Russia's Phobos sample-return mission, called Phobos-Soil (Phobos-Grunt in Russian), is scheduled for launch on 2011 Nov 08 at 20:16:03 UTC, from Baikonur. The Phobos-Soil Project has requested precise positional observations of the spacecraft during the two engine burns that will propel it out of its LEO parking orbit and send it to Mars, which will occur out of range of Russia's tracking network. The request appears on the project's website, which explains the need for the observations, provides trajectory data (including TLEs), and invites prospective observers to register, so that they may report their observations: http://phobos.cosmos.ru/index.php?id=559&L=2 The Ballistics page of the above site includes ground track plots that reveal the opportunity for observers in South America who are sufficiently close to the track, to observe a significant portion of the burns. There are challenges for prospective observers: - the spacecraft will be in eclipse (Earth's shadow) for nearly the entire portion of both burns visible from land. Fortunately, the exhaust plume is expected to be sufficiently bright to be observed from the ground. - the observational data is required in near-real-time (in other words: ASAP, immediately would not be too soon!) - the spacecraft will be at a low altitude, which greatly restricts the radius of visibility - the angular velocity at closest approach will be high for observers near the track The purpose of my post is two-fold. First, I am following-up and amplifying the heads-up that Richard Miles posted here last week, to help get the word out. Another SeeSat-L subscriber, Carlos Bella, who is in Brazil and close to the track of burn #1, has registered to observe and is alerting other observers and groups that he knows. Below are the ground track plots of both burns. The thin ground track line means normal flight; the heavy ground track line means engine is firing, which is of primary interest. The green lines to either side of the ground track are limits of visibility. If you are located between the green lines, near the portion of the track when the engine will be firing, then you may be able to observe. Perhaps you know someone else who could observe? http://phobos.cosmos.ru/uploads/pics/1eb_04.jpg http://phobos.cosmos.ru/uploads/pics/2eb_01.jpg Second, as time permits, I am making myself available to assist those who may have the necessary optical equipment and astronomical knowledge, but who may not be experienced with satellite orbits, TLEs (2-line orbital elements), or astrometry. Later today, I will follow up with some tips on observing strategy, but I can also assist by generating custom ephemerides (look-angles), and perhaps data-reduction. If many observers come forward and seek help, I may not be able to assist everyone, but I am confident that other list-members with as good or better skills will want to help out. Unfortunately, time is running short, so we need to get organized quickly. Ted Molczan _______________________________________________ Seesat-l mailing list http://mailman.satobs.org/mailman/listinfo/seesat-l
This archive was generated by hypermail 2b29 : Wed Nov 02 2011 - 14:13:11 UTC
