I'm personally wondering about those cubesat P-PODs. My lab here has several nanosats in the pipeline that could be ready for launch in roughly that timeframe. Would be really cool to be on this launch. Only 1 of 3 planned is currently manifested.
Quote from: LouScheffer on 12/06/2012 11:40 amThis looks like at least 5 burns of the second stage to me, over many hours. #1, get into orbit with a 720 km apogee, 24 inclination. #2, circularize at 720, release first payload. #3, Next equator crossing, boost to a 6000 km perigee. Coast until apogee, #4, boost to a 12000x6000 orbit and change plane to 45º. Wait the required 3 hours for the final stage restart (#5).I'm not an orbital mechanics guy, but you might get less delta-v by doing the last plane change at the 12,000 km apogee, rather than including it as part of burn #4. That would be yet another burn, and a few more hours.[...] Indeed, changing planes is most efficient with lowest orbital velocity: high apogee, low perigee. Therefore my best guess is:- Launch into 720x250km transfer orbit 24 deg inclination. The 4.5 deg difference to KSC latitude could be included already.- Burn 1: 720x720km, 24 deg incl.- Burn 2: 720x12000km, 24 deg incl.- Burn 3: 720x12000km, plane change to 45 deg incl.- Burn 4: 6000x12000km, 45 deg incl.- Burn 5: as required by contractI don't think there is a way around separating Burn 2/3. But 3/4 could be possibly joined as they both happen at apogee.
This looks like at least 5 burns of the second stage to me, over many hours. #1, get into orbit with a 720 km apogee, 24 inclination. #2, circularize at 720, release first payload. #3, Next equator crossing, boost to a 6000 km perigee. Coast until apogee, #4, boost to a 12000x6000 orbit and change plane to 45º. Wait the required 3 hours for the final stage restart (#5).I'm not an orbital mechanics guy, but you might get less delta-v by doing the last plane change at the 12,000 km apogee, rather than including it as part of burn #4. That would be yet another burn, and a few more hours.
Quote from: Halidon on 12/06/2012 09:49 amQuote from: Ben the Space Brit on 12/06/2012 09:00 amAt the time the type was officially announced, it was implied very strongly that DoD or USAF had urged SpaceX to proceed with Falcon Heavy more quickly than they had initially planned. I wonder if STP-2 was the mission that they had in mind, even then?I don't think this specific mission was on their minds, I think they pushed SpaceX to accelerate FH because F1v1 wasn't meeting their requirements in general. DoD's high valure payloads are big and may be getting bigger.Huh? Unwarranted speculation. This is just a mission made up to test the FH. There is no pushing from the DOD either. The onus is on Spacex to provide the vehicle, the DOD was not looking for another one.
Quote from: Ben the Space Brit on 12/06/2012 09:00 amAt the time the type was officially announced, it was implied very strongly that DoD or USAF had urged SpaceX to proceed with Falcon Heavy more quickly than they had initially planned. I wonder if STP-2 was the mission that they had in mind, even then?I don't think this specific mission was on their minds, I think they pushed SpaceX to accelerate FH because F1v1 wasn't meeting their requirements in general. DoD's high valure payloads are big and may be getting bigger.
At the time the type was officially announced, it was implied very strongly that DoD or USAF had urged SpaceX to proceed with Falcon Heavy more quickly than they had initially planned. I wonder if STP-2 was the mission that they had in mind, even then?
Sounds like a 3 burn mission to me.
Quote from: Antares on 12/06/2012 07:51 pmSounds like a 3 burn mission to me.How do you get from 720x720 to 6000x12000 in one burn, because there is this final requirement for the insertion orbit #2 which accounts for an additional burn: After the coast phase, the LV shall execute an upper stage restart with a minimum duration of 5 seconds (TBR).?
Quote from: ugordan on 12/06/2012 07:57 pmQuote from: Antares on 12/06/2012 07:51 pmSounds like a 3 burn mission to me.Launch into 720x720km, 24 deg incl.Restart 1: Increase altitude to 720x12000km, 24 deg incl.Restart 2: Increase altitude to 6000x12000 and plane change to 45 degRestart 3: as required by contractHow do you get from 720x720 to 6000x12000 in one burn, because there is this final requirement for the insertion orbit #2 which accounts for an additional burn: After the coast phase, the LV shall execute an upper stage restart with a minimum duration of 5 seconds (TBR).?Agreed, I immediately thought it sounded more like a 4-burn mission.
Quote from: Antares on 12/06/2012 07:51 pmSounds like a 3 burn mission to me.Launch into 720x720km, 24 deg incl.Restart 1: Increase altitude to 720x12000km, 24 deg incl.Restart 2: Increase altitude to 6000x12000 and plane change to 45 degRestart 3: as required by contractHow do you get from 720x720 to 6000x12000 in one burn, because there is this final requirement for the insertion orbit #2 which accounts for an additional burn: After the coast phase, the LV shall execute an upper stage restart with a minimum duration of 5 seconds (TBR).?
PDF on DSX http://www.dtic.mil/dtic/tr/fulltext/u2/a531813.pdf
Quote from: Ronsmytheiii on 12/07/2012 02:50 amPDF on DSX http://www.dtic.mil/dtic/tr/fulltext/u2/a531813.pdfFrom this document:DSX is slated to fly in a 6,000 km x 12,000 km elliptical orbit at 120 degrees retrograde.Lucky they relaxed this requirement. That would be the mother of all plane changes!
Quote from: LouScheffer on 12/07/2012 11:19 amQuote from: Ronsmytheiii on 12/07/2012 02:50 amPDF on DSX http://www.dtic.mil/dtic/tr/fulltext/u2/a531813.pdfFrom this document:DSX is slated to fly in a 6,000 km x 12,000 km elliptical orbit at 120 degrees retrograde.Lucky they relaxed this requirement. That would be the mother of all plane changes!The original plan, IIRC, was to fly it along with the next DMSP mission to a polar orbit on an Atlas V (401!) with a lot of excess capability. A plane change from 98 to 120 degrees with such a payload at apogee isn't that difficult.
NBS reports more details on contracts:The U.S. Air Force will pay $97 million for a Falcon 9 rocket to launch in 2014 the Deep Space Climate Observatory, a solar telescope that will be operated by NASA. It will also pay $165 million for a Falcon Heavy rocket for the military's Space Test Program-2 satellite, which is expected to fly in 2015.http://www.msnbc.msn.com/id/50094995/ns/technology_and_science-space/#.UMSQT3dacgpWhy are the prices so high?-- Falcon 9: $M 97 / 54 = 1.8-- Falcon H: $M 165 / 128 = 1.3Is it because these missions are much more complex than typical satellite launch?Or, do they request some additional services?