Bright satellites, GPS, Year 2000

Walter Nissen (dk058@cleveland.Freenet.Edu)
Tue, 28 Jan 1997 17:01:48 -0500 (EST)

Newbies are always asking "What bright sats can I see?".  I have two 
basic answers: 
1)  The best way is to feed a current version of Ted Molczan's list of 
elsets into Mike McCants' QuickSat program and let it tell you.  This is 
fairly close to ideal for the next few days.  And you can anticipate the 
general seasons of visibility for most objects many, many months in 
advance, although the times of passage will probably be wrong by many, 
many minutes. 
Since neither NASA nor RSA provides anticipated elsets for manned vehicles 
nor hardly any useful information about anticipated orbits (if I am wrong 
about this, please, please correct me), you may wish to supplement Ted's 
list with elsets from SeeSat-L, from OIG, from Spacelink at MSFC, or from 
NASA Web pages for Mir and shuttles. 
For poorly observed or rapidly decaying objects, you may find 
supplementary elsets here on SeeSat-L, from OIG, or from various other 
2)  Consult various lists of bright objects.  Among these are the 
VISUAL.TLE list maintained by Jay Respler and distributed with updated 
elsets by TS Kelso (lacks several of the very brightest objects), the 
QUICKSAT.MAG file (part of QS, and available separately; pretty large, 
thus incorporating many lesser lights, and doesn't directly tell you how 
bright the object will be in your sky), the VISIBLE.HD (and VISIBLE.DAT 
and VISIBLE.TLE) files from OIG (showing its age and also large), my "top 
40" which I posted quite a while ago to SeeSat-L (short), and my list of 
objects observed, which presents the brightest magnitude I've actually 
observed and recorded for each satellite.  Your mileage may vary; i.e., 
it's possible the recorded magnitude may have been truly extraordinary. 
Thanks to Neil Clifford, the latest version of my list is now available at 
the following URL (25 KB): 
where you will find the list divided into two parts, the first compiled 
1992-1994 at latitude 39N and the second compiled 1994-1996 at latitude 
One caveat, which I haven't mentioned lately, is that you may find it 
worthwhile to seek out some especially interesting, but fainter objects, 
particularly the NOSS 2-n objects, TiPS and EGP. 
Another is that all lists suffer from latitude bias.  GRO is a very bright 
object, but not from the far north where Russell Eberst and Bj"orn Gimle 
are based. 
Bottom line, I really haven't found anything better than QS.  If you have 
difficulty installing it and getting it running, ask someone for help. 
The newsgroup sci.geo.satellite-nav is the locus of discussion of GPS (of 
course, you could have used the group locator function to 
find that out).  I saw a message there claiming that GPS has its own time 
reference system which requires the receiver to convert it to UTC.  Also, 
that this internal system will overflow (loopback like an odometer) when 
it reaches week 1023 (binary all ones) about 1999 AUG 22, giving receivers 
an early test of the Year 2000 Problem. 
It would seem that the usability of GPS units and systems dowstream from 
them will depend on the adequacy of the software in the individual 
receivers (and downstream). 
Mike McCants tells me that current versions of QuickSat do increment the 
month correctly.  (Not that I ever had the slightest doubt when to expect 
January 32 to arrive). 
Walter Nissen          
Take Back the Diamond-Studded Velvet: 
Support your local dark sky:  (highly recommended)