Gimballed self levelling platforms are totally standard OTS equipment. That's how fishing boats can pick up Sky TV.
Gimballed self levelling platforms are totally standard OTS equipment. That's how fishing boats can pick up Sky TV.It seems very likely that SpaceX could easily solve the video dropout problem, if they thought it was actually a problem.
Also, RP1 + LOX produces ionized gas - is this true?
Quote from: Kaputnik on 06/27/2017 08:34 amGimballed self levelling platforms are totally standard OTS equipment. That's how fishing boats can pick up Sky TV.Then again, fishing boats usually rock slowly in the waves and their antennas don't have to cope with plume impingement from a rocket engine and resulting thrashing and vibrations at tens to hundreds of Hz frequency...
Quote from: Kaputnik on 06/27/2017 08:34 amGimballed self levelling platforms are totally standard OTS equipment. That's how fishing boats can pick up Sky TV.It seems very likely that SpaceX could easily solve the video dropout problem, if they thought it was actually a problem.If they could fix it really easily, don't you think they would have already done it? They already spend quite a few $ getting that feed to where it is, even though it's really only of use to us, the viewers, if it really was an easy fix, it would be cheap, and probably already done.
AFAIK this is unique to SpaceX. This is a very clever solution to a problem unique to SpaceX. Most separations just drift away, and because saving the booster is not an issue, the second stage can fire as soon as it is clear and they don't care if the first stage gets burnt or damaged. SpaceX wants a good distance before the second stage fires and they also want to get this distance very quickly so they can rotate the first stage for the boost back burn. The pusher imparts some momentum to the second stage while slowing down the first stage a little. I know this is small potatoes, but I wonder if that little extra acceleration to the second stage is enough to compensate for the extra fuel used to carry the mass of the pusher mechanism.
Quote from: ugordan on 06/27/2017 08:37 amQuote from: Kaputnik on 06/27/2017 08:34 amGimballed self levelling platforms are totally standard OTS equipment. That's how fishing boats can pick up Sky TV.Then again, fishing boats usually rock slowly in the waves and their antennas don't have to cope with plume impingement from a rocket engine and resulting thrashing and vibrations at tens to hundreds of Hz frequency...No wait, you did not understand. The barge would have a non- or loosely directional antenna to transmit to a nerby boat, and that would have a satellite link. However, there is probably a simple explanation they are not doing it, and it is NOT that they cannot engineer one.
Those big Ku band dishes pretty much stay on target by being perfectly balanced. Tiny stepper motors keep them centered, but even unpowered, the dish stays stays pointing the same way for a while as the boat moves around. I'm still trying to find out if the vibration problem is through the mount or causes trouble directly through the dome.
Quote from: manoweb on 06/27/2017 06:04 pmQuote from: ugordan on 06/27/2017 08:37 amQuote from: Kaputnik on 06/27/2017 08:34 amGimballed self levelling platforms are totally standard OTS equipment. That's how fishing boats can pick up Sky TV.Then again, fishing boats usually rock slowly in the waves and their antennas don't have to cope with plume impingement from a rocket engine and resulting thrashing and vibrations at tens to hundreds of Hz frequency...No wait, you did not understand. The barge would have a non- or loosely directional antenna to transmit to a nerby boat, and that would have a satellite link. However, there is probably a simple explanation they are not doing it, and it is NOT that they cannot engineer one.That explanation is that is not important enough a priority. They will have full quality video at multiple angles from the recordings. Telemetry tells them if the stage landed intact in near real time. There is no operational reason why they need perfect realtime video. Even for us spectators it adds to the drama if it cuts off briefly, and we anticipate the recordings like kids on Christmas Eve. Great fun!
How are they getting live telemetry at landing? Does the booster have a satcom link? Or are the support ships relaying it?
SpaceX BulgariaSat liability insuranceI missed this at the time, but on June 16, the FAA modified SpaceX's liability insurance see LLS 17-101 for the BulgariaSat mission to $68MM, while other missions covered by the same license remain at $30MM.
Have we seen the final orbit yet? I'm still trying to figure out why this was a tough landing. It was a very light bird for GTO so unless it went to a really high energy orbit then the hard reentry was purposeful testing. Even so, seems like that upper stage probably had a lot of energy left.
Reddit user FellowHumanBean noticed an amendment to the FCC launch license for Bulgariasat:QuoteSpaceX BulgariaSat liability insuranceI missed this at the time, but on June 16, the FAA modified SpaceX's liability insurance see LLS 17-101 for the BulgariaSat mission to $68MM, while other missions covered by the same license remain at $30MM.
Quote from: gongora on 06/29/2017 02:17 amReddit user FellowHumanBean noticed an amendment to the FCC launch license for Bulgariasat:QuoteSpaceX BulgariaSat liability insuranceI missed this at the time, but on June 16, the FAA modified SpaceX's liability insurance see LLS 17-101 for the BulgariaSat mission to $68MM, while other missions covered by the same license remain at $30MM.I think FellowHumanBean is reading backward and without context.LLS 17-100, issued in February, required SpaceX to carry $160M in liability insuranceLLS 17-101, issued in March, requires SpaceX to carry $68M liability insurance for BulgariaSat-1 and $30M for subsequent launches.
