Community > Forum > National Aeronautics and Space Administration (NASA) > Are the Shuttles aged or don't they?

Are the Shuttles aged or don't they?

Posted by: Ekkehard Augustin - Wed Aug 27, 2008 7:29 pm
Post new topic Reply to topic
 [ 12 posts ] 
Are the Shuttles aged or don't they? 
Author Message
Moderator
Moderator
avatar
Joined: Thu Jun 03, 2004 11:23 am
Posts: 3745
Location: Hamburg, Germany
Post Are the Shuttles aged or don't they?   Posted on: Wed Aug 27, 2008 7:29 pm
One article under marssociety.de as well as the article "McCain to Bush: Keep Space Shuttle Options Open" ( www.space.com/news/080826-mccain-nasa.html ) are reporting or saying that Shuttles mustn't be retired that time they are scheduled to be.

According to the Space.com-article three Republican Senators including McCain urge to delay the retirement because the chances to get the agreement of the Congress to buy flights from Russia are vanishing because of their war against Georgia.

The same argument can be erad under www.marssociety.de but independently of the three Senators.

In both articles it is said that the replacements of the shuttles will be delayed into 2015.

So what about the lifetime of the Shuttles? Has it expired really?

There are decisions of political authorities - government, Columbia-investigation comitee to retire the Shuttles - can NASA really operate them beyond the limit set by those authorities?



Dipl.-Volkswirt (bdvb) Augustin (Political Economist)


Back to top
Profile
Moon Mission Member
Moon Mission Member
User avatar
Joined: Mon Nov 01, 2004 6:15 pm
Posts: 1233
Location: London, England
Post    Posted on: Wed Aug 27, 2008 8:00 pm
Only now, 4 years after Bush originally said that they would be retired in 2010, are people starting to wake up to how much they are at the mercy of the Russians. I know some individuals and advocacy groups have been banging on about this for years but its taken a Russian invasion to get people hot under the collar.

I think that nothing will change until there is a new president and even then it is unlikely as it will be to late. Some shuttle components need to be ordered years in advance and production lines are already closing down.

My understanding is that the shuttles will need to be recertified and although NASA itself is unsure as to the full details of doing that they do know that it will require a near complete dismantling of the vehicles to enable access to inspect internal structures and equipment. Such a process will not be quick and is still likely to result in a gap of years. NASA would be better off funding some of the craft already under development and utilising some of the surplus staff it will have as the shuttle winds down to lend expertise to struggling companies.

Another option might be to get DARPA to develop the X-37B as a crew transport, it might be possible to build a crew canister along the lines of a shuttle logistics module to fit inside its payload bay. Of course things haven't been going to well with that project as I understand there is some problem with Atlas launch vehicle's RD-180 engine which might delay its planned December launch. Still if the X-37B is ready to fly orbitally then it should take much less time to convert it for crew rather than starting from a much more immature vehicle.

http://www.msfc.nasa.gov/news/x37news/index.html

_________________
A journey of a thousand miles begins with a single step.


Back to top
Profile WWW
Moderator
Moderator
avatar
Joined: Mon Feb 09, 2004 4:01 am
Posts: 747
Location: New Zealand
Post    Posted on: Wed Oct 22, 2008 10:08 pm
The airframes are getting very very old. A lot of onboard equipment has been certified twice outside its original design lifetimes.

_________________
What goes up better doggone well stay up! - Morgan Gravitronics, Company Slogan.


Back to top
Profile ICQ YIM
Moon Mission Member
Moon Mission Member
User avatar
Joined: Mon Nov 01, 2004 6:15 pm
Posts: 1233
Location: London, England
Post    Posted on: Thu Oct 23, 2008 8:37 am
Probably cheaper to build another shuttle based on the original 70s design drawings and replace what internals you can with modern equivalents. Yeah, like that is going to happen. :)

_________________
A journey of a thousand miles begins with a single step.


Back to top
Profile WWW
Space Station Member
Space Station Member
User avatar
Joined: Mon Feb 25, 2008 9:51 am
Posts: 442
Location: Vienna, Austria, Europe, Earth
Post    Posted on: Thu Oct 23, 2008 11:02 am
I think it doesn't really makes a lot of sense to "rebuild" the shuttle with modern technology (that happens anyway to some degree every time one is in maintenance). To me the shuttle is an absolutely amazing piece of technology, something on the lines of the Concorde, in many ways ahead of it's time.

However, the design has some fundamental flaws, which are so big, that it would require a complete redesign to overcome them anyway. So it would be more practical to start from scratch, instead of modernizing it.

Problems are:
Launch configuration: all those "insulation harms TPS"-problems are because of the orbiter being mounted on the side of the Tank/Boosters instead of an inline configuration, but it is just too heavy to simply mount it on top. You could solve this with a (much) smaller orbiter, but imho that would result only in "better looks" than a capsule, but you do not gain much more.
The only other way would be a newer, more robust metallic TPS, but that would probably require other things to change as well.. etc.

Reusability: Technically: yes, financially: not really
The SRBs can be recovered and partially reused, fine, but it takes a lo of work and money to refurbish them. The tank is wasted every time. And then the orbiter. While it technically is a reusable vehicle, it requires so much maintenance after every flight, that you don't really gain anything from its reusability on the money side of things. Especially if you are "only" transporting astronauts to the ISS.
That's why a simple capsule does make a lot of sense for orbital transfer of personnel. (It just doesn't make sense to build a new launcher out of shuttle parts however... why didn't they just man-rate some other launcher and put Orion on top of that?... politics *shrugs*)

But, once they are out of service, there will be something missing in space that can't be replaced by any current or proposed capsule.
This becomes very clear, if you look at the size-comparison between the shuttle and a capsule (the very small Soyuz in this case):
http://en.wikipedia.org/wiki/Image:Spac ... rawing.png

Consider, that the Orbiter is in fact a small space station and multi-purpose vehicle. You just can't do things like servicing a satellite with a capsule (or at least not as easy as with the orbiters cargo bay).
Well you could build some dedicated service module, launch that with Ares5, join them in orbit.. rendezvous with the satellite and... dispose the service-module after every flight. Not the most clever way of doing things.

So I really do want to see a new large "orbiter" of some kind to become a successor to the shuttle, but it only makes sense if it has a completely new launch configuration that makes it a) safer than the shuttle and b) way more cheaper to operate!


Back to top
Profile
Launch Director
Launch Director
avatar
Joined: Tue Oct 16, 2007 11:09 am
Posts: 14
Post The shuttles should be grounded   Posted on: Thu Oct 23, 2008 11:29 am
First off, I absolutely love the shuttles, I grew up with them, but the symbol of the future they were, has become a part of the past. I'd rather push harder to get to the next level instead of keeping old and cranky things around for emotional reasons (i.e. Hubble). Yeah, maybe it's tricky relying on the Russians, but proceeding with grounding the shuttles would:

1) Give resources and pressure to the Ares development, keep it moving ahead at a good clip
2) Give SpaceX (Dragon) and other companies impetus to develop their human spaceflight
3) Give the US and Russia some reason to work together.

I would rather have people on the moon then a shuttle. I'd rather look to the future. A space program should look to the future, otherwise we'd be better off spending all that money on lawn chairs and daiquiris.


Back to top
Profile
Moon Mission Member
Moon Mission Member
User avatar
Joined: Mon Nov 01, 2004 6:15 pm
Posts: 1233
Location: London, England
Post    Posted on: Thu Oct 23, 2008 11:40 am
Andy Hill wrote:
Probably cheaper to build another shuttle based on the original 70s design drawings and replace what internals you can with modern equivalents. Yeah, like that is going to happen. :)


This wasn't a serious proposal, so much for sarcasm. :)

I think that a reusable mini shuttle would be a good idea for LEO operations such as Hubble and ISS, limited in weight to something that can be launched on top of an existing booster. Somewhere in the range of 8 to 15 tons maybe to allow for a craft with some versatility and robustness (the shuttle's TPS is simply to vulnerable and time consuming to maintain).

_________________
A journey of a thousand miles begins with a single step.


Back to top
Profile WWW
Space Station Member
Space Station Member
User avatar
Joined: Mon Feb 25, 2008 9:51 am
Posts: 442
Location: Vienna, Austria, Europe, Earth
Post    Posted on: Thu Oct 23, 2008 11:42 am
What do you think would be the benefit of such a "mini-shuttle" compared to a capsule (of roughly the same size)?


Back to top
Profile
Moon Mission Member
Moon Mission Member
User avatar
Joined: Mon Nov 01, 2004 6:15 pm
Posts: 1233
Location: London, England
Post    Posted on: Thu Oct 23, 2008 2:00 pm
Marcus Zottl wrote:
What do you think would be the benefit of such a "mini-shuttle" compared to a capsule (of roughly the same size)?


I think the main one would be cross range and the ability to land on a runway rather than some large out of the way area or rely on a sea recovery. Lets face it a sea recovery is unlikely to lead to it being reusable without a lot of maintenance.

Having a small payload bay would allow fitting things like grapling arms, tools or work pallets where repairs to satelittes could be made fitting something like that on a capsule would not be so easy. It would also make it possible to recover/deliver large parts from the ISS, specifically things like the Gyros recently delivered by the shuttle. I dont know whether you would want to strap that on to the outside of a capsule.

In the event that you needed to get people down from orbit you could fit an extra crew cabin in the payload and use it as a rescue ship. How could youfit extra sets in a capsule?

_________________
A journey of a thousand miles begins with a single step.


Back to top
Profile WWW
Space Station Member
Space Station Member
User avatar
Joined: Mon Feb 25, 2008 9:51 am
Posts: 442
Location: Vienna, Austria, Europe, Earth
Post    Posted on: Thu Oct 23, 2008 3:22 pm
Andy Hill wrote:
[...]
Having a small payload bay would allow fitting things like grapling arms, tools or work pallets where repairs to satelittes could be made fitting something like that on a capsule would not be so easy. It would also make it possible to recover/deliver large parts from the ISS, specifically things like the Gyros recently delivered by the shuttle. I dont know whether you would want to strap that on to the outside of a capsule.

In the event that you needed to get people down from orbit you could fit an extra crew cabin in the payload and use it as a rescue ship. How could youfit extra sets in a capsule?


Depends how big your "mini" shuttle is supposed to be. I had something in mind along the lines of the never realized CRV which isn't much bigger than the Orion CM. There isn't really much space for a payload bay on either of them.

But if you are thinking of something like the Hermes (http://www.astronautix.com/craft/hermes.htm), which is about twice the size of the CRV, then of course you do have the additional space. Of course, if you design a capsule that has the same pressurized volume as well, then why would it be any more difficult to use half of that volume as a payload bay?
(Well you probably need a completely new launcher to get a 10m diameter capsule into orbit...)

Cross range definitely is a big advantage for any "spaceplane" design but I don't think that reusability requires such a design and isn't possible with a capsule.

I'm not convinced that soft, non-damaging touchdown on land is impossible with a capsule.


Back to top
Profile
Moon Mission Member
Moon Mission Member
User avatar
Joined: Mon Nov 01, 2004 6:15 pm
Posts: 1233
Location: London, England
Post    Posted on: Thu Oct 23, 2008 4:49 pm
A Hermes sized spaceplane is maybe a little big for what I was thinking of, I believe the original shuttle designs were for a much smaller vehicle but after they tried to make it do everything its size bloated to what it is now.

A vehicle of about 12 to 15m long with a payload bay of something like 3-4m would allow enough storage for a lot of equipment. I dont think you would need to use it for longer duration missions and on orbit time of 2-3 weeks should be enough for most tasks, this could always be extended by docking it to the ISS if needed. I'm not keen on using such a small vehicle for long duration flights (Hermes was supposed to stay on orbit for 30-90 days), especially when we already have the ISS and possibly Bigelow stations coming.

At that size Atlas V, Delta IV, Falcon IX or even Arianne would be able to put it in LEO. An Equivalent sized capsule would need a new booster and kick off another round of booster design/feasibility studies (definitely to be avoided).

_________________
A journey of a thousand miles begins with a single step.


Back to top
Profile WWW
Moderator
Moderator
avatar
Joined: Mon Feb 09, 2004 4:01 am
Posts: 747
Location: New Zealand
Post    Posted on: Thu Oct 23, 2008 5:35 pm
Whatever they did next, it is the lower stages that need to be fully recoverable.

Early shuttles had something like a Mach 8 flyback booster.

The current Orbiter siz would allow the majority of its cargo back to be filled with fuel.

The current TPS is way to complex and the SSME's are way to complex. Orbiters should be designed for 10 flights not 100. etc. etc.

But the Shuttle is first and foremost a work for the dole program. Mike Griffins problems have made this pretty clear.

_________________
What goes up better doggone well stay up! - Morgan Gravitronics, Company Slogan.


Back to top
Profile ICQ YIM
Display posts from previous:  Sort by  
Post new topic Reply to topic  [ 12 posts ] 
 

Who is online 

Users browsing this forum: No registered users and 5 guests


cron
© 2014 The International Space Fellowship, developed by Gabitasoft Interactive. All Rights Reserved.  Privacy Policy | Terms of Use