Quote from: Nomadd on 04/24/2018 04:59 am Any particular reason to think the engines were all from one core?Same chain of custody, so to speak. Work with an individual recovered engine would likely be more relevant for the refurbishment of others if all engines experienced (roughly) the same conditions during their first flight. I'm very open to being wrong, though. Just seems intuitive to me that you would want to use engines from the same flight if you were planning on reusing a whole bunch.
Any particular reason to think the engines were all from one core?
I was thinking that certain engines on returning boosters might tend to come through in better shape than others.
Hey @ticklestuffyo these are arriving to the employees at SpaceX this week. The red thread was flown in the nosecones of the side boosters ❤ Note employee number also embroidered into patch. What a sweet keepsake for them!
QuoteHey @ticklestuffyo these are arriving to the employees at SpaceX this week. The red thread was flown in the nosecones of the side boosters ❤ Note employee number also embroidered into patch. What a sweet keepsake for them!https://twitter.com/julia_bergeron/status/1017282170933731328
7239?
Quote from: matthewkantar on 07/12/2018 01:40 pm7239?Employee number.
Quote from: cscott on 07/12/2018 01:45 pmQuote from: matthewkantar on 07/12/2018 01:40 pm7239?Employee number.If I recall correctly this number does not shift downward with attrition, once you get it, it's yours forever. But it means you were the 7238th hire or whatever...
Quote from: Lar on 07/16/2018 01:52 pmQuote from: cscott on 07/12/2018 01:45 pmQuote from: matthewkantar on 07/12/2018 01:40 pm7239?Employee number.If I recall correctly this number does not shift downward with attrition, once you get it, it's yours forever. But it means you were the 7238th hire or whatever...Actually I think it is quite the opposite. It shifts downwards for each employee who leaves the company. I saw some employee collection pictures and the number gets down with each mission.
At my company, you get an employee number on DOH. It is used for everything from badging and company website access to payroll and insurance. It would be nearly impossible to change this number every time someone leaves the company. We also get a seniority (sometimes called longevity) number that does go down every time someone leaves the company. If someone gets rehired, he or she would get the same employee number, but would go to the bottom of the seniority list or as appropriate considering total years of service. Perhaps the term “employee number” has different meanings among employers. It is hard to imagine a number being placed on a commemorative patch that does not identify a specific individual’s permanent association with SpaceX.
Do we know whether Mars flyby helps circularise orbit to keep perigree above Earth apogee? Or maybe changes the inclination of the orbit?
Quote from: crandles57 on 11/03/2018 11:04 amDo we know whether Mars flyby helps circularise orbit to keep perigree above Earth apogee? Or maybe changes the inclination of the orbit?No and No. It won't fly close enough to Mars to significantly alter its orbit in the near future.
Even if it did, by now it likely diverged from the last known tracking solution after launch sufficiently enough that the impact of such a flyby would be indeterminate.
Encounter predictions for s10 (w/radial 1/r^2 non-gravitational acceleration) Date = Nominal encounter time (Barycentric Dynamical Time) CA_Dist = Highest probability close approach distance to body, au MinDist = 3-sigma minimum encounter distance, au MaxDist = 3-sigma maximum encounter distance, au Vrel = Relative velocity at nominal encounter time, km/s TCA3Sg = 3-sigma uncertainty in close encounter time, minutes Nsigs = Number of sigmas to encounter body at nominal encounter time P_i/p = Linearized probability of impact Date (TDB) Body CA Dist MinDist MaxDist Vrel TCA3Sg Nsigs P_i/p ----------------- ----- ------- ------- ------- ------ ------ ------ ------ 2018 Feb 08.09690 Moon .000936 .000936 .000936 3.961 0.41 47509. 0.000 2020 Oct 07.26768 Mars .049530 .048923 .050242 8.150 27.40 6.63E5 0.000 2035 Apr 22.35934 Mars .015504 .004378 .027978 8.219 170.47 31247. 0.000 2047 Jan 11.89023 Earth .031919 .031716 .032123 4.493 249.70 78398. 0.000 2050 Mar 19.52949 Earth .119113 .113778 .124369 7.397 538.54 2.61E5 0.000 2052 Sep 05.15606 Mars .176363 .172469 .180319 5.738 2185.5 8.68E5 0.000 2067 Apr 15.90202 Mars .043270 .025712 .061471 7.192 1115.0 42565. 0.000 2084 Sep 17.92284 Mars .116962 .093449 .141170 9.753 787.45 6.55E5 0.000 2085 Jan 01.96490 Earth .083063 .049368 .112186 6.224 5208.9 1.00E5 0.000 2088 Mar 09.95754 Earth .049146 .033491 .063322 5.106 4505.2 1.17E5 0.000
Quote from: ugordan on 11/03/2018 01:04 pmEven if it did, by now it likely diverged from the last known tracking solution after launch sufficiently enough that the impact of such a flyby would be indeterminate.It was nailed down pretty well for the near future.
Caught this during Gwynne Shotwell's TED presentation, FH being lifted up before being placed on the TEL.