3 ms·

I do agree on the cheap and pragmatic approach, yet they could display actual telemetry over the 3d render. Speeds do not match reality in graphs. It is not a m

by acoye 8y ago

I do agree on the cheap and pragmatic approach, yet they could display actual telemetry over the 3d render. Speeds do not match reality in graphs. It is not a movie but Science to me here. I'd love to hear from a SpaceX engineer if their webcasts indeed shows live telemetry (speed / altitude) or not. Also SpaceX's webcasts illustrations looks like they run in a game engine which is both cheap and highly customizable with input data.

mikejb 8y ago
Yes, SpaceX puts a lot more effort into the webcasts. I don't know if their telemetry is live or precomputed (though it is likely live, see below) - but the fact that they show live feed of the rocket rather than a simulation (except for Stage 2 coasting periods where they render the spacecrafts' orbit) already gives the entire display a different feel. (At this point it's also important to note that this live feed got them into trouble once [1]). I also agree with your sentiment that the movie removes a bit of the scientific aspect. Insert here a good 30 minutes spent on watching launch footage and writing down numbers Ok, at this point I'm deep in looking at launch footage, and I'm more disappointed by the Soyuz launch footage. Whilst it's possible that they followed the exact same launch trajectory (on paper and reality), it's unlikely: MS-08 [2] and MS-09 [3] had the exact same speed, altitude and downrange distance throughout the time telemetry was visible. In contrast, SpaceX showed very different telemetry during launches to the ISS ([4], [5], [6]). Also, it doesn't seem pre-computed: The telemetry during the CRS-7 webcast [7] at least doesn't just continue when the rocket explodes, indicating that it doesn't just display pre-computed numbers. In Soyuz' defense: They probably have a different (older?) system to get telemetry, and it might bear additional challenges to feed them into a publicly accessible live-stream. [1] https://www.space.com/40153-spacex-launch-video-noaa-restrictions.html https://www.space.com/40153-spacex-launch-video-noaa-restric... [2] https://youtu.be/iDebCdDHHpg?t=365 https://youtu.be/iDebCdDHHpg?t=365 [3] https://youtu.be/00uftjSjcnk?t=364 https://youtu.be/00uftjSjcnk?t=364 [4] https://youtu.be/C_Gmgj3N_Z0?t=1270 https://youtu.be/C_Gmgj3N_Z0?t=1270 [5] https://youtu.be/FCCyVCvN2bo?t=1179 https://youtu.be/FCCyVCvN2bo?t=1179 [6] https://youtu.be/rUDLxFUMC9c?t=1036 https://youtu.be/rUDLxFUMC9c?t=1036 [7] https://youtu.be/JYFLoTgO-xQ?t=1286 https://youtu.be/JYFLoTgO-xQ?t=1286
- orbital-decay 8y ago
  > They probably have a different (older?) system to get telemetry, and it might bear additional challenges to feed them into a publicly accessible live-stream. That is correct. Proton-M launches, on the other hand, had a live stream with probably the most detailed telemetry ever. That particular stream wasn't public, but was available to anyone on request.
  - regnerba 8y ago
    Is there a recording available somewhere or an image of how it looked?
    - orbital-decay 8y ago
      Here's a screenshot of their lowres public telemetry stream dated back to 2009 (Eutelsat W7, if I remember correctly). [0] Unfortunately I don't have any screenshots or recordings of the by-request one, but it had tons of info, down to the bus voltages. The L2 section of nasaspaceflight.com might have something available, but I'm not sure. They seem to have closed it somewhere around 2014 or 2015, possibly to avoid bad publicity or speculations. [0] https://i.imgur.com/2pzbGNV.jpg https://i.imgur.com/2pzbGNV.jpg
      - regnerba 8y ago
        Thanks for the link and info. Will d some more looking later this evening.
regnerba 8y ago
SpaceX has lost a vehicle in flight before, CRS-7, so we actually have a comparison. https://youtu.be/Il8w-Fz31Hk https://youtu.be/Il8w-Fz31Hk On mobile so sorry if it isn't the best link. The failure happens as the vehicle cross the 44km altitude mark I believe. So you can scrub to that point.
- princekolt 8y ago
  The telemetry does seem to get "stuck" during the explosion.
  - mikejb 8y ago
    I noticed that too; My best guess is that the display just sticks to what it last knew if it doesn't get any updates, and the leaking LOX from the 2nd stage caused enough damage or interference to interrupt communication. It's at least my assumption, since the 1st stage continued to fire (i.e. accelerate) until some 8 seconds later, according to the NASA report [1] (Page 3) [1] https://www.nasa.gov/sites/default/files/atoms/files/public_summary_nasa_irt_spacex_crs-7_final.pdf https://www.nasa.gov/sites/default/files/atoms/files/public_...
robryan 8y ago
Spacex telemetry is live. People use it to calculate things like flight path and performance of each launch.

by acoye 8y ago

mikejb 8y ago

Yes, SpaceX puts a lot more effort into the webcasts. I don't know if their telemetry is live or precomputed (though it is likely live, see below) - but the fact that they show live feed of the rocket rather than a simulation (except for Stage 2 coasting periods where they render the spacecrafts' orbit) already gives the entire display a different feel. (At this point it's also important to note that this live feed got them into trouble once [1]). I also agree with your sentiment that the movie removes a bit of the scientific aspect. Insert here a good 30 minutes spent on watching launch footage and writing down numbers Ok, at this point I'm deep in looking at launch footage, and I'm more disappointed by the Soyuz launch footage. Whilst it's possible that they followed the exact same launch trajectory (on paper and reality), it's unlikely: MS-08 [2] and MS-09 [3] had the exact same speed, altitude and downrange distance throughout the time telemetry was visible. In contrast, SpaceX showed very different telemetry during launches to the ISS ([4], [5], [6]). Also, it doesn't seem pre-computed: The telemetry during the CRS-7 webcast [7] at least doesn't just continue when the rocket explodes, indicating that it doesn't just display pre-computed numbers. In Soyuz' defense: They probably have a different (older?) system to get telemetry, and it might bear additional challenges to feed them into a publicly accessible live-stream. [1] https://www.space.com/40153-spacex-launch-video-noaa-restrictions.html https://www.space.com/40153-spacex-launch-video-noaa-restric... [2] https://youtu.be/iDebCdDHHpg?t=365 https://youtu.be/iDebCdDHHpg?t=365 [3] https://youtu.be/00uftjSjcnk?t=364 https://youtu.be/00uftjSjcnk?t=364 [4] https://youtu.be/C_Gmgj3N_Z0?t=1270 https://youtu.be/C_Gmgj3N_Z0?t=1270 [5] https://youtu.be/FCCyVCvN2bo?t=1179 https://youtu.be/FCCyVCvN2bo?t=1179 [6] https://youtu.be/rUDLxFUMC9c?t=1036 https://youtu.be/rUDLxFUMC9c?t=1036 [7] https://youtu.be/JYFLoTgO-xQ?t=1286 https://youtu.be/JYFLoTgO-xQ?t=1286

orbital-decay 8y ago
> They probably have a different (older?) system to get telemetry, and it might bear additional challenges to feed them into a publicly accessible live-stream. That is correct. Proton-M launches, on the other hand, had a live stream with probably the most detailed telemetry ever. That particular stream wasn't public, but was available to anyone on request.
- regnerba 8y ago
  Is there a recording available somewhere or an image of how it looked?
  - orbital-decay 8y ago
    Here's a screenshot of their lowres public telemetry stream dated back to 2009 (Eutelsat W7, if I remember correctly). [0] Unfortunately I don't have any screenshots or recordings of the by-request one, but it had tons of info, down to the bus voltages. The L2 section of nasaspaceflight.com might have something available, but I'm not sure. They seem to have closed it somewhere around 2014 or 2015, possibly to avoid bad publicity or speculations. [0] https://i.imgur.com/2pzbGNV.jpg https://i.imgur.com/2pzbGNV.jpg
    - regnerba 8y ago
      Thanks for the link and info. Will d some more looking later this evening.

regnerba 8y ago

SpaceX has lost a vehicle in flight before, CRS-7, so we actually have a comparison. https://youtu.be/Il8w-Fz31Hk https://youtu.be/Il8w-Fz31Hk On mobile so sorry if it isn't the best link. The failure happens as the vehicle cross the 44km altitude mark I believe. So you can scrub to that point.

princekolt 8y ago
The telemetry does seem to get "stuck" during the explosion.
- mikejb 8y ago
  I noticed that too; My best guess is that the display just sticks to what it last knew if it doesn't get any updates, and the leaking LOX from the 2nd stage caused enough damage or interference to interrupt communication. It's at least my assumption, since the 1st stage continued to fire (i.e. accelerate) until some 8 seconds later, according to the NASA report [1] (Page 3) [1] https://www.nasa.gov/sites/default/files/atoms/files/public_summary_nasa_irt_spacex_crs-7_final.pdf https://www.nasa.gov/sites/default/files/atoms/files/public_...

robryan 8y ago

Spacex telemetry is live. People use it to calculate things like flight path and performance of each launch.