Has it been confirmed what sort of burns are expected for this mission? A GPS-III type burn profile was being discussed at the meetup last night, but I didn't catch if that was just being discussed as hypothetical or the actual plan?
Quote from: aero1310 on 04/09/2019 05:09 pmI'm just thinking outside the box here and reasons that would cause extra time to be taken on new rocket engines... with the new thrust numbers Elon announced, were they prepared for that news or do they have to go back and make a ton of adjustments according to the more power the block V produces.Prepared for the news? They are not really "new" engines any more. This is basically the same engine variant that flew on the first Block 5 almost a year ago, potential NASA-mandated turbine changes notwithstanding.
I'm just thinking outside the box here and reasons that would cause extra time to be taken on new rocket engines... with the new thrust numbers Elon announced, were they prepared for that news or do they have to go back and make a ton of adjustments according to the more power the block V produces.
Does anyone know for sure why the delay? Obviously weather being a factor but what about FH itself? Would SpaceX been ready to go if conditions were clear? Just find the minimal communication a little wierd...
Also, how old are the computer systems? I wonder if they are still using old systems for a newer rocket, so adjustments and such still have to be done in which a matter that it takes time.
"if it ain't broke, dont change it." I know SpaceX is always upgrading, making changes, and tweaking things. So the thought behind the question was do they have brand new rockets that are going to run on 10 year old systems, so making adjustments may not be as quick and simple as we might expect.
Quote from: pb2000 on 04/09/2019 02:59 pmHas it been confirmed what sort of burns are expected for this mission? A GPS-III type burn profile was being discussed at the meetup last night, but I didn't catch if that was just being discussed as hypothetical or the actual plan?I would expect a simple two burn mission for the second stage. First orbital insertion, coast to equator and then another burn to raise apogee and lower inclination.
Patch from press kit
Quote from: pb2000 on 04/09/2019 02:59 pmHas it been confirmed what sort of burns are expected for this mission? A GPS-III type burn profile was being discussed at the meetup last night, but I didn't catch if that was just being discussed as hypothetical or the actual plan?As far as I know the trajectory has not been announced. There are several ways increased performance could be used to reduce the delta-V needed by the satellite to reach GEO:(a) Super-synchronous apogee, to make the plane change less costly(b) Reduce inclination at GTO injection burn(c) increased perigee, as GPS did.or even some combination of these. (a) depends on if the operator wants it, and the satellite can handle it. (b) is less efficient that (a), but easy for both the satellite (it's a traditional GTO) and the rocket (just two burns). (c) usually requires a third burn after satellite release to dispose of the second stage. Given the additional complexities of (a) and (c), and since it's an early use of the FH, I'm guessing (b). But the others are certainly possible.
Quote from: LouScheffer on 04/09/2019 03:14 pmQuote from: pb2000 on 04/09/2019 02:59 pmHas it been confirmed what sort of burns are expected for this mission? A GPS-III type burn profile was being discussed at the meetup last night, but I didn't catch if that was just being discussed as hypothetical or the actual plan?As far as I know the trajectory has not been announced. There are several ways increased performance could be used to reduce the delta-V needed by the satellite to reach GEO:(a) Super-synchronous apogee, to make the plane change less costly(b) Reduce inclination at GTO injection burn(c) increased perigee, as GPS did.or even some combination of these. (a) depends on if the operator wants it, and the satellite can handle it. (b) is less efficient that (a), but easy for both the satellite (it's a traditional GTO) and the rocket (just two burns). (c) usually requires a third burn after satellite release to dispose of the second stage. Given the additional complexities of (a) and (c), and since it's an early use of the FH, I'm guessing (b). But the others are certainly possible.Given the above (I agree on b) and the press kit hints what's coming,,,I wonder just how much inclination they can brut force cancel during the second burn on S2... If they can show final GEO-xxx.x orbit numbers that beat A5 launches from South America... Then I think, some folks in Europe are going to have a "moment of clarity"...
I notice from the press kit pdf they have 61 seconds of center core burn time between BECO and MECO...IIRC, that is quite a bit more then the demo flight was (like 30ish seconds IIRC)Must really be throttling back the center core during boost phase to have that much prop left over... On edit... went and found the FH demo press kit... 35 seconds (I was close)SO... THAT extra 26 seconds of center core thrust between BECO and MECO will REALLY make things interesting I think...
Still havent seen confirmation that FH has been rolled out. How long prior to F9 is the vehicle rolled out and Erected?
I am sorry if this is not the place... but I see people seeling "Feel The Heat" tickets. my father just arrived in Miami this night. Maybe he could go to Cape Canaveral for the experience of a life time.How does it works to see a SpaceX launch? Kennedy Space Center visitor center closes pretty early, so I guess you canīt watch a launch as a simple KSC visitor?
Quote from: aceshigh on 04/10/2019 02:43 amI am sorry if this is not the place... but I see people seeling "Feel The Heat" tickets. my father just arrived in Miami this night. Maybe he could go to Cape Canaveral for the experience of a life time.How does it works to see a SpaceX launch? Kennedy Space Center visitor center closes pretty early, so I guess you canīt watch a launch as a simple KSC visitor?I seem to recall having to be at the visitors center by a certain time for the maiden FH feel the heat tickets I think it was closed for regular visitors
