NASA bringing back the capsule??

[jetra2]

Hi,

I heard from a friend that NASA is bringing back the capsule design, some thing about a higher safety record, I think the Shuttle has a 98% safety record, while the capsule was 99%.....

Does anyone know anything about this???

Jason

 

[Justy]

One of the four designs for the Orbital Space Plane, intended to be a kind of Honda Civic of space (a cheap people-mover) compared to the pickup truck that the shuttle was meant to be, is a capsule. The other three designs are closer to what we'd recognize as a mini-shuttle. Here's a picture of all four designs.

It seems to me that saying that delta-wing spaceplanes are unsafe right now is kind of like saying that all hatchbacks are unsafe because a couple of Pintos that were rear-ended at highway speeds exploded in the 80's.
(I've been in a Pinto that was rear-ended, and I'm still alive.)

Furthermore, I'd say your safety figures are inaccurate.

Consider that the shuttle had more than 100 launches. Of those, there have been two failures, and one of those (Challenger) was a failure of the booster and not the spacecraft itself. 2 failures in more than 100 gives us better than 98% reliability. We get better than 99% if we only look at the shuttle itself.

There have been four failures in American capsule-type spacecraft (two unmanned Mercury missions with booster problems, Apollo 1 and Apollo 13 with capsule problems), with 54 launches (by my count, 14 Mercury, 19 Gemini, 17 Apollo, 3 Apollo-Skylab, 1 Apollo-Soyuz... I guess Apollo 1 wasn't technically a launch, but it was a capsule and 3 men died in it). 50/54 = 92.5% reliability. If we ignore the boosters and only look at the capsules, we get 52/54 = 96%.

~98% > 92.5%; the shuttle system has been more reliable than the capsule & booster system.
~99% > 96%; the shuttle itself has been more reliable than the capsules flown.
CONCLUSION: In the American space program, capsules are LESS reliable.

I haven't counted failures in the Soviet capsule program, because I don't have data for them.

 

[graylensman]

I think right now NASA's looking at all possible options for replacing our aging Shuttle fleet. Justy's numbers aside, the Orbiters were designed for about 100 missions. If memory serves, Columbia was at or near mission 100. So even given that the accident apparently is due to tank foam striking the wing, she was close to retirement - or unreliability.

The project initially chosen to follow in the STS footprints ran WAYYYY overbudget and never even got as far as creating a full-sixed testbed vehicle before it was cancelled.

The shuttle itself never delivered on its original billing - a reuseable space vehicle capable of providing cheap access to earth orbit. As the expense of shuttle flights have shown, it may be just as cost-effective to use the Big Dumb Booster (to borrow from Baxter) to put men and materiel in space.

Despite initial problems, the Soyuz has proven itself to be a very reliable vehicle. NASA would be smart to consider the capsule as an option.

just my opinion.. i could be wrong.

 

[PGerringer]

Justy, thanks for the good numbers... but... To be truly accurate, shouldn't alot of the initial capsule failures go into the catagory of testing failures and not be included with the deployed fleet catagory? Just wondering cause a capsule at the beginning of the program (IMHO) would be miles more unstable than on at the end of the capsule program.

Just my $.02

 

[Chilly]

I don't know how I feel about this. If it's part of a larger plan to go beyond low-earth orbit again - some sort of modular building-block system - then do it. Especially if they want to dust off the old Saturn blueprints too...

NASA needs to come into the 21st century and get out of the "operator" business. Do the research, set the standards, run the big-ticket exploration missions. But leave the day-to-day up & down to orbit stuff to us civilians...then maybe we can truly make it a "day-to-day" occurence.

If the airline business had developed the way manned spaceflight has, we'd probably still be slugging around in DC-3s. The Air Force is already trying to impose their needs onto the OSP, which was a big reason the space shuttle ended up being such an overweight mess.

 

[Justy]

Originally posted by graylensman
I think right now NASA's looking at all possible options for replacing our aging Shuttle fleet. Justy's numbers aside, the Orbiters were designed for about 100 missions. If memory serves, Columbia was at or near mission 100. So even given that the accident apparently is due to tank foam striking the wing, she was close to retirement - or unreliability.

The orbiters were designed for about 100 missions, EACH. The shuttle fleet had just broken 100 missions not so long ago, TOGETHER. Columbia was at or around her 20th. She was the oldest operating orbiter, though... I'm sure that when they designed the shuttles, they figured they'd each reach their 100 mission retirement marks in less than 20 years.

Originally posted by PGerringer
Justy, thanks for the good numbers... but... To be truly accurate, shouldn't alot of the initial capsule failures go into the catagory of testing failures and not be included with the deployed fleet catagory? Just wondering cause a capsule at the beginning of the program (IMHO) would be miles more unstable than on at the end of the capsule program.

That's fair enough. We ignore the 5 unmanned Mercury flights (we'll keep the one with the chimp), that gives us 9 good Mercury flights... 2 capsule failures in 49 capsule flights [no booster failures], and we get to compare the numbers again.

~98% > 96%; the shuttle system has been more reliable than the capsule & booster system.
~99% > 96%; the shuttle itself has been more reliable than the capsules flown.
CONCLUSION: In the American space program, capsules are STILL less reliable.

But you're right, a capsule designed now would probably be considerably safer than a capsule designed in the 1960's, not just because of 20 years of capsule flights to build on, but because of 40 years of spaceflight and material research. And, as NASA examines all possible options, maybe they'll determine that capsules are the best tool for the job... I don't know why, but they're in the space program and I'm not. I'm just saying that the argument that capsules have been safer than spaceplanes is false.

 

[loopy]

Either way, I'm not too picky. I do believe, however, that no matter what, they need to do a demo launch of a Saturn V. You know - just for fun...

Loopy

 

[Justy]

Originally posted by Loopy
Either way, I'm not too picky. I do believe, however, that no matter what, they need to do a demo launch of a Saturn V. You know - just for fun...

Loopy

Agreed!! (though I can't back that up with hard numbers

 

[graylensman]

Justy - thanks for the correction. And I agree with Loopy - let's launch a Saturn V again - IDEA! we could make a reality show out of it! Contestants compete for seats in the CM, until finally we have our crew!


>ducking thrown objects<

 

[jetra2]

Originally posted by graylensman
IDEA! we could make a reality show out of it! Contestants compete for seats in the CM, until finally we have our crew!

Now THAT is a reality show I would watch!!!!!!!

Jason

 

[Chilly]

Watch? WATCH? What about PARTICIPATE? Pity the fool who gets between me and a Saturn V!
Supposedly the guy who produces "Survivor" has been working on a similar concept, except the ride would be on a Soyuz. I can think of worse things. The original concept was called "Destination Mir" until, well, the destination went away.

 

[Chilly]

I've been reading a lot about this over the last several months. As usual, there's a wealth of info out there on the internet.

PROS:
- It's a simple, proven design. It's supposed to be the best aerodynamic shape for reentry, especially for managing the thermal loads.
- Advanced materials & manufacturing methods could turn out quite a few of them cheaply, and they would conceivably be reusable for maybe a dozen or so flights. Keep the assembly line moving and you'll drive down costs.
- Much less modification required to the Atlas & Delta booster. A couple of engineers have commented that they simply weren't designed for the twisting moments a winged payload would create. Since a major OSP stipulation is that it be launched on existing boosters, that alone leads me to believe capsules are coming back. Redesigning already brand-new boosters probably isn't an option.
- Modular design allows a building-block approach for spacecraft that would go beyond LEO. This isn't publicized much but is a serious consideration inside NASA at the big-picture level. It's already being suggested that the notional "service module" wouldn't be discarded. They'd be left in orbit to be used as tugs or whatever else. This would eventually require a refueling capability, which is also being studied.

CONS:
Presuming they stick to the design goal of moving people and LIMITED cargo to & from orbit, then the only real limitations are in recovery. A ballistic reentry capsule has limited cross-range. It also needs recovery assets in place ahead of time.

I'm no engineer so maybe I'm oversimplifying. But put the pieces together and I think you'll see it's "back to the future", and here's my final reason: in a NASA graphic of notional OSPs, conspicuously amongst the familiar spaceplanes was an Apollo-derived CSM. Far as I know, that had never been publicly suggested before. I think NASA was already leaning in that direction and this was their way of dropping hints.

 

[graylensman]

Originally posted by Chilly
Pity the fool who gets between me and a Saturn V!

You can have the window seat if you want, Chilly - just don't take mine!

 

[jetra2]

DIBS!!!!

I get the OTHER window seat!

Chilly, I liked the Pros and Cons post you did......that is really neat.

Jason

 

[Chilly]

UPDATE: check out the "Space Review" website at www.thespacereview.com/article/38/1