5 ms·
Iirc F9 had its main challenge in that final suicide burn. Usually the boosters made it there just fine and then "only" failed to get the parameters aligned jus
by usrusr 3y ago
Iirc F9 had its main challenge in that final suicide burn. Usually the boosters made it there just fine and then "only" failed to get the parameters aligned just right.
Based on what we saw today, the main chokepoint for Starship might be right in that hot reentry telemetry blind spot. Debugging without logs.
- dotnet00 3y agoIt sounded like they might have had flight data recorders on-board which might have survived through reentry with telemetry. If so, they'd have some logs, but yes, figuring out reentry will likely be the main challenge for now, not only is it hard to debug, even getting to it requires everything else to go more or less perfectly.
- smallmancontrov 3y agoWith all the solid state gizmos we have today, is it really that difficult to make a blackbox that can survive serious impact G-forces, especially if it just needs to work and doesn't need to be safety rated?
- DarmokJalad1701 3y agoUnlike with F9, in this case they most probably had high-bandwidth telemetry all the way till the vehicle broke up (if the high-def video stream is anything to go by). So, they probably have a lot more data this time. Even the video can yield information - for example, given that the cameras were mounted on the flaps, they can probably back out the actuation angles from that.
- usrusr 3y agoVideo feed interruption was very much expected, and went through a series of on/off before the final signal. From what we saw in the live presentation, both scenarios are possible: breakup while transmission was up, transmitting as long as latency allows, with hopefully good explanations in the log, or a disconnect from the challenging radio situation in the reentry plasma long before something went wrong. Unless they do find some failure buildup in the logs they did receive, it will be difficult to tell disconnect due to breakup from breakup (long) after disconnect. Gradual signal loss on the receiving side would indicate that it's likely the latter, but I'm not sure a signal loss unrelated to breakup would necessarily be gradual. I'd guess atmospheric properties can change fast at reentry velocity.
- dotnet00 3y agoIn the livestream they mentioned that they lost signal on both Starlink and TDRS simultaneously, which is why they figured it had broken up at that point. They were prioritizing the telemetry over video frames on Starlink, and TDRS can only handle telemetry.
- usrusr 3y agoThanks, must have missed that detail in the stream. Hope they find a good explanation candidate in the data!