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#1720
by
DarkenedOne
on 08 Mar, 2011 00:27
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Hey guys I was just wondering if anybody could tell me whether or not the reusable solid rocket boosters used by the Shuttle were any cheaper than expendable ones.
The costs are pretty much a wash. The rationale for continuing to recover them is more postflight analysis for safety trends than economics.
Why is that necessary especially after a decent number have flown?
1) To serve as an end-check of process integrity and prevent "escapes".
2) Define "decent number". The number of shuttle flights to date (133) would not even suffice for a flight-test program for a typical airliner or military plane. It is still very much an experimental vehicle.
Well by airliner standards it was experimental, but as far as space vehicles go few vehicles have a longer track record.
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#1721
by
Jorge
on 08 Mar, 2011 00:34
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Hey guys I was just wondering if anybody could tell me whether or not the reusable solid rocket boosters used by the Shuttle were any cheaper than expendable ones.
The costs are pretty much a wash. The rationale for continuing to recover them is more postflight analysis for safety trends than economics.
Why is that necessary especially after a decent number have flown?
1) To serve as an end-check of process integrity and prevent "escapes".
2) Define "decent number". The number of shuttle flights to date (133) would not even suffice for a flight-test program for a typical airliner or military plane. It is still very much an experimental vehicle.
Well by airliner standards it was experimental, but as far as space vehicles go few vehicles have a longer track record.
NASA managers fooled themselves into thinking that, too. Got slapped pretty hard by both accident investigation boards for it. Both accident reports emphatically recommended NASA treat the shuttle as experimental. And gathering forensic data after each flight is one thing you do on experimental vehicles.
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#1722
by
iskyfly
on 08 Mar, 2011 00:36
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Great video. Thanks for posting.
Sounds like you haven't seen it before. I would have thought full members would have seen it by now.
Glad to see i havent rehashed something.
PC 'ducer, not booster. PC means "chamber pressure" and 'ducer is short for transducer. Bias means the 'ducer is reading differently than it should.
So in this case, PC should have been 0 since it was pre-ignition?
I'm guessing that this is a known "signature" and therefore doesnt mandate a scrub / troubleshooting? Is there a limit to where a bias would raise eyebrows?
Counting up to roll program, I think, but I'm not an ascent guy.
I thought that as well.... just wondering why I havent seen it done on other launches.
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#1723
by
Jorge
on 08 Mar, 2011 01:16
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PC 'ducer, not booster. PC means "chamber pressure" and 'ducer is short for transducer. Bias means the 'ducer is reading differently than it should.
So in this case, PC should have been 0 since it was pre-ignition?
I *think* the ducer in question returns psia, not psig, so it should have been reading around 14.7 since the nozzle was exposed to ambient pressure.
I'm guessing that this is a known "signature" and therefore doesnt mandate a scrub / troubleshooting? Is there a limit to where a bias would raise eyebrows?
Yes.
Counting up to roll program, I think, but I'm not an ascent guy.
I thought that as well.... just wondering why I havent seen it done on other launches.
If mkirk was still around he might have been able to answer that.
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#1724
by
Lee Jay
on 08 Mar, 2011 01:34
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Well by airliner standards it was experimental, but as far as space vehicles go few vehicles have a longer track record.
Just because it's a space vehicle doesn't make it inherently safer and thus certifiable in a shorter time frame. Quite the contrary, in fact.
http://787flighttest.com/3103 flight hours and 1065 flights so far, and still not certified. Imagine what it would take to fully certify a vehicle that carries 1000 times more energy and has far fewer intact failure and abort options.
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#1725
by
DarkenedOne
on 08 Mar, 2011 02:41
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Quick question for you guys.
Why is it that NASA never bothered to place a flight data recorder in the space shuttles?
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#1726
by
Namechange User
on 08 Mar, 2011 02:44
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Quick question for you guys.
Why is it that NASA never bothered to place a flight data recorder in the space shuttles?
Downlinked telemetry. There is also MADS which records some measurements that aren't down listed
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#1727
by
Jorge
on 08 Mar, 2011 02:49
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Quick question for you guys.
Why is it that NASA never bothered to place a flight data recorder in the space shuttles?
Downlinked telemetry. There is also MADS which records some measurements that aren't down listed
There is also the OPS recorders, since replaced with solid state recorders.
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#1728
by
brettreds2k
on 09 Mar, 2011 09:41
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Was wondering what the out lined plan is when Discovery comes home today, and she is rolled back to the OPF today, what steps and time frame will it take for her to be decommissioned and how much of her internals will she actually loose? After seeing pictures of how enterprise was gutted, I'd hate to see the orbiters have it happen to
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#1729
by
Chris Bergin
on 09 Mar, 2011 09:43
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Was wondering what the out lined plan is when Discovery comes home today, and she is rolled back to the OPF today, what steps and time frame will it take for her to be decommissioned and how much of her internals will she actually loose? After seeing pictures of how enterprise was gutted, I'd hate to see the orbiters have it happen to
Fully outlined in L2. I'll be writing an article on the process post mission.
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#1730
by
JayP
on 09 Mar, 2011 14:21
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...After seeing pictures of how enterprise was gutted, I'd hate to see the orbiters have it happen to
The interior apperance of OV-101 is a result of a combination of the facts that it wasn't ever fitted out completely to begin with and they removed everything that they could use as spares for the rest of the fleet or was dangerous to keep in the orbiter (like pyros). The rest of the fleet will have parts of the MPS including the entire SMEs removed (to be used for testing of future designs) and the hazardous systems will be removed or inerted and that is about it.
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#1731
by
iskyfly
on 09 Mar, 2011 14:49
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...After seeing pictures of how enterprise was gutted,
where can these pictures be found?
thanks!
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#1732
by
JayP
on 09 Mar, 2011 16:52
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...After seeing pictures of how enterprise was gutted,
where can these pictures be found?
thanks!
There's some in Jenkins. You might try googling "enterprise" + " crew cabin" or "payload bay"
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#1733
by
iskyfly
on 09 Mar, 2011 17:37
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There's some in Jenkins. You might try googling "enterprise" + " crew cabin" or "payload bay"
thanks... please disregard though.... i was reading enterprise, but thinking endeavour... i said to myself, "they have already gutted her!??".
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#1734
by
iskyfly
on 09 Mar, 2011 17:40
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has any data from the protuberance tests been released and if so, where can it be found?
thanks
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#1735
by
AnalogMan
on 09 Mar, 2011 18:08
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#1736
by
Namechange User
on 09 Mar, 2011 21:12
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Joe Engle mentioned that the experimental entry maneuvers of STS-2 heated up the wings a little extra and reduced the total number of flights that Columbia would be allowed to make. Do we know the number of flights a shuttle could make before its structure would be considered too fatigued? Just wondering how the number 39 (for Discovery) compares to that number.
The vehicle, 102 included, is certified for 100 missions each. Obviously there are inspections performed every flow and more detailed inspections during OMDP. However, from a structure and system standpoint, there has been and is nothing suggesting that number is less.
Columbia was also still certified for 100 missions at the time of her loss.
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#1737
by
Mark Dave
on 09 Mar, 2011 22:51
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What was used to simulate the tiles for Enterprise? I know from the CAIB report that the RCC is made from fiberglass.
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#1738
by
JayP
on 10 Mar, 2011 00:11
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What was used to simulate the tiles for Enterprise? I know from the CAIB report that the RCC is made from fiberglass.
Polystyrene foam
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#1739
by
Namechange User
on 10 Mar, 2011 00:14
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Joe Engle mentioned that the experimental entry maneuvers of STS-2 heated up the wings a little extra and reduced the total number of flights that Columbia would be allowed to make. Do we know the number of flights a shuttle could make before its structure would be considered too fatigued? Just wondering how the number 39 (for Discovery) compares to that number.
The vehicle, 102 included, is certified for 100 missions each. Obviously there are inspections performed every flow and more detailed inspections during OMDP. However, from a structure and system standpoint, there has been and is nothing suggesting that number is less.
Columbia was also still certified for 100 missions at the time of her loss.
Only 39 out of 100 possible is sadder than I thought. Still at the top of her game, as they keep saying.
Absolutely. There are very intersting metrics that show the number of IPRs, PRs, IFAs, etc down considerably in a very smooth curved trend.
Glad to see i havent rehashed something.