ADEOS orbit changes

BGimle@aol.com
Sat, 5 Jul 1997 08:44:13 -0400 (EDT)

>I have looked at a number of elsets from 97179 to 97184 ...

I made further checks on nine elsets from 97176.24 to 97182.27.
To define the intersection of pre- and post- collision orbits better,
I removed the along-track difference between the elsets. This proved
to be very small, the oldest elset needed +1.37 sec to match 97181.28
at about 03:58, the rest varied from +0.26 to -0.31 sec), so I could
correct the Epochs instead of MM or ndot2 without any measurable side
effects.
After that, the (cross-track) distance reported by COLA when comparing
97179.25
to older elsets was only 0.0 to 0.1 km (03:52-03:55), to 181.21 0.3 km at
03:59:44 , and to the (other) post-collision elsets 1.2-2.7 km (03:58-04:01)

When comparing to 97181.21 elset, the distance to the older ones where
0.3-0.4 km (03:59:44-04:00:05), to the later ones 1.6-3.0 km (03:58-04:00)

Finally, from the 97181.28 elset, 1.2/1.6 km to older ones
(03:58:09-03:58:15)
and 0.2, 0.6, 0.9 km (03:55:39-03:56:23)

Thus, the older elsets show a high positional accuracy/stability, 97181.21
appears affected by the hit that already has taken place, but is not
reflected
in the mean motion, and the newer elsets show a gradual change, that may be
caused by outgassing from damaged equipment.
Looking at line 2 of elsets, MM is slowly decreasing, and so is eccentricity:
97182.27 24277  98.5960 259.5563 0001767 131.3198 228.8143 14.27023671 45373
97181.84 24277  98.5944 259.1452 0001604 115.9118 244.2264 14.27026468 45315
97181.56 24277  98.6025 258.9051 0007628 152.5402 207.5860 14.27033474 45277
97181.28 24277  98.6097 258.6713 0015362 162.3148 197.7449 14.27063794 45235
97181.21 24277 098.5960 258.5286 0002590 097.1446 263.0010 14.27649283045225
97179.25 24277  98.5974 256.5846 0002180  88.2978 271.8453 14.27648911 44949

If the 97181.28 elset is really correct, deltaV (at 03:58:10 from 97179.25
elset) was about 15 m/s, almost 90 degrees from the left and 45 deg. BELOW!
This means that space debris/meteorites are outruled.

The observation that the spacecraft may be rotating only slowly, may indicate
that the impulse was almost central.