CEV: The Last Battlestar?
Honolulu (SPX) May 10, 2005
Tuesday May 3, ought to be marked as a red-letter day in the history of space exploration. It was the deadline for contractors to submit proposed designs for the first hardware element of President Bush's Vision for Space Exploration, the CEV (Crew Exploration Vehicle).
Instead, it has turned out to be a black day, if the design submitted by the Lockheed-led team is typical of the other proposals. The artists concepts released by the LockMart publicity department show a crude modification of their design for the cancelled Orbital Space Plane project. The only thing new is a "Mission Module" grafted onto the stern of the old OSP that contains the extra systems needed for a lunar return mission.
The LockMart CEV is laden with a variety of weighty systems that Apollo somehow got along without: wings, airbags, super-expensive titanium structure, an absurdly thin "Orbital Debris Shield", reusable RCC thermal protection, "active thermal control", elevons driven by huge electric motors, even a "Fire Depression System". This kind of massively overweight grab-bag design is often derided by space engineers with the term "Battlestar Galactica" after a huge spaceship in a cult 1978 TV series (not the pretentious low-budget remake now running on the SciFi Channel).
The Battlestar CEV isn't a serious design for returning to the Moon. It's the kind of proposal you slap together cheaply at the last minute for a dumb program that you know will be cancelled – rather like LockMart's late X-33 program. But I don't blame the engineers or managers at LockMart for this idiotic design. They are just responding to an idiotic Request For Proposals generated by an idiotic planning process set up by NASA's late idiotic administrator Sean O'Keefe.
Apollo Redux? To understand how the CEV competition went off the rails, we first must understand the overall structure of NASA's plan to return men to the Moon (Project Constellation). Basically, it is Apollo with the names of the modules changed to confuse everyone. Here is an authoritative summary from the RFP for the Crew Exploration Vehicle:
The CEV provides crew habitation from launch to lunar orbit and return to the Earth surface, including aborts during Earth ascent. The CEV provides the transportation functions to return from lunar orbit to the Earth surface. The EDS provides the propulsive accelerations needed to transfer the various flight elements (CEV and LSAM) from Low Earth Orbit to lunar orbit and provides the deceleration for lunar orbit insertion. The LSAM provides the crew habitation and transportation functions from lunar orbit, to the lunar surface, and return back to lunar orbit. In addition, the LSAM provides the capability for the crew to conduct science and perform routine EVA on the surface of the Moon.
This table will help readers visualize the system:
In fact Constellation is slightly more capable than Apollo as one would expect from the 160t weight in LEO. The crew on the lunar surface is doubled (since no one stays behind in lunar orbit) and the stay time is supposed to be extended up to ~1 month on later missions. The RFP includes a confusing description of a dedicated cargo vehicle that will eventually be added to the fleet:
Finally, the Cargo Delivery System (CDS) is used to deliver un-crewed elements to low Earth orbit and/or lunar orbit. The CDS consists of an EDS and a Cargo Launch Vehicle.
If this one-way lunar cargo vehicle is really developed and used in significant numbers, Constellation could grow into something more akin to the cancelled "Apollo Applications" moon program or the similar Soviet study "Vulkan".
A significant difference between Apollo and Constellation is the funding level. During the period of maximum development, NASA spent about $16B/yr on Apollo (in modern inflated dollars). This is about the same as the projected TOTAL budget for all NASA activities during Plan Bush. Nobody in their right mind thinks that there will be any significant increase in this funding level. At most, about half of this could be devoted to the manned program (given lots of unpopular cuts in other NASA programs).
So it is inevitable that the Constellation program will be stretched out over a much longer period than Apollo was. Apollo was a crash program whose schedule was deliberately compressed so that the Soviets would be unable to match it. There is no Moon Race at present (outside the fevered imagination of extreme Sinophobes).
This feature of Constellation is known as "go-as-you-pay" or "spiral development" and is a clever method of fitting a quart-sized program into a pint-sized budget. During the development phase, it means that various tasks which were performed concurrently in Apollo will be done in succession. A clear example of this is that the CEV is the only one of the four distinct spacecraft that is now in preliminary development – the other three are still only artist's concepts. And even the CEV will progress at a glacially slow pace, as one can see from the Request For Proposals:
Spiral 1: Earth Orbit Capability. Spiral 1 establishes the capability to test and checkout crew transportation system elements in Low Earth Orbit in preparation for future human exploration missions to the Moon. As new exploration elements necessary for future spirals are developed, they will be tested with the Spiral 1 CEV in the space environment to prepare for future exploration. The objective of crewed access to low earth orbit will be met by 2014.
Spiral 2: Extended Lunar Exploration. Spiral 2 establishes the capability to conduct human exploration missions on the surface of the Moon for extended durations. In this context, extended duration is defined as the capability to support the crew on the surface of the Moon for a minimum of four days. This objective will be met in the 2015-2020 timeframe.
Spiral 3: Long Duration Lunar Exploration. Spiral 3 establishes the capability to conduct routine human long duration missions on the surface of the Moon to test out technologies and operational techniques for expanding the human presence to Mars and beyond. Missions in Spiral 3 will extend in duration from those obtained in Spiral 2 up to several months to serve as an operational analog of future short stay Mars missions. This objective will be met after 2020.
Many critics (including new NASA Administrator Mike Griffin) have questioned the long gap between the first test flight of the boilerplate CEV in September 2008 and the first manned flight in 2014. Those years are needed for the successive development of the LSAV, EDS, and most of all the launch vehicle. The small budget wedge available is simply not adequate to develop all these hardware items in parallel with separate contractors working simultaneously as with Apollo.
Specifications without specificity: The basic problem with the CEV competition as it evolved under Sean O'Keefe is that the project's managers did not decide what kind of vehicle they wanted, even at the most basic level. Look at the absurdly short technical specification section from the Request For Proposals for the CEV:
For purposes of this request for proposals, industry is expected to provide an initial concept for a CEV spacecraft that shall:
Specifications #11 and #15 do contain some hard numbers, but the numbers don't make sense in terms of a lunar landing mission. The life support duration of 16 days is far longer than needed for the run to lunar orbit and back, and the 500 cubic feet of living space seems pretty luxurious for four people.
On the other hand these numbers are quite inadequate for a three-year Mars mission. There is no demand for any kind of solar flare shelter. Where do these requirements come from? Is there a hidden requirement for CEV, such as repairing space telescopes stationed at the Sun-Earth L2 point?
The extraordinary thing about this RFP is that it omits most of the vital specifications that the contractors need to know in order to make any meaningful studies:
-- What is the g-force vs. time envelope the crew can tolerate during launch? During launch aborts? During space maneuvers? During reentry at escape velocity? This will determine what shapes and lift factors can be used on the reentry vehicle, which is probably the most fundamental decision in any spaceship design exercise.
-- What internal atmosphere will be used? At what pressure? This determines the structural strength needed in the pressure hull, and the difficulty of EVAs on the Moon.
-- What propellant choices are allowable for the main engine that thrusts the CEV out of Moon orbit back to Earth? For the maneuvering thrusters? For the reentry thrusters on the RV?
-- The specified life-support time of 16 days apparently does not include the period when the CEV is parked in lunar orbit with the crew off in the LSAV. What is the desired total unmanned space-storage time? This could exclude cryogenic storage of propellants and other consumables.
-- Specifications #5 and #6 say that the CEV needs to dock with the EDS and LSAV. Does it have to be docked with both of them at the same time? What forces must the docking collars absorb during burns of the EDS engine? Must the CEV's thruster system provide attitude control to the other modules while they are docked, or can their own systems assist in this?
-- What degree of cross-range maneuverability is needed during reentry? Can the RV's lift vector remain pointing up or will roll maneuvers be required to reach a particular landing site?
-- Should the parachute system allow some controlled gliding to a precise landing point like X-38?
-- Does the RV normally land on water? Land? Either? If water landings are usual, should it have the ability to survive an emergency descent on land?
-- Is the RV to be reusable on later CEV missions, or sent off to a museum after one flight? Are the contractors responsible for evaluating the cost trade-offs between the two options in their studies?
-- Does the CEV need to have a zero-g toilet like the Shuttle? Should this large item and its contents be returned to Earth in the RV, or can it and other life support gear be in a separate jettisonable module like Soyuz has? What about kitchen facilities?
-- Will NASA be using a Spiral 4 or Spiral 5 version of the CEV command module as the Earth Entry Module on the far-off Mars mission? What is the likely entry velocity on that mission? It only took me 30 minutes to think up all these unanswered questions – real engineers could probably draw up a much longer list.
If we compare this list of questions with the actual LockMart CEV design, we see that in almost every case they have chosen the most expensive, most massive, and most complicated option in each case. Partly this is because most of the design is inherited from the old OSP project, which had a lot of unnecessary requirements, grafted on to it. But if NASA had written reasonable specs for the CEV, LockMart couldn't have gotten away with this "Battlestar O'Keefe" design concept.
The RFP for CEV does contain detailed specifications in one area. The management and budgeting of the project is minutely specified, right down to the details of 129 different reports the contractor must submit. Here we see the dire effects of appointing a professional accountant as NASA Administrator. Sean O'Keefe was the right guy to reform the chaotic budgeting of ISS and Shuttle; he was the wrong guy to supervise a completely new program involving major hardware development.
Interestingly, all the questions about the RFP asked of NASA by potential proposers centered on minor financial details, not the complete absence of sensible technical specifications. This is strong evidence that the aerospace industry recognized from the start that CEV would never be more than yet another paper spaceship.
Rewriting the Lunar Script: The next section of the RFP gives the whole Constellation program the full "Battlestar Galactica" treatment. The proposers are given complete license to change the basic concept of Constellation and introduce all sorts of complications and extra spacecraft not mentioned in the original plan:
These IPP's are not meant to curtail innovation or alternate architectural concepts during Phase 1 activities. To that end, a set of focused cost and performance trades will be conducted prior to SRR against these IPP's to include:
Planning Plan Bush: How could such a useless document as the RFP for the CEV module have been produced? The main reason is that NASA doesn't yet know itself what it wants humans to do on the Moon after they return there. The overall framework of the Vision for Space Exploration is still in flux, with no firm goals or schedule which could have served as a guide to the authors of this document.
There are now no less than 28 – yes, 28 – advisory groups working on various aspects of the VSE. And they are working very hard, or at least debating very hard. One of my best friends is on two of these VSE planning panels and he recently returned from a meeting so exhausted that he slept for 13 continuous hours. To toughen himself up for future meetings he is going on the South Beach Diet.
These 28 panels are filled with distinguished scientists and engineers with impressive track records. But these experts are just as divided and faction-ridden as the rest of the space community. They all have their personal prejudices and agendas. Every possible school of opinion is represented on these panels, with a variety of views about what should be done at the Moon before we go on to Mars.
For instance, some are arguing that the Moon program should explore the physiological effects of 0.38g Martian gravity on the future Mars crew. This faction wants to require that a single Constellation crew stay on the Moon in a rad-shielded base for 12-18 months, performing similar scientific studies as the real Mars crew.
There are two obvious problems with this idea: A) the gravity on the Moon is only 0.15g so the results will not read over to Mars; B) the construction and maintenance of the Moon base will require huge amounts of supplies and spares. Since it costs about five times more to land a pound on the Moon as it does to lift it to LEO, supporting even four persons on the Moon is equivalent to supporting a 20-person ISS crew.
This idea is just the kind of unworkable subplot that could kill off Constellation. It shows no understanding of the real costs and difficulties of space operations. This medical study could be done far more cheaply and correctly by putting a prototype Mars ship hab module in LEO and spinning it to give the correct 0.38g.
It will probably be months or years before this mass of experts produces the definitive plan of exactly what we will do on the Moon and in what order. I shudder to think of what that plan might look like. The whole idea of 28 panels of experts meeting separately to plan such a project is ludicrous. No successful major technology project has been planned this way. This grandiose planning apparatus exists only in order to make every possible interest group feel like their opinions have been taken into account.
Graveyard Spiral Development: Another flaw in the 28 planning groups is that they are meeting too late. The Constellation modules are already being designed without the guidance of any overall program plan. And so the spacecraft may turn out to be inconsistent with the plan that finally appears and incapable of supporting it.
This crazy planning process is exactly the reverse of "Spiral Development". Steps that should be done in logical sequence are instead being done in parallel, in the style of Cold War crash projects. It's more like what pilots call a "Graveyard Spiral": the plane veers off from level flight into a fatal plunge so gradually that no one notices.
Fortunately, Mike Griffin seems to have recognized this and is shutting down the 28 panels. The next thing he should do is to pick about a dozen real experts, lock them in a room, and not let them out until they have produced a basic plan for returning men to the Moon. Then this plan should become the basis for a detailed requirements document for all elements of Constellation, not just the CEV.
Only after these basic planning tasks are accomplished and the results set in concrete can the engineers sit down to actually design real spaceships. The current system of designing hardware when the basic goals and structure of the program are still in flux is a prescription for disaster. The results can only be further delay, confusion, wasted effort, and a spacecraft in the classic battlestar style – unworkably complex, heavy, and too expensive to fly more than once every year or two.
And we can't afford to make that mistake. Every serious observer agrees that the Vision for Space Exploration is the last chance for NASA's manned space program. If it is a failure or even a partial success, it is unlikely that the post-Boomer American voting public would support a Mars mission or any super-expensive manned program.
And no other government on Earth is likely to continue with manned spaceflight if the sole hyperpower gives up on it. If the CEV turns into a battlestar, it will certainly be the last one built on the planet Earth. Jeffrey F. Bell is a retired space scientist.
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