Ed Kyle has an overview of Mike Griffin's plans for a Shuttle-derived launch architecture.

I think that it's a mistake to maintain the expensive Shuttle infrastructure, and an even bigger one to make the president's vision dependent on heavy lift vehicles, particularly when there's only one type, with no resiliency. But as Ed points out, politically, there are a lot of influential congresscritters with Shuttle employees in their districts, so pork may rule the day once again.

It's a pity. The VSE was one of the few Bush policies that I could actually almost find myself supporting--it did have some real potential. But it seems that in their rush to get things moving, they're doing it all wrong. This fetish with Heavy Lift, the silliness about putting a capsule on an SRB, having LRO be yet another in-house developed space probe, etc, etc. The VSE had a lot of potential for actually helping nurture and aid a real cislunar economy, but all of that is being killed slowly by Griffin and company.

The sad thing, is that with all this rush to get something that will be cheap and quick, they're going to find out that it wasn't cheap at all, and will end up taking more time than relying more heavy on those scary unproven enterpreneurial space firms....

Still wouldn't be surprised if the next person to
walk on the moon was a space tourist instead of a
NASA astronaut.

~Jon

Shuttle-C was always a much better idea than what we have now. There's too much energy wasted hauling all that living space up to orbit, and it all has to be dissipated, hopefully without killing the astronauts, before it can come home. Now that we have space station, there is no reason not to put men in space in small Apollo style capsules. Get rid of the shuttle, and the space station finally has a purpose again, the same purpose Von Braun envisioned for it 40 years ago.

As for this "we don't need a heavy launch vehicle" stuff. What are you thinking? Do you have any idea how hard it is to assemble something like a space station when you send it up 40,000 lbs at a shot? Space walks are not like a walk in the park. Also, you have many integration issues that are difficult to address on-orbit. It's hell to find out on-orbit something doesn't fit, or a signal wire has the wrong impedance, or any of a million other things that can go wrong has. The less assembly required on-orbit the better. If we learned any thing from station, it's that.

Alt-space is great, and their ideas, like air breathing first stages, are really good, but don't let your politics get in the way of what makes sense. If you're going to do that, how is alt-space any different from what we've got now?

Orbital assembly is easier than building giant rockets. Just ask the Russians.

As for this "we don't need a heavy launch vehicle" stuff. What are you thinking?

I'm thinking that we shouldn't make the program dependent on a large, expensive launcher which, if it has to stand down for some reason for an extended period of time (as Shuttle has twice now), we have no capability to keep the program going.

Do you have any idea how hard it is to assemble something like a space station when you send it up 40,000 lbs at a shot? Space walks are not like a walk in the park.

No, not when NASA has refused to spend the money to develop decent EVA equipment.

The less assembly required on-orbit the better. If we learned any thing from station, it's that.

If that's what you learned from station, you learned the wrong thing.

to Brad: close. the problem is not the rockets per se, more like the engines which power them.

Engine development is always the most hard and hence expensive part of space launch vehicle design.

The Shuttle was an interesting research project, but ended up being a tremendous waste of money. Doing a family of rockets based on Saturn V technology would have been cheaper and better.

But that was then and this is now. Suposedly they need a Shuttle replacement by 2010. If this is to be done, it is foolhardy to go developing a new engine, or trying to ressurect an engine not in production at this point.

There are off the shelf high performance, reasonably cheap, engines for doing a Moon launch system already. RS-68, RD-180, RL-10.

I think it is perfectly possible to develop a new medium/high lift Moon launch system using this off the shelf technology by the 2010 deadline.

You could do something like a cross of Energia and Ariane 5 or H-2A. The structure would look like Ariane 5, a center body with RS-68 engine(s) and RD-180 strapons. You could have 0-4 RD-180 strapons, with hybrid strapons (sort of like SpaceDevs SSOne engine) as a possible cheaper, low performance, strapon option. The RD-180 strapons could theoretically be reused.

Or you could just the Atlas V Heavy. With a beefed up second stage probably using RL-60s. I suspect it would be cheaper since it needs less engine types.

The problem with doing many launches and in-orbit human assembly is that you need the capacity to either do many launches in rapid succession or have a long loiter time. Humans need food, water, air and shelter, so they do not have a long loiter time unnatended. The inception of the Space Station idea was precisely so you would have a place for humans to rest while doing on-orbit assembly (Space Station Freedom). One reason the station is a miserable failure is simply because the station and the people inside it constantly need lots of consumables from Earth.

If you want in-orbit assembly, you want components with simple standardized interfaces and possibly dimensions, outside and inside (like a ships container), plus automated in-orbit assembly. The humans only go up after the whole thing has built itself, just before it is time to travel to the Moon, or whatever.

By automated in-orbit assembly I do not silly maintenance droids. Like the prepubescent drooling fantasy illustrations I have seen from NASA. The components need to have a kick stage engine anyway. So they have their sea moving legs already, so to speak. Just make them connect together like Progress connected to Mir. To unfurl solar panels you do not need humans either. Satellites have solar panels and no humans go there to unfurl them. This laborious inane 60s idea of how to do in-orbit assembly sometimes drives me nuts.

I mean... space walk moving parts from the Shuttle, use Shuttle arm to move parts, use astronaut to monkey around with bolts, etc. People are expensive, computers are not.

Right, nearly forgot:

The designers call it "The Stick". I call it "The Stick of Dynamite".

:-D

There's doing and there's talking about it.

Gojira is right, there are a lot of problems with on-orbit assembly. Better EVA suits would be great, and are very possible, but develop those separately, don't hinge the future of space exploration on pie-in-the-sky. If you can't get to space, what difference does it make if you have the coolest EVA suit ever?

Heavy lifters are a necessity. They allow large scale integration of the payloads on the ground, where integration is relatively cheap. The man-hours for assembly are relatively cheap. The odds of killing expesive and highly visible astronauts is much lower. Also, a heavy lift vehicle can put a decent size payload on the Moon. Doing something like a Moon shot at less than 40,000 lbs per shot to orbit would be a recipe for disaster. If you take 40,000 to LEO, only 5,000 lbs makes it to the Moon. Does anyone here want to assemble a lunar mission in 5,000 lb chunks?

Let's face it, your problem with the heavy lift vehicles is not technical. It's the fact that the programs that support them take on a life of their own. Wouldn't it be better to deal with that problem directly instead of making your technical solution accommodate the political realities we are forced to put up with today? It was not always like this, and it doesn't have to be this way now.

Well, I see 25t to a 200km LEO parking orbit as 'heavy lift'. 15t medium and 5 is light. Anything above 25t is insane and a luxury (but useful in space races). So in that sense it's a neccessity. It's a matter of context, I suppose. On-orbit assembly with the proper long term architecture (tugs, depots, solar power generators, ...) , or even as it is now isn't hard. Misconnecting wires in zero-G?! How is it different to misconnecting wires or dropping entire multimillion dollar components on the floor in 1G when doing the assembly on the ground?

The only serious argument for the magic number 100 tonnes to leo I've seen is "Apollo was like that, we have the shuttle system it's a mistake to throw it away like the Saturn 5, etc.." I.e. nostalgia. Since the CEV payload(s) have not been yet designed, how can you claim that you *must* have a rocket of such and such capability?!

Perhaps it's a reflection of what I see as a change in (the perception of?) the goals of the VSE? It used to be "President wants *sustainable* space exploration -- LEO, The Moon and beyond" (emphasis mine). Now the interpretation and the tone has changed a bit into "President's directives to *return* to the Moon and close the gap after the sts pronto"

Quite a difference, you'll agree, and so the technical solutions chosen reflect that.

There is one basic point that we should all agree on and that is that spaceflight is and will be for several generations to come, both expensive and dangerous. If we are ever going to explore space, we will need heavy lift to haul all our stuff in orbit. For the best cost effectiveness the BUB (Big Ugly Booster) will be the way to go.

But as Ed points out, politically, there are a lot of influential congresscritters with Shuttle employees in their districts, so pork may rule the day once again.

Pork spending on space - why does this pop into my head?

On a more serious note...I've heard speculation on building a linear accelerator to launch unmanned payloads into orbit (the G forces would be deadly to humans - unless the accelerator is incredibly long). How close are we to having the technology, funding, etc. to make this a practical consideration?

There is one basic point that we should all agree on and that is that spaceflight is and will be for several generations to come, both expensive and dangerous. If we are ever going to explore space, we will need heavy lift to haul all our stuff in orbit. For the best cost effectiveness the BUB (Big Ugly Booster) will be the way to go.

Just because you think that we should all agree on something is not a compelling argument. I agree with none of your statements. Space doesn't have to be either expensive or dangerous, and certainly heavy lift does nothing to ameliorate that situation.

I agree with you regarding space not having to be expensive or dangerous. That's just the excuse we get from the old guard aerospace companies trying to justify their failures - in conjunction with NASA, of course. Their relationship is so incestuous it is hard to tell where one starts and the other ends.

As for defining "heavy launch" capability as 40,000 lbs, that's great if you never plan on going anywhere besides LEO. The Apollo designers didn't decide on 260,000 lbs to LEO because they thought it was a cool number. That was the minimum payload capability required to put a vehicle into orbit that could get to the Moon and back. To start a lunar colony, you'd want a much more substantial number. Multiple launches would work, but you seriously think we are going to establish a Moon base in 5,000 lb chunks or less?

"How is it different to misconnecting wires or dropping entire multimillion dollar components on the floor in 1G when doing the assembly on the ground?"

The difference is obvious. To date, there are no Radio Shack retail stores on-orbit, low or otherwise. Digi-key will ship there, but they are waiting for FedEx to step up.

200 km is now an acceptable LEO? How did you arrive at that? It is too low to be useful commercially. The goal for the shuttle was more like 200 miles (or was it 250 miles?). Just one more thing they failed at. Now people are wondering why anyone would want more altitude. I am always amazed at the process by which failure becomes orthodoxy.

I'm not convinced that a Shuttle-derived heavy lifter would have expensive operation costs similar to the Shuttle. I mean, if you take out the Orbiter and all of the effort spent refurbishing it after every flight (TPS, toxic fuels, and other things), surely that would save a lot. Do the SRBs and ET cost much to build and prep, comparatively?