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Soyuz Ballistic Re-entry 300 Miles Off Course

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."

7 of 197 comments (clear)

  1. Re:Ballistic trajectory? by figleaf · · Score: 4, Informative

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

    So most likely it was not a steering malfunction.

  2. Re:Ballistic trajectory? by trout007 · · Score: 5, Informative

    A capusle can "sort of fly" during reentry. You can use thrusters to change the attitude of the craft which changes the direction. This requires guidance. You usally use this because it's less stressful on the crew and you have pretty good accuracy. The ballistic trajectory is just like you said. Uncontrolled so you fall like a rock. So you spend less time slowing down in the upper atmosphere. You get to the thicker atmosphere sooner and when you do you are going faster which causes very high G deceleration. Not fun but the craft is designed to do it.

    --
    I love Jesus, except for his foreign policy.
  3. Re:How far exactly? by whoda · · Score: 4, Informative

    It says 420km, which gets rounded down to 400 in the headline paragraph.

    420km in miles is 260, which gets rounded up to 300 for the Slashdot article.

  4. Re:Full Manual Re-entry is Possible in Soyuz by johnny+cashed · · Score: 5, Informative

    Addendum:

    According to this link: http://www.astronautix.com/flights/mireo23.htm the landing rockets failed anyway, which resulted in a hard, but survivable landing.

    And according to this: http://www.jamesoberg.com/soyuz.html the crew has no control over the parachute deployment. (This is written in entry 6 B under "Special Questions)

  5. I'm not impressed. by DerekLyons · · Score: 4, Informative

    The fact that they survived the experience is amazing. Say what you want about Soviet technology, this was a very, very neat trick.

    When it comes to Soviet technology only one thing needs to be pointed out: This brings the re-entry failure rate of the current mark of Soyuz to 20% and trending upwards. (This report on Soyuz landing safety with the older marks is sobering reading.)
  6. Heavyside Layers by Anonymous Coward · · Score: 4, Informative

    Alan Shepard hit over 11g during re-entry, and he didn't pass out and could still hit switches. The early astronauts training- had them routinely hitting 10g or more and they didn't pass out.

    There's a difference between the eyes-down load on a fighter pilot sitting in an ejection seat (even the semi-reclining versions, which aren't really very reclined) and the eyes-in loading on a astronaut laying on their back. The main difference is that the person on their back isn't having their blood trying to fill their boots when the Gs strike like the person sitting in a chair.

    The two don't really compare. I'd advise you to do a little research before trying to make that case.

  7. Re:Nice Spin by mlyle · · Score: 5, Informative

    Taken from a web forum, but I've seen similar stuff before:

    http://www.airliners.net/aviation-forums/military/read.main/54404/

    Soyuz (1967-Present)
    Flights: 95
    Failures: 4 (2 non-fatal)
    Failure Rate: 4.21%

    Cosmonauts Flown: 228
    Fatalities: 4
    Fatality Rate: 1.75%

    Shuttle (1981-Present)
    Flights: 116
    Failures: 3 (1 non-fatal)
    Failure Rate: 2.59%

    Astronauts Flown: 692
    Fatalities: 14
    Fatality Rate: 2.02%

    This is a statistical dead heat. There is simply not a big enough sample size to distinguish between a 1.75% and a 2.02% fatality rate. And the "who had an accident more recently" does not establish it either.

    Both are good systems, each has respective advantages (simplicity and low-cost vs. a lot of on-orbit assembly and payload capability). It's good the world has both, and we may never know which would be safer with infinite flights.