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Space Technology

Soyuz Ballistic Re-entry 300 Miles Off Course 197

Posted by CmdrTaco
from the you-know-you-need-the-soviet-russia-joke dept.
call-me-kenneth writes "Soyuz TMA-11, carrying a crew of three returning from the ISS, unexpectedly followed a high-G ballistic re-entry trajectory and ended up landing 300 miles off-course. The crew, including Commander Peggy Whitson and cosmonaut Yuri Malenchenko, are reportedly in good health. Soyuz capsules have previously saved the lives of the crew even after severe malfunctions that might have led to the loss of a less robust vehicle."
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Soyuz Ballistic Re-entry 300 Miles Off Course

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  • by CodeBuster (516420) on Saturday April 19, 2008 @10:55AM (#23127550)

    There is an interesting article [space.gc.ca], written by a Canadian, in which he discusses the manual descent training that he received as part of cosmonaut training. Apparently, one of the back up computer systems is your brain itself (i.e. full manual control or renentry with analog controls and instruments). Queue the Soviet Russia jokes now...In Soviet Russia the re-entry computer is YOU!

    From TA: "Under nominal end-of-mission situations, an automatic re-entry system will return the Soyuz vehicle and crew from space safely back to the ground. However, the crew must be familiar with the several backup modes that exist in instances when the automatic system fails. One of the backup re-entry modes is the crew themselves! For certain hardware and software malfunctions, the crew will be required to manually fly the Soyuz back to Earth through the atmosphere."

  • by johnny cashed (590023) on Saturday April 19, 2008 @11:27AM (#23127694) Homepage
    I agree, but I think that operating the craft "manually" is overstated. I would think that things like the retro ("soft" landing) rockets and the parachutes would be operated automatically. Not only automatically, but I would bet that the cosmonauts wouldn't be able to activate them if they wanted to. Especially since the landing rockets are supposed to fire 1 meter off the ground. If it lost battery power, I'm sure they are screwed regardless.
  • by DieByWire (744043) on Saturday April 19, 2008 @11:54AM (#23127872)

    Mr Perminov said the craft followed the back-up landing plan, a so-called "ballistic re-entry" - a plunge with an uncontrollable, steep trajectory

    He said the crew missed the target because they changed their landing plan at the last minute without telling mission control.

    Astronauts don't just don't go changing re-entry profiles willy-nilly. If they did it, there was a reason they needed to.

    Remember the collision between the Progress supply ship and Mir during the manual docking? The first thing the Soviets did was blame it on the Russian cosmonaut. It turned out the whole operation was poorly planned, rehearsed and was an accident waiting to happen.

    There's a lot more to this story than we've heard yet.

  • by Anonymous Coward on Saturday April 19, 2008 @12:40PM (#23128118)
    This wasn't a re-entry failure at all. It landed and the crew is fine. Ballistic re-entry is a contingency for the Soyuz, and it functioned exactly as it was meant to.

    The Soyuz are rugged little buggers, far more so than any other re-entry vehicles. Their failure rate is excellent considering how long they have been in service.

    It comes down to this: If you were undergoing a re-entry into the Earth's atmosphere and there was a problem, would you rather be in a Soyuz capsule which has proven effective fall-back measures, or would you rather be in a shuttle that have the unfortunate tendency to completely breakup?
  • Re:"less robust" (Score:5, Interesting)

    by call-me-kenneth (1249496) on Saturday April 19, 2008 @12:48PM (#23128164)
    Well, maybe.

    The US hasn't had a man-rated traditional stack since the last Apollo in 1976, but the next-gen Ares launcher will be a traditional inline design with the payload at the top. That, plus the lack of enormous asymmetrical control and lifting surfaces required for (some value of) atmospheric flight pretty much eliminates the sources of danger caused by the shuttle design.

    OTOH, the somewhat... controversial? decision to make the Ares first stage an adaption of the existing shuttle solid rocket boosters is proving rather problematic, owing to the well-known pogo oscillation modthrusterse problems of SRB [flightglobal.com]s. (that's just a random story that popped up on google, no doubt there are much better overviews elsewhere.) Basically as designed the vehicle would crush the crew to jelly with high frequency +/1 70G vertical oscillations (shortly before the entire stack shakes itself to pieces.) (This wasn't a problem on the shuttle because there are two SRBs coupled through the external tank.)

    Anyway, in a few years' time we'll be able to start comparing the safety of like with like.

    No-one outside the space geek community seems to have noticed, but the Ariane-V launched ATV cargo vessel (payload: ~20 tons) has now launched human flight-rated hardware (the ATV, now docked to ISS), albeit without humans in it when it went off. I suspect there are some interesting things being doodled on napkins at cafes and bars all over Darmstadt.

  • Re:Nice Spin (Score:1, Interesting)

    by Anonymous Coward on Saturday April 19, 2008 @03:13PM (#23129050)

    And the "who had an accident more recently" does not establish it either.
    I disagree with this. It's certainly not conclusive, but the fact that the Soyuz's fatalities were all fairly early on indicates that it was a troublesome system at the outset which has now matured into something fairly robust, if not free from error.

    Ironically, the fact that the Soyuz has had more non-fatal incidents makes it safer in my eyes. (The counts on both systems of non-fatal incidents are extremely underestimated in my opinion. There are a large number of incidents with the Shuttle, many like Challenger and Columbia but less severe, and many others, none of which actually affected the mission in the end. There are also a large number of incidents with the Soyuz which didn't end up killing anyone.) It indicates that the system can tolerate failure better, even though it may also be more prone to those failures. You'll never eliminate failures, so it's better to have a system which can recover from them than one which can't but doesn't have them as much.

    It's true that the statistics are not conclusive, but the histories of the respective programs would seem to indicate that the shuttle is dangerously fragile.
  • Re:How far exactly? (Score:3, Interesting)

    by budgenator (254554) on Saturday April 19, 2008 @04:44PM (#23129720) Journal
    Huntsville Al, the city nearest to the Marshall Space flight center has had metric speed limit signs for 40 years that I know of.
  • by Anonymous Coward on Saturday April 19, 2008 @07:56PM (#23131000)
    Just to expand on this, the Soyuz reentry is NOT fully ballistic. Some lift is generated during reentry by designing the capsule so that its center of gravity is offset slightly to one side of the reentry module, so that it tilts slightly. This doesn't generate a lot of lift, but enough to allow the capsule to offset its touchdown point to the left or right a few hundred miles to either side of the entry path, or to lengthen or foreshorten the entry path.

    By controlling the roll attitude to point the "lift vector" in the direction they want to modify the trajectory, the crew can in effect steer the capsule while it reenters. If they are already "on target", they can negate the lift vector by rolling the capsule.

    The same tactic was used with the Gemini and Apollo capsules and is a major reason why those capsules usually landed within sight of their recovery fleets (compared to Mercury, which WAS fully ballistic).

    If the ability to control roll disappears (such as in a guidance failure), then the lift vector will orient towards the earth and foreshorten the entry trajectory, increasing g loads and heating.

    If a comparable guidance failure occurred on a winged vehicle during reentry, it would be raining aluminum.
  • by moosesocks (264553) on Saturday April 19, 2008 @10:14PM (#23131890) Homepage
    The last fatality was in 1971 with a much older version of the spacecraft.

    Saying that Soyuz is no good is like saying that Linux is no good because the 2.2 kernel sucked.

    Soyuz is a $#*#*ing remarkable spacecraft. Its reentry mechanism might not be the most elegant, but is certainly the most robust, and has proven able to get the crew back even after every other system has failed.

    Since the last fatality in 1971, Soyuz cosmonauts have survived two booster failures -- one in which the booster wildly deviated off-course, and another in which the rocket exploded on the pad with the capsule still attached.

    To contrast, the Space Shuttle was destroyed by a piece of foam, and must follow its landing procedure to a T in order for the crew to have even a remote chance of survival.

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