http://www.novosti-kosmonavtiki.ru/content/news.shtmlThe Russian interplanetary probe Phobos-Grunt is able to correct its orbit using its own engines, says Igor Lisov, an editor of Novosti Kosmonavtika. A source from the space industry has informed RIA Novosti that during the last three days the height of the apogei has been lowered to 6.5 kilometers, while the height of the perigee (which had to lower too), had risen to a kilometer due to unknown reason.The observed data is best explained bu the fact the probe keeps its own orientation due to periodic activation of the engine. This is not something that's commanded from Earth - Phobos-Grunt lives its own life. But it cannot talk.
Very interesting!From ISS On-Orbit Status Report for 13/11/2011.Phobos-Grunt Visibility:The ISS crew was notified of viewing/photographing opportunities for the stranded Phobos-Grunt Mars probe from the DC-1 VL-1 and MRM-2 windows as it crossed the ISS trajectory this morning at 4:06:16 AM GMT and 4:52 AM GMT.
...Quote from: Space Pete on 11/13/2011 07:34 pmVery interesting!From ISS On-Orbit Status Report for 13/11/2011.Phobos-Grunt Visibility:The ISS crew was notified of viewing/photographing opportunities for the stranded Phobos-Grunt Mars probe from the DC-1 VL-1 and MRM-2 windows as it crossed the ISS trajectory this morning at 4:06:16 AM GMT and 4:52 AM GMT.
I don't understand what could possibly be gained by attempting to photograph it from ISS. They won't be able to resolve it any more than ground observers can without a powerful telescope.
Quote from: ugordan on 11/13/2011 09:33 pmI don't understand what could possibly be gained by attempting to photograph it from ISS. They won't be able to resolve it any more than ground observers can without a powerful telescope. Depends on how close the pass is, though, doesn't it? Earth-based telescopes are usually limited by seeing to usually worse than the large telephoto lenses on ISS, and the ones that aren't limited by seeing usually have far lower slew-rates than required, whereas I think ISS has a system set up for higher slew-rates (do they still have that set up? okay, probably not, but it was a kludge anyway... an awesome kludge).
Depends on how close the pass is, though, doesn't it?
Quote from: ugordan on 11/13/2011 09:33 pmI don't understand what could possibly be gained by attempting to photograph it from ISS. They won't be able to resolve it any more than ground observers can without a powerful telescope. I can't see it proving any useful information either, even with an image stabilized lens with, IIRC, 1200mm max effective focal length with current assets, which when hand held and 1/8 sec maximum shutter speed (which is borderline, better with 1/30 sec).
It's always possible that the inability to communicate may be due to a broken antennae or cable. A close-up photo from ISS may be able to provide that data.
I'm really pulling for our Russian friends. I hope they can save this mission.
This is what I was thinking about, by the way:http://spaceflight.nasa.gov/gallery/images/station/crew-6/html/iss006e44305.htmlThis is an old photo, and I believe that has been long disassembled, but it is a little better than just hand-tracking.
But we are given to understand that Phobos-Grunt may be holding attitude in solar inertial orientation, to maximize power.
Okay. So If I have this straight their going to try taking a video or pictures of the spacecraft from ISS to see if its tumbling or is otherwise damaged? Did they actually take pictures?
Quote from: JimO on 11/14/2011 12:17 amBut we are given to understand that Phobos-Grunt may be holding attitude in solar inertial orientation, to maximize power.Are we? I wasn't under that impression. Could it be that it is holding LVLH in anticipation of the burns that didn't occur?
In practice, solar inertial pointing clocks completely around the sky once every rev.