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#140
by
Jim
on 21 Dec, 2019 15:10
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Could this anomaly be the result of human error based on the recent discussions on this thread?
I don't see how it could be anything but human error.
We simply don't have enough information to make that kind of judgment call right now. Let's not get ahead of ourselves
Much like anybody stating the issue is company wide.
Any comparison to the Max problem is completely clueless
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#141
by
arachnitect
on 21 Dec, 2019 15:11
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I thought the insertion burn was relatively small. Why do they have to be suborbital to burn that amount of propellant?
Without the phasing delta-v, you'd need:
33 m/s to go from the initial 72 x 181 to 181 x 181
67 m/s to go from 181 x 181 to 181 x 410
65 m/s to go from 181 x 410 to 408 x 410
Throw in another 35 m/s for phasing corrections and other rendezvous/docking jiggery-pokery and you're at a nice round 200 m/s.
I assume that they're using RCS, and not the abort thrusters, so... Isp=210? With a 13 t vehicle, that would eat up 1.2 t of prop. That's not chickenfeed.
Two things:
1) I wonder if having the prop in the SM instead of in the CM gave them trouble with the torque and moment limits for the IDA and NDS.
2) If you were dead-set on justifying your existence by competing on down-mass, you'd want to find a way to burn off every last kg of prop you could. I wonder if Boeing feels that they need to justify their higher price by providing more value on down-mass, and that led them to make what seems to be shaping up to be a dumb call.
This helps, but they're only suborbital for 17% of that.
I'm not saying Starliner doing insertion burn is wrong, I just don't understand the "extraneous abort prop" argument.
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#142
by
argjlg
on 21 Dec, 2019 15:34
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Could this anomaly be the result of human error based on the recent discussions on this thread?
I don't see how it could be anything but human error.
We simply don't have enough information to make that kind of judgment call right now. Let's not get ahead of ourselves
I think the subtlety of the "I don't see how it could be anything but human error" comment was missed. Its what HAL told Dave Bowman when Mission Control told Dave there was a discrepancy between HAL and the ground-based 9000 unit....
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#143
by
Yazata
on 21 Dec, 2019 16:17
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Shows again and again nothing beats a properly trained crew. They would of flown the correct mission.
That's what the astronauts said at the press conference and I have no reason not to believe them. I believe that this was a contingency that they've trained for on the simulators. They sounded frustrated that they weren't up there to handle it and save the mission.
Engineers think their computers can fly the air or spacecraft better and are wrong. The Max is a great example of this taking control away from the crew and causing crashes. Am sad to say Boeing steps in it again.
I'm going to disagree there. This was an unmanned test flight by design. So relying on computers instead of crew was part of the mission description, not an expression of bad Boeing design culture. There may have been some bad software in one of the computers, but that's a different problem.
Looks like Space X will be the first to restore crewed flight to the USA.
Yes, that's probably true. Of course it looked that way even before Friday's events. We probably should remember that SpaceX's Demo-1 mission carried no crew and relied on computers too.
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#144
by
ZachF
on 21 Dec, 2019 16:26
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Could this anomaly be the result of human error based on the recent discussions on this thread?
I don't see how it could be anything but human error.
We simply don't have enough information to make that kind of judgment call right now. Let's not get ahead of ourselves
Much like anybody stating the issue is company wide.
Any comparison to the Max problem is completely clueless
Yes, there is absolutely no way you could say that multiple major problems stemming from poor corporate/managerial culture across several divisions with increasing frequency can be the result of poor overall corporate/managerial culture.
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#145
by
Lee Jay
on 21 Dec, 2019 16:27
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Shows again and again nothing beats a properly trained crew.
There are airplanes (i.e. B2) that couldn't be flown by *any* properly-trained crew, without the assistance of computers. And Atlas' near-perfect orbit insertion could likely not have been flown by any human.
They would of flown the correct mission.
Possibly.
Engineers think their computers can fly the air or spacecraft better and are wrong.
That's a generalization, and thus wrong.
The Max is a great example of this taking control away from the crew and causing crashes.
That statement makes it sound like you know nothing about the 737 Max situation. Hint: Despite a mindbogglingly stupid control design, the flight crews had full control over the elevator trim, had they exercised that control. No one really knows why they didn't. It could have been the "startle" effect.
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#146
by
Rocket Science
on 21 Dec, 2019 16:28
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Could this anomaly be the result of human error based on the recent discussions on this thread?
I don't see how it could be anything but human error.
We simply don't have enough information to make that kind of judgment call right now. Let's not get ahead of ourselves
I think the subtlety of the "I don't see how it could be anything but human error" comment was missed. Its what HAL told Dave Bowman when Mission Control told Dave there was a discrepancy between HAL and the ground-based 9000 unit....
Welcome to the forum!
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#147
by
OM72
on 21 Dec, 2019 16:36
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What I find interesting is whereas Boeing finds it necessary to empty the abort engine fuel tanks on entry into orbit, which would be jettisoned before reentry, SpaceX does not feel the need for this. As well as not emptying the fuel tanks the Dragon capsule retains fuel onboard not only in orbit but through reentry and touchdown.
There's nothing magical about it. Just different concept of operations. Reason for Starliner doing this was a conscious decision to reduce MMOD risk since the vehicle will be there for approximately 6 months at a time during standard missions. Reducing the amount of prop to basically what is required (since abort is no longer in the equation) has an impact on the overall risk assessment.
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#148
by
OM72
on 21 Dec, 2019 16:40
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The Starliner also offers the possibility for Space Station reboost.
I suspect Starliner is pulling the ISS and therefore always docking on IDA-2.
So there should normally be fuel reserves.
https://www.rocket.com/space/human-exploration/cst-100-starliner
Docking does not always necessarily need, nor likely will be, to that IDA/PMA. In the event reboost is planned it will be on the forward docking port for efficiency/structural loads.
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#149
by
marsbase
on 21 Dec, 2019 16:42
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Starliner's early flight profile centers on getting rid of highly explosive and toxic propellants used in the abort system. Dragon and Starliner suffered destructive events due to the same agents. Given the uncertain outcome of any abort attempt and the apparent danger to ground and flight crews of just having the stuff around, is it possible the crews would be safer with no abort system?
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#150
by
meekGee
on 21 Dec, 2019 16:42
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Shows again and again nothing beats a properly trained crew. They would of flown the correct mission. Engineers think their computers can fly the air or spacecraft better and are wrong. The Max is a great example of this taking control away from the crew and causing crashes. Am sad to say Boeing steps in it again. Looks like Space X will be the first to restore crewed flight to the USA.
You could start a running list:
Cases where a live crew would have done better than the computers did, and cases where it's exactly the opposite.
One differentiator between computers and crew is that when you fix a computer mistake, you fix it for all future flights on all vehicles. Human mistakes, OTOH, are bound to recur.
Humans have the advantage in the beginning, when bugs are more common - but they do sometimes also react wrong and turn a small problem into a much larger one. (Shades of Air France 447)
This Starliner incident is a classic where in retrospect, the astronauts say they would have saved the mission.
Nobody can predict what would have happened in reality, as mission control and the astronauts grappled with a malfunctioning crewed vehicle on a suborbital trajectory..
There's a good likelihood that they would have followed the reasoning that informed this mission design and just splashed down right away.
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#151
by
OM72
on 21 Dec, 2019 16:48
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Given the uncertain outcome of any abort attempt and the apparent danger to ground and flight crews of just having the stuff around, is it possible the crews would be safer with no abort system?
This is one of those hypothetical questions that truly can only be answered by history and after the conclusion of the programs. Obviously Starliner and Dragon hope to never have to use the abort system but then again it's possible it will have to be used by one or both. So in the overall design trade space and reducing the risk associated with LOC both vehicles incorporate it.
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#152
by
Lee Jay
on 21 Dec, 2019 16:53
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Could this anomaly be the result of human error based on the recent discussions on this thread?
I don't see how it could be anything but human error.
We simply don't have enough information to make that kind of judgment call right now. Let's not get ahead of ourselves
Much like anybody stating the issue is company wide.
Any comparison to the Max problem is completely clueless
Yes, there is absolutely no way you could say that multiple major problems stemming from poor corporate/managerial culture across several divisions with increasing frequency can be the result of poor overall corporate/managerial culture.
Prove that any of this has stemmed from "poor corporate/managerial culture".
I've had good and bad management. One thing I do is write control software. The quality of my control software has nothing to do with the quality of my management. In fact, management has exactly nothing to do with any of it. I don't know if that's the case inside Boeing, and neither do you.
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#153
by
marsbase
on 21 Dec, 2019 17:04
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Obviously Starliner and Dragon hope to never have to use the abort system but then again it's possible it will have to be used by one or both. So in the overall design trade space and reducing the risk associated with LOC both vehicles incorporate it.
I thought both vehicles incorporate it because NASA requires it. It's not like two independent analyses arrived at the same conclusion. NASA is hyper-sensitive about crew dangers after losing two Shuttles with no escape system. They have talked about the scars remaining from those experiences. I guess Soyuz has had success with an abort system that I think has been used 3 times (?) but I don't think we know how many injuries and deaths have occurred due to the abort system propellants.
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#154
by
Lee Jay
on 21 Dec, 2019 17:05
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So, in case you don't know it, L2 is awesome. One thing in there is every IFA report from every shuttle flight. Long ago, I downloaded them because they make fascinating reading.
I just looked up the one for STS-1. Two interesting things:
There are 73 reports (that was a rough count) for just this one flight. In other words, first-flight issues are common.
The very first one in the document is entitled, "Interface timing skew between primary and backup computer software during countdown." Hmmm...a timing issue. How about that.
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#155
by
meekGee
on 21 Dec, 2019 17:12
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Could this anomaly be the result of human error based on the recent discussions on this thread?
I don't see how it could be anything but human error.
We simply don't have enough information to make that kind of judgment call right now. Let's not get ahead of ourselves
Much like anybody stating the issue is company wide.
Any comparison to the Max problem is completely clueless
Yes, there is absolutely no way you could say that multiple major problems stemming from poor corporate/managerial culture across several divisions with increasing frequency can be the result of poor overall corporate/managerial culture.
Prove that any of this has stemmed from "poor corporate/managerial culture".
I've had good and bad management. One thing I do is write control software. The quality of my control software has nothing to do with the quality of my management. In fact, management has exactly nothing to do with any of it. I don't know if that's the case inside Boeing, and neither do you.
In my organization, the quality department is intentionally separated from the development departments, so it would not be under your control either.
You'd write the best software you can, and quality would go through the motions of "assurance". Sometimes it's effective, sometimes it's a farce.
You know who has major influence on which it is? That's right - management.
One of the few times they actually do something important is when they set up the relationship between these departments and make sure the processes are meaningful and the people involved are effective.
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#156
by
TheRadicalModerate
on 21 Dec, 2019 18:24
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So, in case you don't know it, L2 is awesome. One thing in there is every IFA report from every shuttle flight. Long ago, I downloaded them because they make fascinating reading.
I just looked up the one for STS-1. Two interesting things:
There are 73 reports (that was a rough count) for just this one flight. In other words, first-flight issues are common.
The very first one in the document is entitled, "Interface timing skew between primary and backup computer software during countdown." Hmmm...a timing issue. How about that.
I was an extremely lowly software geek working on BFS (the backup flight system) during that bug. It wasn't really a timing issue, or at least not a tim
er issue, and it certainly wasn't one that was a quarter of an orbit off. Instead, PASS (the primary avionics software, written by IBM) managed to drive all the I/O for one of the flight strings into the wrong 40 ms minor cycle, through something dumb that the interrupt system did. Then when BFS came up, it saw four computers putting out what it thought was wrong information and therefore refused to sync.
I was too lowly to have gone to the cape for the launch, but my boss came back hopping mad, because IBM had seriously out-PRed Rockwell and managed to blame them, when it was clearly IBM's bug. Some things never change.
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#157
by
Jim
on 21 Dec, 2019 18:38
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Max problem should be off topic as it relates to Starliner. Completely different Boeing organizations. The space organization is not even legacy Boeing and totally unrelated to Boeing Commercial Aircraft.
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#158
by
Chris Bergin
on 21 Dec, 2019 19:10
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Max problem should be off topic as it relates to Starliner. Completely different Boeing organizations. The space organization is not even legacy Boeing and totally unrelated to Boeing Commercial Aircraft.
Everyone take note of this. It's been said before. It's obvious. Anyone who does not appreicate needs to know they will get picked up on it here, so don't.
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#159
by
Sam Ho
on 21 Dec, 2019 19:32
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I guess Soyuz has had success with an abort system that I think has been used 3 times (?) but I don't think we know how many injuries and deaths have occurred due to the abort system propellants.
Soyuz SAS has killed 3 ground crew (1966) and saved 6 flight crew (1975, 1983, 2018).
