Results 1 to 8 of 8

Thread: Could the ISS have a moveable sheild it could swing around to protect from debris?

  1. #1
    Join Date
    Dec 2004
    Location
    UK
    Posts
    8,168

    Could the ISS have a moveable sheild it could swing around to protect from debris?

    I read that the ISS sometimes manoeuvres around when it is on collision course with some known debris....I just wondered if there could be a strong sheild separate from the station that could be moved into position to take the hit...might that be a better solution to moving the station around?
    Formerly Frog march..............

    She was only a farmer's daughter, but she was outstanding in her field.

  2. #2
    Join Date
    Mar 2004
    Posts
    15,779
    Here's the description of one Pre-determined Debris Avoidance Maneuver (PDAM), Station Debris Avoidance Maneuver Conducted

    The 7-minute, 9-second maneuver, which was coordinated throughout the day between NASA and Russian flight controllers, used the ISS Progress 54 thrusters from the Pirs Docking Compartment for an increase of one-half statute mile in the stationís altitude. Ballistics officers determined that a fragment of unknown size from the satellite would have made its closest approach to the station around midnight Eastern time, passing within about 1900 feet of the ISS at its radial distance, with an overall miss distance between the debris and the ISS estimated at about 10.5 statute miles.
    So to avoid something estimated to pass within 1900 feet of where it travels (but miss by 10.5 miles) they changed the ISS path 1/2 mile up. They don't sound like the kind of people who'd rather stand their ground and move a shield to the perfect position so the debris (of unknown exact size) might be stopped, maybe, by striking within the borders of said shield. All to avoid an altitude adjustment that would need to be done in due time anyway?

    And these details, How NASA steers the International Space Station around space junk, describe the caution:

    A "red" threshold is assigned to any collision with a likelihood of between 1 (in other words, absolutely certain) and 1-in-10,000. Flight rules are more strict for maneuvers in response to red threshold objects: the station is always moved for a red threshold object, regardless of mission impact, unless a maneuver represents more risk than not maneuvering (for example, if there's a piece of equipment that's damaged on the ISS and a maneuver would exacerbate that damage).
    They jump when the chance is only 1 in ten-thousand. And sometimes at 1 in one-hundred-thousand, for a yellow threshold.

    And it happens less than once a year.

    I'd say they already have their solution.
    0 1 1 0 1 0 0 1 1 0 0 1 0 1 1 0 1 0 0 1 0 1 1 0 0 1 1 0 1 0 0 1 1 0 0 1 0 1 1 0 0 1 1 0 1 0 0 1 0 1 1 0 1 0 0 1 1 0 0 1 0 1 1 0 ...
    Skepticism enables us to distinguish fancy from fact, to test our speculations. --Carl Sagan

  3. #3
    Join Date
    May 2008
    Location
    The Netherlands
    Posts
    14,204
    I wonder how heavy such a shield would be, if it were to be useful to protect from say a heavy bolt. Does the fuel to lift that much extra mass at launch and during stationkeeping wheigh up to the little amount of fuel used for maneuvring? Besides, if, as in this case, the orbit is increased, that is standard operating procedure. ISS has to raise its altitude regularly anyway, so why bother adding some other heavy complex moving part?
    ____________
    "Dumb all over, a little ugly on the side." -- Frank Zappa
    "Your right to hold an opinion is not being contested. Your expectation that it be taken seriously is." -- Jason Thompson
    "This is really very simple, but unfortunately it's very complicated." -- publius

    Moderator comments in this color | Get moderator attention using the lower left icon:
    Recommended reading: Forum Rules * Forum FAQs * Conspiracy Theory Advice * Alternate Theory Advocates Advice

  4. #4
    Join Date
    Dec 2004
    Location
    UK
    Posts
    8,168
    Quote Originally Posted by slang View Post
    I wonder how heavy such a shield would be, if it were to be useful to protect from say a heavy bolt. Does the fuel to lift that much extra mass at launch and during stationkeeping wheigh up to the little amount of fuel used for maneuvring? Besides, if, as in this case, the orbit is increased, that is standard operating procedure. ISS has to raise its altitude regularly anyway, so why bother adding some other heavy complex moving part?
    I wasn't sure how often they had to do it...if it's once a year, then maybe it wouldn't be worth it.

    I was thinking maybe the shield could be made from some kind of light latices material, thick rather than tough and heavy..?. Not sure how tough it might have to be.

    Or maybe it could be cone shaped, so objects would rebound off it away from the ISS, so not necessarily having to absorb all the impact.
    Last edited by Mudskipper; 2017-Dec-07 at 01:24 PM.
    Formerly Frog march..............

    She was only a farmer's daughter, but she was outstanding in her field.

  5. #5
    Join Date
    Mar 2007
    Location
    Falls Church, VA (near Washington, DC)
    Posts
    7,657
    Quote Originally Posted by Mudskipper View Post
    I wasn't sure how often they had to do it...if it's once a year, then maybe it wouldn't be worth it.

    I was thinking maybe the shield could be made from some kind of light latices material, thick rather than tough and heavy..?. Not sure how tough it might have to be.

    Or maybe it could be cone shaped, so objects would rebound off it away from the ISS, so not necessarily having to absorb all the impact.
    At the velocities that can be encountered in a crossing path, you will not get a ricochet off a lightweight cone. You will get an impact crater or a penetration much as you would with a square on hit.

    My educated guess is that evasive maneuvers over the lifetime of the station will take far less fuel than what would be needed to launch an effective shield.

  6. #6
    Join Date
    Sep 2006
    Posts
    426
    Another issue is that you would be likely to increase orbital debris by using shields. With every impact there is a chance of breaking the impacting object and the shield into multiple pieces. So even if the shield worked reasonably well to protect against a specific incident you are actually increasing the chances of debris strikes over-all, in the longer term.

  7. #7
    Join Date
    Mar 2004
    Posts
    15,779
    Quote Originally Posted by Mudskipper View Post
    I wasn't sure how often they had to do it...if it's once a year, then maybe it wouldn't be worth it.
    I think I saw: twice every 3 years, so rough 18 months average.
    0 1 1 0 1 0 0 1 1 0 0 1 0 1 1 0 1 0 0 1 0 1 1 0 0 1 1 0 1 0 0 1 1 0 0 1 0 1 1 0 0 1 1 0 1 0 0 1 0 1 1 0 1 0 0 1 1 0 0 1 0 1 1 0 ...
    Skepticism enables us to distinguish fancy from fact, to test our speculations. --Carl Sagan

  8. #8
    Join Date
    May 2008
    Location
    The Netherlands
    Posts
    14,204
    Quote Originally Posted by Mudskipper View Post
    I wasn't sure how often they had to do it...if it's once a year, then maybe it wouldn't be worth it.

    I was thinking maybe the shield could be made from some kind of light latices material, thick rather than tough and heavy..?. Not sure how tough it might have to be.

    Or maybe it could be cone shaped, so objects would rebound off it away from the ISS, so not necessarily having to absorb all the impact.
    It won't help much to raise an umbrella against this.... but I believe usually the objects to be avoided are smaller. This article (also from ODQN) mentions the 25th avoidance maneuver for ISS, in 2015. Launched in 1998 I think, so less than two maneuvers per year, on average. Not sure why that differs so much from what 01101001 saw: perhaps the number of maneuvers has increased after the Chinese ASAT demonstrator and the Iridium/Cosmos collision.

    ETA: Hey look, you may soon find a study to help you set the parameters your shield might require! Space Debris Sensor.

    Edited to add MORE: This paper has a nice graphic (fig 1) showing how much the orbital debris problem increased by those two big collisions in 2007 and 2009.
    ____________
    "Dumb all over, a little ugly on the side." -- Frank Zappa
    "Your right to hold an opinion is not being contested. Your expectation that it be taken seriously is." -- Jason Thompson
    "This is really very simple, but unfortunately it's very complicated." -- publius

    Moderator comments in this color | Get moderator attention using the lower left icon:
    Recommended reading: Forum Rules * Forum FAQs * Conspiracy Theory Advice * Alternate Theory Advocates Advice

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •