Re: Delta III Galaxy X status

Philip Chien (
Tue, 25 Aug 1998 13:03:56 -0400

Ron Lee <> asked:

>Does anyone have orbital parameters to generate a prelaunch elset?
>Times of burns is also desirable.

The Boeing web site has the times for the major events and some parameters.
With a lot of work somebody may be able to derive at least the orbit at the
time of spacecraft separation.

Here's a couple of the key numbers (my typing - possible typos)

Perigee - 185 km.
Apogee - 30,982.5 km. *
Inclination - 27.5 degrees
Arg Perigee - 178 degrees
Time - 2150 seconds after launch

* - this is the nominal contract value.  The propellants will be burned to
depletion allowing for a higher potential apogee

Launch window for Wednesday (Aug-26) is 8:48-9:53 p.m. EDT

eyeballing the ground plot map shows s/c separation occuring over the East
coast of Africa, close to Madagascar.

I don't have any details on when the satellite will perform its apogee
raising burns or other maneuevers, but one document says the separation
attitude will be so the s/c spin axis is aligned along the velocity vector
at the third apogee.  One might assume that the reason for that is that's
when the burn's scheduled.

Philip Chien, KC4YER
Earth News
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