Quote from: envy887 on 03/04/2019 04:29 pmQuote from: Alexphysics on 03/04/2019 04:20 pmQuote from: mn on 03/04/2019 03:27 pmQuote from: bandito on 03/03/2019 06:19 pmAccording to this document the fate of booster is pretty clear:QuoteA 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. QuoteDragon 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.
Quote from: Alexphysics on 03/04/2019 04:20 pmQuote from: mn on 03/04/2019 03:27 pmQuote from: bandito on 03/03/2019 06:19 pmAccording to this document the fate of booster is pretty clear:QuoteA 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. QuoteDragon 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?
Quote from: mn on 03/04/2019 03:27 pmQuote from: bandito on 03/03/2019 06:19 pmAccording to this document the fate of booster is pretty clear:QuoteA 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. QuoteDragon 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.
Quote from: bandito on 03/03/2019 06:19 pmAccording to this document the fate of booster is pretty clear:QuoteA 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. QuoteDragon 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.
According to this document the fate of booster is pretty clear:QuoteA 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. QuoteDragon 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.
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.
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.
He was talking more about reliability than actually using it again after that. He said something like "we always like to bring hardware back, when you bring hardware back you can have a look at how it went on flight and what are the things we have to improve and that also increases reliability" and then he said what I put up on the other comment.
Gotta have to watch the entire NASA Social briefing because AFAIK there was no OH on the event. Benji Reed was asked about that but he didn't say straightforwardly that they will recover the booster, just that "we would like to recover the rocket, we like to recover hardware but the most important part is that we will get to test the abort system on the Dragon"
Is the NASA DM-1 Social briefing available somewhere (and/or a transcript)?
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.
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.
Quote from: crandles57 on 03/04/2019 06:09 pmIs the NASA DM-1 Social briefing available somewhere (and/or a transcript)?
This seems quite clear this is aspirational for reliability but they are not actually bringing anything back other than dragon.Hope this clears that up (or maybe there was a different question and answer somewhere).
A differing thought on the practicality of trying to recover the first stage booster after the abort. I doubt that the booster will be only partially fueled as that would change the flight dynamics. As the abort will happen well before the normal MECO time, there is going to be a lot of fuel (mass) still in the stage. Even if you jettison the second stage, the first stage is probably going to have too much mass for three engines to control the flight. You either end up with a ballistic missile aiming at the ocean or a very spectacular disintegration.Maybe SpaceX will pack an Easter Egg in the stages to make an even more interesting show when the booster breaks up. Red-white-and-blue smoke streamers maybe?
Quote from: StuffOfInterest on 03/21/2019 02:38 pmA differing thought on the practicality of trying to recover the first stage booster after the abort. I doubt that the booster will be only partially fueled as that would change the flight dynamics. As the abort will happen well before the normal MECO time, there is going to be a lot of fuel (mass) still in the stage. Even if you jettison the second stage, the first stage is probably going to have too much mass for three engines to control the flight. You either end up with a ballistic missile aiming at the ocean or a very spectacular disintegration.Maybe SpaceX will pack an Easter Egg in the stages to make an even more interesting show when the booster breaks up. Red-white-and-blue smoke streamers maybe?My understanding IF the booster survives the In-Flight Abort and IF they decide it's worth preparing to recover it IF it does survive, the payload-less Falcon 9 would continue to fly a nominal downrange trajectory through first stage flight and then land downrange on the ASDS.
My understanding IF the booster survives the In-Flight Abort and IF they decide it's worth preparing to recover it IF it does survive, the payload-less Falcon 9 would continue to fly a nominal downrange trajectory through first stage flight and then land downrange on the ASDS.
Quote from: ChrisGebhardt on 03/21/2019 02:53 pmMy understanding IF the booster survives the In-Flight Abort and IF they decide it's worth preparing to recover it IF it does survive, the payload-less Falcon 9 would continue to fly a nominal downrange trajectory through first stage flight and then land downrange on the ASDS.Doesn't the abort test require that the 1st stage engines shut down in the same way they would during an abort?If so, then only 3 engines have the capability to be started up again, and I'm not sure that is enough engines to allows the 1st stage to continue to gain altitude.Or do the parameters of the abort test assume that the 1st stage engines will NOT shut down?
These stage-to-stage electrical interfaces are tricky. You don't want an abort condition to be missed (and the LAS not firing) at the same time you don't want any false positive either. Make it too trigger happy and it might fire due to a weird electrical fluke, make it too robust, and it will think everything's fine even when all hell broke loose.
If you want to simulate worst case abort, I think you need to simulate first stage engines to remain thrusting.
If they aren't planning on recovering the stage and want to truly test the system, then rig the stage for a fault that ends in RUD during MaxQ. Worse case scenario that proves if the system can handle up to the worst situation.
Launch-escape systems are not designed to save the crew in all cases -- that just isn't realistic.
Quote from: CorvusCorax on 03/21/2019 10:13 pmIf you want to simulate worst case abort, I think you need to simulate first stage engines to remain thrusting.We already kinda saw that before (CRS-7). They could just blow up the 2nd stage tanks again...that would be a good test. EDIT: On second thought....that would probably be the best test possible in my opinion. If it can abort correctly with the engines firing....it can with them off too.
