Space Junk: Collision hazard??

[gofortli]

Hi Folks,<br /><br />I had a question about the hazard of an orbiting spacecraft striking or being struck by space debris. For instance, I know that various junk and objects are monitored and tracked so that collisions don't occur. But I think that monitoring only can be done down to a certain size object.<br /><br />There must be thousands of small objects like bolts, nuts, sheared metal pieces, etc. that are floating around. I would think that an orbiting craft striking or being sruck by a (let's say) metal bolt would pierce the thin skin of a spacecraft and possibly do substantial damage.<br /><br />Have we just been lucky, or does this occur much more than the public is informed of?

 

[willpittenger]

I should note that NORAD tracks a lot of objects from spent boosters to dead satellites. However, most bolts are probably too small to be seen by their RADAR and visual tracking systems. A paint chip once struck Challenger's windshield. Left a gouge something like 1 cm deep.<br /><br />Objects left up there by various spacewalking astronauts:<br />* Camera -- This probably has spent film from Apollo or Gemini. If it could be developed, you could see what he took pictures of.<br />* Solar panel from Hubble -- This would not collapse. As such there was no way to get it back in.<br />* I seem to remember an outer glove getting away from a spacewalker. Not sure how it got off.<br /> <div class="Discussion_UserSignature"> <hr style="margin-top:0.5em;margin-bottom:0.5em" />Will Pittenger<hr style="margin-top:0.5em;margin-bottom:0.5em" />Add this user box to your Wikipedia User Page to show your support for the SDC forums: <div style="margin-left:1em">{{User:Will Pittenger/User Boxes/Space.com Account}}</div> </div>

 

[earth_bound_misfit]

Didn't one of the spacewalkers lose a spanner or something as well? <div class="Discussion_UserSignature"> <p> </p><p> </p><p>----------------------------------------------------------------- </p><p>Wanna see this site looking like the old SDC uplink?</p><p>Go here to see how: <strong>SDC Eye saver </strong>  </p> </div>

 

[earth_bound_misfit]

This post by JonClarke got me thinking of a use for HAARP ionospheric heater. <br /><br />"I recall reading that Skylab came down much sooner than expected because someone forgot to allow for increased atmospheric drag because the the solar maximum. "<br /><br />Maybe by temporary raising the orbit of LEO assets then using Haarp to heat and raise the atmosphere, therefore increasing the drag on debris would cause them to de-orbit quicker. <br /><br />I suppose this is why the military is interested in HAARP, raise the orbit on their assets then use Haarp to de-orbit other spy satellites. Or maybe their interest is to/also disrupt comm.s<br /> <div class="Discussion_UserSignature"> <p> </p><p> </p><p>----------------------------------------------------------------- </p><p>Wanna see this site looking like the old SDC uplink?</p><p>Go here to see how: <strong>SDC Eye saver </strong>  </p> </div>

 

[erioladastra]

"Didn't one of the spacewalkers lose a spanner or something as well? "<br /><br />Several times, most recently on the stage EVA a foot restraint.

 

[erioladastra]

"Everybody has been lucky so far. Mainly due to the tiny, tiny chance of two objects meeting in such a vast place. "<br /><br />I know HST has been hit at least once.

 

[willpittenger]

When did it happen? Do we know what hit it? How bad was the damage? <div class="Discussion_UserSignature"> <hr style="margin-top:0.5em;margin-bottom:0.5em" />Will Pittenger<hr style="margin-top:0.5em;margin-bottom:0.5em" />Add this user box to your Wikipedia User Page to show your support for the SDC forums: <div style="margin-left:1em">{{User:Will Pittenger/User Boxes/Space.com Account}}</div> </div>

 

[spacester]

<font color="yellow">. . . increased atmospheric drag because (of) the solar maximum</font><br /><br />I think that's opposite of reality. I thought that increased solar output actually applies more "pressure" to earth's atmosphere, which has the effect of "shrinking" the atmosphere, thus <i> reducing</i> atmospheric drag. I could be wrong.<br /><br />This seems like more than a pedantic difference . . .<br /> <div class="Discussion_UserSignature"> </div>

 

[willpittenger]

The pressure from the solar wind only affects the side facing the sun. Besides, the Earth's magnetic field probably keeps most of the wind away from the atmosphere except near the poles.<br /><br />The pressure that others mentioned probably comes from heating the atmosphere. <div class="Discussion_UserSignature"> <hr style="margin-top:0.5em;margin-bottom:0.5em" />Will Pittenger<hr style="margin-top:0.5em;margin-bottom:0.5em" />Add this user box to your Wikipedia User Page to show your support for the SDC forums: <div style="margin-left:1em">{{User:Will Pittenger/User Boxes/Space.com Account}}</div> </div>

 

[bdewoody]

Just a thought.<br /><br />Since we always launch from west to east (except for polor orbiting spy satellites) wouldn't most of the junk be traveling generally in the same direction? If that is true wouldn't that reduce the impact velocity since to maintain orbit all objects need to be at roughly the same velocity for any given altitude? <div class="Discussion_UserSignature"> <em><font size="2">Bob DeWoody</font></em> </div>

 

[vogon13]

Eccentricities and inclinations are all over the place, hitting a bolt at 1 or 5 kilometers per second doesn't help much.<br /><br /><br /> <div class="Discussion_UserSignature"> <p><font color="#ff0000"><strong>TPTB went to Dallas and all I got was Plucked !!</strong></font></p><p><font color="#339966"><strong>So many people, so few recipes !!</strong></font></p><p><font color="#0000ff"><strong>Let's clean up this stinkhole !!</strong></font> </p> </div>

 

[willpittenger]

You might want to substantiate that somehow. Otherwise, I doubt you will change Spacester's opinion. <div class="Discussion_UserSignature"> <hr style="margin-top:0.5em;margin-bottom:0.5em" />Will Pittenger<hr style="margin-top:0.5em;margin-bottom:0.5em" />Add this user box to your Wikipedia User Page to show your support for the SDC forums: <div style="margin-left:1em">{{User:Will Pittenger/User Boxes/Space.com Account}}</div> </div>

 

[vogon13]

Exosphere temp and volume correlates to current solar activity level.<br /><br /> <div class="Discussion_UserSignature"> <p><font color="#ff0000"><strong>TPTB went to Dallas and all I got was Plucked !!</strong></font></p><p><font color="#339966"><strong>So many people, so few recipes !!</strong></font></p><p><font color="#0000ff"><strong>Let's clean up this stinkhole !!</strong></font> </p> </div>

 

[spacester]

<font color="yellow">You might want to substantiate that somehow. Otherwise, I doubt you will change Spacester's opinion</font><br /><br />It wasn't an opinion, it was me checking if my understanding was correct because I had a notion but was not at all sure. Another poster has offered an explanation that makes sense to me and indicates that I was right about not being sure. <img src="/images/icons/laugh.gif" /> But hey, the thread's not dead yet.<br /><br />I was willing to expose myself to being wrong for the sake of being sure and possibly making a correction for the benefit of others.<br /><br />I said I could be wrong. If it makes everyone happy: I was wrong.<br /><br />It's actually a very refreshing thing to do. I recommend it highly, maybe some folks here should try it more often.<br /><br />FWIW, the reason I thought such was that it is a little known fact that – with the significant exception of CME events – interplanetary space is understood to have *less* radiation during Solar Max because the solar wind reduces the cosmic background radiation thru increased "pressure".<br /> <div class="Discussion_UserSignature"> </div>

 

[josh_simonson]

I don't know if it's 'less' radiation overall, but it is a different type and the solar radiation is easier to shield astronauts against than cosmic rays.

 

[henryhallam]

It is worth remembering that anything in an orbit below ~600km will reenter in years to tens of years. Junk tends to be fairly small and have a high surface area-to-volume ratio so it will reenter comparatively more quickly than large objects such as satellites due to increased drag.<br /><br />The problem is very real but this stuff doesn't stay up there forever.

 

[spacester]

Yes, that's a good correction. I should have used quotes and a star instead of two stars. <img src="/images/icons/laugh.gif" /> Like this:<br /><br />. . . "less"* . . . <br /><br />(body of post here)<br /><br />(at bottom of post<br />* - "Some rather complicated (and not yet standardized?) means of expressing the total radiation dosage as the sum of effects of two quite different types of radiation, with preliminary data, IIRC, indicating that if CMEs are avoided then the total damage to human flesh appears to be reduced during Solar Max, given the same shielding and time in space.<br /><img src="/images/icons/laugh.gif" /><br /> <div class="Discussion_UserSignature"> </div>

 

[webtaz99]

There are proposals out there to put the big lasers they built out in the deserts for the "star wars" program to use. First they need to build a big radar which can spot things down to 1 cm (and I think I read that this was already in the works). Then target the stuff and give them just enough of a bump to de-orbit them quickly and in a predictable trajectory. <br />Also, warning would have to be given so countries don't mistake space junk for a nuke attack. <div class="Discussion_UserSignature"> </div>

 

[publiusr]

I think the cubesat/smallsat concepts are wastes of time--and would add to more space junk.<br /><br />We need fewer, but larger (shielded assets) like what the Energiya's GLOBIS comsat would have been:<br /><br />http://www.astronautix.com/craft/globis.htm<br /><br />Even better:<br />http://www.astronautix.com/craft/intaltug.htm<br />http://www.astronautix.com/stages/erta.htm<br />http://www.astronautix.com/engines/11b97.htm<br /><br />More payloads for Ares V.

 

[henryhallam]

<font color="yellow">I think the cubesat/smallsat concepts are wastes of time--and would add to more space junk.</font><br /><br />A large number of universities and researchers would disagree with you. It is often the only way to fly an experiment on a reasonable budget and timescale.