Alright! Hello! The following is the hyper-evolved headcanon for a replica shuttle program I started work on 4-5-ish years ago in KSP that I realized about 3 months ago I could turn into an objectively banger alternate history with a strangely low amount of effort. That being said, I have 3 disclaimers first and you could probably infer most of them from that opening sentence:
1. I have no experience whatsoever in writing stories, so except for some outside help, this may not be the most well written, so please bear with me a little bit. I’m not asking for complete excusal if I completely mess it up, this should be at least somewhat readable, just know there will most likely be a visible lack of experience.
2. I am also very much so using this as an excuse to learn more about spaceflight in general because, for some infernal reason, I can not bring myself to read a 171 page paper on what you can do with a shuttle external tank under normal circumstances. But, if I have even one minor practical reason to do so, it will be done in a week. So resultantly, there may be a few things that aren’t exactly feasible. I aim to improve as I go and learn, but especially at the start some things might be a bit sketchy.
3. At the end of the day, this is more about a story. I hope to write a story of what could be done with the extreme versatility of a space shuttle-like vehicle. And my specialty is more mission planning than number crunching, so reason may get thrown out a window every now and then, hopefully rarely though.
(Additional disclaimer for this prologue exclusively, I am not good at all with space politics so if it looks like I’m cutting corners this chapter (?), it’s because I absolutely am, but I think it’s important to explain the start of this story from here and not just go, “suddenly rockets!” and call it a weekend)
In summary, please excuse me somewhat if it’s not the best writing in history (alternate or not), or if some things aren't to the proverbial “T” on realism. Also, I hope to post on a semi-regular basis, under extremely ideal circumstances once a week, but most likely once every two weeks. This is one of a few hobbies I want to keep up with, so depending on my involvement in those, writing on this may happen faster or slower on some weeks. In any case, enjoy the prologue of “Let There Be Fire”:
Prologue: An Ember is Born
“Let's be blunt and get to it, the shuttle is not working nearly as well as any of us would have hoped. Unless anyone has another reason they wish to put on the record, I believe we’re all fairly confident that the principal issue is a blatant lack of purpose. Now, the question we want to ask in this hearing is not so much ‘What more can the STS program do?’, but ‘Where can we go from here?’” stated Representative Jack Harrison in his opening remarks for the Committee on Science, Space, and Technology’s hearing on the otherwise calm morning of March 7, 2005. This whole hearing burned, both for the other Representatives and the NASA personnel present. A program so long running, so promising, so expensive. A lot had come out of the program, to be certain. The ISS and Hubble, among other things, were no small advancements by any means, but the shuttle, as it stood, could not go much farther in its current, deteriorating state. It was becoming more and more expensive, with contractor after contractor going under. Even with all its potential and capability, it's time was drawing to an end.
Both parties showed up knowing this hearing would likely mark the beginning of the end for the STS program; this had, effectively, already been decided. To add a measure of certainty, the hearing opened with a discussion of prepared possible expansions of the existing program. This was done to ensure that all possible paths had been considered and subsequently proved impractical. After about one-and-a-half hours of debate, no viable solutions surfaced, as expected, and the hearing progressed to the next phase. “What now?” Harrison again spoke, “We, of course, do not intend to answer this question here and now. It is this committee’s intention to create a sub-committee to assist in the investigation of possible new programs. I’d like to specify, not just new programs with LEO access only, we shot ourselves in that foot before, we want Lunar access and a sustainable path forward. Ideally, these programs would be STS-derived or adjacent, but other proposals will be considered for due diligence. We believe that STS was, and still is, a solid platform and that the Congress in charge at the time of STS’s creation did not allow for its full potential to be reached. Resultantly, we would like to pursue STS derived alternatives to both take advantage of this unused potential and save unnecessary expense. We realize, of course, no matter what path forward is chosen, this will by no means be either “cheap” or “easy”. We learned what happens when we try to make it that way and we are prepared to do what should have been done back in the 70’s, but we feel derivatives will still dampen the cost as well as save time.”
The hearing went on to discuss the specifics of the sub-committee. It would be composed of members selected by the committee and would supervise groups formed by combined teams from various industry partners; NASA, Boeing, Northrop Grumman, Lockheed Martin, etc. A deadline for proposals was also given, twenty months. The groups would effectively have free reign to design as they pleased, as there would be little (if any) hardware involved. The goal of the investigation period would be to study as many paths as possible, and hopefully converge into a few distinct proposals by the deadline. These last remaining proposals should be in depth plans as hardware was not yet necessary. With all relevant matters discussed, Harrison gave a summary to ensure understanding between both those present and the public and ended with the remark, “Our shadow has been absent from the Moon for over thirty years, it’s time we go back to do more than just put on a show. Let’s get to work.”
After almost a year of investigation, with everything from air-launched shuttles to resurrecting the Saturn V, two programs emerged on top, the Exploration Systems Architecture Study (eventually becoming Constellation and further reduced to CxP) and the Evolved Space Transportation System (E-STS). As hoped, the focus was now almost completely on these two programs. Constellation focused more on the immediate creation of MTV’s for Lunar use later expanding on to Mars. Meanwhile, E-STS focused on a rapid Lunar return with an immensely flexible design which would then be able to produce an MTV down the road with little alteration. The program’s principle launcher would involve a modernized and evolved, “Lunar capable” version of the “stretched orbiter” derivative of the Space Shuttle temporarily called “Spacehawk” (soon changed to Phoenix), a reusable powered external tank known to the program as the Universal Core Stage (UCS), and new recoverable Liquid Rocket Boosters (LRB’s).
The program would feature a new version of the RS-25, the RS-25E, incorporating lessons learned from the previous versions and adding in-flight relight capability. Phoenix would be designed to handle the rigors of Lunar sorties. Such as upgraded Environmental Control and Life Support (ECLS), such as a built in Extended Duration Orbiter (EDO) pallet to last the longer flight durations.Other upgrades included; new capability for cryogenic fueling in the payload bay through the orbiter, upgraded radiation protection, a solar-battery based power system instead of fuel cells, and so on. There would also be an added set of drop tanks that would keep the OMS pods fed for most of the Lunar flights, the tanks would be carried out of Lunar orbit when depleted and discarded on a reentry trajectory after the departure from the Moon. The new orbiter would also involve an even more modular payload bay than its predecessor for the ability to rapidly handle new missions previously unexpected as well as a highly flexible and rapid launch cadence. The heat tiles would change in shape to hexagonal to allow for one uniform model of tile to cover most of the orbiter’s underside, this would allow for easy servicing of the heat shield both between flights as well as potentially on orbit, if absolutely necessary. Additionally the previously used reinforced carbon-carbon, was to potentially be replaced by a new type of tile, TUFROC, if the technology could be sufficiently proven before the first orbital flight test. This looked to be doubtful and the E-STS team decided it would not be a good idea to rush such a critical tile for both the obvious reasons of safety and because the program’s selection was far from guaranteed at this stage. This in mind, the vehicle was designed instead with the old RCC, however, it would have a thin tile layer below the gap behind the RCC, the goal of this layer would hopefully buy the orbiter enough time to survive re-entry, albeit with extreme damage, should damage be present in the RCC.
With the replacement of the fuel cells with batteries, as well as other modernization/minimizing upgrades, the spacecraft was able to support the addition of a small hydro-lox tank set, referred to as the “Abort Tank” which served as an intermediary buffer between the incoming fuel from the UCS and the orbiter’s main engines. This tank would allow all three main engines to remain firing for up to six seconds at typical flight throttle when separated from the UCS, however, most aborts would involve both a lower throttle setting and shutting down either the center engine or the lower two, depending on the center of mass’s location. The new abort method would allow not only safe and stable separations from the core stage during ascent, a substantial jump from the systems precursor, but it even allowed the potential for a pad abort and a drastically expanded abort-to-orbit (ATO) window in most flights.
The UCS would consist of a standard Shuttle external tank as a base with an engine section containing seven RS-25E’s (six in a ring with one in the center). An upgraded spray-on foam insulation (SOFI) would be utilized and covered with a protective layer of paint to minimize (if not eliminate) fracturing, even in vacuum. At this point, two versions had been explored, UCS Block 1 would be an “expendable” variant developed before reuse was considered possible, which would later be intended to be readily converted and used as a wet workshop or any other altered variant. The UCS Block 2 would feature a method of reuse involving a once-around orbit (with an initial adjustment burn in the case of higher energy trajectories). Then, utilizing four flaps which would unfold during the once-around return orbit, the vessel would execute a Shuttle-like forward-facing reentry, pitching up slowly until reaching a near-vertical attitude and a stall condition just east of the Kennedy Space Center. The UCS would then fall engine-first back toward its landing site using body lift to fly back from its overshoot. Upon reaching the landing site (a concrete pad located on the grounds of the LC-39 pads) the center with two outer ring engines, all in a line, would reignite to shed remaining speed. The center engine would then be shut down upon reaching a hover. The UCS would then translate, as needed, and extend its six landing legs (normally stowed inside the engine bay) to reach its landing pad and slowly set down. To facilitate these extra burns, a smaller set of cylindrical fuel tanks would be added. These tanks would be located at the top of the hydrogen tank up against the tank wall closest to the heatshield to preserve balance and add stability during reentry. The same tiles used on Phoenix would also be used to protect the windward side of the UCS.
The LRB’s were mostly a clean sheet design, while liquid boosters were considered for STS, these would instead use a proposed engine from Pratt & Whitney Rocketdyne called Cobra, this engine ticked every box of the programs need for booster engines; rapidly reusable, strong, and reasonably efficient. Issues arose rapidly with the recovery plan, however, which was initially near-identical to the old SRB’s the Shuttle used, involving parachuting the whole booster into the water. The first problem was weight, the engine and tanks were too heavy to reasonably set down together in the ocean without substantial damage, especially to the fragile Cobra. The second was only slightly more pressing, even if the booster could be landed in one piece, the tail heavy configuration would cause the engine to become partially, if not completely, submerged. Both problems would cause immense damage to both the engines and their tankage. After exploring various options ranging everywhere from folded wings for fly back (similar to the Russian “Energia II” boosters) all the way to their own propulsive landings with secondary engines. Eventually, the relatively simple decision was made that, if the booster could not be landed in the ocean in one piece, land it in two. This led to a design involving an additional separation event after being released from the UCS on ascent where the tankage of the booster would jettison the engine unit (EU). The components would deploy their own droge and main chutes and the EU would then inflate a raft-like structure to keep the engine dry after splashing down, engine-up. Meanwhile, the tankage would splashdown horizontally, similar to the original plan, this time including valves to seal the tanks as well as secondary inflatable seals inside the fuel lines in case of a valve failure. Also protecting the tankage would be the same SOFI utilized by the UCS. Both tankage and EU would be fished out of the ocean with the assistance of two cranes aboard an ocean barge.
The program would also include other systems, such as a series of notional upper stages derived from the Delta Cryogenic Second Stage (DCSS). These stages would involve a new engine also being heavily investigated by Constellation, the J2-X. In line with the naming of Phoenix, these stages would be named Firelight and be ordered by the stage’s hydrogen tank diameter; 4.2m, 6.3m, and 8.4m. Firelight 4 would use one J2-X, Firelight 6 would use two, and 8 would use four. Firelight 4 would typically be similar in operation to the Centaur-Shuttle of old. All of the Firelights could be used as upper stages of a modular launcher temporarily called the Universal Core Stage Launch Vehicle (UCS-LV) which would be comprised of a UCS, two to eight LRB’s, and the notional upper stages as needed.
For initial Lunar landings, a derivative of the Firelight 4 stage was studied as a single-stage, dual-axis lander design involving the modified upper stage with an alternative design of an Orion pressure vessel on top, reduced from Constellations proposal to fit in the orbiter’s payload bay and a cylindrical compartment located behind the pressure vessel for abort motors and various commodities. The lander would be fueled before launch from LC-39 and topped off by additional fuel stored in the abort tank fed through a strongback that cradles the lander stage during flight and deployment (normally the abort tank would be emptied after ascent). This version of Orion would not be capable of an Earth return, but would be capable of an abort to Lunar orbit where the crew would be recovered by the Phoenix that deployed the lander, or another Phoenix depending on the scenario. This, temporary, but direct approach would allow a rapid return to the Lunar surface until the program could shift to using transfer vehicles for practice before moving to farther destinations such as Mars.
So far both programs were making great progress. E-STS was becoming the popular option among the general public, with its continuation of the shuttle design which had inspired the world for so many years and adding full reusability on top of it. This newfound popularity eventually gave the program its new name via one of the regular update press conferences. E-STS was jokingly given the name “Let There Be Fire” by the program’s lead, Chris Stryker, in reference to its now definitively chaotic booster jettison involving two separator motors per booster which were expected to effectively occlude the entire vehicle for a moment in their plumes. The name was later coined by the media, and eventually by NASA itself, as the program’s name outside of most official documents and abbreviated to LTBF.
In an effort to gain a head start, since both leading proposals included use of the J2-X, a contract was awarded to P&W Rocketdyne for the engine’s development on February 7, 2006, also tagged onto this contract was funding for a preliminary design study for the Cobra engine. Cobra had lagged behind a bit in its timeline, but this was to be expected as it was a clean-sheet design. The new booster engine was expected to take its first breaths within a year of the selection of a program by the Congressional committee. This, of course, would depend on LTBF winning out, becoming another reason for the post-decision estimate.
As both proposals began to close in on more realistic designs, the initiative gained a massive surge in popularity. Both programs focused on not only Lunar returns, but transfer vehicle designs were beginning to properly materialize (especially in CxP), which gave a grand image of hope to both the United States and the rest of the world. We weren’t just going back to the Moon, that would only be the beginning. We we’re gunning for Mars and this time it was real, no more overly-optimistic proposals, the funding was on the table and real progress was ready to be made. These Mars Transfer Vehicles (MTV’s) differed little in concept between programs. Constellation aimed to utilize a MTV comprised out of specialized modules and stages launched aboard Ares V. Meanwhile, LTBF believed it would be possible to assemble a MTV from more “off-the-shelf” components from elsewhere in the program, such as a propulsion stage made from a spent UCS at the back. Also involved would be an inflatable habitation module up front, and the modules would be separated by a drop tank and truss structure, though Stryker had gone on record in one press conference by saying the UCS might be more useful to the MTV’s construction than previously thought.
Twenty months finally came and went, and the deadline arrived. The committee reconvened along with NASA officials and members from both the Constellation and LTBF teams. The ensuing discussion was long and grueling. Both programs wound up being very similar, with the only real difference being launch vehicles and order of operations. Constellation would pursue MTV’s right out of the gate and used non-reusable Shuttle-derived launch vehicles. Meanwhile, LTBF would pursue Lunar surface access in the fastest and safest way possible by bypassing the MTV entirely for the initial series of landings, instead opting to use the program’s principle lifter, Phoenix. This approach also bought the MTV more development time, which included plenty of time to learn the in’s and out’s of the program’s various systems before committing to a design. This possibility was a major advantage for LTBF since its MTV’s was expecting to incorporate existing program components, meaning that this time to get familiar with said components would result in a much more “understood” (and, perhaps, better overall) MTV in the end. This is in contrast to the Constellation approach which would create a MTV with little experimental knowledge about its true limits/capabilities. The modular MTV proposal also rang bells for Congress, the reuse of already developed components would drop the price drastically during program operation and enable easy and sustainable exploration to boot. LTBF also allowed the launch of both crew and Lunar lander (as well as other cargo) on one reusable vehicle which beat out Constellation’s use of separate rockets for each purpose. In the end, both programs eventually landed close to each other as far as price was concerned, LTBF would be drastically more expensive in development, but would cost substantially less to operate and iterate on. Meanwhile, Constellation would do the opposite, with a more modest (relatively) start, but costly later development in expansion of its capability.
Days of back-and-forth later, on January 15, 2007, the decision was made, Let There Be Fire would be NASA’s next pursuit. The committee arrived at the decision stating that LTBF offered a more realistic schedule for returning human presence to the Moon, skipping the complications of an early designed MTV without removing it from the program’s sights. The program’s flexibility was also highly valued, the program could go any direction it wanted and already have the capability to do so. Also of interest was the system’s ability to simply “get up and go” with the program’s leaders firmly believing a full Phoenix stack could go from its “idle” configuration, to launch in under just 24 hours, vastly increasing the possibility to fly rescue missions without much disruption if they were ever needed. All things considered, LTBF was deemed better in both the long and short terms.
The next step for the program would be to acquire funding, which would be no small hurdle on its own. With the decision made though, a funding bill was drafted and put before Congress. In the meantime, the LTBF proposal team was re-assigned to handle the operation of the program moving forward and NASA was given the go ahead to start work on major hardware, such as the Cobra engine, preparations for orbiter construction in Palmdale, and some rearrangement of the Michaud facility in Louisiana. With the decision made, primary contracts started to become finalized; Boeing would provide both the orbiter and the UCS as well as LRB tankage. The new joint venture between Boeing and Lockheed Martin, United Launch Alliance (ULA), being the new operators of the Delta IV, would advance the DCSS into the Firelight stages. Zodiac, a company specializing in dinghies and inflatable life rafts would handle the reuse system for the Cobra engines, utilizing JPL for consultation, continuing from their own work with the inflatable landing hardware of the Spirit and Opportunity rovers. Finally, P&W Rocketdyne would handle most of the propulsion. With this last step, everything was finally coming together and with the program finally beginning to get traction, the dream was alive once more.
1. I have no experience whatsoever in writing stories, so except for some outside help, this may not be the most well written, so please bear with me a little bit. I’m not asking for complete excusal if I completely mess it up, this should be at least somewhat readable, just know there will most likely be a visible lack of experience.
2. I am also very much so using this as an excuse to learn more about spaceflight in general because, for some infernal reason, I can not bring myself to read a 171 page paper on what you can do with a shuttle external tank under normal circumstances. But, if I have even one minor practical reason to do so, it will be done in a week. So resultantly, there may be a few things that aren’t exactly feasible. I aim to improve as I go and learn, but especially at the start some things might be a bit sketchy.
3. At the end of the day, this is more about a story. I hope to write a story of what could be done with the extreme versatility of a space shuttle-like vehicle. And my specialty is more mission planning than number crunching, so reason may get thrown out a window every now and then, hopefully rarely though.
(Additional disclaimer for this prologue exclusively, I am not good at all with space politics so if it looks like I’m cutting corners this chapter (?), it’s because I absolutely am, but I think it’s important to explain the start of this story from here and not just go, “suddenly rockets!” and call it a weekend)
In summary, please excuse me somewhat if it’s not the best writing in history (alternate or not), or if some things aren't to the proverbial “T” on realism. Also, I hope to post on a semi-regular basis, under extremely ideal circumstances once a week, but most likely once every two weeks. This is one of a few hobbies I want to keep up with, so depending on my involvement in those, writing on this may happen faster or slower on some weeks. In any case, enjoy the prologue of “Let There Be Fire”:
Prologue: An Ember is Born
“Let's be blunt and get to it, the shuttle is not working nearly as well as any of us would have hoped. Unless anyone has another reason they wish to put on the record, I believe we’re all fairly confident that the principal issue is a blatant lack of purpose. Now, the question we want to ask in this hearing is not so much ‘What more can the STS program do?’, but ‘Where can we go from here?’” stated Representative Jack Harrison in his opening remarks for the Committee on Science, Space, and Technology’s hearing on the otherwise calm morning of March 7, 2005. This whole hearing burned, both for the other Representatives and the NASA personnel present. A program so long running, so promising, so expensive. A lot had come out of the program, to be certain. The ISS and Hubble, among other things, were no small advancements by any means, but the shuttle, as it stood, could not go much farther in its current, deteriorating state. It was becoming more and more expensive, with contractor after contractor going under. Even with all its potential and capability, it's time was drawing to an end.
Both parties showed up knowing this hearing would likely mark the beginning of the end for the STS program; this had, effectively, already been decided. To add a measure of certainty, the hearing opened with a discussion of prepared possible expansions of the existing program. This was done to ensure that all possible paths had been considered and subsequently proved impractical. After about one-and-a-half hours of debate, no viable solutions surfaced, as expected, and the hearing progressed to the next phase. “What now?” Harrison again spoke, “We, of course, do not intend to answer this question here and now. It is this committee’s intention to create a sub-committee to assist in the investigation of possible new programs. I’d like to specify, not just new programs with LEO access only, we shot ourselves in that foot before, we want Lunar access and a sustainable path forward. Ideally, these programs would be STS-derived or adjacent, but other proposals will be considered for due diligence. We believe that STS was, and still is, a solid platform and that the Congress in charge at the time of STS’s creation did not allow for its full potential to be reached. Resultantly, we would like to pursue STS derived alternatives to both take advantage of this unused potential and save unnecessary expense. We realize, of course, no matter what path forward is chosen, this will by no means be either “cheap” or “easy”. We learned what happens when we try to make it that way and we are prepared to do what should have been done back in the 70’s, but we feel derivatives will still dampen the cost as well as save time.”
The hearing went on to discuss the specifics of the sub-committee. It would be composed of members selected by the committee and would supervise groups formed by combined teams from various industry partners; NASA, Boeing, Northrop Grumman, Lockheed Martin, etc. A deadline for proposals was also given, twenty months. The groups would effectively have free reign to design as they pleased, as there would be little (if any) hardware involved. The goal of the investigation period would be to study as many paths as possible, and hopefully converge into a few distinct proposals by the deadline. These last remaining proposals should be in depth plans as hardware was not yet necessary. With all relevant matters discussed, Harrison gave a summary to ensure understanding between both those present and the public and ended with the remark, “Our shadow has been absent from the Moon for over thirty years, it’s time we go back to do more than just put on a show. Let’s get to work.”
After almost a year of investigation, with everything from air-launched shuttles to resurrecting the Saturn V, two programs emerged on top, the Exploration Systems Architecture Study (eventually becoming Constellation and further reduced to CxP) and the Evolved Space Transportation System (E-STS). As hoped, the focus was now almost completely on these two programs. Constellation focused more on the immediate creation of MTV’s for Lunar use later expanding on to Mars. Meanwhile, E-STS focused on a rapid Lunar return with an immensely flexible design which would then be able to produce an MTV down the road with little alteration. The program’s principle launcher would involve a modernized and evolved, “Lunar capable” version of the “stretched orbiter” derivative of the Space Shuttle temporarily called “Spacehawk” (soon changed to Phoenix), a reusable powered external tank known to the program as the Universal Core Stage (UCS), and new recoverable Liquid Rocket Boosters (LRB’s).
The program would feature a new version of the RS-25, the RS-25E, incorporating lessons learned from the previous versions and adding in-flight relight capability. Phoenix would be designed to handle the rigors of Lunar sorties. Such as upgraded Environmental Control and Life Support (ECLS), such as a built in Extended Duration Orbiter (EDO) pallet to last the longer flight durations.Other upgrades included; new capability for cryogenic fueling in the payload bay through the orbiter, upgraded radiation protection, a solar-battery based power system instead of fuel cells, and so on. There would also be an added set of drop tanks that would keep the OMS pods fed for most of the Lunar flights, the tanks would be carried out of Lunar orbit when depleted and discarded on a reentry trajectory after the departure from the Moon. The new orbiter would also involve an even more modular payload bay than its predecessor for the ability to rapidly handle new missions previously unexpected as well as a highly flexible and rapid launch cadence. The heat tiles would change in shape to hexagonal to allow for one uniform model of tile to cover most of the orbiter’s underside, this would allow for easy servicing of the heat shield both between flights as well as potentially on orbit, if absolutely necessary. Additionally the previously used reinforced carbon-carbon, was to potentially be replaced by a new type of tile, TUFROC, if the technology could be sufficiently proven before the first orbital flight test. This looked to be doubtful and the E-STS team decided it would not be a good idea to rush such a critical tile for both the obvious reasons of safety and because the program’s selection was far from guaranteed at this stage. This in mind, the vehicle was designed instead with the old RCC, however, it would have a thin tile layer below the gap behind the RCC, the goal of this layer would hopefully buy the orbiter enough time to survive re-entry, albeit with extreme damage, should damage be present in the RCC.
With the replacement of the fuel cells with batteries, as well as other modernization/minimizing upgrades, the spacecraft was able to support the addition of a small hydro-lox tank set, referred to as the “Abort Tank” which served as an intermediary buffer between the incoming fuel from the UCS and the orbiter’s main engines. This tank would allow all three main engines to remain firing for up to six seconds at typical flight throttle when separated from the UCS, however, most aborts would involve both a lower throttle setting and shutting down either the center engine or the lower two, depending on the center of mass’s location. The new abort method would allow not only safe and stable separations from the core stage during ascent, a substantial jump from the systems precursor, but it even allowed the potential for a pad abort and a drastically expanded abort-to-orbit (ATO) window in most flights.
The UCS would consist of a standard Shuttle external tank as a base with an engine section containing seven RS-25E’s (six in a ring with one in the center). An upgraded spray-on foam insulation (SOFI) would be utilized and covered with a protective layer of paint to minimize (if not eliminate) fracturing, even in vacuum. At this point, two versions had been explored, UCS Block 1 would be an “expendable” variant developed before reuse was considered possible, which would later be intended to be readily converted and used as a wet workshop or any other altered variant. The UCS Block 2 would feature a method of reuse involving a once-around orbit (with an initial adjustment burn in the case of higher energy trajectories). Then, utilizing four flaps which would unfold during the once-around return orbit, the vessel would execute a Shuttle-like forward-facing reentry, pitching up slowly until reaching a near-vertical attitude and a stall condition just east of the Kennedy Space Center. The UCS would then fall engine-first back toward its landing site using body lift to fly back from its overshoot. Upon reaching the landing site (a concrete pad located on the grounds of the LC-39 pads) the center with two outer ring engines, all in a line, would reignite to shed remaining speed. The center engine would then be shut down upon reaching a hover. The UCS would then translate, as needed, and extend its six landing legs (normally stowed inside the engine bay) to reach its landing pad and slowly set down. To facilitate these extra burns, a smaller set of cylindrical fuel tanks would be added. These tanks would be located at the top of the hydrogen tank up against the tank wall closest to the heatshield to preserve balance and add stability during reentry. The same tiles used on Phoenix would also be used to protect the windward side of the UCS.
The LRB’s were mostly a clean sheet design, while liquid boosters were considered for STS, these would instead use a proposed engine from Pratt & Whitney Rocketdyne called Cobra, this engine ticked every box of the programs need for booster engines; rapidly reusable, strong, and reasonably efficient. Issues arose rapidly with the recovery plan, however, which was initially near-identical to the old SRB’s the Shuttle used, involving parachuting the whole booster into the water. The first problem was weight, the engine and tanks were too heavy to reasonably set down together in the ocean without substantial damage, especially to the fragile Cobra. The second was only slightly more pressing, even if the booster could be landed in one piece, the tail heavy configuration would cause the engine to become partially, if not completely, submerged. Both problems would cause immense damage to both the engines and their tankage. After exploring various options ranging everywhere from folded wings for fly back (similar to the Russian “Energia II” boosters) all the way to their own propulsive landings with secondary engines. Eventually, the relatively simple decision was made that, if the booster could not be landed in the ocean in one piece, land it in two. This led to a design involving an additional separation event after being released from the UCS on ascent where the tankage of the booster would jettison the engine unit (EU). The components would deploy their own droge and main chutes and the EU would then inflate a raft-like structure to keep the engine dry after splashing down, engine-up. Meanwhile, the tankage would splashdown horizontally, similar to the original plan, this time including valves to seal the tanks as well as secondary inflatable seals inside the fuel lines in case of a valve failure. Also protecting the tankage would be the same SOFI utilized by the UCS. Both tankage and EU would be fished out of the ocean with the assistance of two cranes aboard an ocean barge.
The program would also include other systems, such as a series of notional upper stages derived from the Delta Cryogenic Second Stage (DCSS). These stages would involve a new engine also being heavily investigated by Constellation, the J2-X. In line with the naming of Phoenix, these stages would be named Firelight and be ordered by the stage’s hydrogen tank diameter; 4.2m, 6.3m, and 8.4m. Firelight 4 would use one J2-X, Firelight 6 would use two, and 8 would use four. Firelight 4 would typically be similar in operation to the Centaur-Shuttle of old. All of the Firelights could be used as upper stages of a modular launcher temporarily called the Universal Core Stage Launch Vehicle (UCS-LV) which would be comprised of a UCS, two to eight LRB’s, and the notional upper stages as needed.
For initial Lunar landings, a derivative of the Firelight 4 stage was studied as a single-stage, dual-axis lander design involving the modified upper stage with an alternative design of an Orion pressure vessel on top, reduced from Constellations proposal to fit in the orbiter’s payload bay and a cylindrical compartment located behind the pressure vessel for abort motors and various commodities. The lander would be fueled before launch from LC-39 and topped off by additional fuel stored in the abort tank fed through a strongback that cradles the lander stage during flight and deployment (normally the abort tank would be emptied after ascent). This version of Orion would not be capable of an Earth return, but would be capable of an abort to Lunar orbit where the crew would be recovered by the Phoenix that deployed the lander, or another Phoenix depending on the scenario. This, temporary, but direct approach would allow a rapid return to the Lunar surface until the program could shift to using transfer vehicles for practice before moving to farther destinations such as Mars.
So far both programs were making great progress. E-STS was becoming the popular option among the general public, with its continuation of the shuttle design which had inspired the world for so many years and adding full reusability on top of it. This newfound popularity eventually gave the program its new name via one of the regular update press conferences. E-STS was jokingly given the name “Let There Be Fire” by the program’s lead, Chris Stryker, in reference to its now definitively chaotic booster jettison involving two separator motors per booster which were expected to effectively occlude the entire vehicle for a moment in their plumes. The name was later coined by the media, and eventually by NASA itself, as the program’s name outside of most official documents and abbreviated to LTBF.
In an effort to gain a head start, since both leading proposals included use of the J2-X, a contract was awarded to P&W Rocketdyne for the engine’s development on February 7, 2006, also tagged onto this contract was funding for a preliminary design study for the Cobra engine. Cobra had lagged behind a bit in its timeline, but this was to be expected as it was a clean-sheet design. The new booster engine was expected to take its first breaths within a year of the selection of a program by the Congressional committee. This, of course, would depend on LTBF winning out, becoming another reason for the post-decision estimate.
As both proposals began to close in on more realistic designs, the initiative gained a massive surge in popularity. Both programs focused on not only Lunar returns, but transfer vehicle designs were beginning to properly materialize (especially in CxP), which gave a grand image of hope to both the United States and the rest of the world. We weren’t just going back to the Moon, that would only be the beginning. We we’re gunning for Mars and this time it was real, no more overly-optimistic proposals, the funding was on the table and real progress was ready to be made. These Mars Transfer Vehicles (MTV’s) differed little in concept between programs. Constellation aimed to utilize a MTV comprised out of specialized modules and stages launched aboard Ares V. Meanwhile, LTBF believed it would be possible to assemble a MTV from more “off-the-shelf” components from elsewhere in the program, such as a propulsion stage made from a spent UCS at the back. Also involved would be an inflatable habitation module up front, and the modules would be separated by a drop tank and truss structure, though Stryker had gone on record in one press conference by saying the UCS might be more useful to the MTV’s construction than previously thought.
Twenty months finally came and went, and the deadline arrived. The committee reconvened along with NASA officials and members from both the Constellation and LTBF teams. The ensuing discussion was long and grueling. Both programs wound up being very similar, with the only real difference being launch vehicles and order of operations. Constellation would pursue MTV’s right out of the gate and used non-reusable Shuttle-derived launch vehicles. Meanwhile, LTBF would pursue Lunar surface access in the fastest and safest way possible by bypassing the MTV entirely for the initial series of landings, instead opting to use the program’s principle lifter, Phoenix. This approach also bought the MTV more development time, which included plenty of time to learn the in’s and out’s of the program’s various systems before committing to a design. This possibility was a major advantage for LTBF since its MTV’s was expecting to incorporate existing program components, meaning that this time to get familiar with said components would result in a much more “understood” (and, perhaps, better overall) MTV in the end. This is in contrast to the Constellation approach which would create a MTV with little experimental knowledge about its true limits/capabilities. The modular MTV proposal also rang bells for Congress, the reuse of already developed components would drop the price drastically during program operation and enable easy and sustainable exploration to boot. LTBF also allowed the launch of both crew and Lunar lander (as well as other cargo) on one reusable vehicle which beat out Constellation’s use of separate rockets for each purpose. In the end, both programs eventually landed close to each other as far as price was concerned, LTBF would be drastically more expensive in development, but would cost substantially less to operate and iterate on. Meanwhile, Constellation would do the opposite, with a more modest (relatively) start, but costly later development in expansion of its capability.
Days of back-and-forth later, on January 15, 2007, the decision was made, Let There Be Fire would be NASA’s next pursuit. The committee arrived at the decision stating that LTBF offered a more realistic schedule for returning human presence to the Moon, skipping the complications of an early designed MTV without removing it from the program’s sights. The program’s flexibility was also highly valued, the program could go any direction it wanted and already have the capability to do so. Also of interest was the system’s ability to simply “get up and go” with the program’s leaders firmly believing a full Phoenix stack could go from its “idle” configuration, to launch in under just 24 hours, vastly increasing the possibility to fly rescue missions without much disruption if they were ever needed. All things considered, LTBF was deemed better in both the long and short terms.
The next step for the program would be to acquire funding, which would be no small hurdle on its own. With the decision made though, a funding bill was drafted and put before Congress. In the meantime, the LTBF proposal team was re-assigned to handle the operation of the program moving forward and NASA was given the go ahead to start work on major hardware, such as the Cobra engine, preparations for orbiter construction in Palmdale, and some rearrangement of the Michaud facility in Louisiana. With the decision made, primary contracts started to become finalized; Boeing would provide both the orbiter and the UCS as well as LRB tankage. The new joint venture between Boeing and Lockheed Martin, United Launch Alliance (ULA), being the new operators of the Delta IV, would advance the DCSS into the Firelight stages. Zodiac, a company specializing in dinghies and inflatable life rafts would handle the reuse system for the Cobra engines, utilizing JPL for consultation, continuing from their own work with the inflatable landing hardware of the Spirit and Opportunity rovers. Finally, P&W Rocketdyne would handle most of the propulsion. With this last step, everything was finally coming together and with the program finally beginning to get traction, the dream was alive once more.
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