceflight was being radically reshaped in a way inspired by Enterprises fantastically successful launch.
Artwork by: @nixonshead (AEB Digital on Twitter)
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Spectacular art in the latest update! And excellent content too.
I wonder what the tank volume might first be used for going forward. Garbage storage, like the LOX tank in Skylab, or BEAM IOTL, probably. Though maybe mounting exercise gear would also be desirable for vibration isolation from Enterprise and Leonardo?
EDIT: Internal centrifuge, obviously. The large diameter can help with that, and it might be cheaper to assemble it in space than to launch a dedicated module as with the OTL CAM.
I wonder what the tank volume might first be used for going forward. Garbage storage, like the LOX tank in Skylab, or BEAM IOTL, probably. Though maybe mounting exercise gear would also be desirable for vibration isolation from Enterprise and Leonardo?
EDIT: Internal centrifuge, obviously. The large diameter can help with that, and it might be cheaper to assemble it in space than to launch a dedicated module as with the OTL CAM.
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With a cable and 2 fuel pods, you could have gravity. that should help combat the effect of low gravity on the human body and allow astronauts to spend much longer in space.
Artificial gravity - Wikipedia
Years of study to get into space and Murphy is sent to grow potatoes, as his grandfather did on back in Ireland. 😄
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A lot of its early use is likely to be recreational, as its too much area for them to be scrooge with it so it opens up a lot of area expensive things. For example perhaps a low gravity athletics zone or something where you can play sports or team games, perhaps Blitzball for the Final Fantasy fans out there.
It's so much room you can afford to be generous and experiment with things a bit.
Perhaps instead of having the astronauts take personal items/entertainment down with them on the Shuttle, they can gradually build a library or repository of entertainment that they just keep up there and add to over time so there is more varied things to do. A chess board for when the Russians inevitably visit if you want to stereotype.
Then there's the obvious next step of Greenhouse so you can simulate some of the challenges you'll face, so this'll be high up there given you can experiment with human waste too and how efficient of a system you can set up.
It's so much room you can afford to be generous and experiment with things a bit.
Perhaps instead of having the astronauts take personal items/entertainment down with them on the Shuttle, they can gradually build a library or repository of entertainment that they just keep up there and add to over time so there is more varied things to do. A chess board for when the Russians inevitably visit if you want to stereotype.
Then there's the obvious next step of Greenhouse so you can simulate some of the challenges you'll face, so this'll be high up there given you can experiment with human waste too and how efficient of a system you can set up.
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I think in the 90's as a gimick Coke and Pepsi sent their respective products (Or in the case of Pepsi horse urine) to the ISS and had a taste test.
Apparently it didn't go well. The carbonation needs gravity to work right. Apparently both liquids tasted pretty bad.
I'm hoping a version of this still happens in OTL. But enraged by the results Coke decided to purchase it's own gravity module for the American station so they can (rightfully) win the test.
Pepsi will respond by reactivating their Russian fleet and declaring all out War.
Comparing the internal spaces of the LOX and H2 tanks to multi-storey office towers is apt and hopefully used as a model for future expansion (the ridiculous ideas I've seen for crew module layouts would make Escher roll his eyes.
Finding things to fill the giant H2 tank space while being made from pieces small enough to fit through an airlock might be a challenge still incomplete by the time the station's decommissioned! I think @Simurgh might be right and once some padded wall panels are installed the space might remain a Blitzball arena for the foreseeable future (unless someone gets the wild idea of testing birds in microgravity).
Finding things to fill the giant H2 tank space while being made from pieces small enough to fit through an airlock might be a challenge still incomplete by the time the station's decommissioned! I think @Simurgh might be right and once some padded wall panels are installed the space might remain a Blitzball arena for the foreseeable future (unless someone gets the wild idea of testing birds in microgravity).