Re: MAST : No Show from Colo USA UT Apr 28 050840 in cirrus

From: djlaszlo@aol.com
Date: Sat Apr 28 2007 - 01:52:04 EDT

  • Next message: John Locker: "Re: MAST : No Show"

    I attempted with an 18 inch Newtonian, 40mm eyepiece yielding a 1 
    degree field at 50x.  Thin cirrus rolled in about T minus 10 minutes, 
    so contrast was not perfect. I was hoping for a clean look down to 12th 
    magnitude given the object's motion.  In the minute around the 
    prediction, 10th magnitude stars were still obvious with direct vision 
    around target star 5.9 magnitude HIP 47401 at 9h39.5m  67d16.3m J2000.
    
    I rehearsed the field stars as far as 22 and 27 UMaj, and did a slow 
    sweep estimated to match the orbit, and it's not likely I missed a 10th 
    magnitude object from T minus 5 minutes, to T plus 1 minute.  I'll have 
    to try it at a better phase angle, and I'm also dancing at a bit near 
    the shadow exit with this pass.
    
    I have seen TiPS many times, so I'd be thrilled to see the new tether.
    
    Happy Hunting,
    Dan
    
    
    -----Original Message-----
    From: mmccants@io.com
    To: SeeSat-L@satobs.org
    Sent: Fri, 27 Apr 2007 23:21:30 -0500 (CDT)
    Subject: Re: MAST : No Show
    
       Dan Laszlo posted:
    
    >If the tether is deployed, is it likely the drag has caused a lower
    >orbit and even earlier arrival than minus 4 minutes?
    
    The tles from Space-Track have a fixed value for the BStar term and
    the drag term.  Judging from the very small change in mean motion over
    the last few days, that drag value (which is very small) should be even
    smaller.  A prediction from a tle that is one week old differs from a
    prediction by the current tle by only 2 seconds.
    
    The perigee is pretty high (about 650 Km) - so even if the tether is
    deployed, I think the drag will not increase to be greater than the
    value on the current tles.
    
    Mike McCants
    
    -------------------------------------------------------------------------
    
    Subscribe/Unsubscribe info, Frequently Asked Questions, SeeSat-L 
    archive:
    http://www.satobs.org/seesat/seesatindex.html
    
    
    
    ________________________________________________________________________
    AOL now offers free email to everyone.  Find out more about what's free 
    from AOL at AOL.com.
    
    -------------------------------------------------------------------------
    Subscribe/Unsubscribe info, Frequently Asked Questions, SeeSat-L archive:  
    http://www.satobs.org/seesat/seesatindex.html
    



    This archive was generated by hypermail 2b29 : Sat Apr 28 2007 - 01:53:08 EDT