Could they have used one of the existing satellites orbiting Mars for a relay?
Great work by Chris G at the end there!OK, back to one post of congrats each!Remember (and some keep forgetting) that replies to posts on here should be quoted and posted on the discussion thread. Mods are under strict orders to remove posts from this thread which should be on the discussion thread. I'm off for a stiff drink.
Quote from: envy887 on 02/07/2018 12:49 amQuote from: PeterAlt on 02/07/2018 12:44 amThis is really disappointing. How much extra would it have been to attach a communication and power package to the Roadster?Communicating at Mars' distances is really hard, so a lot extra. This is a mass simulator, remember - not a science payload.Plus it wouldn't get anywhere near Mars for years. There's not much else to see in interplanetary space.Could they have used one of the existing satellites orbiting Mars for a relay?
Quote from: PeterAlt on 02/07/2018 12:44 amThis is really disappointing. How much extra would it have been to attach a communication and power package to the Roadster?Communicating at Mars' distances is really hard, so a lot extra. This is a mass simulator, remember - not a science payload.Plus it wouldn't get anywhere near Mars for years. There's not much else to see in interplanetary space.
This is really disappointing. How much extra would it have been to attach a communication and power package to the Roadster?
So the center core ran out of igniter or prop? The former is surprising given the number of landings. The later means they pushed the envelope just a bit too far.
How far out are we now? Are we past ISS altitude yet?
Quote from: PeterAlt on 02/07/2018 01:03 amHow far out are we now? Are we past ISS altitude yet?The second burn placed it higher than 7,000 miles out. The third burn will be the injection into interplanetary space...
Quote from: Steven Pietrobon on 02/07/2018 12:45 amT+5 hours. I wonder how SpaceX is getting continuous coverage? TDRS?My supposition is that since this extended-coast part of the mission is to demonstrate the ability to satisfy DOD requirements, SpaceX has arranged to use TDRS for continuous telemetry and video coverage, since presumably a priority national security payload going straight to GEO would have access to or might itself require such coverage.
T+5 hours. I wonder how SpaceX is getting continuous coverage? TDRS?
Quote from: MATTBLAK on 02/07/2018 01:06 amQuote from: PeterAlt on 02/07/2018 01:03 amHow far out are we now? Are we past ISS altitude yet?The second burn placed it higher than 7,000 miles out. The third burn will be the injection into interplanetary space...Km - not miles.
Quote from: PeterAlt on 02/07/2018 01:03 amHow far out are we now? Are we past ISS altitude yet?It passed that altitude within minutes after launch
Quote from: Kabloona on 02/07/2018 12:22 amQuote from: Jeff Lerner on 02/07/2018 12:19 amHow does the core run out of igniter ??...there are only so many engines to be restarted and they only restart so many times...Spacex has done this many time before and they hadn't run out of igniter...Does this imply they had a problem restarting a couple of the engnes a number of times on this flight and ran out of,igniter,??I'm just speculating on how this could happen ??It's unlikely, for the reasons you stated. Each restart uses a known quantity of TEA/TEB. We have, however, seen stages run out of propellant during the landing burn.My guess - the rocket does not take the same amount of TEA/TEB, it goes until it ignites. Normally that's the same amount. However in this case the rocket is going faster, tail first, when the re-entry burn happens. That causes more back pressure -> harder to start -> takes more TEA/TEB. So it runs out, the stage can't ignite for the 3 engine burn, and kablooey.This theory is based entirely on the hypothesis that SpaceX are not idiots, so there must be some reason it used more TEA/TEB.
Quote from: Jeff Lerner on 02/07/2018 12:19 amHow does the core run out of igniter ??...there are only so many engines to be restarted and they only restart so many times...Spacex has done this many time before and they hadn't run out of igniter...Does this imply they had a problem restarting a couple of the engnes a number of times on this flight and ran out of,igniter,??I'm just speculating on how this could happen ??It's unlikely, for the reasons you stated. Each restart uses a known quantity of TEA/TEB. We have, however, seen stages run out of propellant during the landing burn.
How does the core run out of igniter ??...there are only so many engines to be restarted and they only restart so many times...Spacex has done this many time before and they hadn't run out of igniter...Does this imply they had a problem restarting a couple of the engnes a number of times on this flight and ran out of,igniter,??I'm just speculating on how this could happen ??
Quote from: LouScheffer on 02/07/2018 12:39 amQuote from: Kabloona on 02/07/2018 12:22 amQuote from: Jeff Lerner on 02/07/2018 12:19 amHow does the core run out of igniter ??...there are only so many engines to be restarted and they only restart so many times...Spacex has done this many time before and they hadn't run out of igniter...Does this imply they had a problem restarting a couple of the engnes a number of times on this flight and ran out of,igniter,??I'm just speculating on how this could happen ??It's unlikely, for the reasons you stated. Each restart uses a known quantity of TEA/TEB. We have, however, seen stages run out of propellant during the landing burn.My guess - the rocket does not take the same amount of TEA/TEB, it goes until it ignites. Normally that's the same amount. However in this case the rocket is going faster, tail first, when the re-entry burn happens. That causes more back pressure -> harder to start -> takes more TEA/TEB. So it runs out, the stage can't ignite for the 3 engine burn, and kablooey.This theory is based entirely on the hypothesis that SpaceX are not idiots, so there must be some reason it used more TEA/TEB.May be some restart hardware (some tube wire or sensor) was destroyed by acoustics on 2 outer engines?
