Author Topic: SpaceX F9 : Crew Dragon In-Flight Abort Test : Jan. 19, 2020 : Discussion (Read 366126 times)

rpapo · « **Reply #640 on:** 01/19/2020 05:04 pm »

Quote from: Nomadd on 01/19/2020 05:03 pm

So, did the 2nd stage blow in the air with the 1st staying intact until hitting the water?

Contrary to what others have said here, Elon thought it was the lower half of the first stage. Because the thrust structure is so robust. Though those pictures sure do look like the interstage and the second stage...

rcoppola · « **Reply #641 on:** 01/19/2020 05:05 pm »

The question of when DM-2 will fly is not just about the technical / data / etc...but also about the political. About the "who" goes first and captures the flag, Spacex or Boeing. That's the vibe I was getting from any Q&A wrt DM-2.

That's the primary reason Jim locked everyone's response down.

punder · « **Reply #642 on:** 01/19/2020 05:12 pm »

Quote from: rcoppola on 01/19/2020 05:05 pm

The question of when DM-2 will fly is not just about the technical / data / etc...but also about the political. About the "who" goes first and captures the flag, Spacex or Boeing. That's the vibe I was getting from any Q&A wrt DM-2.

That's the primary reason Jim locked everyone's response down.

If the long duration option is chosen, conceivably it could push Demo 2 beyond Starliner to give the astronauts time to train up for ISS ops?

Congrats to NASA and SpaceX for an amazing test.

winkhomewinkhome · « **Reply #643 on:** 01/19/2020 05:24 pm »

Quote from: rcoppola on 01/19/2020 05:05 pm

The question of when DM-2 will fly is not just about the technical / data / etc...but also about the political. About the "who" goes first and captures the flag, Spacex or Boeing. That's the vibe I was getting from any Q&A wrt DM-2.

That's the primary reason Jim locked everyone's response down.

So somewhat to that point, Jim intentionally or not laundry-listed THE (apparent) FACTS that SpaceX & Dragon NAILED EVERYTHING, and will proceed to the next step, assuming the data supports the apparent...

Boeing and Starliner did not, all things being equal, should they not repeat the step(s) they failed?

Norm38 · « **Reply #644 on:** 01/19/2020 05:29 pm »

I wish the telemetry question hadn’t been misunderstood. Of course there wouldn’t be telemetry after the F9 failed.
But there was a good 10 seconds between separation and the boom.
I would assume they received those 10 seconds of data. And that data showing how the structure behaved could confirm expectations, or possibly reveal something unexpected.

oiorionsbelt · « **Reply #645 on:** 01/19/2020 05:35 pm »

If I were riding one of the two new vehicles, it would be more reassuring to be in Dragon, having demonstrated what it's capable of in off nominal situation.
StarLiner on the other hand is relying on simulations for their abort certification and given what happened on their last test how much confidence do they have in their simulation now?

Jeff Lerner · « **Reply #646 on:** 01/19/2020 05:43 pm »

This so called friendly “return the flag” challenge, while I’m sure intended to be a motivator, has IMHO, turned out to be the opposite...my sense is that there is a lot more at play here...political games, etc...my opinion only but seems that SpaceX has gone above and beyond NASA requirements for Commercial Crew and yet the reins are pulled back on them to allow Boeing and Starliner to catch up...

If the two first crews assigned to both vehicles were asked, would you fly tomorrow I wonder if both would answer yes...

punder · « **Reply #647 on:** 01/19/2020 05:44 pm »

I've read the the abort was timed for max drag, not max Q. Is that true? I don't understand the difference. I would expect them to be the same thing. Can someone explain it for me?

TrueBlueWitt · « **Reply #648 on:** 01/19/2020 05:44 pm »

Shouldn't Dragon have been recovered by now?

Elon seemed a little less enthusiastic or coy about it after he looked through his phone messages about recovery progress in the presser.

clongton · « **Reply #649 on:** 01/19/2020 05:58 pm »

Quote from: cebri on 01/19/2020 03:32 pm

https://twitter.com/turndownformars/status/1218925720736600066

Source file: https://pbs.twimg.com/media/EOp-eStWsAMnJ0J.jpg

Incredible

What an awesome photo. This answers a question that has been posed here several times:
How fast is the automated command to initiate abort - does crew have time to override? When you listen to the SpaceX Senior Integration Engineer, who was one of the 2 commentators this morning, he said that the sequence of events was that 1st, S1 would be commanded to shut down. Then that loss of thrust would be recognized by Dragon as an abortable event and initiate the abort. 1st, stage 1 shutdown. 2nd, resultant loss of thrust initiates the abort as commanded by Dragon.

This picture demonstrates just how rapid that sequence is. Even though S1 has been commanded to shut down, it is still performing the shutdown, still burning a little when Dragon recognizes that loss of thrust and the abort is initiated by Dragon. F9 and Dragon Engine firing nearly simultaneously is clearly shown in this photo. A fraction of a second later and there would have been no F9 engine activity. This was really, really fast, a million to 1 photo. If any crew had been onboard, the 1st indication they would have that an abort was underway would be the sudden g-forces on them as Dragon accelerated away. That's when they would know for the first time that an abort command had been executed. No crew intervention is possible.

CorvusCorax · « **Reply #650 on:** 01/19/2020 05:59 pm »

Quote from: TrueBlueWitt on 01/19/2020 05:44 pm

Shouldn't Dragon have been recovered by now?

Elon seemed a little less enthusiastic or coy about it after he looked through his phone messages about recovery progress in the presser.

This tweet kinda debunks the "less enthusiastic"

https://twitter.com/joroulette/status/1218956288559910918

rcoppola · « **Reply #651 on:** 01/19/2020 06:04 pm »

Jim Bridenstine texted out a few minutes ago that Dragon has been recovered and is on-board.

clongton · « **Reply #652 on:** 01/19/2020 06:21 pm »

Quote from: rcoppola on 01/19/2020 05:05 pm

The question of when DM-2 will fly is not just about the technical / data / etc...but also about the political. About the "who" goes first and captures the flag, Spacex or Boeing. That's the vibe I was getting from any Q&A wrt DM-2.

That's the primary reason Jim locked everyone's response down.

Whoever EARNS first crewed flight should be awarded first crewed flight - period - without regard to whether it's Boeing or SpaceX. But if SpaceX earns it and NASA delays the flight to allow Boeing to catch up and then awards it to Boeing, there are going to be a LOT of very, VERY upset people, like me for example.

BeamRider · « **Reply #653 on:** 01/19/2020 06:24 pm »

An observation: in the best stabilized fireball photos, I see multiple individual contrails extending forward from the fireball along the flight path. My guess is that those are the Merlin engines, as they would be the heaviest and most structurally strong parts of the booster.

Question: during the pre-test news conference it was stated that the Merlins would be shut down immediately before the Dragon sep was commanded. But in the NSF main page coverage, it is worded that the shutdown would be sensed as a failure by the safety software, and it would initiate the abort, not that it would be human-commanded. This was also the way I had read the process described in previous NSF and other news coverage. Why the two differing explanations?

clongton · « **Reply #654 on:** 01/19/2020 06:39 pm »

Quote from: BeamRider on 01/19/2020 06:24 pm

Question: during the pre-test news conference it was stated that the Merlins would be shut down immediately before the Dragon sep was commanded. But in the NSF main page coverage, it is worded that the shutdown would be sensed as a failure by the safety software, and it would initiate the abort, not that it would be human-commanded. This was also the way I had read the process described in previous NSF and other news coverage. Why the two differing explanations?

Can't answer that but if you assume that a single person on the ground commanded both the shutdown and abort operations, one immediately after the other, it still would not be possible. Less than 700 milliseconds separated Merlin shutdown command and abort initiation command. No human being can execute 2 completely separate commands that fast. Even 2 people working in concert couldn't do it because it would take longer than that for the 2nd person to recognize that the first person had executed his command. So it isn't possible that the entire sequence was human executed. A ground controler could very well have executed the Merlin shutdown sequence, but it was Dragon that saw it and aborted off the F9 - by itself, in less than 700 milliseconds.

Edit: Listening to Elon again it becomes clear that the abort sequencer aboard Dragon was desensitized enough that it detected some artificially created abort condition and Dragon then commanded the F9 engine shutdown, followed almost immediately by Dragon commanding the abort firing. Ground control did not initiate it - Dragon did.

Rondaz · « **Reply #655 on:** 01/19/2020 06:46 pm »

NASA, SpaceX Complete Final Major Flight Test of Crew Spacecraft

James Cawley Posted on January 19, 2020

NASA and SpaceX completed a launch escape demonstration of the company’s Crew Dragon spacecraft and Falcon 9 rocket Sunday. This was the final major flight test of the spacecraft before it begins carrying astronauts to the International Space Station under NASA’s Commercial Crew Program.

The launch escape test began at 10:30 a.m. EST with liftoff from historic Launch Complex 39A at NASA’s Kennedy Space Center in Florida on a mission to show the spacecraft’s capability to safely separate from the rocket in the unlikely event of an inflight emergency.

“This critical flight test puts us on the cusp of returning the capability to launch astronauts in American spacecraft on American rockets from American soil,” said NASA Administrator Jim Bridenstine. “We are thrilled with the progress NASA’s Commercial Crew Program is making and look forward to the next milestone for Crew Dragon.”

As part of the test, SpaceX configured Crew Dragon to trigger a launch escape about 1.5 minutes after liftoff. All major functions were executed, including separation, engine firings, parachute deployment and landing. Crew Dragon splashed down at 10:38 a.m. just off the Florida coast in the Atlantic Ocean.

“As far as we can tell thus far, it’s a picture perfect mission. It went as well as one can possibly expect,” said Elon Musk, chief engineer at SpaceX. “This is a reflection of the dedication and hard work of the SpaceX and NASA teams to achieve this goal. Obviously, I’m super fired up. This is great.”

Teams of personnel from SpaceX and the U.S. Air Force 45th Operations Group’s Detachment-3 out of Patrick Air Force Base will recover the spacecraft for return to SpaceX facilities in Florida and begin the recovery effort of the Falcon 9, which broke apart as planned.

“The past few days have been an incredible experience for us,” said astronaut Doug Hurley. “We started with a full dress rehearsal of what Bob and I will do for our mission. Today, we watched the demonstration of a system that we hope to never use, but can save lives if we ever do. It took a lot of work between NASA and SpaceX to get to this point, and we can’t wait to take a ride to the space station soon.”

Prior to the flight test, teams completed launch day procedures for the first crewed flight test, from suit-up to launch pad operations. The joint teams now will begin the full data reviews that need to be completed prior to NASA astronauts flying the system during SpaceX’s Demo-2 mission.

NASA’s Commercial Crew Program is working with the American aerospace industry as companies develop and operate a new generation of spacecraft and launch systems capable of carrying crews to low-Earth orbit and the International Space Station. Commercial human space transportation to and from the station will provide expanded utility, additional research time and broader opportunities for discovery on the orbiting laboratory. The program also has the benefit of facilitating and promoting for America a vibrant economy in low-Earth orbit.

https://blogs.nasa.gov/commercialcrew/2020/01/19/nasa-spacex-complete-final-major-flight-test-of-crew-spacecraft/

winkhomewinkhome · « **Reply #656 on:** 01/19/2020 06:47 pm »

Apologies if this has been asked...

In this test ALL of the Merlins shutdown, and then the abort initiated...

I imagine there is a constantly evolving algorithm that would evaluate all the variables, and then relative to one, two, four engines out when to proceed to abort.

Thinking of the Falcon9 & CRS flight that lost one engine on the climb would not merit pulling the lever and aborting...

Thoughts and or informed opinions, maybe even facts about abort criteria parameters?

Rondaz · « **Reply #657 on:** 01/19/2020 06:48 pm »

Trust me... surviving a rocket failure by way of a successful abort system made today’s test personal. Thank you @SpaceX & @usairforce Guardian Angels!

https://twitter.com/AstroHague/status/1218930159165812736

Oberon_Command · « **Reply #658 on:** 01/19/2020 06:53 pm »

Quote from: clongton on 01/19/2020 06:39 pm

Quote from: BeamRider on 01/19/2020 06:24 pm
Question: during the pre-test news conference it was stated that the Merlins would be shut down immediately before the Dragon sep was commanded. But in the NSF main page coverage, it is worded that the shutdown would be sensed as a failure by the safety software, and it would initiate the abort, not that it would be human-commanded. This was also the way I had read the process described in previous NSF and other news coverage. Why the two differing explanations?

Can't answer that but if you assume that a single person on the ground commanded both the shutdown and abort operations, one immediately after the other, it still would not be possible. Less than 700 milliseconds separated Merlin shutdown command and abort initiation command. No human being can execute 2 completely separate commands that fast. Even 2 people working in concert couldn't do it because it would take longer than that for the 2nd person to recognize that the first person had executed his command. So it isn't possible that the entire sequence was human executed. A ground controler could very well have executed the Merlin shutdown sequence, but it was Dragon that saw it and aborted off the F9 - by itself, in less than 700 milliseconds.

No, that is not correct in the general case. Experienced, professional real-time strategy gamers take several actions per *second*, for tens of minutes on end. See:
.

For professional StarCraft players, an "actions per minute" score would be up in the 200-300 range. Experienced first-person shooter gamers would notice a single *frame* (16ms) of latency between them activating a control and the game responding.

700 milliseconds is an *eternity* in the real-time video game world. Even amateur gamers start to complain when their network latency goes above 200 milliseconds.

With proper and intensive training, and a properly helpful - and low latency, which I'm willing to believe is the real problem here - user interface, a human could trigger an abort upon seeing an engine shutdown in less than 700 milliseconds. They might not be *as* fast or as accurate as the computer, I'll grant you, but I am very confidant that it can be done.

rpapo · « **Reply #659 on:** 01/19/2020 06:54 pm »

Quote from: winkhomewinkhome on 01/19/2020 06:47 pm

Apologies if this has been asked...

In this test ALL of the Merlins shutdown, and then the abort initiated...

I imagine there is a constantly evolving algorithm that would evaluate all the variables, and then relative to one, two, four engines out when to proceed to abort.

Thinking of the Falcon9 & CRS flight that lost one engine on the climb would not merit pulling the lever and aborting...

Thoughts and or informed opinions, maybe even facts about abort criteria parameters?

In the press conference, Elon seemed to say that they deliberately tightened the parameters for an automatic abort so that they would trigger at a certain part of the flight. Once the Dragon decided an abort was necessary, it commanded the Merlins to shut down. Without waiting for confirmation that that had happened, it then released itself from the Falcon second stage, armed and fired the super-Dracos. All in the space of less than a second.

So the trigger for the abort was not any malfunction of the Falcon, but rather the Falcon behaving normally and the Dragon being overly picky about that behavior. On purpose. For the sake of the test.

Now they simply have to return the definition of "normal" back to the real normal.

EDIT: What is said below by others makes more sense.