After a long delay in the posting of the late-Saturday NORAD tracking fit for Phobos-Grunt, internet watchers were beginning to worry that the spacecraft had already broken up in the atmosphere about a day before most predictions. That vigil ended just a few hours ago. One thing that can be concluded from this update, other than the vehicle being intact, is that the orbit decay trends are continuing fairly smoothly. You probably won’t hear this elsewhere, but that may indicate that ROSCOSMOS has not been completely straight about the tank material housing the toxic propellants. If it were aluminum as stated, the tanks likely would have ruptured after more than a day of being engulfed by plasma, especially since the vehicle seems to be flying in a tanks-first attitude. The propellants would have been scattered by now, dramatically decreasing the mass of the vehicle, and causing a spike in the decay rate. This apparently hasn’t happened. The vehicle seems to have held together so far, and that’s a bad sign. In my opinion, it supports the suspicion that the tanks are really titanium, which will probably survive the reentry all the way to the ground.
Where will the Phobos-Grunt spacecraft crash and when? The timing generally agreed upon by most in the space community is during the day on Sunday, January 15, but the breakup times vary from roughly the earliest time this website predicts, 13:13 UTC (a very unlucky time, apparently…) to about 22:00 UTC Sunday night. In any case, the ground tracks during this period will closely resemble those in this Russian language plot provided by ROSCOSMOS:
Here’s what the day will look like roughly, using Greenwich (UTC) time unless otherwise noted:
Rev#1: Crosses into Northern Hemisphere at 0:38 UTC.
Rev#2: Crosses equator at 2:05 UTC and passes over LA at 6:15 pm. (about 2 hours ago.
Rev#3: Crosses at 3:32 UTC and traverses Canada.
Rev#4: Crosses at 4:59 UTC and flies over New Hampshire at 25 minutes after Midnight, local time.
Rev#5: Crosses at 6:26 UTC and flies over Chicago and North Carolina
Rev#6: Crosses at 7:53 UTC and flies over Seattle at 12:17am local, and Texas roughly 2:24am local.
Rev#7: Crosses at 9:20 UTC and traverses Pacific rim over water.
Rev#8: Crosses at 10:47 UTC and flies over Sri Lanka at about 4pm local and Tierra del Fuego 7:42am local.
Rev#9: Crosses at 12:12 UTC and sims show the first good chance of final plunge at Tierra del Fuego at 13:13 UTC, 8:13am Eastern US time.
Rev#10: Crosses at 13:40 UTC and flies over Saudi Arabia, Russia and TDF.
Rev#11: Crosses at 15:07 UTC and flies over Cairo, Russia, Tokyo and TDF.
Rev#12: Crosses at 16:34 UTC and flies over Africa, Greece, Chile and the Amazon.
Rev#13: Crosses at 18:01 UTC and flies over the Amazon, French Riviera, Italy, Queensland and Peru.
Rev#14: Crosses at 19:27 UTC and flies over Paris, Indonesia and New South Wales.
Rev#15: Crosses at 20:53 UTC and flies over Columbia, London and Chennai.
At the current time, based on the NORAD tracking state from Saturday night, the Grunt’s most likely prediction is for a touchdown very near northern Japan, descending from the northeast at 15:39 UTC, which is 10:39am Eastern US time.
This prediction is made with a +/-6 hour uncertainty, and the following locations are considered to be at low-but-finite risk: Japan, Egypt and the Middle East, Caspian and Black Sea Areas, South America, West Africa, Greece, China, Southern Russian, Hawaii, Oceania, French and Spanish Rivieras and Northern Italy. At the current time, North America, most of Russia, South Africa and Scandinavia appear to be at very low risk.
This information is for general interest and is based on information publicly available with no guarantee of accuracy. Please consult your local authorities for public safety and hazard information.
Final Update: The official Russian pronouncement places the flying fuel-tank down in the Pacific off the southern coast of Chile. Their estimated down time was 10:45pm Moscow time, or 17:45 UTC or 12:45pm Eastern US time. If you look at the rev list above, that would put it just before Rev#13 of the day, just after it had passed south of Japan, across the South Pacific and just before it was to fly across the Amazon, Atlantic, Gibraltar, the Spanish and French Rivieras and Italy. If you locate Gibraltar on the map above, you can follow the blue line backwards across the Atlantic and South America to where it apparently took the plunge.
Is this really where it went down? Nobody knows until fuel tanks start washing ashore at Santiago or debris shows up somewhere else. It’s hard to say, really, since there were no tracking facilities that could see it after it flew over Russia that last time. So who knows? But if you’re in Chile or Japan or Africa, and you see a round metal thing on the beach that looks like a beach ball, don’t use it to put your coconuts in!