[HN Gopher] The disappearance of Gaia, ESA spacecraft will be tu...
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       The disappearance of Gaia, ESA spacecraft will be turned off on 27
       March 2025
        
       Author : croes
       Score  : 31 points
       Date   : 2025-03-26 18:51 UTC (3 days ago)
        
 (HTM) web link (www.cosmos.esa.int)
 (TXT) w3m dump (www.cosmos.esa.int)
        
       | margalabargala wrote:
       | Absent from that link but important context:
       | 
       | The _reason_ why they are actively shutting it down, is that they
       | are running low on fuel, and want to ensure that the spacecraft
       | does not litter important orbital locations.
       | 
       | Gaia has spent its life at Earth's L2 Lagrange point, which is a
       | valuable and limited area of space; they do not want to have to
       | plan around dead spacecraft in future missions. Thus, before the
       | spacecraft runs out of fuel, they have moved it away from L2 into
       | its final graveyard orbit.
       | 
       | It is not capable of performing the science for which it was
       | designed in its graveyard orbit.
        
         | 8bitsrule wrote:
         | Thanks. That page also helped me find one that sums up the
         | mission so far, and explains what's to come in 2026 & 2023.
         | 
         | https://www.esa.int/Science_Exploration/Space_Science/Gaia/L...
        
       | bhouston wrote:
       | Great images from the project here:
       | 
       | https://www.esa.int/Science_Exploration/Space_Science/Gaia
        
       | catlikesshrimp wrote:
       | What is the advantage of keeping the passive in orbit instead of
       | dropping it in an ocean?
       | 
       | If for any reason it fell from orbit, later, it could impact an
       | important surface (city, nuclear plant), and definitely a larger
       | area.
        
         | ocdtrekkie wrote:
         | Generally getting things out of space also requires
         | effort/fuel. A graveyard orbit is specifically easier to get to
         | but uninteresting from a "hitting other things" perspective.
        
         | JumpCrisscross wrote:
         | > _If for any reason it fell from orbit, later_
         | 
         | You'd need about 300 m/s of delta-V to knock something from
         | Sun-Earth L2 to Earth. Not impossible. But akin to the energy
         | required to go from Earth transfer to Mars or Venus transfer
         | [1]. Less likely to fall to Earth than become an orbital pest.
         | 
         | [1]
         | https://en.m.wikipedia.org/wiki/File:Solar_system_delta_v_ma...
        
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       (page generated 2025-03-29 23:00 UTC)