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If you watched live the video of the landing was very patchy. In fact there was just one frame before the rocket landed and it showed the empty barge deck but a

If you watched live the video of the landing was very patchy. In fact there was just one frame before the rocket landed and it showed the empty barge deck but a huge depression in the surface of the ocean on the other side of the barge and there was an instant and loud in take of breath by the SpaceX crowd. It really didn't look good, either the rocket had gone into the ocean there or the rocket somehow had hovered over that spot far from its expected landing zone. The video stopped again for what seemed like a long time might have been 30 seconds the next single frame showed the rocket far off center on the barge deck and there was a huge cheer from the SpaceX crew. It must have been a very close call.

ChuckMcM 9y ago
I too found that particular set of frames quite interesting. So the last telemetry had stage 1 at 5700 km/sec and 22.3 km in altitude (so about 13 seconds from impact). The landing burn starts and at 24:55 "something" impacts the water really hard next to the barge. The announcer calls "landing burn has started" but you don't see any change in the telemetry (altitude or velocity) so its safe to say the downlink is still not functioning at that point). Then at 25:41 (about a minute later) we see the stage sitting on the drone ship. So once again I'm really surprised they haven't figured done something to stabilize video. Even it it were a 'drone dinghy' 500 yards off to the side holding a steady lock on a satellite or an aerial drone. The other interesting bit is at 23:42 where we see one of the grid fins in the process of burning off the side of the rocket. Then we lose downlink video from that point on with the stage. It is flying at nearly 4,000 mph at an altitude of 87,000 feet. The SR-71 goes half that fast at that altitude and experiences significant heating on its skin, since drag is proportional to the square of the velocity you're taking 4x the heating. It has to be a very fine line between burning these things up vs landing them. And clearly the more 'abuse' they will tolerate during re-entry the more fuel you can use toward lift mass. Still, I'm always surprised that they don't use more rocket power to slow down while above 100,000' to avoid the high speed re-entry and then use streamers or drogue chutes rather than RP1 to slow down in the thicker atmosphere.
- jaggederest 9y ago
  The reason they don't use chutes is that the stated long term goal is refuel and refly from the pad with the BFS. Chutes have to be repacked, means it's a no-go. Powered landing is where it's at for true reusability.
  - LoSboccacc 9y ago
    You have to replace the shock adsorber anyway, the chutes could be as well detachable and replaceable with a ready to go packed one, while the spents are sent back for repacking
    - Inconel 9y ago
      From my understanding, the type of parachutes necessary for this, and the associated hardware needed for their safe deployment, are quite heavy and complicated.
  - agildehaus 9y ago
    Chutes also have almost zero utility for a vehicle the size of the ITS when landing on Mars. Every single thing they're doing in this program is prep for Mars.
    - SimbaOnSteroids 9y ago
      Not just SpaceX, everything Elon is doing is centered around mars. Yes some of these are a stretch, a big stretch even. Ok a ludicrous stretch. Anyways by company. SpaceX-pushing rocket tech makes mars a more targetable endevour. Tesla- better solar panels and better batteries mean you can consume and store more power on be red planet. Open AI- it's going to be very important to be able to prefab critical systems before any astronauts get there. AI can help there. Boring Company- Where do you build a home in a place with almost no atmosphere to shield you from radiation? Underground. What's nice and cylindrical and would fit nicely in a tube atop a rocket? Bore segments. Also TBC's bores are being designed with a smaller diameter than your typical bore. Elon says it's so cars can fit in them to revolutionize the LA commute, I see something that can be moduralized and put on top of a heavy lift rocket and used to prefab Martian living quarters.

ChuckMcM 9y ago

I too found that particular set of frames quite interesting. So the last telemetry had stage 1 at 5700 km/sec and 22.3 km in altitude (so about 13 seconds from impact). The landing burn starts and at 24:55 "something" impacts the water really hard next to the barge. The announcer calls "landing burn has started" but you don't see any change in the telemetry (altitude or velocity) so its safe to say the downlink is still not functioning at that point). Then at 25:41 (about a minute later) we see the stage sitting on the drone ship. So once again I'm really surprised they haven't figured done something to stabilize video. Even it it were a 'drone dinghy' 500 yards off to the side holding a steady lock on a satellite or an aerial drone. The other interesting bit is at 23:42 where we see one of the grid fins in the process of burning off the side of the rocket. Then we lose downlink video from that point on with the stage. It is flying at nearly 4,000 mph at an altitude of 87,000 feet. The SR-71 goes half that fast at that altitude and experiences significant heating on its skin, since drag is proportional to the square of the velocity you're taking 4x the heating. It has to be a very fine line between burning these things up vs landing them. And clearly the more 'abuse' they will tolerate during re-entry the more fuel you can use toward lift mass. Still, I'm always surprised that they don't use more rocket power to slow down while above 100,000' to avoid the high speed re-entry and then use streamers or drogue chutes rather than RP1 to slow down in the thicker atmosphere.

jaggederest 9y ago
The reason they don't use chutes is that the stated long term goal is refuel and refly from the pad with the BFS. Chutes have to be repacked, means it's a no-go. Powered landing is where it's at for true reusability.
- LoSboccacc 9y ago
  You have to replace the shock adsorber anyway, the chutes could be as well detachable and replaceable with a ready to go packed one, while the spents are sent back for repacking
  - Inconel 9y ago
    From my understanding, the type of parachutes necessary for this, and the associated hardware needed for their safe deployment, are quite heavy and complicated.
- agildehaus 9y ago
  Chutes also have almost zero utility for a vehicle the size of the ITS when landing on Mars. Every single thing they're doing in this program is prep for Mars.
  - SimbaOnSteroids 9y ago
    Not just SpaceX, everything Elon is doing is centered around mars. Yes some of these are a stretch, a big stretch even. Ok a ludicrous stretch. Anyways by company. SpaceX-pushing rocket tech makes mars a more targetable endevour. Tesla- better solar panels and better batteries mean you can consume and store more power on be red planet. Open AI- it's going to be very important to be able to prefab critical systems before any astronauts get there. AI can help there. Boring Company- Where do you build a home in a place with almost no atmosphere to shield you from radiation? Underground. What's nice and cylindrical and would fit nicely in a tube atop a rocket? Bore segments. Also TBC's bores are being designed with a smaller diameter than your typical bore. Elon says it's so cars can fit in them to revolutionize the LA commute, I see something that can be moduralized and put on top of a heavy lift rocket and used to prefab Martian living quarters.