101
votes
Accepted
Did Feynman cite a fallacy about only circles having the same width in all directions as a reason for the Challenger disaster?
This was indeed an avenue of investigation for Feynman. From his autobiographical book What Do You Care What Other People Think?:
Then I investigated something we were looking into as a possible ...
- 3,932
45
votes
Accepted
Space Shuttle Challenger bringing back Salyut-7
No work was ever done on this in the Shuttle Mission Simulator (SMS), so they were nowhere "close to an actual mission". Not even any testing.
Source: I worked to some extent on all missions ...
- 187k
40
votes
Accepted
Challenger Shuttle: could the crew have survived?
One of the major errors in the Space Transportation System (STS) design was the lack of a crew escape system usable from launch to landing.
Escape systems are costly, take up mass allowance that can ...
- 187k
39
votes
Accepted
Why were they using segmented boosters on Space Shuttle?
Four companies submitted bids to build the solid rocket boosters for the Space Transportation System based on the requirements provided by the Space Shuttle Program.
Three of the designs were ...
- 187k
33
votes
Accepted
Challenger hypothetical - what if the SRB breach faced outboard?
Do we get to pick our assumptions? I don't see how to answer this otherwise.
I'll assume the hole kept growing at a "slow rate" and the booster didn't come apart. (If the booster came apart, the ...
- 187k
30
votes
Accepted
Challenger disaster: how full was the external tank at the time of destruction?
I did a crude spreadsheet sim using the Rogers Commission report to get throttle times, to wit:
Throttle down to 94% at 24 seconds
Throttle down to 65% at 42 seconds
Throttle up to 104% at 65 seconds
...
- 187k
26
votes
Challenger disaster: how full was the external tank at the time of destruction?
The breakup of Challenger occurred about 73 seconds into flight. Main engine cutoff normally occurs about 510 seconds into flight, implying that about 86% of the fuel would be remaining. (Many sources ...
- 170k
25
votes
Did Feynman cite a fallacy about only circles having the same width in all directions as a reason for the Challenger disaster?
In addition to Nuclear Wang's answer, Feynman also mentions this during a PBS Newshour interview with Jim Lehrer.
(the relevant part starting at 7:30)
While he ...
22
votes
Did Feynman cite a fallacy about only circles having the same width in all directions as a reason for the Challenger disaster?
Supplemental answer -
Here is a diagram of the Circumferential Alignment Tool that was used during stacking when the SRB segments were "severely" out-of-round.
This diagram is from Volume 2 Appendix ...
- 187k
20
votes
Space Shuttle Challenger bringing back Salyut-7
From the article I can read that they were pretty close to a actual mission
The article doesn't say this. It reports what a modern documentary claims, and then goes on to say that the documentary's ...
- 7,846
18
votes
Was a method available to save the Challenger Crew?
My reading of the function of the SRB manual separation control is that it would not actually trigger a separation while the boosters were firing (bold mine):
SRB separation is normally performed ...
- 170k
17
votes
Challenger Shuttle: could the crew have survived?
Similar systems certainly exist but not at this scale
Some spherical cow approximations - a parachute for a 70kg human weighs 14kg, giving 0.2kg of parachute per kg of payload.
The dry mass of the ...
- 23.4k
14
votes
Accepted
"LVLH" on Challenger's cockpit voice recording: What was that switch for?
Background:
A primary flight instrument for the shuttle pilots was the Attitude Direction Indicator (ADI). In the STS-51L days this was a electromechanical instrument, indicated in the photo by the ...
- 187k
8
votes
Challenger disaster: how full was the external tank at the time of destruction?
A few facts:
SRB Burn Time is 127 seconds
Start of Challenger Incident- 64 s
Vehicle breakup- 72 s
Nominal time to orbit- 510 s.
So the SRBs were about half-way done with their burn time before the ...
- 122k
8
votes
Could Dick Scobee have flown a RTLS on Challenger 51L
Hypothetically speaking, let's assume the boosters could have somehow detached at T+74s, and had no impact the shuttle. Let's also assume there is no leaking fuel somehow.
The acceleration at T+74s ...
- 122k
7
votes
"Reading 486" air speed from Challenger disaster: What units?
The units are knots, the parameter is Equivalent Airspeed (EAS). Equivalent Airspeed is the speed you'd have to be flying at sea level standard conditions to give your current dynamic pressure.
Back ...
- 187k
6
votes
Why were they using segmented boosters on Space Shuttle?
As alluded to by Organic Marble, transport from factory to assembly is/was a major issue. The SRB segments are transported mainly by rail flatcar and so have to fit within the standard dimensional ...
- 61
5
votes
Challenger hypothetical - what if the SRB breach faced outboard?
The correct response to this question, is that it could not happen.
The only location in which a Challenger type leak could occur is within 10 degrees of the ET attachment. The interaction between the ...
- 767
3
votes
"LVLH" on Challenger's cockpit voice recording: What was that switch for?
In order to measure your attitude (orientation) in space, you need a reference frame (something to measure against). In some cases, you might want to use an inertial reference frame - essentially ...
- 2,069
3
votes
Could Dick Scobee have flown a RTLS on Challenger 51L
No, it was impossible.
This graph shows that three engines out prior to SRB sep always results in a black zone (defined as "loss of control and/or structural failure or ditching").
Also note that a ...
- 187k
3
votes
Could Dick Scobee have flown a RTLS on Challenger 51L
TL;DR: No
Successful SRB Sep would have been impossible prior to Pc<50
The SRB-to-ET forward attach fitting was a ball-and-socket joint that carried 100% of the SRB thrust loads to a thrust beam ...
- 17.4k
3
votes
Why were they using segmented boosters on Space Shuttle?
Railroad historian here. The apocryphal Roman chariot story actually has a lot of truth to it. To summarize: Roman chariots had a particular, standardized wheel track. This was designed on the ...
2
votes
What was the Lockheed design solution for the shuttle SRB field joint and how was it superior to the failure prone Morton Thiokol field joint?
Partial answer: Image of the joint, no attempt to describe if or why it was better.
From TECHNICAL REPORT
ANALYSIS AND DESIGN
STUDY OF SOLID ROCKET MOTORS
FOR A SPACE SHUTTLE BOOSTER Volume 2 Book 1
...
- 187k
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