Quote from: sewebster on 01/25/2016 07:10 amQuote from: deruch on 01/25/2016 06:50 amThe big problem with this method is that it would take A Very Long TimeTM. Sure, your all-electric bird has a great Isp. But what its engines don't have is very much actual thrust, so it ends up taking "forever" to raise the orbit. This is a potential problem for 2 reasons. 1. You've lost revenue generating time to orbit raising time. Depending on a company's economic analysis, maybe this is okay. It could theoretically be made up for by lengthening the satellite's lifetime on orbit. 2. It means that the satellite also ends up spending quite a long time getting through the Van Allen radiation belts, which is not good for the hardware on the satellite.I guess Eutelsat 115 West B already made the transfer using all electric propulsion and is now operational? Edit and ABS-3A?Here's a paper with a bunch of plots of various tradeoffs for this strategy:http://erps.spacegrant.org/uploads/images/images/iepc_articledownload_1988-2007/2007index/IEPC-2007-287.pdfGreat link, thanks! Just as a note though, macpacheco was talking about going from LEO to GEO, not GTO to GEO. Though, I should have made clear that he already mentioned my "problem #1" in his post.
Quote from: deruch on 01/25/2016 06:50 amThe big problem with this method is that it would take A Very Long TimeTM. Sure, your all-electric bird has a great Isp. But what its engines don't have is very much actual thrust, so it ends up taking "forever" to raise the orbit. This is a potential problem for 2 reasons. 1. You've lost revenue generating time to orbit raising time. Depending on a company's economic analysis, maybe this is okay. It could theoretically be made up for by lengthening the satellite's lifetime on orbit. 2. It means that the satellite also ends up spending quite a long time getting through the Van Allen radiation belts, which is not good for the hardware on the satellite.I guess Eutelsat 115 West B already made the transfer using all electric propulsion and is now operational? Edit and ABS-3A?Here's a paper with a bunch of plots of various tradeoffs for this strategy:http://erps.spacegrant.org/uploads/images/images/iepc_articledownload_1988-2007/2007index/IEPC-2007-287.pdf
The big problem with this method is that it would take A Very Long TimeTM. Sure, your all-electric bird has a great Isp. But what its engines don't have is very much actual thrust, so it ends up taking "forever" to raise the orbit. This is a potential problem for 2 reasons. 1. You've lost revenue generating time to orbit raising time. Depending on a company's economic analysis, maybe this is okay. It could theoretically be made up for by lengthening the satellite's lifetime on orbit. 2. It means that the satellite also ends up spending quite a long time getting through the Van Allen radiation belts, which is not good for the hardware on the satellite.
Peter B. de Selding @pbdes 6m6 minutes agoSpacecom of Israel: We are planning for an Aug. 22 launch, on SpaceX Falcon 9, of our Amos-6 Ku-/Ka-band telecom sat for 4 deg W.
FCC has posted the latest transmitter permit application here:https://apps.fcc.gov/oetcf/els/reports/STA_Print.cfm?mode=current&application_seq=72213&RequestTimeout=1000Drone ship coordinates are:28 6 11 N74 34 0 WThis is about 45 miles west of the JCSAT-14 coordinates, ie closer to the Cape. This is quite a change, since the SES-9, JCSAT-14, Thaicom-8, and Eutelsat/ABS ASDS positions were all within 11 miles or so of each other.The AMOS-6 launch date has just been announced as August 22, so this permit may be for AMOS-6, which is listed as 5500 kg. That's 700 kg more than JCSAT-14, which could explain the big difference in ASDS positions.Also, 5500 kg is probably the upper limit for stage 1 recovery on GTO missions. The SpaceX F9 "capabilities" web page gives an F9 price of $62M for payloads up to 5500 kg to GTO. And LouScheffer's calculations have deduced an upper limit in this ballpark as well.So AMOS-6 may turn out to be another "limiting case" stage 1 recovery experiment for SpaceX.
So we really don't have any idea yet which launch this is for?
Peter B. de Selding @pbdes 20m20 minutes agoNew target date for SpaceX launch of Spacecom's Amos-6 geo telecom satellite is 3-4 Sept (was 22 Aug.)
According to Reddit, the core is now en-route to SLC-40 after completing its full-duration test burn at McGreggor.
Hopefully the stage is on its way to the Cape after the (reported) successful full engine burn at McGregor. If the stage arrives this weekend that would be 3 weeks away from a Sept. 3/4 launch date. ~3 weeks is the recent cadence between stage arrival at the Cape and launch.
Quote from: Ben the Space Brit on 08/17/2016 08:46 amAccording to Reddit, the core is now en-route to SLC-40 after completing its full-duration test burn at McGreggor.That's just a speculation
Quote from: Kabloona on 06/23/2016 02:15 pmFCC has posted the latest transmitter permit application here:https://apps.fcc.gov/oetcf/els/reports/STA_Print.cfm?mode=current&application_seq=72213&RequestTimeout=1000Drone ship coordinates are:28 6 11 N74 34 0 WThis is about 45 miles west of the JCSAT-14 coordinates, ie closer to the Cape. This is quite a change, since the SES-9, JCSAT-14, Thaicom-8, and Eutelsat/ABS ASDS positions were all within 11 miles or so of each other.The AMOS-6 launch date has just been announced as August 22, so this permit may be for AMOS-6, which is listed as 5500 kg. That's 700 kg more than JCSAT-14, which could explain the big difference in ASDS positions.Also, 5500 kg is probably the upper limit for stage 1 recovery on GTO missions. The SpaceX F9 "capabilities" web page gives an F9 price of $62M for payloads up to 5500 kg to GTO. And LouScheffer's calculations have deduced an upper limit in this ballpark as well.So AMOS-6 may turn out to be another "limiting case" stage 1 recovery experiment for SpaceX.So we really don't have any idea yet which launch this is for?