Monday, December 19, 2011

Quick Phobos/Grunt Update 4

@SPACEFLIGHT101 reports: Attempts to fire Phobos-Grunt's engines are stopped.

"Attempts to start the Main Propulsion Unit of the Phobos-Grunt Spacecraft via direct commands from the ground have been stopped. ESA has ceased contact attempts last week and will not continue its efforts unless the Mission’s situation changes which has not been the case since our last update. During the brief period of constant sun-exposure, no contact was made with the Spacecraft suggesting that there is no chance of establishing any type of communication with the vehicle. Russian Mission Controllers have also stopped sending commands to the spacecraft that would fire its engines blindly to raise its orbit somehow. According to Russian Sources, the engine can not be fired because the vehicle’s orientation is unknown and an ignition could send the spacecraft the wrong way. Teams will continue attempts to obtain vehicle telemetry should there be any life left in Phobos-Grunt. These communication attempts via Russian Ground Stations will continue until the Re-Entry of the Spacecraft, but officials have already indicated that the Phobos-Grunt Spacecraft is lost.

The Spacecraft is currently in a 198 by 270-Kilometer Orbit inclined 51.4 Degrees. Phobos-Grunt’s decay rate is showing normal properties and is responding to solar activity which has reduced drag over several days of last week – pushing back re-entry predictions by about 24 hours. Also, the Vehicle seems to have found a stable orientation as satellite trackers did not report any new indications of obvious signs of tumbling. This is not necessarily due to the attitude control system making adjustments. Many previous re-entering spacecraft have shown a stabilization period because the vehicles achieve an aerodynamically stable position due to trace amounts of air particles that are present at these altitude levels. Official Russian Entry estimations range from January 6 to 19. Space Surveillance sources are currently predicting a January 12 (+/- 5 Days) Re-Entry."

I planned my workflow perfectly last night to put myself in optimum position to see Phobos/Grunt transit the early morning sky...alas a building East Wind brought a cloud of moist valley fog right over my position minutes before the Mag. 1.5 spacecraft was due. That wispy cloud, backlit by the waning quarter moon made seeing the dim satellite invisible to my trained eyes.

Phobos/GruntWatch will light up first week of January pending status changes in the probe's orbit.

1 comment:

  1. Santayana's quote should read, "the one who does not remember history is bound to live through it again" from the book "Life of Reason" (actually it's five volumes). So, we are not "condemed" but rather susceptible to historical reoccurrence (WWII and genocide is what he is writing about) if our memories are corrupted by forgetting (they say it takes three generations to forget) the tragic events of history.

    The tribes of Australia have the same philosophy.

    Whoever did the "integral payload" for this Russian Sat you keep yaking about made a big mathematical error. Oops!