An object, a few meters across doesnt look much from 25km distance. I doubt that any astronaut would be able to tell any details without magnification gear like a very good binocular or small telescope.
Disadvantage would be that Russians on ISS could also observe the satellite at the 25km approach. So unless proximity to ISS was key to its mission I can't see why they'd let their supersecret experiment wander so close to ISS.
Quote from: cscott on 05/30/2017 02:20 pmDisadvantage would be that Russians on ISS could also observe the satellite at the 25km approach. So unless proximity to ISS was key to its mission I can't see why they'd let their supersecret experiment wander so close to ISS.None of this conjecturing about the NROL-76 payload seems convincing to me, but this point has technical issues.From where would the cosmonauts observe nadir?I am sure someone here knows exactly where windows are located in Zvezda etc. Are there any Earth facing windows on the Russian side?
Launch date NET is April 16 with the window opening at 7am local, for around two hours.
Here is an argument against the ISS spying:Quote from: Chris Bergin on 03/31/2017 12:16 pmLaunch date NET is April 16 with the window opening at 7am local, for around two hours.If it was planned to chase the ISS, it seems odd to have a 2 hour launch window. Unless you have two ~ 1-min discrete launch windows within 2 hours exactly 92 minutes and 39 seconds apart..There was also this odd 15 minute delay of the launch, rescheduling it to 7:15 instead of 7:00 local. Might have been done to target the station, might be coincidence.
Quote from: Semmel on 05/30/2017 08:12 pmHere is an argument against the ISS spying:Quote from: Chris Bergin on 03/31/2017 12:16 pmLaunch date NET is April 16 with the window opening at 7am local, for around two hours.If it was planned to chase the ISS, it seems odd to have a 2 hour launch window. Unless you have two ~ 1-min discrete launch windows within 2 hours exactly 92 minutes and 39 seconds apart..There was also this odd 15 minute delay of the launch, rescheduling it to 7:15 instead of 7:00 local. Might have been done to target the station, might be coincidence.The ISS position at launch is irrelevant. A tiny orbital maneuver will allow any spacecraft launch in phase to match it. All that is needed is a slight lowering or raising of the orbit, and eventually you'll drift closer to ISS.
Quote from: Lars-J on 05/30/2017 11:02 pmQuote from: Semmel on 05/30/2017 08:12 pmHere is an argument against the ISS spying:Quote from: Chris Bergin on 03/31/2017 12:16 pmLaunch date NET is April 16 with the window opening at 7am local, for around two hours.If it was planned to chase the ISS, it seems odd to have a 2 hour launch window. Unless you have two ~ 1-min discrete launch windows within 2 hours exactly 92 minutes and 39 seconds apart..There was also this odd 15 minute delay of the launch, rescheduling it to 7:15 instead of 7:00 local. Might have been done to target the station, might be coincidence.The ISS position at launch is irrelevant. A tiny orbital maneuver will allow any spacecraft launch in phase to match it. All that is needed is a slight lowering or raising of the orbit, and eventually you'll drift closer to ISS.You mean any launch in plane, not any launch in phase. Which brings up another point... Falcon 9 doesn't do yaw steering, so launches to a specific plane are instantaneous windows.Of course, this could have been a de facto instantaneous window even though they announced it as a 2 hour window. Or they could have been targeting a specified range of planes around ISS, which would have allowed a small window instead on an instantaneous one. But not 2 hours.
Falcon 9 doesn't do yaw steering, so launches to a specific plane are instantaneous windows.
Quote from: envy887 on 05/30/2017 11:20 pmFalcon 9 doesn't do yaw steering, so launches to a specific plane are instantaneous windows.We know this simply because they never announced it can do it, or it has been confirmed it cannot? I am not an expert at all, is specific hardware needed that is obviously not present on the Falcon 9?
The yaw steering question has come up in the past and Jim has stated definitively that SpaceX does not do yaw steering during ascent, and that it is an avionics issue. Take that as you will, I suspect various posters have different theological positions on Jim's infallibility.
Quote from: envy887 on 05/30/2017 11:20 pmQuote from: Lars-J on 05/30/2017 11:02 pmQuote from: Semmel on 05/30/2017 08:12 pmHere is an argument against the ISS spying:Quote from: Chris Bergin on 03/31/2017 12:16 pmLaunch date NET is April 16 with the window opening at 7am local, for around two hours.If it was planned to chase the ISS, it seems odd to have a 2 hour launch window. Unless you have two ~ 1-min discrete launch windows within 2 hours exactly 92 minutes and 39 seconds apart..There was also this odd 15 minute delay of the launch, rescheduling it to 7:15 instead of 7:00 local. Might have been done to target the station, might be coincidence.The ISS position at launch is irrelevant. A tiny orbital maneuver will allow any spacecraft launch in phase to match it. All that is needed is a slight lowering or raising of the orbit, and eventually you'll drift closer to ISS.You mean any launch in plane, not any launch in phase. Which brings up another point... Falcon 9 doesn't do yaw steering, so launches to a specific plane are instantaneous windows.Of course, this could have been a de facto instantaneous window even though they announced it as a 2 hour window. Or they could have been targeting a specified range of planes around ISS, which would have allowed a small window instead on an instantaneous one. But not 2 hours.Yes, I meant plane. And you are correct, the fact that they had a 2hr launch window indicates that the near plane to ISS was a coincidence, not the plan. (unless the secret launch window really was instantaneous)