Inmarsat Rkt missing? revisited
Philip Chien (kc4yer@amsat.org)
Mon, 16 Dec 1996 22:53:26 -0500
Background information - Inmarsat 3 F2 was launched on a Khrunichev Proton
rocket on September 6th. We now review previous messages to Seesat-L
>Ron Lee <scubalee@pcisys.net> commented:
>>
>>>Inmarsat?
>>>1 24307U 96053A 96252.42962384 +.00000003 +00000-0 +00000-0 0 00030
>>>2 24307 002.6362 288.8347 0007265 303.6198 349.0974 00.98533748000011
>>>Inmarsat Proton r?
>>>1 24308U 96053B 96253.43993837 .00584666 11904-4 25232-3 0 195
>>>2 24308 51.5963 244.9395 0002267 177.8088 182.2893 16.21982880 446
>>>Inmarsat Proton r?
>>>1 24309U 96053C 96253.43424779 .12249659 12336-4 10141-2 0 173
>>>2 24309 51.5920 244.8768 0003355 123.9526 236.2371 16.38910270 444
>>
>>Something about this sets of elements does not make sense to me.
>>
>>How did Inmarsat get to geosync orbit without a transfer orbit other
>>than inclination = 51.6 degrees? I would expect a rkt body in some
>>inclination less than 51 degrees and with e about 0.6/0.7.
>>
>>What am I missing?
At the Inmarsat 3 F3 press conference I asked about the details on the I3F2
launch.
I verified that the GE-4000 bus was modified so it did not include an
Apogee Kick Motor (a first for that satellite bus) and the Proton DM upper
stage was used to put the satellite in to a true geostationary ( MM = 1, e
= 0, i = 0) orbit. This is the normal Proton comsat launch profile, with
the DM stage performing the perigee and apogee burns and final inclination
removal. So the DM stage is now in a geosynchronous drift orbit.
I would not expect to see any significant size medium eccentricity object
from this launch, but would expect to see an additional object in
geosynchronous orbit.
It's *possible* that either the B or C object is the DM stage, captured on
NORAD radars early in its ascent, and presumably eventually will be
cataloged in geosynchronous drift orbit.
In any case, tomorrow's Inmarsat launch should be much simpler to track - a
Centaur stage in a geosynchronous transfer orbit, and a satellite
eventually in geostationary orbit over 178 degrees East.
Philip Chien, KC4YER
Earth News - space writer and consultant
note new E-mail address - pchien@digital.net