[Neocp_artsats] WMAP returns

[Bill Gray]

Hi folks,

    A reminder that WMAP will be returning to visibility.  I wrote about 
this last month,

https://projectpluto.com/pipermail/neocp_junk_projectpluto.com/2025-February/000102.html

    The best opportunity to see it will be around April 10,  as it 
passes through opposition,  but it may already be visible to larger 
telescopes.  Ephemerides from two solutions are given at

    https://www.projectpluto.com/sat_eph.htm

    Look for the check-boxes for "2001-027A = WMAP (soln 1)" and 
"2001-027A = WMAP (soln 2)".

    I'm currently leaning toward thinking that solution 1 is more likely 
to be on target.  I computed that solution using astrometry from both 
before and after the 2010 October 19 burn that put WMAP into 
heliocentric orbit,  solving for the time and delta-V of that burn.  The 
result is quite close to what the WMAP navigation team got at the time, 
giving me a little more confidence that it matches reality.  But the 
largest source of uncertainty is probably the fact that we haven't seen 
it since 2011.  Accumulated non-gravs could be a problem.

-- Bill