Quote from: mn on 05/01/2017 03:06 pmQuote from: M.E.T. on 05/01/2017 11:08 amBoth yesterday and again today, the presenter of the webcast stated that the Falcon 9 is 12m in diameter. I am right that he is confusing the F9 - which I thought is 3.6m in diameter - with the Falcon Heavy, correct?The presenter said 12ft (at about 15:50 into the webcast replay) which is close enough with rounding.Since he said it two days in a row, it was an error in his script (meters instead of feet). He got it right later, or should I say the script was correct.
Quote from: M.E.T. on 05/01/2017 11:08 amBoth yesterday and again today, the presenter of the webcast stated that the Falcon 9 is 12m in diameter. I am right that he is confusing the F9 - which I thought is 3.6m in diameter - with the Falcon Heavy, correct?The presenter said 12ft (at about 15:50 into the webcast replay) which is close enough with rounding.
Both yesterday and again today, the presenter of the webcast stated that the Falcon 9 is 12m in diameter. I am right that he is confusing the F9 - which I thought is 3.6m in diameter - with the Falcon Heavy, correct?
Quote from: RonM on 05/01/2017 03:15 pmQuote from: mn on 05/01/2017 03:06 pmQuote from: M.E.T. on 05/01/2017 11:08 amBoth yesterday and again today, the presenter of the webcast stated that the Falcon 9 is 12m in diameter. I am right that he is confusing the F9 - which I thought is 3.6m in diameter - with the Falcon Heavy, correct?The presenter said 12ft (at about 15:50 into the webcast replay) which is close enough with rounding.Since he said it two days in a row, it was an error in his script (meters instead of feet). He got it right later, or should I say the script was correct.To be fair, the commentary was using a mix of units...imperial for the vehicle dimensions and metric for the velocity and irritating analogy units for vehicle performance (thrust of a 747? What model? What engines? What thrust rating?!?!). Has to get confusing when trying to keep up that cheerful patter.Cheers!
Another thing we can see from the excellent video footage is the ignition sequence at the start of the entry burn. The center engine starts first, making the "ring of fire," then about 3 seconds later the other two engines light, changing the shape of the plume:https://www.instagram.com/p/BTjVdLVB1bO/
With this launch, LC 39 Pad A has handled more launches this year than any other launch center, let alone launch pad. Likely temporary, but shows how hard SpaceX is pushing to recover from AMOS 6.This was the tenth successful first stage landing and the fourth at LZ-1. Nine first stages have now flown to recovery (one twice). Something like four of those have apparently been retired.Among v1.2 variants, this had the shortest first stage burn (137 seconds) and the second longest boost-back burn (40 seconds).F9-34 performed the 98th LC 39A liftoff. - Ed Kyle
It's been noted elsewhere that this mission like USA-193 features a brown raptor bird in its patch.https://m.facebook.com/photo.php?fbid=116648047531&l=169616826b
I was wondering why we can see the nitrogen jets. After all, nitrogen is pretty transparent (we look through kilometers of it every day). And it can't be that it's cold enough to condense water out of the air, since there is almost no atmosphere until it returns to much lower altitudes.The only thing I can think of is that the free expansion cools the jet so much that droplets of liquid nitrogen condense, and scattering from these drops is what we see.
Quote from: edkyle99 on 05/01/2017 03:25 pmWith this launch, LC 39 Pad A has handled more launches this year than any other launch center, let alone launch pad. Likely temporary, but shows how hard SpaceX is pushing to recover from AMOS 6.This was the tenth successful first stage landing and the fourth at LZ-1. Nine first stages have now flown to recovery (one twice). Something like four of those have apparently been retired.Among v1.2 variants, this had the shortest first stage burn (137 seconds) and the second longest boost-back burn (40 seconds).F9-34 performed the 98th LC 39A liftoff. - Ed KyleDid the longest bootback belong to one of the CRS flights?My instinct tells me the higher the apogee, the shorter the boostback needs to be. With a high enough apogee, they don't need to reverse their velocity, just cancel enough of it so by the time they coast up and back down, the Earth has rotated. OG2 is a good example.
I may have missed it but I don't recall the grid fins heating up as much as the last time. That could be due to other factors than upgraded fins of course... (a different reentry burn for example)
Thinking about the rapid flip at stage sep, on past flights it appears that the interstage takes quite a blast from the second stage engine ignition. Is the rapid flip an attempt to shield the interstage interior from the plume and reduce damage/wear? The plume may also assist with the flip by pushing on one side, but I doubt that's the primary reason.
Quote from: Norm38 on 05/01/2017 04:21 pmThinking about the rapid flip at stage sep, on past flights it appears that the interstage takes quite a blast from the second stage engine ignition. Is the rapid flip an attempt to shield the interstage interior from the plume and reduce damage/wear? The plume may also assist with the flip by pushing on one side, but I doubt that's the primary reason.Probably propellant conservation is the main reason. The sooner the flip, the sooner boostback burn starts, and the less time the stage spends coasting downrange away from the landing pad, so less propellant is needed for boostback.
Quote from: edkyle99 on 05/01/2017 03:25 pmWith this launch, LC 39 Pad A has handled more launches this year than any other launch center, let alone launch pad. Likely temporary, but shows how hard SpaceX is pushing to recover from AMOS 6.This was the tenth successful first stage landing and the fourth at LZ-1. Nine first stages have now flown to recovery (one twice). Something like four of those have apparently been retired.Among v1.2 variants, this had the shortest first stage burn (137 seconds) and the second longest boost-back burn (40 seconds).F9-34 performed the 98th LC 39A liftoff. - Ed KyleDid the longest bootback belong to one of the CRS flights?
Note that none of the LZ 1 stages has re-flown to date.