The thread is about delaying a Starlink launch until after a NASA launch so that you can say the data is not available, rather than not having the time to review it. You don't use the data either way.It is not about whether it is worth reviewing it if it is available and you have the time.
Quote from: steveleach on 10/25/2023 06:09 pmThe thread is about delaying a Starlink launch until after a NASA launch so that you can say the data is not available, rather than not having the time to review it. You don't use the data either way.It is not about whether it is worth reviewing it if it is available and you have the time.You don't use the DETAILED review either way. But you have plenty of time to review perhaps the most important piece of information - did the rocket place the payload into the intended orbit.A successful flight is one of the three main requirements for certification. One of the others, having a "Post Flight Operations/Anomaly Resolution Process" should be knowable in advance. Only the third element, "NASA Flight Margin Verification" might not be able to complete in time.
......This entire discussion going on in this thread revolves around the fallacy of believing that you might miss an issue that crops up conveniently "only" in the last planned mission before an important NASA mission:...
Quote from: woods170 on 10/25/2023 11:42 am......This entire discussion going on in this thread revolves around the fallacy of believing that you might miss an issue that crops up conveniently "only" in the last planned mission before an important NASA mission:...I think you have it backwards.The question of this thread is whether you believe in the fallacy that delaying planned launch n-1 somehow benefits launch nEdit: removed most of the quote and left only the relevant section I'm responding to.
Quote from: edzieba on 10/25/2023 09:40 amQuote from: LouScheffer on 10/24/2023 09:02 pmBut once a rocket has launched many times, and the manufacturer has addressed the potential problems found in prior NASA reviews, it would seem the chance of a NASA review catching something the manufacturer missed would be slight.That assumes the vehicle and its operations are static, which is not the case with Falcon 9.That doesn't change the fact that delaying the "less important" launch till after the high value launch only reduces the amount of data the high value launch has to work with.This is purely and entirely a CYA exercise.
Quote from: LouScheffer on 10/24/2023 09:02 pmBut once a rocket has launched many times, and the manufacturer has addressed the potential problems found in prior NASA reviews, it would seem the chance of a NASA review catching something the manufacturer missed would be slight.That assumes the vehicle and its operations are static, which is not the case with Falcon 9.
But once a rocket has launched many times, and the manufacturer has addressed the potential problems found in prior NASA reviews, it would seem the chance of a NASA review catching something the manufacturer missed would be slight.
Quote from: mn on 10/26/2023 04:06 pmQuote from: woods170 on 10/25/2023 11:42 am......This entire discussion going on in this thread revolves around the fallacy of believing that you might miss an issue that crops up conveniently "only" in the last planned mission before an important NASA mission:...I think you have it backwards.The question of this thread is whether you believe in the fallacy that delaying planned launch n-1 somehow benefits launch nEdit: removed most of the quote and left only the relevant section I'm responding to.Emphasis mine.NASA clearly believes in that so-called "fallacy". They have now allowed SpaceX to delay planned "launch n-1", to let "launch n" go first, at least three times (Crew-5, Crew-6 and Psyche).From the viewpoint of NASA "launch n" clearly benefits from delaying planned "launch n-1". Specifically because it allows "launch n" to fly on schedule, instead of running the risk of being delayed while waiting for planned "launch n-1" to actually launch.There's your "somehow benefits".Not everything revolves around decreasing risk thru data review/data analysis.
It was said that the launch was delayed because if it launches they would be required to review the data and there would not be sufficient time to review, and therefore it is better to delay launch n-1. That is what was claimed and that is what we are discussing. (Whether or not this is true is irrelevant to our discussion, we are just discussing the logic behind such a decision)
NASA clearly believes in that so-called "fallacy". They have now allowed SpaceX to delay planned "launch n-1", to let "launch n" go first, at least three times (Crew-5, Crew-6 and Psyche).From the viewpoint of NASA "launch n" clearly benefits from delaying planned "launch n-1". Specifically because it allows "launch n" to fly on schedule, instead of running the risk of being delayed while waiting for planned "launch n-1" to actually launch.There's your "somehow benefits".Not everything revolves around decreasing risk thru data review/data analysis.
Quote from: meekGee on 10/25/2023 04:23 pmQuote from: edzieba on 10/25/2023 09:40 amQuote from: LouScheffer on 10/24/2023 09:02 pmBut once a rocket has launched many times, and the manufacturer has addressed the potential problems found in prior NASA reviews, it would seem the chance of a NASA review catching something the manufacturer missed would be slight.That assumes the vehicle and its operations are static, which is not the case with Falcon 9.That doesn't change the fact that delaying the "less important" launch till after the high value launch only reduces the amount of data the high value launch has to work with.This is purely and entirely a CYA exercise.Emphasis mine.Which is not a bad thing, for two reasons:- Although there is large commonality between Falcon 9 and Falcon Heavy, using single-stick Falcon 9 flight data to directly assess the risk of a 3-core FH launch is questionable. NASA is much more likely to assess Falcon Heavy launch risk by looking at Falcon Heavy flight data.- But, in the IMO unlikely case that NASA actually uses single-stick Falcon 9 flight data to assess FH launch risk, there is the fact that NASA already is in possession of a literal mountain of Falcon 9 flight data (courtesy of its very high flight rate). One launch less won't make a significant difference to the knowledge that NASA has in hand already.
Quote from: mn on 10/27/2023 10:54 amIt was said that the launch was delayed because if it launches they would be required to review the data and there would not be sufficient time to review, and therefore it is better to delay launch n-1. That is what was claimed and that is what we are discussing. (Whether or not this is true is irrelevant to our discussion, we are just discussing the logic behind such a decision)If its not true then the rest of the discussion is pretty pointless. Is there doubt about whether it is?
Quote from: dondar on 10/23/2023 08:21 pmThe only practical reason for NASA review delay (i.e. extra work) is some out of family event during (one of) previous Falcon launch, which SpaceX team has to process and to wrap some "satisfactory story" for NASA review committee.No, NASA does the data review.
The only practical reason for NASA review delay (i.e. extra work) is some out of family event during (one of) previous Falcon launch, which SpaceX team has to process and to wrap some "satisfactory story" for NASA review committee.
Without debating the merits of a review, can we all agree that the following statement is true? IF (NASA mandates a review of any F9/FH mission prior to the NASA mission AND reviews take a known potential maximum time window ) THEN SpaceX cannot schedule any F9/FH missions in that time window prior to the scheduled NASA mission.
lol, they review reports prepared by SpaceX. .....
NASA has no say about other SpaceX flights.
dude. why? You write rather normal posts about NASA etc. every time SpaceX pops you go bananas. Why?
what is the size of Falcon 9 group in SpaceX? 10% of the initial size? 20%? they are squeezed by NASA reviews up and don't have spare eyes for the rest. You see typical "test" crunch. The mere idea about NASA controlling SpaceX flights in general is beyond bizarre. They can ask, but why?
Quote from: steveleach on 10/27/2023 12:28 pmQuote from: mn on 10/27/2023 10:54 amIt was said that the launch was delayed because if it launches they would be required to review the data and there would not be sufficient time to review, and therefore it is better to delay launch n-1. That is what was claimed and that is what we are discussing. (Whether or not this is true is irrelevant to our discussion, we are just discussing the logic behind such a decision)If its not true then the rest of the discussion is pretty pointless. Is there doubt about whether it is?Someone either in this thread or some other thread claimed that it was a SpaceX decision to delay and not NASA, sorry can't find that post right now.But if it's not true then it's just a hypothetical discussion, we've had plenty of those around here.Edit to add: Here is the source of the delay and reason given. Whatever this other poster posted somewhere that I can't find is apparently not correct.https://forum.nasaspaceflight.com/index.php?topic=50260.msg2530831#msg2530831
Quote from: mn on 10/27/2023 02:30 pmQuote from: steveleach on 10/27/2023 12:28 pmQuote from: mn on 10/27/2023 10:54 amIt was said that the launch was delayed because if it launches they would be required to review the data and there would not be sufficient time to review, and therefore it is better to delay launch n-1. That is what was claimed and that is what we are discussing. (Whether or not this is true is irrelevant to our discussion, we are just discussing the logic behind such a decision)If its not true then the rest of the discussion is pretty pointless. Is there doubt about whether it is?Someone either in this thread or some other thread claimed that it was a SpaceX decision to delay and not NASA, sorry can't find that post right now.But if it's not true then it's just a hypothetical discussion, we've had plenty of those around here.Edit to add: Here is the source of the delay and reason given. Whatever this other poster posted somewhere that I can't find is apparently not correct.https://forum.nasaspaceflight.com/index.php?topic=50260.msg2530831#msg2530831Delaying Starlink missions in favour of NASA missions has so far always been SpaceX decisions. At least one time such decision was made by SpaceX after a request from NASA. Not an order, but a request.
Also data review of previous F9 launches by LSP must be complete before proceeding with Psyche launch. This includes Starlink 7-4. Also, LSP asked for the Starlink 6-22 launch delay after weather scrub on October 9, until after Psyche, due to the same post launch analysis reason.
Yep, assuming LSP = "Launch Service Provider", it seems like a SpaceX decision.
Quote from: steveleach on 10/29/2023 10:20 pmYep, assuming LSP = "Launch Service Provider", it seems like a SpaceX decision.LSP = NASA's Launch Services Program.