Flyglobal
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Why Not Just To Build New Space Shuttles

Sat Jan 01, 2011 2:20 pm

Not sure of this topic was raised here a long time or some time ago, otherwise I apologize in advance.

I am following space developments from time to time.

With the space shuttles beeing phased out before a replecement system is in place I have my doubhts that this really was a wise decisison. And in my opinion the orion program isn't an adequate decisison to somehow go back to apollo style methods instead of just developing a new advanced space shuttle type space ship.

Now I wonder: why wouldn't it be possible to just build another 2 or 3 space shuttles for just continuing the missions to the space station for some more time until a new system is really available.
Financing (investment, engineering) could be spread around the later users, states, such like European countries, Japan, Korea, even Russia and China paying of with lower cost per mission over time.

Wss this ever considered? Ad when, what were the reasons not to do it.


Regards

Flyglobal
 
hka098
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RE: Why Not Just To Build New Space Shuttles

Sat Jan 01, 2011 4:20 pm

I would say money... The United States just doesn't have the money to spend on such articles now. Also, that type of expense might be hard to justify in this economy. Giving up the technological lead in this area is kind of sad, but there are bigger fish to fry.

I would put politics in as another reason. There is an amazing amount of handwringing over building a multinational fighter (F-35). I hardly believe the international community could come together to build a large spacecraft. I think NASA is hoping the Private Sector will come up with something.
 
nomadd22
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RE: Why Not Just To Build New Space Shuttles

Sat Jan 01, 2011 4:32 pm

They don't need new shuttles. If they want to keep the program going, the existing ones could easily do the job. The problem is that the shuttle program money is what will pay for any new system. You can't get the new system going without shutting down the shuttle program first. The other problem is that you can't just start up a production line that's been shut down for 30 years. Even Endevour onkly got built because they had most of the parts on hand. It would make more sense to build an entirely new system.
And, other countries are very interested in establishing their own capability. They don't want to be dependent on the US, like the US is going to be dependent on Russia for several years.
Anon
 
rfields5421
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RE: Why Not Just To Build New Space Shuttles

Sat Jan 01, 2011 5:11 pm

The Space Shuttle design and safety concepts are almost 40 years old. We know a lot more today, how to do it better and safer. It is time for the Shuttles to go - especially the SRB system.

Building a couple new shuttles would cost much more than the existing shuttles. Much of the tooling is gone. It would have to be rebuilt scratch. Many of the parts suppliers are either out of business or no longer make those parts. Extremely expensive to restart.

The Next-Generation Vehicle will use much of the newer technology developed for the USAF unmanned reusable orbiter vehicle.
 
DiamondFlyer
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RE: Why Not Just To Build New Space Shuttles

Sat Jan 01, 2011 6:43 pm

Because quite honestly, the STS system never, ever ever met its design goals. The whole system was sold on economies of scale. The whole system basically was dependent on 50+ launches per YEAR, to get to the point that it was affordable. Needless to say, that never happen.

When it comes to money, it is no doubt cheaper to launch cargo on something like a Delta IV or Atlas V, and then people on something smaller, like a Falcon 9 sized vehicle. Take a look at the amount of weight that is wasted in the space shuttle, and you'll realize we have no need to be launching something in the Saturn V weight class for LEO operations.

-DiamondFlyer
From my cold, dead hands
 
zanl188
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RE: Why Not Just To Build New Space Shuttles

Sat Jan 01, 2011 8:13 pm

Quoting hka098 (Reply 1):
The United States just doesn't have the money to spend on such articles now. Also, that type of expense might be hard to justify in this economy

The decision to shutdown the shuttle program was made long before the current economic uncertainty.

Primary reason for shutting down the shuttle program was this Columbia Accident Investigation Board recommendation:

"R9.2-1 Prior to operating the Shuttle beyond 2010, develop and conduct a vehicle recertification at the material, component, subsystem, and system levels. Recertification requirements should be included in the Service Life Extension Program. (p. 209, 227) "

Recertification would have been prohibitively expensive and would have resulted in a vehicle that had no capabilities that we didn't already have. Much more desireable to put the cash in a new spacecraft that could leave low earth orbit.
Legal considerations provided by: Dewey, Cheatum, and Howe
 
hka098
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RE: Why Not Just To Build New Space Shuttles

Sat Jan 01, 2011 8:26 pm

There has to be a financial reason behind why a new spacecraft has not been developed. There has to be a way to research new ways into spaceflight without having to rely on expendable forms of propulsion. Writing out of my posterior here...
 
zanl188
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RE: Why Not Just To Build New Space Shuttles

Sat Jan 01, 2011 11:10 pm

Quoting hka098 (Reply 6):
There has to be a financial reason behind why a new spacecraft has not been developed.

Actually several are being developed.. Orion, Dragon, etc
Legal considerations provided by: Dewey, Cheatum, and Howe
 
JBirdAV8r
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RE: Why Not Just To Build New Space Shuttles

Sat Jan 01, 2011 11:28 pm

Quoting hka098 (Reply 1):
I would say money... The United States just doesn't have the money to spend on such articles now. Also, that type of expense might be hard to justify in this economy. Giving up the technological lead in this area is kind of sad, but there are bigger fish to fry.

The STS program is quite literally peanuts in the national budget. It's within what many government agencies would probably call a "rounding error." It's expensive, and human spaceflight eats up a big chunk of NASA's budget. But it's not prohibitively expensive to have a manned spaceflight program by any stretch.

Quoting flyglobal (Thread starter):
With the space shuttles beeing phased out before a replecement system is in place I have my doubhts that this really was a wise decisison. And in my opinion the orion program isn't an adequate decisison to somehow go back to apollo style methods instead of just developing a new advanced space shuttle type space ship.

Of course this "gap" in manned spaceflight capability is a bad thing and never should have happened.

But I think calling a capsule-type system a step backward in and of itself is short-sighted. Shuttle's biggest obstacle is itself. Yes it's expensive, laborious to maintain, has several Achilles' heels, etc. But it's greatest limiting factor is its inability to go anywhere but low earth orbit. Among other things, the biggest reason is that it's just too heavy.

When a Space Shuttle launches it's carrying literally tons of stuff that it only needs for a very few minutes of operation. The main engines and associated hardware. Wings, tail and landing gear. Hydraulic systems and APUs to gimbal the engines and move the aerosurfaces. Etc. It's a huge upmass penalty, and getting that behemoth to move around in space is "expensive" from a fuel perspective. There would be no way to carry enough fuel to do a translunar and transearth injection. Obviously the same applies for Mars, with the added problems that the Orbiter is only good for a month on orbit, radiation concerns, etc.

So then we have to examine what capabilities we're losing with the Space Shuttle. We're losing a safe, effective way to land-recover the vehicle. That much is clear. We're losing almost all of our downmass (bringing things from space to the ground) capability. Things like the Cargo Dragon and stuffing as much as you can into manned re-entry vehicles make up for some of it, but we no longer will have the ability to bring home satellites (we've not done that very much at all, and don't really need to) and MPLM's full of cargo from the ISS. We're losing the world's only real hypersonic research vehicle. I'm excited to see the X-37 fly but that's a military program and a different concept. We're sacrificing astronaut comfort (a capsule re-entry isn't as benign as an orbiter re-entry). Can we live without those things? Yes we can.

If we can design a capable capsule-based spacecraft, we can do amazing things. We can go back to the Moon, carrying more stuff at lighter weight than ever before. We can establish a presence on the Moon. We can go to Mars...the technology is out there waiting for us. But there is little political will to support a bloated-budget "space truck" and a brand-new exploratory program.

Quoting hka098 (Reply 6):
There has to be a financial reason behind why a new spacecraft has not been developed.

Heck, private companies are doing it.

Quoting hka098 (Reply 6):
There has to be a way to research new ways into spaceflight without having to rely on expendable forms of propulsion.

TANSTAAFL. There ain't no such thing as a free lunch.

Quoting ZANL188 (Reply 5):
Primary reason for shutting down the shuttle program was this Columbia Accident Investigation Board recommendation:

"R9.2-1 Prior to operating the Shuttle beyond 2010, develop and conduct a vehicle recertification at the material, component, subsystem, and system levels. Recertification requirements should be included in the Service Life Extension Program. (p. 209, 227) "

Recertification would have been prohibitively expensive and would have resulted in a vehicle that had no capabilities that we didn't already have. Much more desireable to put the cash in a new spacecraft that could leave low earth orbit.

You're right--CAIB did provide the impetus to end the program. Before Columbia there were rumblings of SLEP extending the Shuttle fleet through 2020. But Shuttle really ended up killing itself.
I got my head checked--by a jumbo jet
 
wvsuperhornet
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RE: Why Not Just To Build New Space Shuttles

Sun Jan 02, 2011 9:27 pm

I would say money and up keep it has been very expensive to keep the current fleet running and also the US space agency is looking to go deeper into space the shuttle just isnt built for that kind of mission.
 
GDB
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RE: Why Not Just To Build New Space Shuttles

Mon Jan 03, 2011 10:34 am

I may have missed the thread, but I don't recall one on here about the successful launch recently of the Space-X rocket and a Dragon capsule.
As the US VP said of another (also controversial) program, that success was a big f*****g deal.
 
nomadd22
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RE: Why Not Just To Build New Space Shuttles

Mon Jan 03, 2011 12:22 pm

Quoting GDB (Reply 10):
I may have missed the thread, but I don't recall one on here about the successful launch recently of the Space-X rocket and a Dragon capsule.
As the US VP said of another (also controversial) program, that success was a big f*****g deal.

I was a small thread, but it's there.
Dragon First Flight (by connies4ever Dec 8 2010 in Military Aviation & Space Flight)
Anon
 
kalvado
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RE: Why Not Just To Build New Space Shuttles

Tue Jan 04, 2011 2:59 pm

I would say it's not even about money. Shuttle was designed for tasks it never really performed, with design parameters it never met. Well, Hubble service missions are the only thing that matches what was envisioned in 1970's when system was designed.
Actually entire paradigm shifted over the years. Shuttle had to become universal, cheap, reliable, quick turn around launch vehicle. After Challenger crash, it turned out it's not so reliable, not so easy to operate. Turn around time soared, costs went out of control, and at the same time military scaled back their needs. So much for being universal. Manned program focused on longer-term presence in space, something Shuttle is not designed for. Assembly of space station is close, but probably still outside original scope.

Despite manned flights being so cool, they are not bread and butter of space program. Navigation (GPS), communications, imaging (weather, scientific, military) do not need manned flight program and bring more value. Deep space research does not need manned flights either. Probably it would be wise to scale back manned program to get most value (scientific data, customer usable things, whatever military wants) for those money.
 
BEG2IAH
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RE: Why Not Just To Build New Space Shuttles

Tue Jan 04, 2011 6:57 pm

Quoting JBirdAV8r (Reply 8):
I'm excited to see the X-37 fly but that's a military program and a different concept.

Yeah, X-37B looks cool.

http://boeing.mediaroom.com/index.php?s=43&item=1541

BEG2IAH
Aviation is not so much a profession as it is a disease.
 
Flighty
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RE: Why Not Just To Build New Space Shuttles

Tue Jan 04, 2011 11:12 pm

Philosophically, I think the Shuttle is just too dangerous to be human rated. The brave astronauts who rode it to fix the Hubble are, simply, heroes.
 
rwessel
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RE: Why Not Just To Build New Space Shuttles

Wed Jan 05, 2011 5:38 am

Quoting Flighty (Reply 14):
Philosophically, I think the Shuttle is just too dangerous to be human rated.

Sure, but so are all the other manned launchers.
 
DiamondFlyer
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RE: Why Not Just To Build New Space Shuttles

Wed Jan 05, 2011 7:35 am

Quoting Flighty (Reply 14):
Philosophically, I think the Shuttle is just too dangerous to be human rated.

I don't know if I'd go that far. As far as I know, the STS and the entire Soyuz program have basically the same fatality per flight rate. That said, the failure modes on a Soyuz are significantly more survivable that that of the STS.

I think the STS is too complex to be used as a routine, low cost, effective means of getting people to LEO.

-DiamondFlyer
From my cold, dead hands
 
jwenting
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RE: Why Not Just To Build New Space Shuttles

Wed Jan 05, 2011 10:45 am

Quoting Flighty (Reply 14):
Philosophically, I think the Shuttle is just too dangerous to be human rated. The brave astronauts who rode it to fix the Hubble are, simply, heroes.

And that's the kind of attitude that's the death of western civilisation.
We've become so risk averse we're afraid to try anything new at all in case someone might stub a toe.

If Columbus tried to get his expedition to cross the Atlantic to China funded today he'd not get approval on "health and safety" grounds.
I wish I were flying
 
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pylon101
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RE: Why Not Just To Build New Space Shuttles

Wed Jan 05, 2011 6:48 pm

Quoting jwenting (Reply 17):
If Columbus tried to get his expedition to cross the Atlantic to China funded today he'd not get approval on "health and safety" grounds

That is true. Witty and funny.
I am just wondering how DiamondFlyer calculated fatality rate Soyuz vs. STS?
The last Soyuz related fatalities were in 1971 or 1972. Or I forgot anyone?
And the number of Soyuz missions was massive.

Still STS (and unmanned flight of "Buran") was a great achievement. It possibly could not be profitable.
But only STS could deliver bulky stuff to build ISS - and actually any construction for deeper exploring.

It should be admitted that fundamental science did not deliver within those three decades.
As a result we have very little progress in all spheres.
 
bennett123
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RE: Why Not Just To Build New Space Shuttles

Wed Jan 05, 2011 7:45 pm

The comments about risk remind me of reading "The right stuff" about early space flight.
 
kalvado
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RE: Why Not Just To Build New Space Shuttles

Wed Jan 05, 2011 7:46 pm

Quoting pylon101 (Reply 18):

That is true. Witty and funny.
I am just wondering how DiamondFlyer calculated fatality rate Soyuz vs. STS?
The last Soyuz related fatalities were in 1971 or 1972. Or I forgot anyone?

so far, Soyuz flown 108 times - 2 fatal accidents
http://en.wikipedia.org/wiki/List_of_Soviet_manned_space_missions
http://en.wikipedia.org/wiki/List_of_Russian_manned_space_missions

So far, Space Shuttle flown 132 missions - 2 fatal accidents
http://en.wikipedia.org/wiki/List_of_space_shuttle_missions

It may be argued that major problems in Soyuz program are worked out in early days (1 and 10 flights catastrophic), while both Shuttle catastrophic events occurred in mature program (25 and 113 flight); but raw numbers are in Shuttle's favor.
 
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pylon101
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RE: Why Not Just To Build New Space Shuttles

Wed Jan 05, 2011 7:59 pm

Hm, you are right. I remember Soyuz as long as I remember myself.
I just recalled how we had taken 3 lives lost in 1971.

Actually American tragedies were taken by Russians very close.
I believe there is some kind of general understanding or feeling that in space exploring we are in the same boat.
No need to say that the same relates to 9/11.
 
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ADent
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RE: Why Not Just To Build New Space Shuttles

Wed Jan 05, 2011 8:27 pm

Money - STS costs over a billion dollars a launch.
 
rwessel
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RE: Why Not Just To Build New Space Shuttles

Wed Jan 05, 2011 8:41 pm

Quoting kalvado (Reply 20):
It may be argued that major problems in Soyuz program are worked out in early days (1 and 10 flights catastrophic), while both Shuttle catastrophic events occurred in mature program (25 and 113 flight); but raw numbers are in Shuttle's favor.

And both have had close calls. Consider STS-1 (unexpectedly high overpressure from SRB ignition exceeded the structural limits of several components, damaging the forward RCS tank supports and other stuff), STS-9 (APU fire near landing), STS-51-F (one engine shutdown, and a second shutdown stopped by a controller, preventing a risky TAL abort), STS-93 (dual engine electronics failure and hydrogen leak - came close to forcing a *very* risky RTLS about). Or Soyuz 5 (after beginning reentry the service module failed to detach - broke off in time for reentry module to survive), Soyuz 18a (second stage separation failure, escape system worked, although crew was injured by 20+G forces), Soyuz 23 (landed on frozen lake, broke through ice and sank, Soyuz T-10-1 (caught fire on pad, escape system worked), Soyuz TMA-11 (similar to Soyuz 5, service module failed to detach during reentry).

In addition both programs have had a variety of "minor" incidents, some of which were precursors to major ones. For example, partial O-ring burn through (STS-8, 51-C and others) and foam loss/damage (at least STS-1, 4, 5, 7, 27, 32, 50, 53, 63, 112) had been observed on shuttle flights before the Challenger/Columbia accidents. And there have been a number of additional engine shutdowns.

But there really isn't enough data for either program to do more than say their safety records are similar. And there's not really enough data on any of the other manned programs to provide much of any ranking.

The reality is that spaceflight is dangerous.
 
kalvado
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RE: Why Not Just To Build New Space Shuttles

Wed Jan 05, 2011 9:48 pm

Quoting rwessel (Reply 23):
The reality is that spaceflight is dangerous.

To put things in perspective - airlines with good safety rating have 1 crash over 4 million cycles, give or take.
So a pilot who flies short haul - say 1 hour legs comes mostly - close to 1% chance of death due to crash over long 40 years career.
One flight into space gives approximately same 1%.

Quoting rwessel (Reply 23):

But there really isn't enough data for either program to do more than say their safety records are similar. And there's not really enough data on any of the other manned programs to provide much of any ranking.

I doubt any plane would get certified after just 150 cycles test program. Shuttles are retired before 150 cycles fleet-wide.
with 10's-100's million dollars a cycle, space flights are to expensive to be done by same safety standards as regular flight operations.
 
Flighty
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RE: Why Not Just To Build New Space Shuttles

Wed Jan 05, 2011 10:11 pm

Quoting rwessel (Reply 23):
The reality is that spaceflight is dangerous.

We are comparing 2 systems with many admitted shortcomings. Can "spaceflight" ever exceed those performance levels, my hope is yes!

Quoting kalvado (Reply 24):
I doubt any plane would get certified after just 150 cycles test program. Shuttles are retired before 150 cycles fleet-wide.

Maybe computer simulations (unavailable in the 70s) would assist battle-testing these designs in the future.
 
rwessel
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RE: Why Not Just To Build New Space Shuttles

Thu Jan 06, 2011 12:08 am

Quoting Flighty (Reply 25):
We are comparing 2 systems with many admitted shortcomings. Can "spaceflight" ever exceed those performance levels, my hope is yes!

I believe safety and reliability can be increased somewhat, perhaps into the range of a loss-of-vehicle accident every ~500 flights, although not cheaply or easily. So long as spaceflight depends on difficult to handle fuels, insanely high fuel ratios, and extreme burn rates, we're not going to do better than that. Probably the best bet is to separate crew launches from cargo launches, and accept a severe weight penalty for safety systems for the crew launches.

Quoting Flighty (Reply 25):
Maybe computer simulations (unavailable in the 70s) would assist battle-testing these designs in the future.

It'll help, but many things are very difficult to model.
 
DfwRevolution
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RE: Why Not Just To Build New Space Shuttles

Thu Jan 06, 2011 4:15 am

Quoting kalvado (Reply 20):
It may be argued that major problems in Soyuz program are worked out in early days (1 and 10 flights catastrophic), while both Shuttle catastrophic events occurred in mature program (25 and 113 flight); but raw numbers are in Shuttle's favor.

Don't forget about some of the close calls with Soyuz TMA flights this decade.

Quoting DiamondFlyer (Reply 4):
Because quite honestly, the STS system never, ever ever met its design goals.

That's not the reason we are not building new Shuttles.

We are not building new Shuttles because the Shuttle paradigm does not meet the objectives of our future spaceflight program. We don't need to launch cargo and crew together anymore. We don't need to return bulky payloads from space anymore. And we need the capability to leave Earth orbit and return directly - which is difficult to do with wings.
 
DiamondFlyer
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RE: Why Not Just To Build New Space Shuttles

Thu Jan 06, 2011 4:25 am

Quoting dfwrevolution (Reply 27):
That's not the reason we are not building new Shuttles.

We are not building new Shuttles because the Shuttle paradigm does not meet the objectives of our future spaceflight program. We don't need to launch cargo and crew together anymore. We don't need to return bulky payloads from space anymore. And we need the capability to leave Earth orbit and return directly - which is difficult to do with wings.

That's very true, but if the STS met its design goals on per pound cost to orbit, it would by far be the cheapest thing to get cargo to space. But, then again, had NASA met those cost estimates and flight estimates, NASA would have used 14 shuttles to end of life, from 1982 to now, by having flown over 1400 flights. Imagine what that would be like.

-DiamondFlyer
From my cold, dead hands
 
kalvado
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RE: Why Not Just To Build New Space Shuttles

Thu Jan 06, 2011 4:37 am

Quoting dfwrevolution (Reply 27):

Don't forget about some of the close calls with Soyuz TMA flights this decade.

fortunately Soyuz had a fallback scenario - ballistic landing. Similar fallback for shuttle would be scattered all over Texas.
Aerodynamic forces at those speeds are not a joke.

Quoting DiamondFlyer (Reply 28):

That's very true, but if the STS met its design goals on per pound cost to orbit,

Key question to ask is if it would be possible to learn all the lessons and have those parameters met in shuttle-2 program. Looks like 40 years after shuttle-1 launch the answer is still negative.. Maybe another 20-50 years? who knows..
 
jwenting
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RE: Why Not Just To Build New Space Shuttles

Thu Jan 06, 2011 8:58 am

Quoting dfwrevolution (Reply 27):
We don't need to launch cargo and crew together anymore

only because NASA has abandoned human spaceflight except for renting space to bring a few people to the ISS until it is retired in a few more years (design life for ISS has it scrapped by 2015)...

After that, the US administration has decided last year, the United States will no longer have a space program. The moon and Mars missions have been scrapped, most other things cut back far enough they're effectively no longer viable.
The launches that will continue will be commercial and military, no science, exploration, etc.
A society that abandons the quest for knowledge and expanding its horizons signs its own death warrant... This has always been the case, for as long as humanity has existed.
I wish I were flying
 
rwessel
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RE: Why Not Just To Build New Space Shuttles

Thu Jan 06, 2011 10:45 am

Quoting jwenting (Reply 30):
After that, the US administration has decided last year, the United States will no longer have a space program. The moon and Mars missions have been scrapped, most other things cut back far enough they're effectively no longer viable.
The launches that will continue will be commercial and military, no science, exploration, etc.
A society that abandons the quest for knowledge and expanding its horizons signs its own death warrant... This has always been the case, for as long as humanity has existed.

Just to remind you that there's an alternative view: The manned program has never been about science, and while it produced some (although far less than NASA and its boosters like to claim), that came at immense cost. The real value of NASA's space program is in the unmanned stuff, which always got slammed whenever the manned program took (another) cost overrun. Discarding most of the vainglory manned program will allow NASA to concentrate on real science with the unmanned program.
 
jwenting
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RE: Why Not Just To Build New Space Shuttles

Thu Jan 06, 2011 11:57 am

the new missions planned to the moon and Mars were to have been (mostly) scientific and preparotary for putting in place permanent bases there.
In the past science was indeed not always the main reason for launching the missions, but it was an important sideshow that produced a lot of valuable data that cannot be attained by robotic systems.

Anyway, if we loose the guts and will to engage in manned spaceflight we're dooming ourselves to extinction. Mankind needs to expand, and the only way left to do so is to leave the cradle behind.
If we decide now we're too chicken to do so (and that's the real reason) it's lights out. By the time it's either get our act together and evacuate or face extinction, it'll be too late.
I wish I were flying
 
nomadd22
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RE: Why Not Just To Build New Space Shuttles

Thu Jan 06, 2011 12:31 pm

The deaths in the shuttle program were from people ignoring unmistakable data, not from an inherently unsafe vehicle. It was well known that the SRB seals were leaking and the leaks were worse with cold. It was also well known that large chunks of foam were coming off and hitting the wings. In both cases, management made sure the results of the analysis came out to be what they wanted. No vehicle ever made would be safe with that kind of attitude.
Anon
 
DfwRevolution
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RE: Why Not Just To Build New Space Shuttles

Thu Jan 06, 2011 4:32 pm

Quoting kalvado (Reply 29):
fortunately Soyuz had a fallback scenario - ballistic landing. Similar fallback for shuttle would be scattered all over Texas.

Soyuz does not have a survivable failure mode if the service module does not detach.

Quoting nomadd22 (Reply 33):
The deaths in the shuttle program were from people ignoring unmistakable data, not from an inherently unsafe vehicle

If it was unmistakable, they wouldn't have mistook it. We are saying that it was "unmistakable" due to hindsight. The Shuttle had suffered tile damage on virtually every flight without danger. Six flights had especially large damage. When no harm resulted from repeated foam strikes, NASA concluded they were relatively harmless. Once you establish a perception, it is very difficult to see it any other way.

Quoting nomadd22 (Reply 33):
It was well known that the SRB seals were leaking and the leaks were worse with cold

Actually, the data was contradictory. One of the worst SRB "blow bys" occurred on the warmest flight of the Shuttle program to date. However, NASA had zero data on flights below ~50 degF as it was on the morning of STS-51L.

Quoting jwenting (Reply 30):
only because NASA has abandoned human spaceflight except for renting space to bring a few people to the ISS until it is retired in a few more years (design life for ISS has it scrapped by 2015)...

No, because transporting cargo and crew separately enhances crew safety.

The ISS will be extended for many years, at least through 2020.

You're also contradicting yourself. You say that NASA has abandoned human spaceflight except for "renting" transport. Well, then NASA has not abandoned human spaceflight. They are simply shifting to a more cost effective model to reflect the growing capability of the private sector.

When the Department of Agriculture wants to send employees somewhere, they don't design an airplane from scratch and operate it themselves. They buy them tickets on an airline.
 
kalvado
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RE: Why Not Just To Build New Space Shuttles

Thu Jan 06, 2011 5:49 pm

Quoting dfwrevolution (Reply 34):

Soyuz does not have a survivable failure mode if the service module does not detach.

as far as I understand there are calibrated failure points, so in case of explosive bolts not working separation would still occurs by aerodynamic forces. That is too late for a controlled landing, but high-g forces of ballistic landing are still better than loss of lives.
 
DiamondFlyer
Posts: 2168
Joined: Wed Oct 29, 2008 11:50 pm

RE: Why Not Just To Build New Space Shuttles

Thu Jan 06, 2011 7:32 pm

Quoting dfwrevolution (Reply 34):
Soyuz does not have a survivable failure mode if the service module does not detach.

There is a heck of a lot less than has to go right after a failure on a Soyuz than has to go right on a Shuttle. If I had to pick between riding a Soyuz with a major booster failure or a Shuttle with a major booster failure, there is no doubt I'd pick the Soyuz. Quite honestly, the Shuttle is just too complex for what needs to be done with the current mission.

-DiamondFlyer
From my cold, dead hands
 
JBirdAV8r
Posts: 3454
Joined: Sun Jun 24, 2001 4:44 am

RE: Why Not Just To Build New Space Shuttles

Thu Jan 06, 2011 9:24 pm

Quoting dfwrevolution (Reply 34):
Quoting nomadd22 (Reply 33):
It was well known that the SRB seals were leaking and the leaks were worse with cold

Actually, the data was contradictory. One of the worst SRB "blow bys" occurred on the warmest flight of the Shuttle program to date. However, NASA had zero data on flights below ~50 degF as it was on the morning of STS-51L.

I wouldn't call the data "contradictory"--when you come right down to it the problem was a design that didn't mitigate joint rotation in a way that prevented hot gas from impinging on the O-rings.

Joints will always rotate. The cold decreased the resilience of the O-rings to the point where at SRB ignition when the joints were rotating ("vibating" if you will), the O-rings were so cold they didn't create a seal of this constantly-changing "gap." The blow-by was so severe it damaged the primary and secondary o-ring--and the debris formed a delicate "patch" that prevented complete blow-by until around ~50s, where the stack encountered very strong windshear (still, IIRC, the heaviest shear ever encountered in the program) when the "patch" broke. The fact Challenger made it off the pad that day is a miracle in and of itself.

The solution was to incorporate a capture feature into the tang of the joint to limit rotation with a third O-ring, a new "J-seal" insulation barrier was incorporated, among other enhancements. Actually many of these changes were to be already slated to be incorporated into the new filament-wound boosters for the Vandenberg launches but, of course, those never happened.
I got my head checked--by a jumbo jet

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