Jon Goff has some more good posts up on exploration (and particularly lunar) architectures. Here’s a key point that undercuts NASA’s rationale for HLVs:

Why doesn’t NASA land enough stuff to support 4 people for 6 months on a single lander? Or 6 people for a year? Because it would require much too big of a lander, which would cost too much to develop, and way too much to operate. By making the lander smaller, and less capable, but using LSR, ESAS provides a much cheaper approach than trying to do a Battlestar Galactica scale lunar lander. However, you could see where that logic goes…

And Doug Stanley more or less admitted it. He said that had the 4 people for 7 days edict not been “blessed” by Mike Griffin as one of the ground rules, that EELV based architectures would have traded a lot better compared to the chosen ESAS architecture. And he’s right. All the numbers I’ve run show that you could probably do a reasonable 2-man lunar architecture using st0ck, or nearly st0ck EELVs (or EELV equivalents like Falcon IX if it becomes available).

They admit the need for assembly on the moon, because they know that (as Jon notes) it’s completely unrealistic to get a full-up base to the surface with a single launch of any vehicle short of Sea Dragon (come to think of it, that’s one HLV that I could get behind, because it’s innovative and wouldn’t necessarily cost that much). Now admittedly, it is easier to do assembly in a gravity field (though in some ways, it’s harder as well, since with weight, you need cranes, etc.). But it’s not so much easier that they should have ruled out doing orbital assembly, something that we need to learn to do anyway, and that they will have to do for Mars, even with Ares V.

Again, as Jon points out, the entire architecture, and justification for an expensive (in both development and operations) heavy lifter is based on an arbitrary requirement–four crew for seven days. Remove that constraint, and the trade space blossoms tremendously. But it apparently doesn’t satisfy political imperatives, whatever their source.

When NASA first proposed a single-SRB-based launcher, one of the issues that jumped out immediately to many familiar with vehicle design and Shuttle design was roll control. As designed for the Shuttle, there are two SRBs, both of which can gimbal the engines. This allows roll control of the Shuttle stack by gimbaling them in opposite directions. But when there’s only one, the engine gimbal provides pitch and yaw control, but there’s no way for it to control roll.

There are two potential solutions to this–to modify the SRB itself to add roll-control thrusters, or to incorporate them into the new upper stage. The latter has the disadvantage of oversizing the roll-control system for the period after stage separation, which adds weight and affects performance, but it simplifies design by requiring only one system.

In any event, the concept seems to be in trouble. Now this certainly isn’t a show stopper, and issues like this are inevitable in the development of a new launch vehicle, but it’s just one more demonstration of the fact that deriving a new launcher from existing pieces isn’t as easy as has been advertised by many, both within and out of the agency.

[Late morning update]

Gary Hudson emails one other option:

There is a third possibility: let it roll. Depending on the rate and duration, it may not be a problem. Some current vehicles do this (Taurus, for one) and we are planning a subset of it for the AirLaunch QuickReach. In our case, we have a Stage Two roll thruster but its purpose is to limit the rate, not hold a specific roll attitude. Makes for a much small thruster. It is later used as part of the normally smaller sized Stage Two attitude control subsystem.

When NASA first proposed a single-SRB-based launcher, one of the issues that jumped out immediately to many familiar with vehicle design and Shuttle design was roll control. As designed for the Shuttle, there are two SRBs, both of which can gimbal the engines. This allows roll control of the Shuttle stack by gimbaling them in opposite directions. But when there’s only one, the engine gimbal provides pitch and yaw control, but there’s no way for it to control roll.

There are two potential solutions to this–to modify the SRB itself to add roll-control thrusters, or to incorporate them into the new upper stage. The latter has the disadvantage of oversizing the roll-control system for the period after stage separation, which adds weight and affects performance, but it simplifies design by requiring only one system.

In any event, the concept seems to be in trouble. Now this certainly isn’t a show stopper, and issues like this are inevitable in the development of a new launch vehicle, but it’s just one more demonstration of the fact that deriving a new launcher from existing pieces isn’t as easy as has been advertised by many, both within and out of the agency.

[Late morning update]

Gary Hudson emails one other option:

There is a third possibility: let it roll. Depending on the rate and duration, it may not be a problem. Some current vehicles do this (Taurus, for one) and we are planning a subset of it for the AirLaunch QuickReach. In our case, we have a Stage Two roll thruster but its purpose is to limit the rate, not hold a specific roll attitude. Makes for a much small thruster. It is later used as part of the normally smaller sized Stage Two attitude control subsystem.

When NASA first proposed a single-SRB-based launcher, one of the issues that jumped out immediately to many familiar with vehicle design and Shuttle design was roll control. As designed for the Shuttle, there are two SRBs, both of which can gimbal the engines. This allows roll control of the Shuttle stack by gimbaling them in opposite directions. But when there’s only one, the engine gimbal provides pitch and yaw control, but there’s no way for it to control roll.

There are two potential solutions to this–to modify the SRB itself to add roll-control thrusters, or to incorporate them into the new upper stage. The latter has the disadvantage of oversizing the roll-control system for the period after stage separation, which adds weight and affects performance, but it simplifies design by requiring only one system.

In any event, the concept seems to be in trouble. Now this certainly isn’t a show stopper, and issues like this are inevitable in the development of a new launch vehicle, but it’s just one more demonstration of the fact that deriving a new launcher from existing pieces isn’t as easy as has been advertised by many, both within and out of the agency.

[Late morning update]

Gary Hudson emails one other option:

There is a third possibility: let it roll. Depending on the rate and duration, it may not be a problem. Some current vehicles do this (Taurus, for one) and we are planning a subset of it for the AirLaunch QuickReach. In our case, we have a Stage Two roll thruster but its purpose is to limit the rate, not hold a specific roll attitude. Makes for a much small thruster. It is later used as part of the normally smaller sized Stage Two attitude control subsystem.

I’m going to be very interested in this briefing on lunar architectures next week.

George Abbey, who ran NASA’s manned spaceflight program in the Goldin years, seems to be attempting to position himself to replace Mike Griffin with the advent of a Democrat administration. There are some grammar problems with this report of a recent speech by him (it reads sort of like a live blog of the speech). I know that you will all be shocked to hear this, but he doesn’t want to replace the Shuttle–he wants to keep operating it:

The space program needs realism, Abbey said. Putting an end point on the shuttle forces NASA to focus all of its remaining missions on the space station, giving little leeway for other missions.

What other missions? Other than Hubble, what does he have in mind? Surely he doesn’t think that we can afford to do deep space exploration with it as a launch vehicle?

If we don’t retire it, how long does he expect to be able to keep operating it? What happens when (not if) we lose another orbiter?

The major difference between the two craft, Abbey said, is versatility a handy attribute when working in space [sic–I assume that there is supposed to be some kind of punctuation after the word “versatility”]. (Orion) is not as capable as the shuttle it cant [sic] do any of the things the shuttle can do.

Well, it certainly can’t do all the things that the Shuttle can do, but it can certainly (at least in theory) deliver crew to space and back, which is one of the things that the Shuttle can do. Whether or not it even should be able to do all of the things that the Shuttle can do is barely even debatable any more, given the consensus of most observers of the program that a primary problem with Shuttle is that it had too many conflicting requirements. This is thinking right out of the early seventies, and it’s also thinking born of a career at NASA, in which it is automatically assumed that we can only afford one vehicle type, so it must do everything (ISS was severely crippled by this attitude as well). And of course any system that has to have so much capability, if it’s possible at all, will be very expensive to develop and operate, so the notion that we can only afford one becomes a self-fulfilling prophecy.

I find his concern about other space nations misplaced. Certainly China isn’t going to make any great strides at their current place. And his spinoff argument is typical NASA fluff. The only thing he says that I agree with, in fact, is about ITAR (at least I assume that’s what he’s talking about when he says):

First, Abbey said too much government red tape is making it very difficult for wanting nations to purchase satellites from the U.S. The red tape is forcing nations to other competitors those competitors are surpassing us.

Of course, it’s hard to know exactly what he said, or meant, given the quality of the reportage.

I’ll probably have some commentary on this when I get more time (i.e., when relatives aren’t visiting for the weekend), but Jon Goff has an interesting post on some candid comments by Doug Stanley on ESAS. I’m sure that Doug is sincere in his beliefs that a) Mars is more important than the moon and b) ESAS is the best way under the political circumstances to make it happen. But I think he’s wrong on both counts, and more importantly it is not his place (or even Mike Griffin’s) to make policy. If he has problems with VSE as stated, and wants to do a touch and go on the moon (ignoring the president’s directive), he should work to get the policy changed, rather than pervert the architecture in his preferred direction without such a debate.

[Update on Monday morning]

More interactions with Dr. Stanley, from Keith Cowing.

Jon Goff is unaccountably questioning the value of his blogging. I haven’t been linking to him as much as I should, but he has been putting up a lot of well-thought-out and thought -provoking posts on potential space architectures that would be far superior to NASA’s current plans. Head over there and tell him to keep it up.

I do second the recommendation to get off Blogspot, though. If nothing else, it would allow him to post his URL in comments here.

Clark Lindsey notes that the FAA-AST web site has been revamped, by folding it into the general FAA web site. While the improvements he notes are worthwhile (though the changing of permalinks definitely is not), I’m unthrilled with the concept of entwining AST even more deeply with the FAA. AST was originally the Office of Commercial Space Transportation, reporting directly to the Secretary of Transportation. The Clinton administration demoted it, and folded it into FAA in the early nineties.

This had two deleterious effects. First, it gave it less clout within the department, since the AA for it now had to report to the SecTran up through the FAA administrator. Second, it placed it in an agency that, after the Valujet crash, had its responsibility declared solely for public safety, with none to promote the aviation industry (one of its charters in the early days).

But the infant space transportation industry needs a different balance between safety and promotion than a mature aviation industry, and there is a potential clash of regulatory cultures as long as AST remains within FAA. Its current bureaucratic abode makes it much easier to justify nannyism that could strangle it in the cradle. I think that there should be a push on by the space activist community to restore it to its original position as a separate administration within DOT, and I’m not happy whenever I see its status as a subset of FAA further entrenched.

Right after the election, I pointed out one of the less-obvious consequences of it–Jim Oberstar’s potential strangling of an infant industry in the cradle. Taylor Dinerman expands on the thought today.

In spite of some weasel wording, the hard legal requirements of Oberstar