At 6100 kg this is the heaviest Falcon 9 GTO launch so far, right?
'Single stage to orbit' anyone? Don't use acronyms if people can't agree on what they stand for. Spell it out - you are not limited to 140 characters.
Quote from: Star One on 05/02/2017 12:25 pmQuote from: Steven Pietrobon on 05/02/2017 12:19 pmQuote from: macpacheco on 05/02/2017 11:44 amSSTO = super sync transfer orbit, aka similar to GTO but higher energy (likely as partial compensation for the delays).Ahhh, I thought the acronym meant Sun Synchronous Transfer Orbit! :-)These acronyms are uninformative when they can be interpreted more than one way.A Super-synchronous Transfer Orbit (SSTO) has an apogee height considerably above the GEO belt, with the added implications that after the perigee height is raised to GEO altitude, and inclination lowered to near-Equatorial, additional braking burns must be performed to lower the apogee height back down to GEO altitude, circularizing the final orbit. Not to be confused with an sSTO, or sub-synchronous transfer orbit, where the apogee altitude is considerably lower than GEO....
Quote from: Steven Pietrobon on 05/02/2017 12:19 pmQuote from: macpacheco on 05/02/2017 11:44 amSSTO = super sync transfer orbit, aka similar to GTO but higher energy (likely as partial compensation for the delays).Ahhh, I thought the acronym meant Sun Synchronous Transfer Orbit! :-)These acronyms are uninformative when they can be interpreted more than one way.
Quote from: macpacheco on 05/02/2017 11:44 amSSTO = super sync transfer orbit, aka similar to GTO but higher energy (likely as partial compensation for the delays).Ahhh, I thought the acronym meant Sun Synchronous Transfer Orbit! :-)
SSTO = super sync transfer orbit, aka similar to GTO but higher energy (likely as partial compensation for the delays).
What is the source for the SSTO orbit? Is it current and reliable? If the information didn't originate from a SpaceX or Inmarsat source within the last 6 months or so I wouldn't really trust it.
Quote from: gongora on 05/02/2017 02:39 pmWhat is the source for the SSTO orbit? Is it current and reliable? If the information didn't originate from a SpaceX or Inmarsat source within the last 6 months or so I wouldn't really trust it.Nothing was assumed. SpaceX is the source, three days ago.
Quote from: BabaORileyUSA on 05/02/2017 06:09 pmNothing was assumed. SpaceX is the source, three days ago.I just did a quick scan through SpaceX.com's press releases and looked at the SpaceX twitter feed for the past couple days and didn't see anything about Inmarsat. Was there a post-launch presser yesterday that mentioned it? Do you have a link to indicate the launch is in fact super-synch GTO? Thanks.
Nothing was assumed. SpaceX is the source, three days ago.
If this does end up going to a super-synchronous transfer orbit, then it will provide an interesting comparison with the Echostar 23 launch. Echostar 23 was ~5500kg and was sent to 179km x 35903km x 22.43o, which works out to about GTO-1711. Inmarsat is currently listed as 6100kg. If they have enough performance in the F9 to get it to super-synch, this may be the first definite upgraded performance launch (there seems to be a bit of debate whether NROL-76 used upgraded thrust or not).
Slips could still happen but would I be correct in saying that this [45th Space Wing updating their Twitter page to show Inmarsat on 15 May] indicates a high level in confidence that the launch can happen on 5/15, all going well with the pad flow?
Slips could still happen but would I be correct in saying that this indicates a high level in confidence that the launch can happen on 5/15, all going well with the pad flow?