About Paul Drye

I'm a guy who managed to parlay an abiding interest in the corners of the world into two role-playing game books and a web column about alternate history. Writing longer projects is difficult with my coffee-fueled, ferret-like attention, so I'm trying my hand at sneaking up on another book one odd historical anecdote at a time.

A New Project

Hello, faithful readers!

Before that title starts to worry you: False Steps is still continuing, and in fact I’m aiming for a new entry next week. You may have noticed the recent downtime, though, downtime which I’ve been using to launch a new project blog. There may not be a lot of overlap in the “space travel aficionado” and “baseball fan” Venn diagram, but on the off-chance that some of you might be interested….

Forgive a little self-promotion and please be invited to They Played The Game, which like my last two blog projects is aimed at ultimately producing a book. The topic this time is baseball players who looked like they were going to be all-time greats but failed to do it for whatever reason. We’ll be looking at their stories, and trying to figure out what they could have done if everything broke right instead of going wrong.

We now return to your regularly scheduled Moon shots—in the literal sense of the words and not as a metaphor for hitting a baseball a long, long way.

The Douglas ASTRO: An Air Force Launcher

douglas-astro

The ASTRO, as pictured in the September 3, 1962 issue of Missiles and Rockets. Image artist unknown and copyright status uncertain, but believed to be in the public domain. Via the Internet Archive.

What it was: A lifting body craft proposed to the USAF by Douglas Aircraft. It would initially be used as a suborbital trainer then, after up-scaling and being paired with a second lifting body in an unusual nose-to-tail arrangement, evolve into a fully reusable vehicle with a nine-tonne payload capacity to LEO.

Details: In late 1962, the USAF was on the cusp of deciding how it would go forward with its plans to put military men in space. The X-15 had made its first flight mid-year, and the X-20 program was ramping up. Doubts about the latter were getting stronger, though, and would ultimately result in the Air Force deciding to work on the Manned Orbiting Laboratory instead.

It was at this point that an article was published in the now-defunct Missiles and Rockets magazine outlining a proposal from Douglas Aircraft that was supposedly being evaluated by the USAF. What it outlined was a two-part development program that would check the usual laundry list of military applications for space as perceived in the early 1960s.

The core of the ASTRO (Advanced Spacecraft Truck/Trainer/Transport Reusable Orbiter) was the answer to a question the USAF had proposed to North American Aviation and Douglas, as well as Boeing, Vought, and Republic: how to train pilots for the X-20 on actual flights prior to the X-20 being built. North American had come back with what they called the STX-15, which was a way of reconfiguring an X-15 to have the projected flight characteristics of an X-20 (except for, of course, the highest speed and orbital parts). The Phase I of Douglas’ ASTRO was their significantly more ambitious counter to the NAA proposal.

astro-schematic

A schematic of the ASTRO’s A2 vehicle, which would be both independent for suborbital hops, or be boosted to the point that it could be lifted into orbit by a derivative of the same vehicle. Note the booster nose’s ghostly presence at the far right of the image. Same source as previous. Click for a larger view.

Unfettered by the previously existing X-15, Douglas wanted to build a completely new craft dubbed A2, which would be capable of suborbital hops of about 5000 miles (8000 kilometers) after taking off from a runway under the impetus of a J-2 engine, the same rocket engine used by the Saturn V’s second and third stages. Pilots would get their space training, the USAF would have themselves a reusable vehicle with intercontinental range which could carry ten people, or a similar amount of payload. Two RL-10s, as used on the Centaur, would provide a little extra oomph.

Phase II was where Douglas diverged from the question being asked. Take the A2, modify it so that it only carried one crew and two extra J-2 engines, then stick it nose to bumper on the end of another A2 built to the Phase I spec. Turn it 90 degrees and launch it vertically, with the two separating from each other at altitude and speed (both unspecified). The sole crew member aboard the booster would glide back to Earth, while the uppermost A2 would ignite its engines, hopefully after allowing a bit of distance to build from the booster, and carry on into orbit. Douglas projected two crew and about a tonne of cargo to LEO in this configuration.

Phase III scaled up the booster, now dubbed B, and equipped it with two J-2s and one M-1, a never-built LH2/LOX engine that dwarfed even the F-1 engines used on the Saturn V’s main stage. Also launched vertically, this would be the ultimate version of the craft.

The full, two-stage Phase III vehicle was to have been 159 feet long (48.5 meters) and while mass was not mentioned the propellant capacity of the stages (165,000 pounds for the A2 and 594,000 pounds for the B) are—this suggests a total loaded vehicle mass at launch of about 380 to 400 tonnes. Total payload, as mentioned previously, was about nine tonnes, including crew, and there’s a sign that Douglas was nervous about this: the article specifically mentions wanting to launch due east from the Equator, which is an odd thing to be suggesting in 1962, well after the US had committed to launching from the continental USA.

If built, the program was expected to run from 1964 to 1970, with the first flight of the Phase III craft at the end of that period.

What happened to make it fail: It’s difficult to fit the ASTRO into the chronology of the X-20. Phase I appears to have been an attempt to come up with a “Gemini” for the X-20’s “Apollo”, giving the USAF the capability of sending pilots on long suborbital jaunts to train them for the environment they’d encounter when aboard the fully orbital X-20. Phase III would then have been a follow-up to the X-20, increasing crew capacity and payload over that craft.

If this is the case, then, it explains why the ASTRO never went anywhere. The craft made its sole notable public appearance in September of 1962, and American Secretary of Defense Robert McNamara was definitely thinking about cancelling the X-20 no later than March 1963—and possibly earlier. When the X-20 was stopped, then ASTRO would go with it. This is particularly true if one assumes, as seems likely, that the USAF was never very warm about the idea at all, and that it primarily existed as a pitch from Douglas leaked through Missiles and Rockets magazine to drum up support. There’s essentially no reports or discussion of ASTRO post-dating the magazine’s unveil.

What was necessary for it to succeed: It’s not easy to see a way forward for this one. X-20 was dead in the water less than six months later (eventually being formally cancelled in December 1963), and the payload capacity of even the Phase III ASTRO was marginal for what would have been an expensive program. There’s also the issue of Douglas vastly exceeding the question posed by the USAF—it’s unclear that there was any interest on the part of the Air Force in anything other than Phase I. This in turn defeated the purpose of building a fully operational craft for pilot training.

Sources

“Air Force Studies Space Trainer”, Missile and Rockets. September 3, 1962.

ACTS: Europe and Russia Try Again

acts

A somewhat notional view of the ACTS as envisioned once its capsule shape was selected in 2008. By developing a command module with relatively steep walls, the ESA and Roscosmos hoped to solve the problem of cramped quarters aboard the Soyuz, and handle up to six crew. Adapted from an image by Jérémy Naegel, used under a Creative Commons ShareAlike 3.0 license. Click for a larger view.

What it was: A traditional capsule-based spacecraft to be developed jointly by the European Union and Russia, after those two failed to reach agreement on the Kliper lifting body (and further on Europe failing to the get the Hermes spaceplane off the ground).

Details: It’s been interesting the last twenty years or so to watch the gold standard for new crew return vehicles move away from small spaceplanes and lifting bodies back to capsules, as had been the preference through the 1960s. The watershed was sometime around 2006, when mockups of NASA’s Orion ceased to show a lifting body and changed to a capsule, and right about when the tandem of EU/Russia stopped looking at the Kliper and started talking about the Advanced Crew Transportation System (ACTS).

At the end of 2005, the Kliper foundered on the fact that Russia was to design and build it almost entirely. Despite that failure, the ESA was still fetching about for a crewed space project as they had also been rebuffed in approaches to the United States about sharing development of Orion’s capsule prior to Kliper. And so Russia came back into the picture within a few months.

As it happened, the EU had been working on the ATV, an unmanned supply spacecraft for the International Space Station, and it had already been noted that it bore a certain resemblance to a spacecraft service module. “Why not,” the thought ran, “have Russia develop a crew capsule to put on top of an adapted ATV?” Do so and you’d end up with something usable in Earth orbit for short missions, such as going to the ISS.

csts_eurosoyuz

The so-called “EuroSoyuz” first envisioned for the ACTS. This image is even more notional than the previous, based as it is on ideas being considered at the time and not any actual plans. The habitation module at the left, in particular, never progressed beyond an intent to make one eventually. Image by Jérémy Naegel, used under a Creative Commons Attribution 3.0 License.

Initially the craft was envisioned by RKK Energia as sort of “Soyuz, Mark 2”, which Energia called the Soyuz-2, with a Soyuz-shaped re-entry module, if not the one from an actual Soyuz. Rather it would be oversized, perhaps derived from work down on a mid-80s Soyuz replacement called the Zarya. This had stuttered along as late as 1995, when it was jointly proposed by Energia, Khrunichev and Rockwell as a lifeboat for the ISS. The ESA and Russia committed to a two-year study of the idea, with the ultimate intention of producing a spacecraft that could orbit the moon. This configuration was still in the lead as of August 2007.

The study’s mid-2008 deadline coincided with that year’s Farnborough Air Show, and the details that were announced then had moved on from the initial concept. Now the upper half of the ACTS was a conical capsule, built by the Russians and integrated by them onto the European service module. Many sources describe it as Apollo-like, but it was fairly different in being much more vertical, a mere twenty degrees from vertical on its side walls. This was a throwback to a proposed European capsule, Viking, which had popped up for a while immediately post Hermes before fading out after one subscale, suborbital test (the Atmospheric Reentry Demonstrator) in 1998.

Though the craft was not designed to the point of precise specs, we know that it would have probably have been under 18,000 kilograms, as one of the proposed ways of getting one to orbit was via Kourou Space Centre on top of a crew-rated Ariane-5, though figures bounced around from as low as 11 tonnes and as high as 20. The Russians also talked about launching the ACTS from Vostochny, probably for use on an Angara A5 (though that rocket is still under development even as late as December 2016); a Proton was also a possibility if the difficulties of launching cosmonauts on top of rocket fueled with nitrogen tetroxide and UDMH, and there was nebulous talk of a Zenit derivative (a rocket that had not been used.in Russia as the dissolution of the USSR left its manufacturer in Ukraine).

The capsule would have been five meters across the base and with its high vertical angle would have been roomy enough for six astro/cosmonauts (or four, if going to the Moon); one source reports 2.5 cubic meters of space, but this is no larger than a Soyuz and seems unlikely.

Ultimately the plan was to have a habitation module too, and the responsibility for this was assigned to Europe, but until the core ACTS spacecraft was much further along this was little more than a planned future commitment, with no details at hand. At the forward end, ACTS would at first have a Soyuz-style docking arrangement to take advantage of the matching ports on the ISS. Once it began its lunar missions, though, the plan was to have a common active/passive system with the Americans’ future craft so that joint missions would be easier.

On re-entry, the Russian-made capsule would have borrowed a trick from previously mentioned Zarya: a re-entry to land under a minimal parachute, with primary responsibility for landing being passed on to 12 solid rocket motors that would begin firing at about 300-800 meters up. Retractable landing legs were also mooted, as part of a general desire to make the capsule re-usable (with one Russian official hopefully suggesting ten flights in a lifetime). Rumor had it that this hair-raising retro-motor approach was made necessary by the Russians insisting on their historical requirement that their crews return to land in Russia, and with much of Central Asia now thoroughly Kazakh, the area they had to hit was much smaller than before—and parachutes normally cause one to drift quite a bit.

What happened to make it fail: Europe started showing signs of cold feet in the spring of 2008, just as the ACTS was making its splash at the Farnborough Air Show. The reasons are bureaucratically murky, but seem to have reflected the ascendance of a faction in the ESA that wanted to focus on “ATV Evolution”, a more ambitious approach where they’d upgrade the ATV so that it could return cargo, then upgrade the return module into a capsule, and then even turn it into the core module of a small space station. All this would be indigenous to Europe, with no Russian involvement.

ACTS might have survived this, but two competing financial tides worked against it. The Great Recession kicked off in late 2007, and for the next six years Europe had to deal with repeated sovereign debts crises that made money scarce. Not only was ATV Evolution shelved, even a shared spacecraft with the Russians was too expensive.

In the other direction we had a surging price for oil and gas (bar a severe but short drop near the start of the recession), reaching $140 per barrel in June 2008. Replete with petrodollars, Russia came to the conclusion that they didn’t need to put up with European waffling any more and could go ahead with their own, solo version of the ACTS. Political opinion at home favored this course anyway, and local laws on technology transfer made it difficult for Roscosmos and Energia RKK to come up with a legal framework for transferring technical information on Soyuz and other ACTS-related work out of Russia. This last issue is what is generally cited in official ESA documents as the main cause of ACTS’ failure.

Then in August 2008, Russia invaded Georgia in support of separatists there, followed by a gas pipeline dispute with Ukraine in January of 2009 that affected several EU countries. European confidence in Russia as a partner nosedived, and it became politically distasteful for the ESA to continue working with their Russian counterparts on such a high-profile project. Both sides quietly went on their way.

What was necessary for it to succeed: ACTS as such could have gone ahead in the face of most of the difficulties just listed. Certainly the financial crisis could have been ridden out for a few years, and the Russia oil boom didn’t last. What’s been the real killer has been the frosty relationship between Europe and Russia, kept chilled by further events like the latter’s clandestine invasion of eastern Ukraine. It’s difficult to see ACTS restarting any time after 2008, despite occasional French noises about re-establishing partnership with Russia.

Unlike most other projects discussed here, though, ACTS didn’t lead to no flying craft, or even to one. Rather it’s changed into two, and that’s not even counting the ATV Evolution which the ESA bravely claims is still on the table despite little sign of movement for about eight years. The Russian ACTS derivative was first called the PPTS, then it became the PTK. While that project has faced a long and slow road, it was formally dubbed Federation this year and, is still looking like it will fly in the 2020s.

On the European side, NASA announced in January 2013 that the previous design of the Orion service module was being replaced with an ATV-derived service module for at least the EM-1 unmanned test out past the Moon, currently scheduled for a year next September. Whether it will be used again after that mission is an open question, but so far it looks like it’s going to be used once. The initial idea that the ATV would work if someone else supplied a capsule for it was right, they’d just picked the wrong partner at first.

So the ACTS has survived after all, and did so by being cut in two. As mentioned, the Russian half has a name already, but seems fitting to name the as-yet-anonymous American/European half after King Solomon.

Sources

“Advanced Crew Transportation System”, Anatoly Zak. RussianSpaceWeb.com.

“Collapse of ESA-Roscosmos Crew Vehicle Partnership Holds Lessons”, Peter B. de Selding. SpaceNews.

“Potential European-Russian Cooperation on an Advanced Crew Transportation System”, Frank De Winne. Belgian Science Policy Office.

LANTR LTV/LEV: A New Way to the Moon

lantr-lev-side-by-side-comparison

Two versions of the LANTR LTV/LEV. On the left is one suggested for a SSTO launcher that could carry 20 tons to orbit and had a 13.5 meter payload bay. The one on the right could fit in a 9.5 meter cargo bay, at the cost of using less efficient methane for lander fuel, a smaller crew capsule, and a fiddly tank-within-a-tank to hold some of the craft’s liquid oxygen oxidizer. Public domain image composited from two separate diagrams in NASA’s Human Lunar Mission Capabilities Using SSTO, ISRU and LOX-Augmented NTR Technologies A Preliminary Assessment. Click for a larger view.

What it was: A mid-90s proposal for a lunar mission using an innovative rocket engine for the trip to the Moon and some basic lunar industry to refuel its chemically-driven lander for the trip back. It was one of the first proposals for a Moon mission to try and move away from a brute-force Apollo-style mission that was impossible to fund.

Details: The core difficulty with a Moon mission, or a mission to much of anywhere really, is that you need such massive vehicles. The Saturn V, for example, was 2950 tonnes when fueled, and was 111 meters tall. It was accordingly expensive: approximately US$700 million in 2016 dollars. Reusability was the route taken in the decades since to try and bring this down, but the Space Shuttle ended its life costing US$450 million per launch and for a considerably smaller payload being taken to orbit too.

By the early 1990s, in-situ resource utilization (ISRU) was seen as the next coming thing for making missions cheaper. This is to say, don’t haul all the mass you need up into space, take advantage of whatever mass is already there wherever you’re going. The difficulty here is that that mass is useless rock and, to a much lesser extent, water ice. The most obvious thing to do would be to refine cryogenic rocket propellants from it, as both rock and ice can be sources of oxygen and hydrogen. By the mid-90s people had been thinking for several years about how to do that, and what what would be possible once it could be done.

The most famous fruit of this effort was planning for Mars missions, partly because the vehicles for a traditional flight there would be ridiculously large even by Saturn V standards and partly because Mars’ carbon dioxide atmosphere is almost trivially easy to turn into methane (a decent rocket propellant) if you bring along some hydrogen from Earth. Less well-known is a lunar mission using ISRU which was developed at NASA’s Lewis Research Center.

In the early 1990s Lewis had been involved in the development of a nuclear rocket of an unusual type, what they called a LOX Augmented Nuclear Thermal Rocket (LANTR). A regular nuclear thermal rocket like NERVA runs on pure hydrogen, not burning anything at all and simply relying on nuclear power to heat the propellant and produce a high specific impulse. Unfortunately liquid hydrogen is very low density, and so the tank to hold it has to be large—and it doesn’t matter how light something is if you literally can’t fit it into the cargo bay of the Space Shuttle, or however else it is you’re planning on getting it into orbit.

The LANTR solved this problem by using liquid oxygen along with the hydrogen. After being heated by the reactor, the hydrogen was mixed with oxygen, which would then burn. This had the paradoxical effects of reducing the engine’s specific impulse, but also radically reducing the amount of hydrogen needed and making the necessary hydrogen tank much smaller. Liquid oxygen is seventy times denser than LH2, so its tank would be small too. The usual mix of oxygen to hydrogen is near 1:2 (as the chemical formula “H2O” would suggest), but even when mixed 5, 6 or 7:1 with the hydrogen the reduced specific impulse of the LANTR was still considerably better than you got with a conventional LOX/LH2 rocket while also being smaller than a pure-hydrogen nuclear rocket..

artist

“Artist’s Illustration of a Self-Contained, Modular LUNOX Production Unit”, plus an astronaut apparently taking a selfie. Public domain image from A Revolutionary Lunar Space Transportation System Architecture Using Extraterrestrial LOX-Augmented NTR Propulsion. Click here for a larger view.

The leap to lunar ISRU came with the realization that oxygen was a major component of the Moon’s soil. For example, the orange soil famously (and excitedly) discovered by Jack Schmitt during Apollo 17 contained hydrated iron oxide, and was rich in oxygen and water. At Lewis, the combination of LANTR and ISRU for a Moon mission crystallized in a flurry of papers spearheaded an engineer there, Stanley Borowski, in combination with a variety of colleagues. Rather than go with an already compact Moon mission using entirely Earth-sourced oxygen, why not use the Moon’s native oxygen for oxidizer on the way back? The result would be smaller and cheaper still.

The result was a proposal to build a Moon landing ship that was embedded in some basic Lunar industry that would be set up prior to the crewed landing. The first step would be to send an automated lander with a teleoperated mining equipment to a site where ilmenite or some other oxygen-rich rock had been pinpointed from orbit. Also included would be a 35-kilowatt nuclear reactor, which would provide the heat to break down the lunar rock with the hydrogen that would be brought along too, producing water. The water in turn would be broken down to oxygen and hydrogen, the former being stored and the latter recycled to start the process again on the next batch of rock.

Once 10.5 tons of liquid oxygen had been built up (a process which would take a year), the LANTR LTV/LEV (Lunar Transfer Vehicle/Lunar Excursion Vehicle) crewed mission would begin. Here a little bit of variation appears. When first suggested in 1994 the craft was assumed to be using a Shuttle-C, a derivative of the Shuttle for cargo only, to get to orbit—the LANTR wasn’t powerful enough to lift the whole works by itself (and no-one was very keen on firing a nuclear engine at ground level in any case). The Shuttle-C was already a cancelled project, however, and by 1995 NASA had been pinning its hopes on the VentureStar or some similar SSTO. At the time the LANTR LTV/LEV was being bruited about, the size of the SSTO’s payload bay hadn’t been nailed down and while NASA had specified 20 tons to LEO it was unclear how long the cargo it carried could be, Accordingly Lewis Research Center came up with two LANTR LTV/LEV configurations, each of which would be lifted in three pieces and mated in orbit.

If the SSTO gave them 13.5 meters to work with, the result was a 58.8-ton, 26.2 meter-long craft. Compare that with roughly 140 tons and 35 meters for the Apollo LM/CSM/S-IVB that launched the Apollo astronauts to the Moon. This version of the LANTR LTV/LEV would have be entirely fueled by LOX and LH2, excepting (presumably, as none of the sources say) hydrazine for the RCS thrusters as usual. On top was a curiously inverted command module; the author could find no discussion of how that was handled when time came for re-entry, so one presumes rotatable seats for the crew.

The longest part of this variation was the joint LH2/LOX tank for the transfer vehicle, while the widest was the bulbous hydrogen tanks on the lander. Both had to go to get into the smaller 9.5-meter SSTO payload bay suggested. The lander was switched to a more-compact but less efficient fuel, liquid methane, while one of the two oxygen tanks for the LANTR was moved to inside the LH2 tank, and outfitted with a double wall that would keep the supremely cold hydrogen from solidifying the oxygen within. The resulting craft was slightly lighter at 58.5 tons and definitely shorter at 24.2 meters, but in return they had to come up with some way of shaving 700 kilograms off of the crew capsule. Both variations of the capsule were approximately the same size as the Apollo CM, though the first’s was slightly larger than the second.

profile

The LANTR LTV/LEV mission profile. Note the direct descent and direct return. Public domain image via NASA from Human Lunar Mission Capabilities Using SSTO, ISRU and LOX-Augmented NTR Technologies A Preliminary Assessment. Click here for a larger view.

There was no LM, though, because the LEV was a direct-descent, direct-return vehicle. This did mean that if the stay on the lunar surface was to be of any length, a third mission, automated like the LOX plant, would have to be sent beforehand to give the astronauts a habitat. The LEV itself was inadequate otherwise.

What happened to make it fail: Though the mission was considerably cheaper than an Apollo-style trip to Moon—Johnson Space Center was looking at the time to spend less than US$1 billion on a Lunar return mission—not even that amount of money turned out to be available in NASA’s budget, particularly after the decisions were taken to continue with the Space Shuttle and build the International Space Station around the same time as the proposed first flight of a LANTR LTV/LEV’s, around 2001.

It also didn’t help that the craft came to an unwieldy size. It was intended to be launched on the VentureStar, and that never came to fruition. A comparable mission restricted to launch vehicles that actually existed needed one Shuttle mission and one launch of a Titan IV (which could lift longer payloads than the Shuttle could), a peculiar and expensive combination.

Something like it still could have begun as late as the about ten years ago, but then a discovery about the Moon put the final nail in its coffin. From 1994 through 2009 it became increasingly clear that the Moon had ice in some of its South Polar craters, with the case being settled by the Chandrayaan-1 probe. This changed the game for ISRU, since ice is a lot more useful raw material than lunar soil. Essentially all serious planning for a Moon mission since then has reflected this, and lunar rock has fallen by the wayside.

What was necessary for it to succeed: Much like the First Lunar Outpost, the LANTR LTV/LEV’s best bet would have been at the time the Clinton Administration was trying to decide how to help occupy the former Soviet Union’s rocket scientists so that they wouldn’t end up designing missiles for who knows what country. The decision to go for an joint space station rather than a joint lunar mission or base was a relatively easy one, given the USSR’s experience with stations, but it’s not too difficult to see the US deciding to go for the public relations spectacle of the Moon over the more staid ISS.

Otherwise the LANTR LTV/LEV is a sound concept if the promised Isp advantage holds, to the point that (by the standards of this blog) something much like it still would be worth building and flying. The primary difficulty with it in 2016 might be, oddly enough, that it’s too small. Sixty tons falls into the “between two stools” range that we discussed in the entry on the R-56, too big for something like an Ariane 5 or Delta IV Heavy, but too small for the upcoming SLS. Given that you’re going to have to use an SLS and that rocket will quickly outstrip 60 tons by a lot, why not design a spacecraft that uses up the extra payload capacity? Fans of SpaceX’s Falcon Heavy effort might want to take some notes, though.

Sources

A Revolutionary Lunar Space Transportation System Architecture Using Extraterrestrial LOX-Augmented NTR Propulsion. Stanley K. Borowski, Robert R. Corban, Donald W. Culver, Melvin J. Bulman, and Mel C. Mcilwain. 1994

Human Lunar Mission Capabilities Using SSTO, ISRU and LOX-Augmented NTR  Technologies A Preliminary Assessment. Stanley K. Borowski, 1995

High Leverage Space Transportation System Technologies for Human Exploration Missions
to the Moon and Beyond. Stanley K. Borowski and Leonard A. Dudzinski. 1996

Sidebar: The Langley Water Lander

langley-water-lander

A diagram of the Water Lander if it were full sized, as opposed to the one-eighth scale model that was built. Note the curvature of the wings as seen from the front, not coincidentally like the hull of a boat. Public domain image via NASA from Model Investigations of Water Landings of a Winged Reentry Configuration having Ourboard Folding Wing Panels. Click for a larger view.

There are two fundamental dichotomies in spacecraft design (or three, if you count the types of fuels used for their rockets). You have ballistic capsules in opposition to winged craft/lifting bodies, and you have water landings as opposed to coming in on solid ground. Three of the four possible combinations have been used by crewed spacecraft but one hasn’t: a water landing of a winged vehicle.

That’s not to say it hasn’t been examined, though. NASA studied the ramifactions of an emergency ditching of a Shuttle Orbiter (conclusion: a lot of damage to the underside, but it would stay afloat for a while as long as the wings weren’t badly holed), and the Australians famously photographed the USSR retrieving a BOR-4 test article from the Indian Ocean in 1983. Even earlier, the American ASSET, originally conceived for testing the alloys earmarked for the X-20’s heat shield, splashed down off Ascension Island after a suborbital jaunt from Cape Canaveral.

lander2

The Water Lander model in its tank. Public domain image from same source as previous. Click here for a larger view.

As far back as 1959, NASA was testing the concept using a water tank at Langley Research Center in Virginia. They had a chicken-and-egg problem, though. How do you build a water-landing spacecraft without tests to tell you what it will look like? But then how do you do the necessary tests without having it built first? Ultimately they had to just go ahead and build it based on first principles and common sense. What they came up with never had a name, so for convenience’s sake we’ll call it the Langley Water Lander.

The re-entry vehicle they posited was a light one, just 3600 pounds (1.6 tonnes), which is only a few hundred pounds more than a Mercuty capsule. Given that much of it was wings, it would have definitely seated only one astronaut, perched in a slim fuselage.

And it really was a lot of wing for its size, 27 feet from tip to tip and with an area of 263 square feet (7.0 meters and 24.4 square meters); it had no tail at all, though it did have a large vertical fin. The wing was gently curved, making a cross-section something like a boat so that the craft could rock from side to side on the surface of the water without the tips of the wings dipping below the surface. This was made even more unlikely by the fact that the wingtips were designed to fold up once the craft had gone subsonic.

On its underside were two retractable 4.7-foot × 0.67-foot (1.4m × 0.20m) water skis and a smaller triangular skid aft, roughly a foot to a side, for drag; this was found to be more stable during the final run-out than anything involving a single nose ski.

Thus configured, a one-eighth scale model was built and tested, with the conclusion that the landings were not so bad at all. The Water Lander wasn’t too sensitive to a little yaw in the touch-down, and even with small waves (eight inches high and fifty feet long, or 20 cm and 20 meters,to scale) the run-out was only three to four hundred feet with a maximum of 5.1 g deceleration. On smooth waters, it came in at under 3.0 g and 100 feet further travel after touchdown.

The Water Lander was never intended to be built for actual use, but rather was a reflection of where NASA was in late 1959. They examined a great many basic possibilities for the crewed space program, many of which have fallen into obscurity. In the case of winged water landers, the reason likely was that there’s no advantage to them. A ballistic capsule, almost uncontrolled, can benefit from a target as big as the South Pacific Ocean. But the whole point of a winged re-entry vehicle is that it can be directed once in the atmosphere, and if you can do that you might was well direct it towards a runway.

Source

Model Investigations of Water Landings of a Winged Reentry Configuration having Ourboard Folding Wing Panels, William W. Petynia. Langley Research Center. December 1959.

STCAEM-CAB: A Mouthful of a Mars Mission (Space Exploration Initiative, Part II)

STCAEM-CAB schematic diagram

A schematic of the STCAEM-CAB Mars space vehicle. The twin heat shields (the scoop-shaped structures) were needed as the craft was too massive to aerobrake in one piece even after the TMIS was jettisoned. The MEV and MTV would separate before the Mars encounter, aerobrake and enter orbit separately, then rendezvous and dock while high above the Red Planet. Public domain image by the author, based on one published in Space Transfer Concepts and Analysis for Exploration Missions, Implementation Plan and Element Description Document (draft final) Volume 2: Cryo/Aerobrake Vehicle. Click for a larger view.

What it was: One of the products of 1991 study by Boeing for a Mars mission vehicle. Technologically it was the most conservative of the possible craft they suggested, relying entirely on cryogenic propulsion, but the trade-off was a hair-raising mission profile including a hard aerobraking maneuver at Mars.

Details: In 1989 the then-President of the United States, George H. W. Bush, put forward a proposal to (among other things) send astronauts to Mars. While NASA had always kept Mars contingency plans up to date since even before Apollo 11, this was one of the few times where it looked for a while like they might actually be able to put their plans into motion. In 1989 they produced a strategic plan known informally as the “90 Day Study” and then set various contractors to work on its different goals.

One of these was “deliver cargo reliably to the surfaces of Moon and Mars, and to get people to these places and back safely”. Boeing was the contractor primarily concerned with this this one, and performed an initial study in 1989 before amplifying it in 1991-92. For Phase 1 of the later study they worked their way through the pros and cons of several different approaches to crewed Mars missions for NASA to choose between, most of which involved novel propulsion systems like nuclear rockets and solar-electric ion engines.

One was more conventional though, closely hewing to NASA’s own baseline for the mission, and was presented first in their Phase 1 final study. All the Mars craft were assigned the clumsy name of the study, Space Transfer Concepts and Analyses for Exploration Missions (STCAEM), and differentiated by their propulsion method. The first craft was accordingly the STCAEM-CAB, the final thee letters standing for “cryogenic/aerobraking”.

The Mars mission was placed firmly in the context of the whole Space Exploration Initiative, not least because the vehicle in question was going to ring in at a whopping 801 tons. No conceivable rocket was going to lift it in one piece, and so the SEI’s space station Freedom was to serve as a base for the in-orbit assembly of the massive ship. A Moon base was also assumed, and served two purposes insofar as Mars was considered: as a test bed for the various technologies, and also a place to put a deliberately isolated habitation module that would simulate a long Mars mission without leaving the immediate vicinity of the Earth-Moon system.

Shuttle-Z in

Another Shuttle-derived launcher (not the Shuttle-Z) charmingly called the “Ninja Turtle” configuration–lifting the STCAEM-CAB’s two aeroshells off Earth and to Freedom. Public domain image from NASA, same source as previous. Click for a larger view.

Using what was called the Shuttle-Z (a variant on the Space Shuttle wherein the orbiter was replaced almost entirely with 87.5 tons of payload, leaving only the main engines, the boosters, and the iconic orange tank), eight trips would be made to Freedom with various components of the ship. After assembly, the STCAEM-CAB would consist of several sections, the largest of which was the Trans-Mars Injection Stage (TMIS) at 545.5 tons. Fuelled with liquid hydrogen and liquid oxygen, the cryogenics referred to in its name, the four-engined TMIS would push the entire craft into a Mars-bound trajectory before being jettisoned. Boeing studied a number of missions that could be flown and came to the conclusion that the relatively less efficient cryogenics propellants would work best when Mars was at opposition, leading to a 580-day mission.

Missions for Mars have often included odd wrinkles in their plans to help cut down the amount of propellant needed to pull them off; for example, the Integrated Program Plan’s mission avoided a circularization burn at Mars, leaving it in an elliptical orbit that made the lander’s descent to the surface start at a higher speed—but better to have to slow down the relatively small MEM than the entire interplanetary craft. In the case of the STCAEM-CAB the trick was unusual enough to warrant mention. For the bulk of the outbound trip, the two other main components of the craft, the Mars Excursion Vehicle (MEV) and the Mars Transfer Vehicle (MTV), would stay docked, with a small transfer tunnel between the two of them. In this configuration it would serve as the habitation for the crew of four astronauts, with the MTV’s crew module being 7.6 meters by 9 meters. This would give each astronaut something on the order 50 cubic meters to live in, with another 50 for everyone to share in the MEV, at least on the way out. With fifty days to go before Mars, however, the two would separate (the crew staying in the MTV, which had the capability of returning them to Earth) so that they could each dive into the Martian atmosphere at closest approach and slow down behind their individual heat shields.The MEV would brake first, 24 hours before the MTV and crew, giving Mission Control a chance to observe Mars close up and decide if it was safe for the second aerobraking maneuver.

Side and front views of the Mars Excursion Vehicle

Side and front views of the MEV after jettisoning its aerobrake and landing on Mars. Public Domain image from NASA, same source as previous. Click here for a larger view.

This approach also had the advantage of making the aerobraking shells smaller, as even done this way they approached the length of a Shuttle Orbiter (30 meters, as opposed to 37.2 meters) and so the shell for a singular craft would have been impossible for a Shuttle-derived stack.

After both had aerobraked and entered orbit, they would dock again, the crew would transfer to the MEV, and then descend to the surface. Several landers were mooted, from one with a 0.5 lift-to-drag ratio (the favored option, pictured at left), one with a 1.1 ratio, and a biconic lander that was going to require a launcher back on Earth that had a diameter of 12 meters(!).

The astronauts would stay on Mars for 30 days, then a subset of the MEV (the third and uppermost of the circles in the MEV image shown, as well as the tankage underneath it) would launch skywards again to dock with the MTV. This would in turn get them back out of Mars orbit and home to Earth, where they would aerobrake again to bleed off some velocity and enter Earth orbit. The crew would finally enter an 3.9 meter wide by 2.7 meter tall Apollo-like capsule for re-entry to somewhere in the ocean. Optionally the MTV would remain in orbit and be refurbished for another journey.

Mars Transfer Vehicle and aeroshell

A closer view of the MTV, which alone would make the journey back from Mars with the crew aboard. The aeroshell would make the trip too, as the craft would aerobrake into Earth orbit too. Public domain image from NASA, same source as previous. Click for a larger view

Boeing scheduled out the launch of the first Mars mission three different ways. One was a “Minimum Program”, intended to do no more than meet the 90 Day Study’s stated goals, one was a “Full Science Program”, while the last was an eyebrow-raising “Industrialization and Settlement Program”. The latter was on Mars by 2009, and saw a permanent Mars base with 24 inhabitants in 2024, some astronauts staying there for years. The science-oriented program made it by late 2010, and saw a permanent lunar base of four (the settlement plan saw 30!) but only a periodically inhabited Mars base of six astronauts. The minimum options saw a first Mars landing, by coincidence, in 2016. It had neither permanent Mars or Moon base. As for the cost of each, Boeing includes various graphs but only gives one number, for the Industrial and Settlement Program: an eye-watering $100 billion from 2001 to 2036, with a peak of $19 billion in 2020.

What happened to make it fail: Well, “$100 billion…with a peak of $19 billion” for a start. While the Bush Administration was obviously looking for their own version of a “Kennedy Moment” when they announced the Space Exploration Initiative, they were not all that keen on actually paying for it. Couple that with extreme hostility from Congress anyway, and the SEI’s ultimate goal of Mars mission was in trouble right from the start. Likewise NASA blew it by proposing grandiose plans like an 800-ton Mars ship, the full space station Freedom, and a permanent lunar base, to the point that the backlash led to the “faster, better, cheaper” era under Dan Goldin (which had its own problems, but that’s another story). Boeing even spent some pages in Phase 1 trying to determine returns on investment and the like, with some of their anxiety at the cost coming through in their prose. This includes an unflattering comparison to the development of the Alaskan oil pipeline and the investment in supertankers during the closure of the Suez Canal from 1967-75.

As far as the STCAEM-CAB in particular was concerned, it also suffered from being “good under most circumstances but never the best”. Boeing preferred the Nuclear Thermal Rocket variation, and focused on that going forward from Phase 1 of the study, even though Goldin had been NASA administrator for a year and a half by the time their final work on the project was completed. The NTR variant was certainly not going to go ahead thanks to NASA’s new focus, and the CAB had already fallen by the wayside.

Ultimately, though, this mission suffers from the same problem as the Integrated Program Plan’s Mars Mission from the early 70s. It existed down near a long line of large programs, few of which actually happened. You need to join back up several links in a chain to get to the launch of this spacecraft. Ultimately, quite a few things would need to change for STCAEM-CAB to make its trip, making it quite unlikely under any circumstances.

Sources

Space Transfer Concepts and Analysis for Exploration Missions, Implementation Plan and Element Description Document (draft final) Volume 2: Cryo/Aerobrake Vehicle, Gordon.R. Woodcock. Boeing Aerospace and Electronics. Huntsville, Alabama. 1992.

The Early Lunar Shelter: Stay Just a Little Bit Longer

Garrett AiResearch Lunar Shelter

The Garrett Early Lunar Shelter, showing its roots in the LM Truck and, in turn, the LM that actually landed on the Moon. The tanks draped around it are hydrogen and oxygen for the fuel cells, shelter pressurization, and recharging the astronauts’ suits after EVA. Public Domain image via NASA from Early Lunar Shelter Design and Comparison Study, Volume IV. Click for a larger view.

What it was: A two-astronaut shelter/living quarters for use with the Apollo program once it had progressed to needing 30-day stays on the surface, studied in 1966-67 by Garrett AiResearch at NASA’s request. Variants for three astronauts and for a mobile version that could be hitched to a lunar rover were also examined.

Details: Certain big names show up repeatedly in conjunction with the American space program: North American Rockwell, Grumman, Boeing, Lockheed, and so on. Around the fringes, though are less familiar names such as Bendix and TRW. Another one of the latter was Garrett AiResearch, a mid-sized aerospace pioneer best known (at least as far as the space program goes) for designing and building the atmosphere controls for Mercury, Gemini, and Apollo.

In 1966, NASA commissioned Garrett to move beyond what they’d done to that point, and work on a  full-fledged, if tiny, Moon base. Dubbed the “Early Lunar Shelter” (ELS), the intention was to build it following the J-Class missions—what turned out to be Apollo 15 through 17. Having progressed from short surface stays like Apollo 11 to longer ones that had a lunar rover to work with, like Apollo 17, the next step was to be month-long stays and that required more than a single LM.

From the beginning, the Moon landings had been quite restricted in mass, as much of an LM was taken up with astronauts, the consumables they needed, and the fuel and engines needed to get them back to the CSM for the flight home to Earth. If you could forgo all of that with an automated lander, you could haul a lot more equipment to the Moon—to wit, 4.67 tonnes of it.

The fruit of this thinking was the LM/T, or Lunar Module Truck, which was for all intents and purposes a rocket-powered mule that would head to the Moon some time before its associated astronauts would start their journey in their own LM (called the LM Taxi in this context). Landing close to the LM/T, the astronauts could walk over, unload everything, and enjoy a huge quantity of equipment as compared to Aldrin and Armstrong.

There were any number of configurations for the LM/T, constrained only by the volume an LM occupied on top of a Saturn V and the limit to the mass it could safely land, but the Early Lunar Shelter was the answer to one particular question: “Suppose we devote the Truck’s volume entirely to living quarters for two astronauts and the scientific equipment they’d use. What would that be like?”

What Garrett came up with was a stubby cylinder, 8.1 feet in diameter and 16 feet long (2.5 meters by 4.9 meters) which rested on its side above the LM/T’s descent stage, looking not unlike contemporary bathyscaphes. It would be launched atop a Saturn V along with a crewed CSM, which would dock to a hatch on its upper side, then ferry it to the Moon after the usual Saturn IV-B trans-lunar injection. After reaching their destination, the CSM would disengage and return its crew to Earth, while the ELS would land automatically.

The shelter could sit on the Moon for as much as six months before its astronaut-dwellers arrived (thanks to another Saturn V/CSM combination), with a minimum seven days prior to their launch for checkout of the shelter. A SNAP-27 radiothermal generator would power the ELS until activation. Once aboard, the minimum time the astronauts would use it was assumed to be 14 days, with 50 days being the upper end of possibility. The first day days of the mission would be devoted to the astronauts activating the shelter for their use, unloading it, switching the shelter to running off fuel cells (which would also supply water) and transferring the RTG to their LM Taxi so their ride home could be deactivated but kept “alive” until it was needed at the end of the mission.

Interior layout of the Early Lunar Shelter

The interior layout of the ELS, same source as previous. One presumes the outer hatch was closed when the toilet was in use. Click for a larger view.

The interior of the shelter was to be divided into two main areas. One was a lunar EVA airlock taking up one end, the CSM hatch on top being used solely for docking with a CSM. It would have been big enough for two astronauts at the same time as well as storage of two hard space suits. The bulk of the shelter was 628 cubic feet (17.8 m3) of living space. Though about half of this would be taken up with supplies, bunks, and spacesuit storage, its shirt-sleeve environment compared well with a regular LM’s 4.5 cubic meters of habitable volume. Alternatively, as the Moon does supply gravity, the ELS can be sized another way: it would have had 68 square feet of floor space (6.3 square meters).

The arrangement of bunks/radiation refuge quarters in the ELS.

The spartan arrangement of bunks/radiation refuge quarters in the ELS. No Apollo astronaut was taller than 71 inches. Same source as previous. Click for a larger view.

The shelter was double-walled aluminum and fiberglass (the latter in the inside), with 58 mils (0.058 inches, or 0.15 cm) between them for meteoroid protection—the usual tactic, as invented by Fred Whipple. The other major danger entertained was radiation, and the aluminum walls couldn’t be made thick enough to sustain 500 rads (a hypothetical solar flare) without weight close to a half ton more than was otherwise necessary. Accordingly the study suggested putting the necessarily numerous  PLSS recharging canisters (for the life-support backpack worn while on the surface) stored in water filled sleeves around the bunk area located at the opposite end from the airlock. Altogether, they, the walls, and the bunk material made an acceptable, if awfully cramped, radiation refuge for everyone on-board.

One final, intriguing safety touch was the dual-purpose boom attached near the airlock. While primarily intended for unloading instruments or a rover, it would also have been used to get an incapacitated astronaut up next to the entrance to the shelter.

Arranged around and behind the shelter were four tanks: one compressed gaseous oxygen, one liquid oxygen, and two liquid hydrogen. These weren’t intended for use with the Truck’s landing engine—it had its own tankage—but rather for use by the astronauts and the fuel cells (and so, accordingly, their water). Garrett pinpointed the storage of LOX and LH2 for up to six months before the astronauts arrived as the main technical challenge facing the ELS.

Another issue was what atmosphere they would breathe: pure oxygen at 5.0 psia, or nitrogen/oxygen mix comparable to Earth. The former was desirable for mass reasons, and to keep the ELS as close in technology to the rest of the Apollo program as possible, but Garrett were concerned that there were no medical studies of a pure oxygen atmosphere for a long period of time; the 30-day maximum they note was apparently just an educated guess. They ended up punting the problem down the road as essentially an issue of how much they could keep the ELS from leaking; if that could be minimized, the problem was moot. Safety concerns weren’t mentioned at all, and in fact the final filing of Garrett’s study was on February 8th, 1967, not even two weeks after the Apollo 1 fire. After that the CSM would switch to a oxy-nitrogen atmosphere for launch, though the LM would stay with the low-pressure pure oxygen.

Mobile ELS variant, hitched to a notional rover.

The Mobile ELS variant, hitched to a notional rover. Same source as previous. Click for a larger view.

As well as being a shelter, the ELS would have been a miniature scientific outpost. It would be equipped with a drill capable of getting 100 feet down into the Moon’s crust, carry explosive charges for seismic readings, and had three remote instrument stations that would be deployed far from the landing site thanks to the extended EVA capability the shelter would provide. All told, the shelter would come with 3470 pounds (1.57 tonnes) of science gear, while the shelter itself was a remarkably light 985 pounds (447 kg). Add in the expendables and altogether it could be successfully landed on the Moon by the LM/T with a mere pound and a half to spare. Let it not be said that they didn’t squeeze all the juice out of this one.

If the project had gone ahead, Garrett anticipated that the ELS would be operational in 1972. The study is silent on cost, apparently because the construction work was to be handed off to Grumman, and so it was their problem.

What happened to make it fail: It got caught up in the rapid ramping down of the Apollo program that started in 1968, not least the fact that Saturn V production was shut down and the rockets they had were all they were going to get.

By scrimping and saving (and cutting a couple of Moon landings) NASA managed to save Skylab, and eventually the detente-driven Apollo-Soyuz Test Project, but that was it. As any mission involving the Early Lunar Shelter was going to require two Saturn V launches it was an obvious target for a cut, taking up as it would two slots that could be used by two different, separate Moon missions. It was one of the first things to go, and did not make it out of 1968.

What was necessary for it to succeed: It’s interesting to compare the Early Lunar Shelter to the other Moon bases we’ve examined so far, Barmingrad and Project Horizon. Both were hugely ambitious and nowhere near happening in reality, while for this project the key word was early. A lot of people tend to conflate Moon bases with lunar colonies, or at least the next rank down of permanently inhabiting the Moon even if the personnel are swapped out periodically. What NASA put its finger on was that we’re not likely to make that big a leap all in one go. The first lunar bases are probably going to be temporary, just like the first space stations were before we worked our way up to Mir and the ISS.

On that basis it’s easy to get the ELS to fly, as it was a big part of the logical next step in lunar exploration (ignoring the elephant in the room that was automated exploration, mind you). With probably no more than some minor redesigning there could have been one on the Moon just a few years after when Garrett AiResearch pictured it: 1972.

As ugly as the post-1969 picture was for NASA’s funding, it’s not too much of stretch to see the three or four more necessary missions past Apollo 17 making it through the budget grinder and “Apollo ELS” flying sometime around late 1974 or early 1975. It’s a lot likelier than much of what NASA proposed post-Apollo 11, at least, if only because one mission like that would be as much or more of a punctuation mark at the end of the program as any other mission bar Apollo 11 itself.

Sources

Early Lunar Shelter Design and Comparison Study, Volume I and Volume IV, W.L. Burriss, N.E. Wood, and M.L. Hamilton. Garrett AiResearch. Los Angeles, California. 1967.