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

[Jcc]

A question I wished they asked during the DM-1 post-launch press conference is what are the plans for refurbishing the DM-1 Dragon for the in-flight abort test. Are they planning on replacing specific components, do they have a plan to evaluate what components need replacing, what is the process to certify the refurbished Dragon for in-flight abort, etc.

Or did I miss something?

[rockets4life97]

A question I wished they asked during the DM-1 post-launch press conference is what are the plans for refurbishing the DM-1 Dragon for the in-flight abort test. Are they planning on replacing specific components, do they have a plan to evaluate what components need replacing, what is the process to certify the refurbished Dragon for in-flight abort, etc.

Or did I miss something?

I don't expect a full refurbishment. For example, there is no need to replace the life support system, since it won't be an essential element of the test.

The key subsystems for the inflight abort seem to be: avionics, parachutes, super dracos, and the heat shield. This is probably (likely) an incomplete list, but you get the idea.

[lonestriker]

A question I wished they asked during the DM-1 post-launch press conference is what are the plans for refurbishing the DM-1 Dragon for the in-flight abort test. Are they planning on replacing specific components, do they have a plan to evaluate what components need replacing, what is the process to certify the refurbished Dragon for in-flight abort, etc.

Or did I miss something?

I don't expect a full refurbishment. For example, there is no need to replace the life support system, since it won't be an essential element of the test.

The key subsystems for the inflight abort seem to be: avionics, parachutes, super dracos, and the heat shield. This is probably (likely) an incomplete list, but you get the idea.

Agreed minus the heatshield replacement.  They won't need a functioning heat shield for this test.  I would bet even after the IFA test they could refurbish this capsule for cargo, but it'll likely go up on the ceiling as another SpaceX trophy.

[Prettz]

I would be curious to see if they keep recovery hardware on 1048. But maybe instead of the titanium gridfins, maybe a spare set of the cheaper aluminum ones. While they won’t send OCISLY and the fleet out for a recovery attempt, they will try a soft landing like 1050 and the other core that survived a water landing if the booster survives the abort and try to recover it if it survived. Not to expect to see 1048.5, but to collect data of how the booster fared through such an abort.

If it doesn’t survive as expected, no real loss.

Do we know whether they have any aluminum fins left?

[crandles57]

I would have thought after problem detected, first issue command to shut down engines (already happened but launch abort system doesn't know that) then abort separation then issue command to push out grid fins to slow down booster and S2 and help maximise distance separating booster and S2 from capsule (is such a command then possible? maybe command issued earlier because it can't be done after separation?).

Suspect this could mean they may need to have usual grid fins on flight to test this?

Or is worse case they are trying to test, a situation where recovery of booster is not planned so no grid fins or landing legs?

(I am no expert so do correct me if wrong and maybe I'll learn something )

[gongora]

I don't think the grid fins are designed for deployment in the atmosphere.

[Coastal Ron]

I don't think the grid fins are designed for deployment in the atmosphere.

I wouldn't think so either, at least not while still traveling forward. I wonder if they are strong enough to be deployed when the booster is traveling at a significant velocity backward (i.e. engine first down)?

[bandito]

According to this document the fate of booster is pretty clear:

A  Falcon  9  (Block  5)  first  stage  booster  would  be  used  for  the  abort  test  (Figure  2-2).  The  booster would be a standard Falcon 9 first stage and configured in an expendable configuration for the abort test. Landing legs and grid fins would be removed. No booster recovery burns would be attempted. As such, a full triethylaluminum-triethylborane (TEA-TEB) mixture used as a first and second stage ignitorwould not be used. The booster would be capable of flying a mission profile that allows for the target abort  velocity  to  be  achieved.  The  booster  would  include  nine  M1D  engines  and  be  configured  to perform  an  ascent  abort  shutdown. 

Dragon and the trunk would separate from the second stage and continue to coast to its apogee, eventually dropping the trunk and deploying the drogue parachutes. At the point where Dragon and the trunk separate, the first and second stage would become unstable and break up approximately 2–4 miles down range from the shore.

And whole 2.1.9 subsection with various possibly off-nominal scenarios.

[WBailey]

According to this document the fate of booster is pretty clear:
-snip-

And whole 2.1.9 subsection with various possibly off-nominal scenarios.

In section 2.3, Alternatives Considered But Not Carried Foward:

SpaceX originally considered recovering the Falcon 9 first stage booster during the abort test by
conducting a boost-back and landing at LZ-1. However, due to the abort test mission parameters
requiring Dragon separation at max Q, SpaceX was unable to create a trajectory that would allow boostback and landing. Similarly, SpaceX evaluated having the first stage re-light after Dragon separation and
fly further out in the Atlantic Ocean, either for a droneship landing or impact with the ocean 124–186
miles offshore. Issues with achieving approval for flight termination qualification after the Dragon
separation event proved impossible for these options.

[gongora]

For those who missed it we had some discussion on that document in this thread a few months ago:
https://forum.nasaspaceflight.com/index.php?topic=45279.msg1880955#msg1880955

[Norm38]

Anyway, here's a comparisim between CRS-16 and DM-1. A major differentiator between the two missions is S1 RTLS for CRS-16 vs ASDS for DM-1. The ΔV gained is partly spent lofting the extra 3 odd tonnes of capsule mass to orbit, but there is some extra margin available, so what has it been spent on?

For this mission, the bucket is back, big time. The sim predicts that although CRS-16 throttled to 74% for Max-Q, DM-1 throttled back to 67%. That is, DM-1 went from 1.75g back to 1.2g at the bottom of the bucket. What this achieved of course, is reduced dynamic pressure on the vehicle, and for the Crew Dragon demo mission, this might have been extremely motivating. The sim suggests that Max-Q was reduced from around 24kPa to 21kPa for DM-1.

I have a question based on OneSpeed's simulation.  If they did indeed throttle back deeply at MaxQ, how closely to these g/kPa values do they have to be for the abort test to be valid?
And once they have conducted the abort test, are they then forever locked into that trajectory?
Point is, do they have to conduct the abort test at 1.75g, 24kPa, to ever fly crew on that trajectory?  (assumption is that it is more fuel efficient to not throttle down more than necessary)

[abaddon]

Modeling should be sufficient to cover any minor differences, but generally speaking there's a reason every vehicle throttles down to prevent even higher pressures, and it's unlikely anything would change in that regard.

[mn]

According to this document the fate of booster is pretty clear:

A  Falcon  9  (Block  5)  first  stage  booster  would  be  used  for  the  abort  test  (Figure  2-2).  The  booster would be a standard Falcon 9 first stage and configured in an expendable configuration for the abort test. Landing legs and grid fins would be removed. No booster recovery burns would be attempted. As such, a full triethylaluminum-triethylborane (TEA-TEB) mixture used as a first and second stage ignitorwould not be used. The booster would be capable of flying a mission profile that allows for the target abort  velocity  to  be  achieved.  The  booster  would  include  nine  M1D  engines  and  be  configured  to perform  an  ascent  abort  shutdown. 

Dragon and the trunk would separate from the second stage and continue to coast to its apogee, eventually dropping the trunk and deploying the drogue parachutes. At the point where Dragon and the trunk separate, the first and second stage would become unstable and break up approximately 2–4 miles down range from the shore.

And whole 2.1.9 subsection with various possibly off-nominal scenarios.

This document is from 2018, Hans statement is later and therefore should be considered more up to date.

He said they 'are going to try to bring it home', you can 'try' to twist it however you want but it couldn't be more clear to me. Either he misspoke (maybe he doesn't know about 'this document'), or they are still looking for a solution.

[Alexphysics]

According to this document the fate of booster is pretty clear:

A  Falcon  9  (Block  5)  first  stage  booster  would  be  used  for  the  abort  test  (Figure  2-2).  The  booster would be a standard Falcon 9 first stage and configured in an expendable configuration for the abort test. Landing legs and grid fins would be removed. No booster recovery burns would be attempted. As such, a full triethylaluminum-triethylborane (TEA-TEB) mixture used as a first and second stage ignitorwould not be used. The booster would be capable of flying a mission profile that allows for the target abort  velocity  to  be  achieved.  The  booster  would  include  nine  M1D  engines  and  be  configured  to perform  an  ascent  abort  shutdown. 

Dragon and the trunk would separate from the second stage and continue to coast to its apogee, eventually dropping the trunk and deploying the drogue parachutes. At the point where Dragon and the trunk separate, the first and second stage would become unstable and break up approximately 2–4 miles down range from the shore.

And whole 2.1.9 subsection with various possibly off-nominal scenarios.

This document is from 2018, Hans statement is later and therefore should be considered more up to date.

He said they 'are going to try to bring it home', you can 'try' to twist it however you want but it couldn't be more clear to me. Either he misspoke (maybe he doesn't know about 'this document'), or they are still looking for a solution.

This is an environmental impact report issued by the FAA. If anything changes substantially (like, for example, trying to recover the first sgage) this would have to change to reflect that an assess the impacts of that change. We have seen zero changes and since government > crazy Elon ideas, you bet they won't recover the first stage unless there is an approval for that of some form.

[mn]

According to this document the fate of booster is pretty clear:

A  Falcon  9  (Block  5)  first  stage  booster  would  be  used  for  the  abort  test  (Figure  2-2).  The  booster would be a standard Falcon 9 first stage and configured in an expendable configuration for the abort test. Landing legs and grid fins would be removed. No booster recovery burns would be attempted. As such, a full triethylaluminum-triethylborane (TEA-TEB) mixture used as a first and second stage ignitorwould not be used. The booster would be capable of flying a mission profile that allows for the target abort  velocity  to  be  achieved.  The  booster  would  include  nine  M1D  engines  and  be  configured  to perform  an  ascent  abort  shutdown. 

Dragon and the trunk would separate from the second stage and continue to coast to its apogee, eventually dropping the trunk and deploying the drogue parachutes. At the point where Dragon and the trunk separate, the first and second stage would become unstable and break up approximately 2–4 miles down range from the shore.

And whole 2.1.9 subsection with various possibly off-nominal scenarios.

This document is from 2018, Hans statement is later and therefore should be considered more up to date.

He said they 'are going to try to bring it home', you can 'try' to twist it however you want but it couldn't be more clear to me. Either he misspoke (maybe he doesn't know about 'this document'), or they are still looking for a solution.

This is an environmental impact report issued by the FAA. If anything changes substantially (like, for example, trying to recover the first sgage) this would have to change to reflect that an assess the impacts of that change. We have seen zero changes and since government > crazy Elon ideas, you bet they won't recover the first stage unless there is an approval for that of some form.

And of course Hans doesn't know all this?

[gongora]

And of course Hans doesn't know all this?

Which press conference did Hans mention this?

[envy887]

According to this document the fate of booster is pretty clear:

A  Falcon  9  (Block  5)  first  stage  booster  would  be  used  for  the  abort  test  (Figure  2-2).  The  booster would be a standard Falcon 9 first stage and configured in an expendable configuration for the abort test. Landing legs and grid fins would be removed. No booster recovery burns would be attempted. As such, a full triethylaluminum-triethylborane (TEA-TEB) mixture used as a first and second stage ignitorwould not be used. The booster would be capable of flying a mission profile that allows for the target abort  velocity  to  be  achieved.  The  booster  would  include  nine  M1D  engines  and  be  configured  to perform  an  ascent  abort  shutdown. 

Dragon and the trunk would separate from the second stage and continue to coast to its apogee, eventually dropping the trunk and deploying the drogue parachutes. At the point where Dragon and the trunk separate, the first and second stage would become unstable and break up approximately 2–4 miles down range from the shore.

And whole 2.1.9 subsection with various possibly off-nominal scenarios.

This document is from 2018, Hans statement is later and therefore should be considered more up to date.

He said they 'are going to try to bring it home', you can 'try' to twist it however you want but it couldn't be more clear to me. Either he misspoke (maybe he doesn't know about 'this document'), or they are still looking for a solution.

This is an environmental impact report issued by the FAA. If anything changes substantially (like, for example, trying to recover the first sgage) this would have to change to reflect that an assess the impacts of that change. We have seen zero changes and since government > crazy Elon ideas, you bet they won't recover the first stage unless there is an approval for that of some form.

Are you sure about that? SpaceX already has submitted an EIS and received approval to recover F9 boosters both on and off-shore. Why would they need a new EIS to do what they have already been doing for years?

[mn]

And of course Hans doesn't know all this?

Which press conference did Hans mention this?

It was quoted upthread, I was looking for the OP of this statement and source, didn't find it yet. (Perhaps in the post DM-1 launch press conference?)

Just to be clear, I'm not discussing whether or not they will try to recover this stage. (My knowledge of that is limited strictly to what I read here)

My discussion is directed only at those who try to twist what someone said to not mean what it clearly means because it doesn't fit with prior knowledge.

Of course if he didn't say it and this quote is incorrect that would work just fine.

[gongora]

The quote I remember being upthread was from Benji, and when I watched the video of that press conference (NASA Social?) he did not say anything definitive about trying to recover it.

[Alexphysics]

According to this document the fate of booster is pretty clear:

A  Falcon  9  (Block  5)  first  stage  booster  would  be  used  for  the  abort  test  (Figure  2-2).  The  booster would be a standard Falcon 9 first stage and configured in an expendable configuration for the abort test. Landing legs and grid fins would be removed. No booster recovery burns would be attempted. As such, a full triethylaluminum-triethylborane (TEA-TEB) mixture used as a first and second stage ignitorwould not be used. The booster would be capable of flying a mission profile that allows for the target abort  velocity  to  be  achieved.  The  booster  would  include  nine  M1D  engines  and  be  configured  to perform  an  ascent  abort  shutdown. 

Dragon and the trunk would separate from the second stage and continue to coast to its apogee, eventually dropping the trunk and deploying the drogue parachutes. At the point where Dragon and the trunk separate, the first and second stage would become unstable and break up approximately 2–4 miles down range from the shore.

And whole 2.1.9 subsection with various possibly off-nominal scenarios.

This document is from 2018, Hans statement is later and therefore should be considered more up to date.

He said they 'are going to try to bring it home', you can 'try' to twist it however you want but it couldn't be more clear to me. Either he misspoke (maybe he doesn't know about 'this document'), or they are still looking for a solution.

This is an environmental impact report issued by the FAA. If anything changes substantially (like, for example, trying to recover the first sgage) this would have to change to reflect that an assess the impacts of that change. We have seen zero changes and since government > crazy Elon ideas, you bet they won't recover the first stage unless there is an approval for that of some form.

Are you sure about that? SpaceX already has submitted an EIS and received approval to recover F9 boosters both on and off-shore. Why would they need a new EIS to do what they have already been doing for years?

Since when has been SpaceX doing in-flight abort tests of their rockets for years? It is a whole different scenario and a different environment. The permits they have to land all have included in them that they are for a typical Falcon 9 mission, so obviously not for an in-flight abort test.