Phobos-Grunt to come down today

By Phil Plait | January 15, 2012 6:45 am

[Update 2 (18:40 UTC): According to the US Strategic Command, Phobos-Grunt re-entered over the Pacific ocean, not far west of Chile. This is unconfirmed, but STRATCOM is usually quite reliable. As I write this, I’m pretty sure the spacecraft is down, and hopefully we’ll know more about where it came down in the next few hours.]

[Update 1 (15:50 UTC): The predicted re-entry time is now around 17:20 UTC or so, but still not exact (Eastern US time is UTC – 5 hours, so 12:20 in the afternoon). The Russian space agency Roscomos has created a map of the predicted final orbit:

That’s over more land than I would’ve expected, but still lots of water. And remember, even if it falls over land the odds of it hitting anyone are incredibly low. Follow PhG_Reentry and me on Twitter for constant updates.]

I’ve been referring to Phobos-Grunt as "the doomed Russian space probe". Today, that name gets verified: it’s due to re-enter Earth’s atmosphere today, sometime around 18:30 UTC (plus/minus 3 hours), though the exact time is still unsure.

Emily Lakdawalla at The Planetary Society has an excellent blog post with lots of details on what we know. Basically, the third stage on the rocket failed to ignite, stranding the spacecraft in Earth orbit. The air is thin up there, but still exerts a small force, dragging the spacecraft’s orbit lower and lower. In the past few months it’s been dropping, and sometime today it will get low enough that the Earth’s air will consume it.

Since there are too many variables in the re-entry, it’s impossible to know when it will come down with any real accuracy until right before the actual event. And since it’s moving at about 8 km/sec (5 miles/sec), being wrong by five minutes in time means a difference of 2500 km in distance. That’s half the width of the US, so that’s why it’s not known where it will come down. Since the Earth is mostly water, the chances are it’ll drop into the Pacific, but that’s just statistics. We don’t know for sure.

If you want constant (and somewhat technical) updates, follow PhG_Reentry on Twitter. As we get more info, I’ll update this post, as well as tweet about it and post on Google+ too.

Related posts:

Doomed Russian Mars probe seen from the ground
ESA writes off Phobos-Grunt
Phobos-Grunt scheduled to launch at 20:16 UT
Final: ROSAT came down in the Bay of Bengal
UARS official re-entry… and up next: ROSAT

MORE ABOUT: Phobos-Grunt, re-entry

Comments (29)

Links to this Post

  1. Doomed Space Probe of the Day - TDW Geeks | January 15, 2012
  1. Chris P

    On a blog I read they had a video of Stephen Colbert talking about Phobos-Grunt. Of course, being in the UK the video wouldn’t play so I headed over to youtube and started typing ‘Phobos Grunt Colbert’ but it auto-completed it for me as ‘Phobos Grunt Conspiracy’.
    My goodness everything is a plot to some people isn’t it? Apparently the ‘fuel’ tanks are in fact filled with a bio weapon that will be distributed (I’m assuming over America) as the probe burns up in the atmosphere :facepalm:

  2. Messier Tidy Upper

    Sad end for a promising spaceprobe – Emily Lakdawalla put it really well there -thanks for that link BA.

    This youtube animation – in Russian alas :

    gives us an idea of what we’re missing with its loss.

    Wonder if there’ll be a later attempt at a redo of it, Phoenix lander style?

    The space-dot-com news site has on-going coverage of the last hours for Phobos-Grunthere :

    Thinking of conspiracy theories if this is any guide :

    it looks like Russia’s hearing plenty of then too. :-(

  3. Paul

    Chris: all these conspiracy theories are being deliberately generated to hide the REAL conspiracies. :)

  4. Jon H
  5. The latest report is that it won’t hit North America. So I can remove my hard hat. And my tinfoil hat, also.

  6. Here are the predictions from Roscosmos, complete with ground tracks :

  7. Rexerkik

    Have you ever considered to request self-destructive programmes in all space connected equipment just for the case of failure? Wouldnt ist show the responsibility of science and scientists in a good and remarkable way? Some kind of “science governance”? Of course, driving cars or flying airplanes is much more dangerous. But, it might be good that scientists show that they are concerned, and not just to say that if somebody is hit, it is just bad (statistical) luck.

  8. VinceRN

    It would have been such a cool mission. At the Russians are ttrying.

  9. Chris

    Darn, I was hoping to see it burn up over my house.

    Amazing, big news story and not one mention on the CNN homepage.

  10. Mike Saunders

    It is re-entering over Mongolia, is the latest reports. Should be interesting!

    Woops, nevermind! over the china sea now…

  11. Mike Saunders

    Bisecting Jeju island now! Jeju island is a tropical resort island in South Korea.

  12. Mike Saunders

    Even twitter is too slow for this… When the astronomers told everyone at Jeju island to look up, it was already long gone…

    Looks like its home will be the Pacific. Statistics wins again!

    Flying over Guam soon…

  13. Chris

    Coming down in 30 minutes

  14. Mike Saunders

    Both p-g and the satellite tracking website crash today…

  15. Chris

    Unfortunately seems to have crashed in the ocean

  16. Mike Saunders

    They want people in Spain to look for it, but that seems exceedingly over optimistic.

  17. Pete Jackson

    It is obvious that if Russia (and any other nations) want to have a serious space program, they need to invest in world-wide tracking and communication facilities. The cost of this is trivial compared to the cost of a space program. They could contract to have facilities built at existing installations such as Parkes in Australia, and/or support countries more allied to Russia such as Cuba or Venezuela to build new facilities.

  18. KC

    “Have you ever considered to request self-destructive programmes in all space connected equipment just for the case of failure? ”

    Of course its been considered – but you fail to consider the consequence of exploding a large 13-ton spacecraft. It would certainly contribute to space junk which could kill astronauts in orbit and destroy other working spacecraft. Or it might send 13 tons of junk careening into the atmosphere and onto a city.

    Its just not that simple…

  19. Andres Minas

    My crystal ball says it will hit the Philippine Deep, 230 km NE of Babuyan islands.

  20. Blargh

    Chris: … unfortunately? You wanted it to hit somewhere populated? ūüėģ

    Pete Jackson: well, it isn’t a cost issue. They’d love to have world-wide tracking and comms. It’s a political issue. One traditionally solved by colonization (a complete bust in their case) or strong-arming (in which their only real clout is with their close neighbors, which doesn’t help with reaching world-wide coverage)…

  21. Chris

    @21 Blargh
    Well it would have been nice to get some photos of the burn up. We’ve had 3 satellites burn up recently and no one got any pictures. Who among us wouldn’t love having a piece of space land in our backyard? And if I have to go, getting vaporized by a falling piece of space junk is the way I’d prefer.

  22. Wzrd1

    @#7, Rexerkik, so, what is your suggestion for self-destruction? Explosives, which would, as was mentioned above, spread debris all over low Earth orbit, damaging or destroying anything in their path, creating more junk?
    A nuclear warhead, to fry anything in orbit that passes the charged particles whipping back and forth for at least a decade, following magnetic field lines?
    Fire the booster to deorbit? The booster that didn’t fire to leave Earth orbit?
    The ONLY practical thing to do is what was done, watch in horror as a highly valuable project is incinerated (mostly) when it reenters the Earth’s atmosphere.
    And it’s a crying shame too, it WAS a worthwhile experiment. I hope that Russia manages to fund a replacement and successfully launches it.

  23. Update 2 (18:40 UTC): According to the US Strategic Command, Phobos-Grunt re-entered over the Pacific ocean, not far west of Chile. This is unconfirmed, but STRATCOM is usually quite reliable. As I write this, I’m pretty sure the spacecraft is down, and hopefully we’ll know more about where it came down in the next few hours.

    Yep. BBC World News online says (link attached to my name here) that Phobos-Grunt has fallen into the ocean about 1,000 km west of Chile. Although I guess they may be taking that from STRATCOM too, but anyhow.

    My condolences to all those involved in the mission. Vale Phobos-Grunt. :-(

  24. puppygod

    re: self-destruct
    As stated above, that idea was considered and, mostly, it’s not really viable. Though personally I think that in some cases of especially large hardware (space station size) it might be reasonable to install several non-explosive (thermite maybe?) charges in key structural points to disassemble it during re-entry. Reasoning being that multiple, one-ton or so objects would lose more energy in atmosphere than single, multi-ton object moving at several km/s. On the other hand, there is problem with tracking multiple objects with erratic trajectories and spreading damage over larger area. Not to mention, that such system means more potential points of failure, so… Well, the bottom line is that self destruction in some 99% of cases is bad idea, and even when it isn’t, the advantage is not necessarily obvious.

  25. @ 24. Messier Tidy Upper:
    The BBC apparently bases this on a Ria-Novosti press release that has since been retracted.

    Basically, it is not known currently where Phobos-Grunt exactly reentered. Yet the south Pacific indeed has the best papers.

    @ Phil:

    All USSTRATCOM has released so far, is the brief text: “Object Decayed Inside Predicted Window” ….nothing more than that.

    That presumably refers to their previous TIP which mentioned a predicted window between 16:59 – 17:47 UT.

    While the southern Pacific leading up to the coast of Chile is within the later part of that window, 16:59-17:47 UT is still representing an enormous swath of the earth.

    The problem is, that neither the Russians nor the US has much in terms of tracking facilities in those southern Ocean areas. They are “blind” there.

  26. Tim

    Another major embarrassment for the Russian space federation. The mission was ill-prepared according to the space chief in order to make the launch in time for the narrow Earth-Mars transit window. They need to get their act together because what happens when a Soyuz rocket carrying American astronauts to the ISS explodes?? They’ve got to have better accountability over there!

  27. Philip

    I was on flight CX251 from Hong Kong to London Heathrow last night. As a result of the re-entry we were required to orbit for 50 minutes in Chinese airspace as a result of space junk re-entry. I presume this to have been related to Phobos-Grunt.

    A diversion to Amsterdam for more fuel and we were only three hours late into London. Notwithstanding low probablities of impact, I didn’t mind being late just on the off chance…

  28. Calli Arcale

    Tim — for some perspective, it’s worth noting that Phobos-Grunt was actually intended for the *last* Mars window. It missed that one. So they were already a year and a half behind schedule. That might help explain their “go fever”. That, plus the additional urgency of knowing that there was a very real chance that if they didn’t launch during this window, Phobos-Grunt would end up in a museum — and they themselves would be out of job. There’s also the matter of engineering talent. They are in a serious situation there, where most of the experienced engineers are close to retirement; they could retire before the next Mars window. There are young engineers to replace them, but they have no experience with deep space flight, because there haven’t been any successful deep space flights from Russia since the 80s (and apart from Phobos-Grunt, just one attempted flight, about fifteen years ago).

    I think they had little choice but to launch Phobos-Grunt in this window. It was probably their last chance.


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