Quote from: edkyle99 on 04/02/2015 01:11 pmOne month after launch, Eutelsat is at 3,072 x 61,868 km x 19.36 deg. ABS 3A is at 1,139 x 64,561 km x 17.54 deg. Interesting that the two satellites appear to be using different ascent profiles at this point, with ABS 3A focusing more on inclination reduction. - Ed KyleCould this be deliberate attempt at gaining as much experience about electric drive as possible?
One month after launch, Eutelsat is at 3,072 x 61,868 km x 19.36 deg. ABS 3A is at 1,139 x 64,561 km x 17.54 deg. Interesting that the two satellites appear to be using different ascent profiles at this point, with ABS 3A focusing more on inclination reduction. - Ed Kyle
Quote from: rpapo on 04/02/2015 01:52 pmQuote from: edkyle99 on 04/02/2015 01:11 pmOne month after launch, Eutelsat is at 3,072 x 61,868 km x 19.36 deg. ABS 3A is at 1,139 x 64,561 km x 17.54 deg. Interesting that the two satellites appear to be using different ascent profiles at this point, with ABS 3A focusing more on inclination reduction. - Ed KyleCould this be deliberate attempt at gaining as much experience about electric drive as possible?Or maybe they're trying to manoeuvre the two satellites apart as soon as possible. Why? Maybe to avoid possible mutual interference due to RCS plumes.That said, how far apart are ABS-3A and Eutelsat-115WB's target orbital slots?
Space is big. You just won't believe how vastly, hugely, mind- bogglingly big it is. I mean, you may think it's a long way down the road to the chemist's, but that's just peanuts to space.
Quote from: Douglas AdamsSpace is big. You just won't believe how vastly, hugely, mind- bogglingly big it is. I mean, you may think it's a long way down the road to the chemist's, but that's just peanuts to space.The satellites are in no danger of affecting each other.
Falcon 9 second stage: 370 x 63,359 km x 25.32 deg
QuoteFalcon 9 second stage: 370 x 63,359 km x 25.32 degWhat is the reason the 2nd stage is still out there? Does it take that long to deorbit?
Quote from: Tonioroffo on 04/17/2015 09:44 amQuoteFalcon 9 second stage: 370 x 63,359 km x 25.32 degWhat is the reason the 2nd stage is still out there? Does it take that long to deorbit?The perigee is rather high at 370 km, where the drag is quite low, and only happens during a short part of the orbit, so yes it will take a long time to deorbit.This high perigee was probably chosen because of the electric propulsion used by the satellites launched: since the electric propulsion is raising their orbit rather slowly, they would have experienced a lot of drag using a usual perigee altitude for GTO launches (~185 km).There are software available, where you can estimate the decay of satellites, but you have to know several parameters of the object (such as shape, weight, ...). Maybe someone here can give an estimation?
Quote from: Tonioroffo on 04/17/2015 09:44 amQuoteFalcon 9 second stage: 370 x 63,359 km x 25.32 degWhat is the reason the 2nd stage is still out there? Does it take that long to deorbit?The rule is that you are supposed to leave the stage in an orbit that will decay in less than 25 years, so it does not remain a long-term hazard. If I recall correctly, that means less than a (roughly) 400 km perigee for GTO orbits and typical second stage drag numbers. The current perigee is not much less than 400 and so the stage may well be up there for another decade or so.
As of March 15, 2015ABS 3A: 449 x 63,530 km x 24.99 degEutelsat 115 WB: 439 x 63,363 km x 24.99 degFalcon 9 Stg 2: 366 x 63,372 km x 25.03 deg - Ed Kyle
As of May 12, 2015Falcon 9 second stage: 386 x 63,327 km x 25.55 deg Eutelsat 115 West B: 6,635 x 62,713 x 8.64 degABS 3A: 8,262 x 62,508 km x 7.16 deg - Ed Kyle