STS Leading Mir, STS reentry viewing
Fri, 29 Mar 1996 12:59:40 -0500

>An STS isn't going to head up to go home, so it will 
>always lead on the way home; and conversely, trail on the way >up.  Subject,
of course, to any actual operational difference, >which we haven't seen yet. 

I agree completely with the identificaton of STS-76 leading Mir on
observations this morning.  Per NASA TV, at 0830 UT, STS-76 was about 50
nautical miles ahead of Mir, with the gap widening by 9 nm per orbit.
 However, on the previous STS-Mir mission, within a few hours of separation,
Mir was clearly ahead of the Shuttle when it made its pass for us in

Now it gets interesting.  Early morning landing opportunities for STS-76 on
3/30/96 are:

Opportunity number 1.  Deorbit burn at 0530 CST (UT minus 6).  This commits
the shuttle for landing at 0657 CST at KSC, with a path over Montana, the
Dakotas, SW Minnesota, Iowa, Illinois, Western Kentucky, Tennessee, Alabama,
Georgia, to Florida.  If I were in Montana I'd start looking by 30-40 minutes
before touchdown to be safe.

Opportunity number 2.  Deorbit burn about 0700 CST.  I'll be lusting for this
one.  The path should be similar to the path of STS-63, Discovery, which
landed on Feb 11 1995.  The path ran from Washington State, north of Denver,
CO, north of Tulsa, OK, near Memphis, TN, and Birmingham, AL.  Forgive me for
reposting the following data, taken from NASA TV videotape narration of the
STS-63 landing.  With your atlas, you should be able to reconstruct the path:

Minutes to touchdown     Location      NMiles to KSC     Altitude (feet)

23min     Puget Sound, Wash

19.25min     ----------     1633nmi     225,000f     14750

18.5min     N Colo, 105 deg W     1410nmi     219,000f

16.5min     97 deg W, 37.5 deg N, ground view circle from latitude 30 deg to
45 deg

15min     ----------     771nmi     189,000f     10,500

14min     90 deg W     600nm     185,000f     9,500

12.5min     ----------     450nm     -----     -----

12min     Birmingham Ala

10min     -----------     195nm     131,000f     4,300

9min     ----------     161nm    125,000f     3,700

7min     ----------     110nm     107,000f     2,900    

6min     ----------     59nm     80,000f     1,500

Perhaps Neil Clifford can grab the graphics from NASA TV and post them as
previously, eh Neil?

The path of Discovery was within 20 degrees of the zenith, slightly north,
for Fort Collins.  I have not seen a daytime reentry, but I would speculate,
at magnitude minus 5 on an overhead pass, the Shuttle ought to be visible
with a little luck.  To improve your odds, you might try techniques to darken
the sky such as 1)high elevation, 2)red filter, 3)polarizer.  An infrared
viewer might be very effective, darkening the sky and showing the hot
orbiter.  Jeff Brower tells me that camcorder CCD's can be quite infrared
sensitive, so it's another option to try.  Watch for phenomena such as
contrails and ABSOLUTELY allow time for a sonic boom, since one was heard in
Colorado on the Discovery reentry, about 3 minutes after the 
orbiter went over. 

You might try the shuttle web page for NASA tracking software images if you
don't have NASA TV, use

or for the current NASA TV frame:
The latter may get you a shot of a room full of technicians, though...


Dan Laszlo,