QuoteSpaceX Dragon Rendezvous and Docking Waved Off for TodayPosted on February 22, 2017 at 4:38 am by mcsumner.The SpaceX Dragon cargo spacecraft waved off its planned rendezvous with the International Space Station at 3:25 a.m. EST. Onboard computers triggered the abort after recognizing an incorrect value in data about the location of the space station. Per the re-rendezvous plan built into every mission, the spacecraft automatically reset for another rendezvous and docking attempt in 24 hours.The spacecraft is in excellent shape with no issues, and the crew aboard the space station is safe. The next rendezvous attempt is targeted for Thursday morning. NASA TV coverage will begin at 4 a.m. with grapple expected around 6 a.m. Installation coverage will begin at 8 a.m. Watch live on NASA TV and online at: http://www.nasa.gov/live.https://blogs.nasa.gov/spacestation/2017/02/22/spacex-dragon-rendezvous-and-docking-waved-off-for-today/
SpaceX Dragon Rendezvous and Docking Waved Off for TodayPosted on February 22, 2017 at 4:38 am by mcsumner.The SpaceX Dragon cargo spacecraft waved off its planned rendezvous with the International Space Station at 3:25 a.m. EST. Onboard computers triggered the abort after recognizing an incorrect value in data about the location of the space station. Per the re-rendezvous plan built into every mission, the spacecraft automatically reset for another rendezvous and docking attempt in 24 hours.The spacecraft is in excellent shape with no issues, and the crew aboard the space station is safe. The next rendezvous attempt is targeted for Thursday morning. NASA TV coverage will begin at 4 a.m. with grapple expected around 6 a.m. Installation coverage will begin at 8 a.m. Watch live on NASA TV and online at: http://www.nasa.gov/live.
Just guessing, but I imagine it would be more fuel efficient to circle the ISS slowly than quickly. They could of course choose not to circle the ISS, but another reason for the 24 hours is to allow lots of time to solve unknown problem.
Quote from: Roy_H on 02/22/2017 03:20 pmJust guessing, but I imagine it would be more fuel efficient to circle the ISS slowly than quickly. They could of course choose not to circle the ISS, but another reason for the 24 hours is to allow lots of time to solve unknown problem.rescheduling activities on the ISS for the crew may also play a role...
This was from Raul's hazard map. If you zoom out far enough to see Australia, you'll see the re-entry hazard zone for the upper stage. I have seen no information on the accuracy of the actual reentry. This was just the planned area.
Something like this orbit
I've got a question about the second stage reentry. *snip*
Look at the 2nd stage re-entry track in the spaceflight101 article. http://spaceflight101.com/dragon-spx10/falcon-9-deorbit-burn-seen-over-iran-kuwait/
Quote from: whitelancer64 on 02/22/2017 08:57 pmLook at the 2nd stage re-entry track in the spaceflight101 article. http://spaceflight101.com/dragon-spx10/falcon-9-deorbit-burn-seen-over-iran-kuwait/I assume you're talking about this image. That's a ground track, not a reentry zone. Those video views were due to fuel dumps and the very brief deorbit burn. Reentry would still be very far downrange -- recall the Shuttle deorbit burns which would take place near Australia, yet land in US? Thank you, but my question stands
Interestingly if you look here: https://www.n2yo.com/?s=42053|25544 dragon and iss are still far apart. (not sure how many miles, no idea how to translate lat/lng to miles)Edit: 273.5 km according to http://www.movable-type.co.uk/scripts/latlong.html.Edit 2: this is not taking into account altitude.
The first is the NOTAM map showing a region extending down to 61 deg South. The second is the ISS orbital track showing paths down to the nominal 51.6 deg South. The thing is, that reentry is NOT something like that orbit, for reasonable values of "something" Why was the reentry zone planned for so much further south than the orbital track? 10 degrees of inclination is nothing to sneeze at. Was SpaceX doing a delta-V / plane-change test with their second stage, after Dragon sep?
Do the ground track image and the "something like this orbit" image match up?
So, your question revolves around the reentry zone going further south than the inclination of the station. It looks like the zone is also much wider than it needs to be. I think somebody just had to calculate the worst case scenario for the reentry zone, such as if it lost TVC during the burn but didn't shut off the engine, how far off track could it go before it ran out of fuel. I think you are just reading too much into it.
In a worst case scenario, do we know how many berthing attempts the Dragon's fuel capacity can provide for, before having insufficient propellant left for a successful return to Earth?
I've got a question about the second stage reentry. In the launch updates thread, these two reentry map images were posted (click the quote links to see the images):Quote from: deruch on 02/22/2017 03:03 amThis was from Raul's hazard map. If you zoom out far enough to see Australia, you'll see the re-entry hazard zone for the upper stage. I have seen no information on the accuracy of the actual reentry. This was just the planned area.Quote from: Bargemanos on 02/22/2017 08:09 amSomething like this orbitThe first is the NOTAM map showing a region extending down to 61 deg South.The second is the ISS orbital track showing paths down to the nominal 51.6 deg South. The thing is, that reentry is NOT something like that orbit, for reasonable values of "something" Why was the reentry zone planned for so much further south than the orbital track? 10 degrees of inclination is nothing to sneeze at. Was SpaceX doing a delta-V / plane-change test with their second stage, after Dragon sep?