[HN Gopher] Tractor Beams Are Real, and Could Solve a Major Spac...
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       Tractor Beams Are Real, and Could Solve a Major Space Junk Problem
        
       Author : belter
       Score  : 11 points
       Date   : 2023-11-05 16:14 UTC (6 hours ago)
        
 (HTM) web link (www.livescience.com)
 (TXT) w3m dump (www.livescience.com)
        
       | sfink wrote:
       | Maybe it's not a big deal, but it seemed weird to me that this
       | article didn't mention that the cleanup satellite would need to
       | burn fuel for propulsion to drag things around. The way it was
       | written seemed to violate conservation of energy: you zap a junk
       | satellite with this magic beam, and it starts moving without
       | having any effect on the cleanup satellite.
       | 
       | You would of course need fuel to propel both satellites together
       | into the disposal orbit, and then more fuel if you want to come
       | back for another load. (Ok, maybe not fuel, if this is slow
       | enough that solar power would be enough. But you'd still need
       | reaction mass of _some_ sort.)
        
         | cwillu wrote:
         | "The electrostatic tractor would use a servicer spacecraft
         | equipped with an electron gun that would fire negatively
         | charged electrons at a dead target satellite, Champion told
         | Live Science. The electrons would give the target a negative
         | charge while leaving the servicer with a positive charge. The
         | electrostatic attraction between the two would keep them locked
         | together despite being separated by 65 to 100 feet (20 to 30
         | meters) of empty space, she said."
        
           | plorg wrote:
           | So by that description we're still talking space tugboats. I
           | guess the advantage is supposed to be a lower chance of
           | collisions damaging the tug and producing extra debris?
        
             | sand500 wrote:
             | Physically attaching something is probably really
             | complicated and you need to make sure the junk doesn't
             | rotate out of control as you burn to de orbit it.
        
         | Sharlin wrote:
         | Solar electric (ion drive) would work fine here, a few kg of
         | xenon would last for a long time. And you could feed the
         | tractor beam with the electrons stripped from the xenon
         | atoms...
        
       | dharmab wrote:
       | "With the commercial space industry booming, the number of
       | satellites in Earth's orbit is forecast to rise sharply. This
       | bonanza of new satellites will eventually wear out and turn the
       | space around Earth into a giant junkyard of debris..."
       | 
       | All modern commercial satellites are required to have a safe
       | deorbit plan. The FCC regulates that LEO satellites must deorbit
       | within 5 years of mission completion.
       | 
       | Disclaimer: I work for a commercial satellite operator. Our
       | satellites deorbit and burn up without intervention at the end of
       | their lifecycle.
        
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       (page generated 2023-11-05 23:02 UTC)