SpaceX F9 : Crew Dragon In-Flight Abort Test : Jan. 19, 2020 : Discussion

[marsbase]

Used but nice block 5 S1

I love that SpaceX rockets can be hustled like a used car.  It's used but nice.   But you make a good point about everything being in actual flight condition including fuels.  So what trips the abort?  Is it just a program flag that says "abort" or is there some NASA requirement to show that the computer would flag an abort situation from sensors?  You suggest blowing the helium tank in S2.  Is SpaceX actually going to trigger some real event?  Never heard of that.

[John Alan]

Used but nice block 5 S1

I love that SpaceX rockets can be hustled like a used car.  It's used but nice.   But you make a good point about everything being in actual flight condition including fuels.  So what trips the abort?  Is it just a program flag that says "abort" or is there some NASA requirement to show that the computer would flag an abort situation from sensors?  You suggest blowing the helium tank in S2.  Is SpaceX actually going to trigger some real event?  Never heard of that.

Me too (the used but nice quip) 
My guess is they will just add a line in Dragon's code such that...
IF GPS speed and position falls within this window THEN abort as if astronaut pushed the abort button on panel...
Or just a timer in the code that will trip at a certain point after liftoff (calculated to be close enough)

I'm suggesting they add something that actually ruptures and ignites S2's tanks... to really make it worse case...   
Demo that when the break wire tears open, the actual system being relied on will send the right signals to the right places and it all does the right thing...

I have no knowledge of the actual plans...

[Billium]

I'll go on the record now and predict... 

Used but nice block 5 S1
New and completely equipped block 5 S2 (even the Mvac would fire, no parts missing)
The Dragon test spacecraft planned...
FULLY fueled on all components... and flown off Pad 39 as if it's going to space...

Why?...
Because the last thing we need... is the internet and NASA arguing later it was not a legitimate worse case test... 
MAKE IT worst case... screw trying to save S1...
Blow S2 Amos style right at Max-Q (high in the stack, worst case) and watch Dragon hopefully do it's job outrunning the carnage in it's rear view mirror...

The $30 mil covers S2 and the launch costs...
S1 was used already and took one for the team... no big deal in the grand scheme...
They hopefully get Dragon back in fine shape... and they better hang it up somewhere so we can see it...
Doing it this way is actually the cheapest IMHO...
No going out of normal manned launch process...
No special parts or special programming trying to save S1...
Just blow it all to heck at Max-Q and show that it works... period... 

My 2 cents... 

Someone should start a poll...

I basically agree with you, except I don’t thing the would waste an Mvac on the 2nd stage. Otherwise I think it will just be like an actual launch. They will just unzip all the fuel tanks at max-q.

[Jim]

Dragon 2 is only flying from 39 so why would the abort test  use any other pad?

Why wouldn't they? It's not like they'll need a crew access arm.

You don't know that.  There might be a need for access to the cabin before the test.

Also, the umbilicals for the Dragon2 are not needed for other pads.  So why modify on TEL and pad cabling for one test?

Everything needed will be at 39

In case you had failed to notice: SpaceX plans to attach the CAA AFTER their DM-1 mission.
So why should SpaceX have on-pad access to the in-flight abort Dragon, when it is NOT necessary to have on-pad access to the DM-1 Dragon?

If we follow your (IMO flawed) line of reasoning the pad-abort test should not have flown from LC-40 either. Yet, it did.

Your flawed response ignores that pad abort didn't have a Falcon launch vehicle involved and had  specific GSE built.

[Coastal Ron]

I suspect they have improvements to block 5 that make them think they can recover the booster successfully after the abort test.  If so, then the GSE changes to the pads make doing the test on a block 5 from LC39A logistically convenient.

Although no one will want to see a Block 5 booster lost at this time.  I have to think the milestone payment from NASA for completing this test will be more profitable than most of SpaceX’s other launches.

So fly that thing and get on with it.

The milestone payment isn't that much ($30M).  http://www.parabolicarc.com/2015/03/04/spacex-cctcap-milestones/

I don't have the latest figures at hand, but wouldn't $30M allow them to break even if the have to sacrifice a new Block 5? And this one will be previously flown?

Have we heard anything official about them wanting to recover the 1st stage, or stating it would be expended?

[marsbase]

I'm wondering if there may be a misunderstanding here.  A reddit post suggested a tour guide said that there would be a Block 5 booster making its third flight.  But today another reddit post shows a Block 4 with two flights at McGregor.   
https://www.reddit.com/r/spacex/comments/8po6cr/drove_by_mcgregor_today_and_spotted_this/

Maybe, just maybe it's a Block 4  S1 making it's third flight paired with a Block 5 S2.  These things have a way of getting mixed up via verbal communications.

[Alexphysics]

It is not known if that's really a Block 4 booster and if it is a Block 4 the only Block 4 it could be is B1042. The rest of the possible boosters are either Block 2 or Block 3.

[OneSpeed]

... I'm suggesting they add something that actually ruptures and ignites S2's tanks... to really make it worse case...

... I basically agree with you, except I don’t thing the would waste an Mvac on the 2nd stage. Otherwise I think it will just be like an actual launch. They will just unzip all the fuel tanks at max-q.

The in-flight abort test needs to demonstrate the ability of the capsule to escape the rocket at max-Q, i.e. with the rocket still thrusting, and maximum drag. This is the scenario that requires the most thrust from the launch abort system, and so is the real worst case.

[woods170]

Dragon 2 is only flying from 39 so why would the abort test  use any other pad?

Why wouldn't they? It's not like they'll need a crew access arm.

You don't know that.  There might be a need for access to the cabin before the test.

Also, the umbilicals for the Dragon2 are not needed for other pads.  So why modify on TEL and pad cabling for one test?

Everything needed will be at 39

In case you had failed to notice: SpaceX plans to attach the CAA AFTER their DM-1 mission.
So why should SpaceX have on-pad access to the in-flight abort Dragon, when it is NOT necessary to have on-pad access to the DM-1 Dragon?

If we follow your (IMO flawed) line of reasoning the pad-abort test should not have flown from LC-40 either. Yet, it did.

Your flawed response ignores that pad abort didn't have a Falcon launch vehicle involved and had  specific GSE built.

Emphasis mine.

The active GSE for the pad abort test was very simple in nature and is the kind of stuff that can be easily added to the current GSE set-up at LC-40.
And whether-or-not a Falcon 9 is present is irrelevant in this discussion given that both LC-39A and LC-40 can host one.

You asked this question, in response to Nomadd:

Also, the umbilicals for the Dragon2 are not needed for other pads.  So why modify on TEL and pad cabling for one test?

Well, guess what: SpaceX modded pad cabling at LC-40 and even built custom GSE for the pad abort test. Why would they (theoretically) not do so for the in-flight abort test?

Look, I agree with you that the in-flight abort test will most likely be launched from LC-39A. But IMO you were dismissing a possible in-flight abort test from LC-40 for the wrong reasons:
- you mentioned the possible need for the CAA whereas it is almost a given that it won't be needed.
- you questioned the need for LC-40 pad GSE and cabling to be modified for one test. Yet, that clearly has already been done at least once before.

The correct reason, IMO, for dismissing a possible in-flight abort test from LC-40 is financial: why spent money on duplicating stuff at LC-40 that already exists at LC-39A?

[hkultala]

One of my hopes and dreams was that SpaceX would eventually take one of the recovered but not destined to be reused for a mission Dragons, and a recovered first stage and just huck that Dragon up as high as it could go with the first stage boost, leaving enough fuel to re-land the booster, and skip a second stage.  Isn't that basically free practice? 

I realize there are huge problems with that, biggest probably being that there is currently no known way to attach a Dragon directly to a first stage, much less release it reliably at any particular desirable point.

Actually, there is. They need that for the in-flight abort test.

[DistantTemple]

One of my hopes and dreams was that SpaceX would eventually take one of the recovered but not destined to be reused for a mission Dragons, and a recovered first stage and just huck that Dragon up as high as it could go with the first stage boost, leaving enough fuel to re-land the booster, and skip a second stage.  Isn't that basically free practice? 

I realize there are huge problems with that, biggest probably being that there is currently no known way to attach a Dragon directly to a first stage, much less release it reliably at any particular desirable point.

Actually, there is. They need that for the in-flight abort test.

Aren't SX going to fly the in flight abort with the flight hardware? i.e. a stage 2 etc. so it is a valid as possible?

[clongton]

One of my hopes and dreams was that SpaceX would eventually take one of the recovered but not destined to be reused for a mission Dragons, and a recovered first stage and just huck that Dragon up as high as it could go with the first stage boost, leaving enough fuel to re-land the booster, and skip a second stage.  Isn't that basically free practice? 

I realize there are huge problems with that, biggest probably being that there is currently no known way to attach a Dragon directly to a first stage, much less release it reliably at any particular desirable point.

Actually, there is. They need that for the in-flight abort test.

Aren't SX going to fly the in flight abort with the flight hardware? i.e. a stage 2 etc. so it is a valid as possible?

The Abort will be triggered at Max-Q during 1st stage operation.

[envy887]

One of my hopes and dreams was that SpaceX would eventually take one of the recovered but not destined to be reused for a mission Dragons, and a recovered first stage and just huck that Dragon up as high as it could go with the first stage boost, leaving enough fuel to re-land the booster, and skip a second stage.  Isn't that basically free practice? 

I realize there are huge problems with that, biggest probably being that there is currently no known way to attach a Dragon directly to a first stage, much less release it reliably at any particular desirable point.

Actually, there is. They need that for the in-flight abort test.

Aren't SX going to fly the in flight abort with the flight hardware? i.e. a stage 2 etc. so it is a valid as possible?

They are testing the capsule, not the rocket. Look at how other capsules like Apollo and Orion did in flight abort tests.

[rpapo]

The Abort will be triggered at Max-Q during 1st stage operation.

That wasn't his question.  There no doubt whatsoever that the abort will be triggered during stage one operation, at or immediately after max-Q.  The only real question is whether the stack will include a second stage so that the test may be more true to actual flight conditions.

The example of the Apollo in-flight abort test argues "no".  The 50+ years of increasingly cautious NASA since then argues "yes".

Experience = the painful memories of one's past mistakes.  NASA thought they knew about pain in 1965.  They know a lot more about it now.  Why Boeing gets a pass on this test is a nice question.

[Addition] Thinking back on it, the SpaceX in-flight abort test was originally going to be done with a first stage only, but with only three engines because there would be no second stage weighing things down.  That indicates that they probably solved the problem of mounting Dragon on top of a single stage.

[Robotbeat]

“Increasingly cautious NASA” is testing Orion on a ballistic missile, similar to Apollo tests. SpaceX would be just fine testing Dragon without a second stage. It’d be closer to the real thing than what NASA is doing with Orion.

[Jim]

“Increasingly cautious NASA” is testing Orion on a ballistic missile, similar to Apollo tests. SpaceX would be just fine testing Dragon without a second stage. It’d be closer to the real thing than what NASA is doing with Orion.

No.  The point of the test is aeroloads and not an end to end test.  How Orion gets there is meaningless. 

[Jim]

That wasn't his question.  There no doubt whatsoever that the abort will be triggered during stage one operation, at or immediately after max-Q.  The only real question is whether the stack will include a second stage so that the test may be more true to actual flight conditions.

actual configuration of the booster is meaningless as long as it provides the right flight conditions.  Having a second stage or not, has no bearing on the test. 

[Robotbeat]

“Increasingly cautious NASA” is testing Orion on a ballistic missile, similar to Apollo tests. SpaceX would be just fine testing Dragon without a second stage. It’d be closer to the real thing than what NASA is doing with Orion.

No.  The point of the test is aeroloads and not an end to end test.  How Orion gets there is meaningless.

We are in violent agreement.

[RoboGoofers]

That wasn't his question.  There no doubt whatsoever that the abort will be triggered during stage one operation, at or immediately after max-Q.  The only real question is whether the stack will include a second stage so that the test may be more true to actual flight conditions.

actual configuration of the booster is meaningless as long as it provides the right flight conditions.  Having a second stage or not, has no bearing on the test.

maybe no bearing on the test results, no. Operationally, though, are they going to mount the Dragon on the top of the first stage?

[abaddon]

“Increasingly cautious NASA” is testing Orion on a ballistic missile, similar to Apollo tests. SpaceX would be just fine testing Dragon without a second stage. It’d be closer to the real thing than what NASA is doing with Orion.

Not to mention, Starliner isn't even doing an in-flight abort test... at all.