All these problems and its high cost doesn't bode well for the future of Pegasus XL. This could end up being the last flight of this rocket.
Very unlikely. I rather expect IXPE to be awarded to NG/Pegasus.
Quote from: Kim Keller on 06/11/2018 11:40 pmVery unlikely. I rather expect IXPE to be awarded to NG/Pegasus.Spacecraft mass is 292 kg from the fact sheet. The Minotaur 4/Orion 38 launched the 140 kg ORS-5 into 0° 600 km orbit, but that looks too low in mass for IXPE. LauncherOne could do it, but probably could not get qualified in time. Electron is out due to the inclination and not having the performance. Looks like NASA doesn't have much choice."The Imaging X-ray Polarimetry Explorer will be launched on or after November 20, 2020 from Kwajelein Atoll into a 540-km circular orbit at 0° inclination."https://ixpe.msfc.nasa.gov/about/index.htmlhttps://ixpe.msfc.nasa.gov/about/fact_sheet.html
Mission Design and Operations Concept• Pegasus launch from Kwajalein (RTS) on or after 11/20/2020• 540-km circular orbit at nominal 0° inclination• Two-year mission• Point-and-stare observations of known targets• Science Operations Center (SOC) at MSFC• Mission Operations Center (MOC) at CU/LASP• Ground Station at Malindi (backup: Singapore)
Quote from: Steven Pietrobon on 06/12/2018 06:26 amQuote from: Kim Keller on 06/11/2018 11:40 pmVery unlikely. I rather expect IXPE to be awarded to NG/Pegasus.Spacecraft mass is 292 kg from the fact sheet. The Minotaur 4/Orion 38 launched the 140 kg ORS-5 into 0° 600 km orbit, but that looks too low in mass for IXPE. LauncherOne could do it, but probably could not get qualified in time. Electron is out due to the inclination and not having the performance. Looks like NASA doesn't have much choice."The Imaging X-ray Polarimetry Explorer will be launched on or after November 20, 2020 from Kwajelein Atoll into a 540-km circular orbit at 0° inclination."https://ixpe.msfc.nasa.gov/about/index.htmlhttps://ixpe.msfc.nasa.gov/about/fact_sheet.htmlYes, the fact sheet baselines Pegasus. There aren't many launchers that can get to an equatorial LEO.QuoteMission Design and Operations Concept• Pegasus launch from Kwajalein (RTS) on or after 11/20/2020• 540-km circular orbit at nominal 0° inclination• Two-year mission• Point-and-stare observations of known targets• Science Operations Center (SOC) at MSFC• Mission Operations Center (MOC) at CU/LASP• Ground Station at Malindi (backup: Singapore)
I think all the DIVM, AV 401, and F9R/ASDS can do 2000+ kg to 540 km circular equatorial LEO. And Delta II out of Canaveral, if that were still available, could do 400+ kg. Perhaps Minotaur C or Antares 2xx as well. Of course Pegasus is cheaper than any of those, at least at the moment.
Quote from: envy887 on 06/12/2018 07:24 pmI think all the DIVM, AV 401, and F9R/ASDS can do 2000+ kg to 540 km circular equatorial LEO. And Delta II out of Canaveral, if that were still available, could do 400+ kg. Perhaps Minotaur C or Antares 2xx as well. Someone on NSF, and I am ashamed to admit that I can't remember who, modeled a Falcon 9 launch to a zero degree inclination orbit. The potential payload was around 3000 kg, and that was probably before Block 5.
I think all the DIVM, AV 401, and F9R/ASDS can do 2000+ kg to 540 km circular equatorial LEO. And Delta II out of Canaveral, if that were still available, could do 400+ kg. Perhaps Minotaur C or Antares 2xx as well.
The explanation for the move of ICON from Kwaj to Cape in this SFN article makes no sense to me. According to NASA, ICON is headed to a 27 degree circular orbit. The article states that it was originally slated for Kwaj since the Cape did not have the desired performance.But this seems odd. Surely the L-1011 can fly south from the 28.5 degree Cape to get within the 27 degree orbit - that's only about half way to Miami. And if it launches within the 27 degree orbit, then no plane change is required, and the performance should be the same from both sites. At the equator, the full speed of the Earth is available, but only cos(i) is in the direction you need. At the northern tip of the orbit, only cos(i) of the Earth's speed is available, but it's all in the direction you need. The two effects cancel, and the capacity is the same.So what am I missing? Perhaps the Eastern range cannot cover the launch if they fly south first, so a plane change is required after all?
We flew Stargazer for 45 minutes on Novenber 19th. Crew had only one squawk. Last flying L1011 in the world and still flying great. Got 2 missions on the books to last us to 2017 and we hope Pegasus will take us into the 2020's.