Boldly Going: A History of an American Space Station
- Thread starter e of pi
- Start date
Not really.
If you wanted a vehicle design to start from, the Rockwell Platypus SSTO would be better:
I mean, come on! It's called the Platypus! How could you not want a Shuttle II that looks like that!
I think it was mentioned before it'll also combine features of Boeing's lifting body, so I imagine the final design will look quite interesting.
I find it notable how many of the 'alternative shuttle' designs have much smaller wings than the OTL Orbiters, does anyone know if that's because a lifting-body is assumed or if they were just expected to have a much steeper glide angle?
This ahead-of-it’s-time design featured an innovative first stage based on a soap bubble.Not really.
If you wanted a vehicle design to start from, the Rockwell Platypus SSTO would be better:
Part 29: A hanger needed, a tank available. Enterprise acquires a shuttlebay.
Boldly Going Part 29
By 2010, congressionally approved programs were underway both to replace the space shuttle and to convert the existing Conestoga landing system into a fully reusable vehicle. At this point NASA began to turn its eyes skyward once again, toward the goal that had sat at the far end of program roadmaps for decades: Mars. The development of orbital servicing techniques and support technologies aboard Enterprise had provided extensive experience with the challenges of outfitting a Mars mission. Moreover, the station itself could serve as a platform for the construction and outfitting of a reusable transfer habitat for missions to the red planet. However, while Enterprise crews had spent nearly five years doing an excellent job of maintaining their orbital neighbors Galileo and Hubble, the conditions the job was undertaken in were rough compared to the dream of an orbital spacedock.
The payload bay of OV-101 Enterprise had been full, even on the original launch to orbit. The station’s airlock had been crammed at the aft end of the LLM, bare centimeters from the station’s Canadarm2 and the stowed Enterprise Power Module solar arrays. For twenty years, this cramped “back porch” had been the only location for operational EVAs staged from the station. While either of the station’s two Kelper lifeboats could act as contingency airlocks, doing so would reduce the orbital life of the capsules. Kepler wasn’t designed to operate for extended periods with the cabin in vacuum, nor was it equipped to recover cabin atmosphere during depressurization instead of venting it overboard, and so its use in any but the most dire emergency was discouraged in mission planning.
Similarly, while Enterprise was equipped with a number of robotic manipulator arms that could reach almost all areas of the station, viewing the results of their use was more challenging. Work on Hubble and Galileo was typically performed ‘in situ’, Galileo using its forward APAS port to dock and retrieve Hubble, then approaching the station to be berthed with its aft port to Node 2’s forward CBM. This configuration left both vehicles visible from both the Orbital Operations Center and the Cupola attached to Node 2’s port side, as well as close enough to OV-101’s airlock for the arm to ferry astronauts to the work site without a “walkoff” maneuver. Unfortunately, it also left any crew working on the telescope and miniature station precariously far from the station structure proper. Combined with worries of visiting vehicle thrusters impacting the sensitive telescope, mission rules dictated that work in this location was prohibited when Shuttle visits were scheduled.
These restrictions limited work schedules and often resulted in delays while teams waited for orbital sunrise. Moreover, delicate equipment and circuits were forced to be serviced with panels removed while on the most extreme end of the station, leaving them vulnerable to freak orbital debris and other risks. Furthermore, any tools or hardware that were lost off-structure were lost forever to the void, only to be tracked as debris. Over the life of the station, records indicated that the EVA toolboxes of Enterprise had gone through more than one complete replacement due to on-orbit losses. Worse, this was one of the few areas of the station in clear view from both the Orbital Operations Center and the Cupola. The Cupola could see down past OV-101’s radiators for some Earth imaging experiments and control of the arm near the portside truss and the Japanese Lab. The rest of the station, including all operations with the arm based on the Node 1 flight releasable grapple fixture, required that the control was carried out with the camera view from the arm alone. All of this was in direct contrast to the experiences outfitting the ET-007 LOX tank habitat, where work had been eased by direct access, full control of lighting and environment, and the divorcing of tasks on the worksite from visiting vehicles and proximity operations. To remedy these continuing issues, and to better equip Enterprise for it’s continuing mission as the home port to a growing fleet of spacecraft destined for missions orbital, cis-lunar, and beyond, there was a need for some kind of “space dock” or “hanger.” A new module for the purpose, launched via space shuttle or other vehicle, was extensively studied.
Image from: Centaur Operations at the Space Station: Cost and Transportation Analysis (1988)
The new build concepts for an orbital hangar ran into trouble immediately as they evolved from concepts and wishlists to attempts to craft budget requests. There was a limited supply of open berthing locations on the station where such a new module could be housed long-term, and worse a new design would have substantive development expenses. Instead, for one last time, Enterprise planners would turn their eyes back twenty years to adapt hardware on orbit since the station’s original launch on STS-37R in 1989. Ever since the ET-007 hydrogen tank was sealed against the vacuum of space by the crew of STS-38R, the tank had waited for its moment in the sun. Conversion of the cavernous (1500 m³) volume into laboratory, habitation, or commercial spaces had been repeatedly considered, but no need had yet justified the scope of the task. The outfitting work would require several times the labor taken in turning the original ET-007 LOX tank into habitation space. Moreover, the new volume added by converting the hydrogen tank to functional pressurized volume would dwarf the existing station but would be reliant on the old and more limited SpaceLab rack drawer standard instead of the newer, larger, and more capable International Standard Payload Racks. The new, larger racks were too big to fit through the 36” diameter manhole hatch which served as the entry point into either tank. Thus, the hydrogen tank had largely sat vacant, barring occasional use as a large, but sheltered space for the safe testing systems of EVA suits and procedures that were intended to work in near-vacuum without the risks of going off-structure. In other words, it already met most of the criteria for the desired hanger conversion.
By filling the sealed tank with nitrogen, welding operations and other systems installation (such as wiring for lighting grids and robotic arm mounts) could be carried out safely and conveniently, making use of the tank as a pressurized work environment right until it was cut open to space. After that point, however, the new hangar could never be sealed again, as NASA had judged it unlikely that astronauts working with tools in space would be able to cut a hangar door into the tank in such a way that any kind of trustworthy seal could be installed. The simplest conversion was to simply install all the desired support systems in the new hangar, permanently seal the manhole, and then cut the new hangar access panels from the outside. This would give an enclosed, well-lit space, by itself a massive improvement to the prevailing working conditions for servicing spacecraft at Enterprise.
NASA, however, was tempted to try for something a bit more ambitious. By evaluating which items on their wishlist for a Shuttle-deployed hangar could be incorporated into Enterprise’s improvised equivalent, program managers hoped to develop a capability in excess of the simple open workspace. Ideally, a hangar would have a redundant airlock, a pressurized path into any vehicles docked within it, and a robotics control station with a view of the work site to enable astronauts on EVA to better coordinate with robotics operators inside the pressurized zone. For the Shuttle-launched new-build hangar, the plan had been to launch a standard 4.27m (14 foot) module with a “cupola” of windows on its axial end as a “control booth” for robotics activities. The module would also either incorporate an airlock, or have one attached at a radial port. Docked to the station using another radial or axial port, the control module could also offer a docking port available for any craft housed within the bay. This single integrated module (or assembly of modules) would provide all the command and control functions for the new hangar, acting as the “control tower” for the work site.
If such a module were mounted into the new LH2 tank hangar, the conversion of ET-007 aboard Enterprise could be just as functional as the new-build alternative. Indeed, since the proposed Shuttle-launched alternatives tended to rely on tension-stabilized fabrics or plastic sheeting for the sidewalls of the hangar, the aluminum skin and spray-foam insulation of the converted ET-007 LH2 tank would actually be more robust and offer better radiation shielding than the new-build hangar. The 4.27m diameter of the proposed Hangar Control Module would fit into ET-007’s 8.4m diameter with room to spare. Even with its length, the volume remaining in the bay would still more than exceed the volume of a Space Shuttle cargo bay or standard 5-meter payload fairing.Thus, the bay could still host and service almost any payload a Space Shuttle or NSSL-class rocket could launch. The issue, of course, was that there was no docking port on the interior of the tank’s manhole. However, by this point, welding trials inside Enterprise’s hydrogen tank were old hat. Such welding experiments had been carried out on the station for more than a decade in one form or another, and their results were already being considered critical to install structural mounts for robotic arms, lighting grids, payload mounting trunions, and other fixtures if a hangar conversion went ahead. The engineers proposed simply shipping up a standard APAS docking ring in two sections, each small enough to pass through the 36” manhole, but designed to be joined to each other and the tank forward dome in space. By incorporating an inner hatch inside the newly installed ring, the structure could be proof tested without ever venting the bay to space, enabling astronauts to work on the task until it functioned properly. The installation of a docking port on a vehicle already in space would push the state of the art from mere servicing to actual fabrication. Checkout of the process could be carried out on the ground, with only a few permanent seals to be installed and joined on orbit. Testing of the procedure in the LH2 tanks associated with the Space Station Enterprise LOX Tank Outfitting Mockups in Houston showed the concept to be viable.
Within the cost-constrained environment of the lead up to the expected approval of a Mars program in coming years, NASA recognized that the hydrogen-tank hangar conversion, as jury-rigged as it was, was the best they were likely to get. Once again, time and money would dictate the expedient over the perfect for the expansion of Space Station Enterprise. The concept’s implementation was approved in 2011, with conversion in orbit planned to begin in 2015. Thus, the new hangar at Enterprise would be completed and tested well before any reusable Mars or lunar vehicle would depend on its capabilities.
Artwork by: @nixonshead (AEB Digital on Twitter)
By 2010, congressionally approved programs were underway both to replace the space shuttle and to convert the existing Conestoga landing system into a fully reusable vehicle. At this point NASA began to turn its eyes skyward once again, toward the goal that had sat at the far end of program roadmaps for decades: Mars. The development of orbital servicing techniques and support technologies aboard Enterprise had provided extensive experience with the challenges of outfitting a Mars mission. Moreover, the station itself could serve as a platform for the construction and outfitting of a reusable transfer habitat for missions to the red planet. However, while Enterprise crews had spent nearly five years doing an excellent job of maintaining their orbital neighbors Galileo and Hubble, the conditions the job was undertaken in were rough compared to the dream of an orbital spacedock.
The payload bay of OV-101 Enterprise had been full, even on the original launch to orbit. The station’s airlock had been crammed at the aft end of the LLM, bare centimeters from the station’s Canadarm2 and the stowed Enterprise Power Module solar arrays. For twenty years, this cramped “back porch” had been the only location for operational EVAs staged from the station. While either of the station’s two Kelper lifeboats could act as contingency airlocks, doing so would reduce the orbital life of the capsules. Kepler wasn’t designed to operate for extended periods with the cabin in vacuum, nor was it equipped to recover cabin atmosphere during depressurization instead of venting it overboard, and so its use in any but the most dire emergency was discouraged in mission planning.
Similarly, while Enterprise was equipped with a number of robotic manipulator arms that could reach almost all areas of the station, viewing the results of their use was more challenging. Work on Hubble and Galileo was typically performed ‘in situ’, Galileo using its forward APAS port to dock and retrieve Hubble, then approaching the station to be berthed with its aft port to Node 2’s forward CBM. This configuration left both vehicles visible from both the Orbital Operations Center and the Cupola attached to Node 2’s port side, as well as close enough to OV-101’s airlock for the arm to ferry astronauts to the work site without a “walkoff” maneuver. Unfortunately, it also left any crew working on the telescope and miniature station precariously far from the station structure proper. Combined with worries of visiting vehicle thrusters impacting the sensitive telescope, mission rules dictated that work in this location was prohibited when Shuttle visits were scheduled.
These restrictions limited work schedules and often resulted in delays while teams waited for orbital sunrise. Moreover, delicate equipment and circuits were forced to be serviced with panels removed while on the most extreme end of the station, leaving them vulnerable to freak orbital debris and other risks. Furthermore, any tools or hardware that were lost off-structure were lost forever to the void, only to be tracked as debris. Over the life of the station, records indicated that the EVA toolboxes of Enterprise had gone through more than one complete replacement due to on-orbit losses. Worse, this was one of the few areas of the station in clear view from both the Orbital Operations Center and the Cupola. The Cupola could see down past OV-101’s radiators for some Earth imaging experiments and control of the arm near the portside truss and the Japanese Lab. The rest of the station, including all operations with the arm based on the Node 1 flight releasable grapple fixture, required that the control was carried out with the camera view from the arm alone. All of this was in direct contrast to the experiences outfitting the ET-007 LOX tank habitat, where work had been eased by direct access, full control of lighting and environment, and the divorcing of tasks on the worksite from visiting vehicles and proximity operations. To remedy these continuing issues, and to better equip Enterprise for it’s continuing mission as the home port to a growing fleet of spacecraft destined for missions orbital, cis-lunar, and beyond, there was a need for some kind of “space dock” or “hanger.” A new module for the purpose, launched via space shuttle or other vehicle, was extensively studied.
Image from: Centaur Operations at the Space Station: Cost and Transportation Analysis (1988)
The new build concepts for an orbital hangar ran into trouble immediately as they evolved from concepts and wishlists to attempts to craft budget requests. There was a limited supply of open berthing locations on the station where such a new module could be housed long-term, and worse a new design would have substantive development expenses. Instead, for one last time, Enterprise planners would turn their eyes back twenty years to adapt hardware on orbit since the station’s original launch on STS-37R in 1989. Ever since the ET-007 hydrogen tank was sealed against the vacuum of space by the crew of STS-38R, the tank had waited for its moment in the sun. Conversion of the cavernous (1500 m³) volume into laboratory, habitation, or commercial spaces had been repeatedly considered, but no need had yet justified the scope of the task. The outfitting work would require several times the labor taken in turning the original ET-007 LOX tank into habitation space. Moreover, the new volume added by converting the hydrogen tank to functional pressurized volume would dwarf the existing station but would be reliant on the old and more limited SpaceLab rack drawer standard instead of the newer, larger, and more capable International Standard Payload Racks. The new, larger racks were too big to fit through the 36” diameter manhole hatch which served as the entry point into either tank. Thus, the hydrogen tank had largely sat vacant, barring occasional use as a large, but sheltered space for the safe testing systems of EVA suits and procedures that were intended to work in near-vacuum without the risks of going off-structure. In other words, it already met most of the criteria for the desired hanger conversion.
By filling the sealed tank with nitrogen, welding operations and other systems installation (such as wiring for lighting grids and robotic arm mounts) could be carried out safely and conveniently, making use of the tank as a pressurized work environment right until it was cut open to space. After that point, however, the new hangar could never be sealed again, as NASA had judged it unlikely that astronauts working with tools in space would be able to cut a hangar door into the tank in such a way that any kind of trustworthy seal could be installed. The simplest conversion was to simply install all the desired support systems in the new hangar, permanently seal the manhole, and then cut the new hangar access panels from the outside. This would give an enclosed, well-lit space, by itself a massive improvement to the prevailing working conditions for servicing spacecraft at Enterprise.
NASA, however, was tempted to try for something a bit more ambitious. By evaluating which items on their wishlist for a Shuttle-deployed hangar could be incorporated into Enterprise’s improvised equivalent, program managers hoped to develop a capability in excess of the simple open workspace. Ideally, a hangar would have a redundant airlock, a pressurized path into any vehicles docked within it, and a robotics control station with a view of the work site to enable astronauts on EVA to better coordinate with robotics operators inside the pressurized zone. For the Shuttle-launched new-build hangar, the plan had been to launch a standard 4.27m (14 foot) module with a “cupola” of windows on its axial end as a “control booth” for robotics activities. The module would also either incorporate an airlock, or have one attached at a radial port. Docked to the station using another radial or axial port, the control module could also offer a docking port available for any craft housed within the bay. This single integrated module (or assembly of modules) would provide all the command and control functions for the new hangar, acting as the “control tower” for the work site.
If such a module were mounted into the new LH2 tank hangar, the conversion of ET-007 aboard Enterprise could be just as functional as the new-build alternative. Indeed, since the proposed Shuttle-launched alternatives tended to rely on tension-stabilized fabrics or plastic sheeting for the sidewalls of the hangar, the aluminum skin and spray-foam insulation of the converted ET-007 LH2 tank would actually be more robust and offer better radiation shielding than the new-build hangar. The 4.27m diameter of the proposed Hangar Control Module would fit into ET-007’s 8.4m diameter with room to spare. Even with its length, the volume remaining in the bay would still more than exceed the volume of a Space Shuttle cargo bay or standard 5-meter payload fairing.Thus, the bay could still host and service almost any payload a Space Shuttle or NSSL-class rocket could launch. The issue, of course, was that there was no docking port on the interior of the tank’s manhole. However, by this point, welding trials inside Enterprise’s hydrogen tank were old hat. Such welding experiments had been carried out on the station for more than a decade in one form or another, and their results were already being considered critical to install structural mounts for robotic arms, lighting grids, payload mounting trunions, and other fixtures if a hangar conversion went ahead. The engineers proposed simply shipping up a standard APAS docking ring in two sections, each small enough to pass through the 36” manhole, but designed to be joined to each other and the tank forward dome in space. By incorporating an inner hatch inside the newly installed ring, the structure could be proof tested without ever venting the bay to space, enabling astronauts to work on the task until it functioned properly. The installation of a docking port on a vehicle already in space would push the state of the art from mere servicing to actual fabrication. Checkout of the process could be carried out on the ground, with only a few permanent seals to be installed and joined on orbit. Testing of the procedure in the LH2 tanks associated with the Space Station Enterprise LOX Tank Outfitting Mockups in Houston showed the concept to be viable.
Within the cost-constrained environment of the lead up to the expected approval of a Mars program in coming years, NASA recognized that the hydrogen-tank hangar conversion, as jury-rigged as it was, was the best they were likely to get. Once again, time and money would dictate the expedient over the perfect for the expansion of Space Station Enterprise. The concept’s implementation was approved in 2011, with conversion in orbit planned to begin in 2015. Thus, the new hangar at Enterprise would be completed and tested well before any reusable Mars or lunar vehicle would depend on its capabilities.
Artwork by: @nixonshead (AEB Digital on Twitter)
Huzzah, at last, a purpose for the H2 tank!
Getting the new airlock and fittings set up, then cutting the tail off to make space access, is going to be a very interesting bit of work. Looking forward to it!
I wonder if after all the practical experience with orbital construction someone gives a push for trying all those old plans of mining the moon for construction materials when building Enterprise's successor station.
Getting the new airlock and fittings set up, then cutting the tail off to make space access, is going to be a very interesting bit of work. Looking forward to it!
I wonder if after all the practical experience with orbital construction someone gives a push for trying all those old plans of mining the moon for construction materials when building Enterprise's successor station.
Boeing Phantom Express:
Rockwell X-33:
Teledyne Brown Engineering Spaceplane:
Less of a lifting body, more of a tube-with-delta-wings.
Most of these designs and others are propellant tanks which are empty during descent, meaning even if they have the same overall length/diameter as the OTL orbiter, they're lighter overall during descent. That tends to mean smaller wings assuming the same wing loading.
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Not really.
If you wanted a vehicle design to start from, the Rockwell Platypus SSTO would be better:
Ohhh! A "Platypus" pic I haven't seen! Backgrounded and thanks
Good question because this is my 'version' of the Saturn Shuttle in another of my (numerous
) time line notes. I even have the notes for a "Program Patch" (semi-official which is part of the story-line, and "The Administrator" of NASA has more than a little bit of an issue with the moto: "Heus tu Ominus, Vigilate Hoc" that those "Marshall Engineers" tacked on )Internal propellant tanks mean these designs are 'lighter' and 'fluffier' on the way down and in flight. This is also why they don't need or use the tile heat shields.
Randy
It's joke about how the plume looks like a soap bubble, or so I assume because...well...it looks like a soap bubble!
It is. Just some artist bitchyness about the depiction of the drive plume (a weakness of mine).
Aside from the alternate designs being much less dense than Shuttle, thanks to their internal tanks, there is the matter of why Shuttle had such large wings in the first place. Many early designs had small wings (and internal tanks). But the military demanded wings with enough cross-range for the ridiculous "once around" launch profile: polar launch from Vandenberg, deploy, reenter, land back in California 1000 miles cross-range.
Spacedock!
And, wow. I was worried about scratching the walls putting something down it, but I really didn’t process how wide the ET is. Huh.
And, wow. I was worried about scratching the walls putting something down it, but I really didn’t process how wide the ET is. Huh.
Not a problem but thank you anyway because now I can't 'unsee' that
Not exactly. That was a military wish but it wasn't the "requirement" that drove the Shuttle's wings, NASA had planned for the large delta just like they planned the large payload bay and essentially use it being a military requirement at justification. They always favored the "high cross range" designs because, (in theory at least) they could more easily handle landings with more massive cargo than the low-cross range designs.
The military "once-around" mission profile was never a serious mission consideration because it had only a few "questionable" uses. Snatching a Soviet satellite in a single pass was possible but unlikely at best and the other use was an attack profile but (despite some Soviet belief in the possibility) in context that mission was unlikely to be either successful or a surprise given the amount of effort needed to prepare a Shuttle stack for flight.
NASA needed Air Force buy-in or at the very least non-opposition to the Shuttle because the only way it could work even marginally "economically" was if it was, in the end, the ONLY US launch vehicle and that's the way the pitched it. Being everything to everyone and fulfilling all missions and requirements, as long as those missions and requirements where something that NASA wanted.
Randy
There was a certain NASA narrative that liked to blame Shuttle design compromises on Air Force involvement. But you're right -- the wing design really originated at NASA.
Getting kind of an F-35 vibe here...