Posted on 08/02/2005 8:56:13 AM PDT by jbstrick
For its next generation of space vehicles, NASA has decided to abandon the design principles that went into the aging space shuttle, agency officials and private experts say.
Instead, they say, the new vehicles will rearrange the shuttle's components into a safer, more powerful family of traditional rockets...
..."As long as we put the crew and the valuable cargo up above wherever the tanks are, we don't care what they shed," he said. "They can have dandruff all day long."...
...A main advantage, supporters say, is that the big rocket could lift five or six times as much cargo as the shuttle (roughly 100 tons versus 20 tons), making it the world's most powerful space vehicle. In theory, it would be strong enough to haul into orbit whole spaceships destined for the Moon, Mars and beyond....
(Excerpt) Read more at nytimes.com ...
The escape rocket is vectored along a path away from the direction of the launch vehicle. In the case that the launch vehicle is rotating and going in unknown directions, the vector of the escape system could be anything and the result would be successful unless the booster happens to veer in the exact wrong direction at the wrong time. Odds of that are very small.
>> ... solids can't be throttled or shut down
> Actually it's done all the time. They blow a hole
> in the end opposite the nozzle.
But not while the solid is still attached to a stack,
manned or otherwise.
As I look at the proposed Crew Vehicle, I'm seriously
wondering under just what scenarios, and during which
windows the use of the escape rocket is a survivable event.
As opposed to sending a brickyard into orbit?
That always bothered me about the Space Shuttle. Or lack of that.
> I guess they were just wasting their time with
> these vehicles then...
Not at all. Those escape systems sat of top of liquid
boosters, which could be shut down to allow the escape
system to get away.
The shuttle's 3 main engines can be throttled. The boosters are going full blast but the mains can be throttled back for an overall loss of thrust.
I think they're planning a chained-link of B6-4s... Shouldn't hit much more than 4-5 G.
Plus it fills the need for both a passenger vehicle and a useful cargo hauler.
What we have in the space shuttle is akin to a six door pickup truck. It can carry people and stuff, but it isn't the best for either job. :)
The PDF shows the size relative to an alternative lift plane, a modified 747 (with REALLY LONG landing gear). It's not as big as you think, though considerably bigger than SS1.
I wouldn't be a bit surprised to see Rutan/Branson pursue this one themselves, anyway. Who says all of the NASA launches have to be on the NASA built system? If they can demonstrate the capability AND undercut the per launch cost... well, even NASA isn't that dumb... all the time...
Why a 747? Aren't there any B-52's available?...
Invest in Gravitational Potential Energy.
It's moving up!
An exploding liquid booster cannot be "shut down." Those towers were designed to get the capsule away from the stack in the event of a catastrophic booster failure. yes, there was a finite chance that the vehicle would not get away quickly enough, but factor in directional changes and it gave the crew a chance, more than they have now with STS.
> And therefore proposed continuing business for his employer.
Actually, got that backwards: before he came here to ATK, he and other astronauts were proposing to fly pretty much what's being shown. So he came to ATK to get it done, since LockMart and Boeing weren't going to do it.
> I actually think that using solids might be more reliable and potentially safer than liquids.
Quite true. As far as American launch vehicle stages, solids have a better reliability than liquids.
> The escape rocket is vectored along a path away
> from the direction of the launch vehicle.
That presupposes that the capsule is uncoupled from the
upper stage. If the S1 booster is still accelerating,
separation may be impossible, regardless of the intended
escape vector.
I'm sure the NASA sliderules are working on all of this,
but right now, this looks a lot like the ejection seats
on STS-1 and the bail-out procedure for recent flights.
Successful scenarios were unlikely, and even they had
very narrow windows of execution.
I'd rather see NASA man-rate one of the ELVs, and run it
until the first space elevator is up.
I picked up a chunk of solid rocket fuel from a rocket that had exploded at the pad. A few pounds of sort of rubbery compound, yellowish and not particularly grainy. I took it home and put it in the woodstove and burned it. It wasn't easy to get it to burn and it burned hard--took a good roaring wood fire. Even then, I don't think it added much to the fire, but it did combust fully eventually.
So after 20 plus years, we are going back to the man in a can rocket shot.
All in all, not a bad idea.
> if they can ever get around the solids having only two power settings
Solids *are* throttlable. Back in the '60's Aerojet and Thiokol built competing solids that could throttle on command, stop, and restart. Complex, but doable.
And the Shuttle SRB has a programmed thrust/time trace. It's not "full blast" until burnout.
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