Cropped version of SoaceX landing photo. I know the side on angle isn't great, but to me it looks mainly like dirt (sand?) on the pad, the pad paint job seems to have held up pretty well?
Quote from: FutureSpaceTourist on 08/15/2017 04:00 amCropped version of SoaceX landing photo. I know the side on angle isn't great, but to me it looks mainly like dirt (sand?) on the pad, the pad paint job seems to have held up pretty well?The landing pad is concrete. This has been definitively established multiple times. It's surrounded by a ring of compacted dirt.
The grid fins seemed to be much more active during the landing sequence, compared to previous missions.
I believe @FutureSpaceTourist was talking about what looks like a bit of a wash of dirt/sand on the pad, not what the pad is made of, and suggesting that it is in fact dirt/sand and not damage from the rocket plume. As noted, it is difficult to say for sure due to the angle, but I would tend to agree.
you will notice some of the block 4 differences if you have a good eye and watch the flight footage and not all are small differences but most are. I'll leave you with that until launch day.
Looking side way, looks like 20-25 degree angle of attack.
The takeoff looked quicker to me, but I compared it to CRS-11 and it's almost identical.Looking at both videos, at the frame where the clock ticks from 6 to 7, the bottom of the booster is about 3 "floors" above the top of the FSS just behind it. Side by side, it looks exactly the same to me. The telemetry at this frame shows 53 m/s for CRS-11, and even a little less for CRS-12 (51 m/s). So certainly a 10% thrust increase is ruled out - that would change the initial acceleration from something like 0.3 G up to 0.4 G up, which would be clearly noticeable. Instead the two launches look identical to within the accuracy of the webcast.
Maybe the thrust increase was for the second stage. CRS-12 second stage burn time was 10 seconds shorter than CRS-11 (6:38 versus 6:48). Of course, different payload mass, orbit and throttling could help to explain the difference.
The first Block 4 did make use of increased-thrust Merlin 1D engines. The thrust increase of the Merlin 1Ds is also incremental, with a final thrust increase set to debut on the Block 5.
Published on 16 Aug 2017SpaceX launches Dragon Spacecraft to the International Space Station under the Commercial Resupply Services (CRS) program. This video synchronizes the launches of CRS-1 through CRS-12 and you can see how the technology and launch profiles have changed.The were a few Dragon missions prior to this which were technology demonstrators for the Commercial Orbital Transportation Services (COTS) program, the second of which berthed at the ISS in May 2012. This is missing from the video because 13 is not a convenient number for this presentation Mission control audio is chopped up with sections from all launches intermixed to highlight the major events.The music is by Test Shot Starfish who do all the music for the SpaceX livestreams.https://soundcloud.com/testshotstarfishTracks are 'Re - Flight', 'Approaching Dragon' and 'Andromeda'https://soundcloud.com/testshotstarfi...https://soundcloud.com/testshotstarfi...https://soundcloud.com/testshotstarfi...
If there was a thrust increase on the first stage it was so slight as to not be noticeable. There are some really good telemetry graphs and two comparisons between CRS-11 and CRS-12 that can be found on this reddit post. Its quite obvious that, everything else being relatively equal, both CRS-11 and CRS-12 were flown with basically the same thrust (but different max-q throttling).I'm very curious what was meant by the above quote. Did it just mean that the flown engines were uprated but flown at same thrust levels?
Fun video by Scott ManleyQuotePublished on 16 Aug 2017SpaceX launches Dragon Spacecraft to the International Space Station under the Commercial Resupply Services (CRS) program. This video synchronizes the launches of CRS-1 through CRS-12 and you can see how the technology and launch profiles have changed.The were a few Dragon missions prior to this which were technology demonstrators for the Commercial Orbital Transportation Services (COTS) program, the second of which berthed at the ISS in May 2012. This is missing from the video because 13 is not a convenient number for this presentation Mission control audio is chopped up with sections from all launches intermixed to highlight the major events.The music is by Test Shot Starfish who do all the music for the SpaceX livestreams.https://soundcloud.com/testshotstarfishTracks are 'Re - Flight', 'Approaching Dragon' and 'Andromeda'https://soundcloud.com/testshotstarfi...https://soundcloud.com/testshotstarfi...https://soundcloud.com/testshotstarfi...