The front-page article in this week’s issue of Space News (not available online) summarizes some technical changes NASA has made to the Crew Exploration Vehicle and Crew Launch Vehicle. Most of those changes have been publicized elsewhere, including a decision to drop the requirement for a methane/LOX engine for the CEV and lunar module ascent module. NASA has also elected to go with a five-segment SRB for the CLV and use a J-2S engine, rather than a modified SSME, for the upper stage. (The heavy-lift launcher will also use five-segment SRBs and J-2S engines for its upper stage.) NASA has also shrunk the CEV somewhat to save weight, decreasing its diameter from 5.5 to 5 meters. (That decision has, according to one source, put the two teams competing for the CEV contract into “total chaos”.)
These decision, particularly the five-segment SRB and J-2S changes, have ramifications for the NASA budget. As the Space News article notes, that propulsion combination “entailed more up-front expense and technical risks, but would be cheaper over the long-run.” That’s why NASA originally went with a four-segment SRB and modified SSME. NASA claims that the amount of technical risk remains the same since the agency has dropped the methane engine requirement, and the five-segment SRB and J-2S are not wholly untried technologies. NASA officials declined to comment on the budget implications of the change in advance of the release of the President’s FY07 budget proposal, but the last thing NASA needs right now—as it grapples with a shuttle funding shortfall of several billion dollars—is additional near-term expense for its cornerstone exploration programs, even if those decisions promise savings over time. Will Congress be willing to open its pocketbook a little wider in such an environment if NASA needs it?
I understand the necessity for the fuel and booster changes, however, I am troubled by the reduction in the size of the capsule from 5.5 to 5 meters in diamater. The capsule choice made in the CEV architecture was never very spacious. With this change, essential activities such as having four crew members putting on or taking off an EVA suit are going to be extreemly difficult in a down-sized CEV. This may mean that astronauts will either have to live in their space suits fo the duration of the voyage — an unpleasant prospect at best — or not wear them at all, an even more unplesant alternative. This, of course, doesn’t even address the basic crew living space requirements which were tight even in 5.5 meter diameter version of the CEV. It seems to me that this change, more than the others, will be almost impossible to modify or correct as we move to longer duration missions and the limited space inside the capsule becomes a potentially crippling limitation.
Bob: “With this change, essential activities such as having four crew members putting on or taking off an EVA suit are going to be extreemly difficult in a down-sized CEV.”
At 5 meters the CEV will still be over twice the volume of the 3.9 meter Apollo where 3 crew members got into and out of EVA suits, so why would 4 crew have a problem doing the same with a 5 meter CEV?
Cecil: Twice the volume, but also an extra crew member and good deal more to cram inside. In addition, I heard an interview with Gary Harris, a key designer of the Apollo space suit, and apparently the top man in the space suit design field. He was very troubled at the possibility of having four astronauts trying to put on the new EVA suits (which apparently are significantly bigger and heavier than the Apollo version) in the 5.5 meter CEV. There is no gurantee that the next generation suits will be smaller and lighter according to him. Also, remember, the objectives for the CEV are a good deal more ambitious than they were for the Apollo module. I suppose it is possible to shift some of the oxygen and fuel stores from inside the CEV out to the service module which now has only the RCS thrusters, the main rocket engine, the fuel needed to send it back to earth, and the solar cell array. That might give them the extra room to maneuver inside the CEV. I am certainly no expert on this, but it seems like a disturbing turn of events.
I’ll boil it down for everybody: NASA has no design, and no idea how to design its new space craft and launch missiles.
Dr. Mickey M. Griffin’s only fixed principles are:
(1) Apollo worked, so retro Apollo on steroids must be the right approach;
and
(2) keep Thiokal, his future, post-NASA emploeyr, happy.
Asinine, juvenile posts filled with grade school playground name calling like the above by Mr. Davenport are the main reason I rarely bother to visit here anymore.
Cecil, I fully agree! While I often agree with David’s propulsion views, his arrogent, aggressive, and self-important delivery makes it very difficult to take him seriously.
Regarding the propulsion changes, I’m not sure why the new version should cost that much more than the earlier design. Doesn’t this remove the requirement for an altitude start of the SSME, which I understood to be a non-trivial development project? Haven’t five-segment SRBs been successfully fired? The J-2 needs to be re-developed anyway.
I’m more conserned about the loss of the methane engine, not least because we need new engine development to keep the propulsion contractors in business. I fear that Aerojet will leave the business if they don’t have a shot at a new development.
Regarding the new capsule size, will the more efficient avionics, and reduced cooling requirements, take less space?
— Donald
LOL, I can see this coming:
NASA will screw this up, just like they screwed up the next gen RLV. After multiple and massive budget overruns, bad design and management- decisions, they will finally come to the conclusion that ” going to the moon is not possible with todays technology”.
CU
Skipjack
Do you work for Thiokal or a Thiokal-related vender, Cecil?
” going to the moon is not possible with todays technology”
You’re right. For example:
This may mean that astronauts will either have to live in their space suits fo the duration of the voyage — an unpleasant prospect at best — or not wear them at all, an even more unplesant alternative. This, of course, doesn’t even address the basic crew living space requirements which were tight even in 5.5 meter diameter version of the CEV. It seems to me that this change, more than the others, will be almost impossible to modify or correct as we move to longer duration missions and the limited space inside the capsule becomes a potentially crippling limitation.
Obviously, travel to the Moon is not feasible without a crew capsule larger than 5.5 meters in diameter. :0\ !
Nope, can’t go fly to the Moon in a austere peewee aluminum can like the item below.
We’re more sophisticated now, and the proposed new CEV has to fulfill many additional functional requirements.
Bloatware? Don’t know what you’re talking about.
Other Designations: Command Module. Part of: Apollo CSM. Class: Manned. Type: Spacecraft Module.
Crew Size: 3. Length: 3.47 m. Basic Diameter: 3.90 m. Maximum Diameter: 3.90 m. Habitable Volume: 6.17 m3. Mass: 5,806 kg. Structure Mass: 1,567 kg. Heat Shield Mass: 848 kg. Reaction Control System: 400 kg. Recovery Equipment: 245 kg. Navigation Equipment: 505 kg. Telemetry Equipment: 200 kg. Electrical Equipment: 700 kg. Communications Systems: 100 kg. Crew Seats and Provisions: 550 kg. Crew mass: 216 kg. Miscellaneous Contingency: 200 kg. Environmental Control System: 200 kg. RCS Coarse No x Thrust: 12 x42kgf. RCS Propellants: N2O4/UDMH. RCS Isp: 290 sec. RCS Impulse: 26,178.00 kgf-sec. Main Engine Propellants: n/a. Main Engine Propellants: 75 kg. L/D Hypersonic: .3. Electrical System: Batteries. Electric System: 20.0 kWh. Battery: 1,000.0 Ah.
http://www.astronautix.com/craft/apollocm.htm
Astronauts at NASA will feel cheated if they go from the shuttle to this. The shuttle is the Winnebago of human spaceflight. This is more like a Ford Echo with no windows.
The biggest problem is that the change in size is putting the entire program 6 months behind. After a huge number of man hours by the two teams they are now asked to cram everything into a smaller sized can. This is only three? months before the proposals are due.
Requirements changes are anathama to any program seeking to maintain schedule and remain on budget. The further this gets delayed the larger the probability that the program will be killed, either post 2006 congressional elections or after election 08.
Mike Griffin was in the senior exploration position the last time around this game and ought to have enough sense to know that he is killing the effort with all of these changes.
As far as the CLV goes it does not matter as much as Thiokol just got their contract underway a few weeks ago but there has been a huge amount of effort by the two contractors on the CEV.
The only real excuse for downsizing the CEV is for that inevitable day when they realize that the CLV is not going to be able to be built for anywhere near the costs envisioned and that they will have to back up and use the EELV heavy birds.
Astronauts at NASA will feel cheated if they go from the shuttle to this.
And we should care… why?
Paul: Of course you should realize that I don’t mind. The point is that it is yet another contradiction in the strategic plan. The astronauts are influential in this illogical business.
100 billion dollars to put four men on the moon (presumably the equator, no less) 15 years from now. Mars in 30 years in a capsule? Anone with any brains at all here, can easily see how only an overly patriotic, paranoid American fascist can see the logic of this.
“STS-114 pilot Jim Kelly has stated he’d be happy to give up a possible role as a commander on one of the remaining Shuttle missions, if it resulted in gaining a seat on a debut flight of the CEV (Crew Exploration Vehicle).”
http://www.nasaspaceflight.com/content/?id=4169
You may now return to your usual idiocy.
We could put a lightweight CLV capsule on the Delta IV MEDIUM now. My guess is that is Boeing’s backup COTS plan anyways.
Bob commented to Cecil about EVA suit-donning volume needed: [CEV has] Twice the volume [of Apollo], but also an extra crew member and good deal more to cram inside.
I’ll add that the Apollo suitup volume was effectively somewhat larger since they were in zeegee, and could use all the volume and orientations available. An LSAM cabin crew at 1/6th Eegee and all psuits oriented in the same direction will be wasting a significent portion of its total volume in a simultaneous suitup
Spike R. MacPhee
100 billion dollars to put four men on the moon (presumably the equator, no less)
Nope, lunar south pole.
Astronauts at NASA will feel cheated if they go from the shuttle to this.
And we should care… why?
Does it bother anyone that the prposed Apollo on steriods will only be able to land at Edwards or some other location near the Pacific? Landings at Kennedy will not be possible. That’s OK with everyone?
Landings at Kennedy will not be possible. That’s OK with everyone?
One-way airfare for the astronauts back from Edwards will not break the bank. Any hardware that’s going to be reused is going to be salvaged and sent back to the factory for refurbishment, won’t it?
They gotta go to Houston anyway.
Being experts on aerospace matters, you fellows are aware that the Apollo on Steroids (TM) capsule will be too big to load inside a C-5 A or B?
Cargo Compartment Height 13 feet, 6 inches (4.10 meters); width 19 feet (5.76 meters).
C-5A/B Galaxy
…
Specifications
Primary Function strategic airlift.
Contractor Lockheed-Georgia Co.
Power Plant Four General Electric TF39-GE-1C turbofan engines.
Thrust 41,000 pounds (18,450 kilograms), each engine.
Length 247 feet, 10 inches (75.3 meters).
Height At Tail 65 feet, 1 inch (19.8 meters).
Maximum Takeoff Weight 769,000 pounds (346,500 kilograms).
Maximum Wartime Takeoff Weight 840,000 pounds (378,000 kilograms).
Takeoff/Landing Distances 12,200 feet (3,697 meters) takeoff fully loaded;
4,900 feet (1485 meters) land fully loaded.
Wingspan 222 feet, 9 inches (67.9 meters).
Stabilizer Span 68 feet, 9 inches (20.8 meters).
Cargo Compartment Height 13 feet, 6 inches (4.10 meters); width 19 feet (5.76 meters).
Range 5,940 miles (5,165 nautical miles) empty.
Ceiling 34,000 feet (10,303 meters) with a 605,000-pound (272,250-kilogram) load.
Speed 541 mph (Mach 0.72)
Load 291,000 pounds (130,950 kilograms) maximum wartime payload
Sling load it under a chopper.
For that matter, ship it as an oversize load on the interstate system.
SupperGuppy or one of those big Ruskie Transports too.
Paul: Of course you should realize that I don’t mind. The point is that it is yet another contradiction in the strategic plan.
Or perhaps not.
The astronauts are influential in this illogical business.
Evidently not as influential as you think.
I’ll add that the Apollo suitup volume was effectively somewhat larger since they were in zeegee, and could use all the volume and orientations available. An LSAM cabin crew at 1/6th Eegee and all psuits oriented in the same direction will be wasting a significent portion of its total volume in a simultaneous suitup
Don’t confuse the CEV with the LSAM – they are two separate vehicles. This CEV design change has no bearing whatsoever on LSAM suiting.
This is more like a Ford Echo with no windows.
If that’s what we can afford, that’s what we should build.
I am undecided on whether this is good or bad news. The re-redesign is undoubtedly bad news. However, I have always supported a smaller capsule that can launch on any medium-class vehicle. That give’s you the maximum flexibility and lowest launch costs. So, they’ll be a bit uncomfortable on the way to the moon. Build them a bigger shelter at the other end. Put your money on the moon, not the transportation. . . .
— Donald
Actually, they should be quite comfortable on the way to the Moon considering the additional volume of the LSAM coupled with the CEV will dwarf the per-Astronaut volume of Apollo CM-LM combined.
Things might be a bit cramped on the way back, however but it appears they should still have more usable per-Astronaut volume than with the Apollo CM.
For those who ignore facts that don’t agree with their preconceived notions (AKA Mr Davenport):
“The Super Guppy’s cargo compartment is 25 feet tall, 25 feet wide and 111 feet long. The aircraft can carry a maximum payload of more than 26 tons. It has a unique hinged nose that can open more than 200 degrees, allowing large pieces of cargo to be loaded and unloaded from the front.”
Yikes, another supposed “problem” solved!