Resurrecting Apollo? The Orbital Spaceplane may be dumped. (3 Viewers)

[Ashley Seymour]

I was hoping Jack could tell me why you couldn't take the Shuttle and fit it with a piece of molded aluminum on the bottom and spray that heat resistant crap on the bottom. When the Shuttle slowed to subsonic speeds, the shield would be pushed, or blown off and parachute to earth, to be cleaned and refitted for the next launch.

 

[Andrew Testa]

Ashley,

I can give you a number of reasons why that isn't a practical solution:

1st, I doubt that material can compete with the current silica tiles in terms of heat rejection. Surviving a blowtorch is not even close to the reentry temperatures and pressures. The current tiles survive reentry just fine.

2nd, there are a lot of other factors to consider other than heat rejection. How does it behave in vacuum or in multiple hot and cold soaks? Many materials out-gas their solvents in vacuum which may contaminate other systems. The temperature cycles on orbit may cause it to become brittle, shrink, or crack. It's much harder to make a single large surface resist these factors than many small, interconnected pieces. The current system is designed to compensate for thermal cycling and related changes in shape.

3rd, The material would have to be perfectly sculpted to the orbiter designed outline for each flight. The orbiter relies on laminar flow in the early stages of reentry. Any deviation from the design shape would alter the wing response. Even the current system shows the sensitivity of this. If the inter-tile caulking protrudes up from between tiles even a little, the laminar flow can break earlier than planned. It has been reported that on earlier Columbia flights one wing lost laminar flow before the other because it wasn't quite as smooth.

4th, No one would ever allow anything like an aluminum plate to rest against the existing tiles. The launch vibrations would cause the aluminum plate to shatter every single tile underneath it.

5th, No one would ever allow such a plate to just drop off an orbiter. The possibility of a huge plate like that hitting the orbiter as it released is too great.

The current tile system is a pain in the ass and incredibly maintenance intensive, but it works perfectly as designed. The problem we experienced with Columbia was because management began allowing foam strike events to occur when the design spec for the orbiter stated that no strikes on the thermal protection system were acceptable. The system was operating outside of its design so a failure occurred. Complacency is always enemy number one when dealing with space flight. It's never routine, and its never safe enough to say "that didn't hurt us before, so let's not worry about it happening again".

I hope this helped answer your question.

Andy

 

[Ray B.]

As far as the Soyuz landing is concerned, they never land where they're predicted to. I may be wrong, but I don't think they are steerable once they enter the atmosphere. They can use thrusters to steer until the aero forces become too great, then they are simply ballistic.

The Soyuz does nominally use onboard guidance, but is not steerable when running the backup flight software. And, for the first time since 1979, it was for this landing. The crew saw something like 8.2gs this time, which is fairly hairy for a Soyuz entry. Sure, it was off by 248nmi, but that's within the expected range for ballistic entry mode.

By the way, hi everyone. This is my first post here. I've been lurking for a while, enjoying Andrew's posts, as well as others. I'm a flight controller for the Space Shuttle program, specifically a Rendezvous Officer, so I'd imagine Andy and I aren't too far from one another right now.

 

[BrianW]

Welcome, Ray. Thanks for jumping aboard. I know that I, for one, am richer for Andy's presence here, and I anticipate more of the same from your participation.

Andy, you are SO busted!

 

[Lee L]

Anyone else think we just had a really close call with the recent Soyuz landing? I mean, if something happens to one of those things any time soon, I reall fell that the public will lose all interest in manned space flight.

Maybe someone like Andy or Jack can enlighten me but the description I read in the paper, while not coming out and saying so seemed like there were some major problems.

 

[Ray B.]

Maybe someone like Andy or Jack can enlighten me but the description I read in the paper, while not coming out and saying so seemed like there were some major problems.

If I may...

I wouldn't be quick to conclude there was a problem. While it's still undetermined why, exactly, the vehicle went into its backup flight software mode (like the Shuttle's BFS), the entry and landing seen in that backup mode were within the established norms.

 

[Jack Briggs]

Ray, as with Andy, you are most welcome here. I look forward to many more posts from you and your colleague. We have a lot to discuss!



The late Columbia's "rough" left wing is now very much a newsmaker.

Andy, Ray: How confident are either of you in using the present system for maybe as long as until 2020? It's the most amazingly complex vehicle ever to fly and so much can go so wrong. I remember reading some of the speculation coming out of NASA about truly dramatic design upgrades, the most dramatic of which called for dumping the SRBs in favor of liquid-fueled boosters. (I've always been troubled by the vibration stresses caused by SRBs.)

Or has the STS-107 tragedy started to cause some of the decision-makers to reconsider using the STS for that long?

(Comment: Except for HST servicing, I don't think an Orbiter should be sent into space on any mission that doesn't involve ISS. I've always felt that, long before STS-107 [which, as a mission, I felt was unnecessary].)

 

[Andrew Testa]

Andy, you are SO busted!

Hey, I did qualify that by saying I might be wrong. And I certainly would be grateful if other experts call bullshit on me if I get something wrong. I don't want to mislead anyone here, and I like to learn too.

Welcome, Ray.

I'm not only real close, but I've probably seen the back of your head while flipping through all the mission control channels during dull MER duty. I'm pretty sure there are more of us on here: I've seen several people with location tags for League City or Clear Lake. Between the two of us, this one thread has probably contained more information than a month's worth of sci.space.shuttle.

Last news report I read about the crew landing stated that Don had injured his arm, but they "don't know why". At > 8gs I don't think it's too hard to figure out.

Andy

 

[Andrew Testa]

Jack,

Whether we want to or not, we are locked into using the present orbiters for ISS servicing for many years to come. There are proposals floating around to curtail shuttle flights to ISS only, or at least to have all flights (excepting HST service)launch into ISS orbit so an emergency docking can be made.

The history of why the shuttle was used for certain flights is very arguable. I believe that many satellite deployment flights would have been better left to expendables, but NASA has in the past tried to show that the shuttle can replace the expendable vehicles. There certainly have been many flights that could only have been done with an orbiter, where experiments had to be retrieved and returned, or repairs made to existing satellites. Some of the Earth observation or astronomy missions probably cost less to do on the shuttle than developing a satellite bus to carry the equipment, but I'm not sure about that. There's certainly a need for shuttle-only flights, but they have been used for jobs I believe could have been better carried out on other vehicles.

As far as upgrades go, I hope we'll see a turnaround in the approach. I've seen a wall chart in someone's office at JSC that has an orbiter drawing and call-out boxes pointing to all the areas where a major upgrade was planned with a drawing of the new system. As each of the upgrades was canceled, someone put a red X through that box. Last time I saw it almost all the boxes were Xed out. I hope that gets changed. I do not believe the orbiters can continue to fly without a continuing program for upgrades and maintenance techniques. The orbiters are on-going experiments in materials failure: no one has experience with how a vehicle ages going through all the mission cycles these orbiters have experienced. I believe it's asking for trouble to adhere to maintenance routines written into the original specifications as if the orbiters were new. Changes have been made, but not as much as they should. As the orbiter age further we'll likely see an increase in materials failures discovered during processing, such as the recent fuel line cracks and ball cracks. I think it's a mistake to believe the orbiters can safely operate as is for their designed lifetime of 100 missions.

I would love to see more dramatic upgrades, like the use of liquid fuel boosters. I'd go so far as to say they should resurrect the Shuttle-C concept. Shuttle-C was an unmanned variant of the shuttle for launching payloads that didn't require human interaction. Much cheaper than the manned orbiters since it didn't have to be man-rated, and could carry larger payloads without all the cabin and life support. This would limit crew exposure to flights that required their presence, and increase the lifespan of the manned fleet. Much cheaper than developing a whole new launch system.

Andy

 

[Lance Nichols]

I just thought of a question that has me puzzled. Likely just one of those damned legal things. Why not open up any concept system that has "failed" to an open source/fully public access.

that is, if the Venture Star/X-33 composite tank failure was just due to poor composite lay ups, why not open the design to the public. Maybe some aerospace start up, or even one of the existing companies could take the designs and run with it, spending as much, or as little money needed to prove a system or not.

The contracts to build were tendered to a public agency. It might be a good gain for space access if say, the x-33 concept was shown to work.

Afterall, one of the promising X-prize attempts is essentially a new version of the V2/Atlas/Mercury thrust chambers. A lot of research already done, and the benefit of 40+ years of metallurgical and composite science on top of it.

I have not put much thought into this, but surely soneone has thought this though a bit...

 

[Tony Whalen]

Ray, Andy & Jack and everyone else...

...just wanted to say this thread is fascinating! Thanks!

 

[Ray B.]

I'm pretty sure there are more of us on here: I've seen several people with location tags for League City or Clear Lake.

I actually live in League City, where I'm a volunteer firefighter. Space + fire trucks =

 

[Jack Briggs]

You know, seeing as how I'm a writer and all and knowing that the press office at JSC could use some better material, well... (You guys are making me extremely envious. Speaking of the trenches, any of you read Gene Kranz's book which came out last year? I enjoyed the hell out of it. I love insiders' stories.)

 

[Tony Whalen]

Gene Kranz put out a book? Crap! I didn't know that.

Guess I'm off to Chapters tonight....

 

[Ray B.]

any of you read Gene Kranz's book which came out last year?

Of course! Good book. He still comes into the control center once in a while. Kinda makes you sit up straight.

 

[Ray Chuang]

I still think a small spaceplane will get developed.

Remember, since the spaceplane doesn't have to sport lifting engines or space for large cargo items, it can be quite small even when carrying up to seven crew members--small enough that it can be placed on top of a Boeing Delta IV Heavy or uprated Lockheed Atlas V launch rocket.

Unlike the Space Shuttle, since the spaceplane literally sits on top of the launch rocket, that means no worries about falling ice from the booster rocket. Orbital has designed the space plane to have considerable safety margins in case have to jettison the booster rocket for an emergency landing.

One wonders if the Orbital spaceplane is light enough to be launched by the same rocket used to launch the Soyuz capsules.

 

[Lance Nichols]

Tony, it is titled "Failure is not an option" Wonderful read, and his website updates errata and such in the book. Great read.

I love the NASA Mission reports as well, published for all to read by a Canadian publishing company. When I was down in Houston in March I was amused to see that I could get better, and more copies of the reports up in Canada then I could @ JSC.

 

[BrianW]

Hey, I did qualify that by saying I might be wrong.

Sorry, Andy, that's not what I meant. (Have you ever been wrong?) All I meant when I said you'd been "busted" is that you had been "discovered" by a coworker to be participating in a forum, presumably on "company time." I certainly didn't mean to impugn your veracity. But that's okay. Nobody here gets my "jokes" anyway, except maybe for Jack. And he usually ignores my humor in order to appear more, well, more normal.

 

[Holadem]

Don't feel bad Brian, I knew what you meant if it's of any consolation

--
Holadem

 

[CharlesD]

Here's an article on what might have gone wrong with the Soyuz (the Americans blame the Russian software, the Russians blame the American astronauts)

http://www.msnbc.com/news/909677.asp

The Article mentions the technique Andrew mentioned for steering the capsule during descent.