SeaStar, and new LEO objects

Bjoern Gimle (bjorn@tt-tech.se)
Fri, 15 Aug 1997 13:57:19 +0200

After two obs. of SeaStar/OrbView I have assigned the standard
magnitude of 24883  4.6 for SkyMap satmag.dat ( 3.9 for QuickSat)
One obs. of 24884 gave 7.0 ( 6.3 for QuickSat )

Tonight, SeaStar shadow exit is at 56 N, unless the orbit has
been raised again.

No more elsets at 09:00 UT, but a new GTO object, and a rocket
and debris? in 53 degrees inclination:
SATNO = 24894
1 24894U 97041A   97227.16644650  .00423069  00000-0  80466-1 0    32
2 24894  49.9518 288.0146 7261497 352.2231   1.0273  2.31460313    48
SATNO = 24895
1 24895U 97041B   97227.22696206  .00086260  12220-4  10000-4 0    11
2 24895  53.1655 287.4125 0019907 219.1768 140.7368 16.35621178    69
SATNO = 24896
1 24896U 97041C   97227.22665091  .04680518  12284-4  15000-3 0    14
2 24896  53.1675 287.3416 0021480 216.4693 143.4894 16.42409242    35

The GTO object is best seen in the evening around lat.30 S
at 700 km, if anything still in that orbit.
The rocket enters shadow around lat.45 S, and exits in the morning
shortly before northern apex, with excellent viewing opportunities
for those who are usually "latitude challenged" in either direction.

But beware - ndot2 appears far too small ! On the C object it is more
reasonable, and SatEvo gives decay at Aug. 15.92

Looking at SeaStar Mean Motions, they now show a pattern of 
double burns, to maintain near-circular orbits.

Running COLA on pairs of orbits, I get the following transitions:

Epoch Iss. MM___ Closest intersection To MM___ Range(km) Age(days)

223.14 09 15.88 8/11/1997 23:01:03.6  #20 15.82    1.1      -0.15
223.14 09 15.88 8/11/1997 23:00:38.7  #21 15.82    1.7      -0.20
224.15 21 15.82 8/12/1997  5:57:18.7  #22 15.76    1.6      -0.29
224.53 22 15.76 8/14/1997  5:44:25.9  #23 15.70   22.5      -0.07
                8/14/1997  6:21:06.0  #23 15.70   23.7      -0.05
226.31 23 15.70 8/14/1997  9:41:11.3  #25 15.64    0.3      -0.29
226.31 23 15.70 8/14/1997  9:48:59.3  #26 15.64    1.4      -0.35

Elset #22 was quite old at the time of computed transition, hence
the large range, and double solutions.

Perigees for issues 09,22,25,26 were near 210 degrees ( 30 S )
For 20,21,23 they were near 300 degrees. Though not 180 degrees
apart, they still show (along with orbital heights) that
essentially the apogee of the old orbit became the perigee
of next one.

-- 

------------------------------------------------------------
-- bjorn@tt-tech.se       (office)   +46-8-59095783       --
-- b_gimle@algonet.se     (home)     +46-8-7428086        --
-- 59.22371 N, 18.22857 E            AND member of :      --
-- http://www.algonet.se/~b_gimle    SeeSat-L             --
------------------------------------------------------------