STS Leading Mir, STS reentry viewing
DJLaszlo@aol.com
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
Colorado.
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)
Speed(MPH)
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
http://shuttle.nasa.gov/sts-76/demos/
or for the current NASA TV frame:
http://shuttle.nasa.gov/sts-76/ntv/
The latter may get you a shot of a room full of technicians, though...
Regards,
Dan Laszlo, djlaszlo@aol.com