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UA9FBV > SAT 17.01.04 23:02l 41 Lines 1749 Bytes #999 (0) @ AMSAT
BID : ANS-018.02
Read: DB0FHN GUEST
Subj: <empty subject>
Path: DB0FHN<DB0FOR<DB0MRW<OK0PPL<DB0RES<ER3KAZ<UA9FBV
Sent: 040117/2110Z @:UA9FBV.PRM.RUS.AS #:47589 [Perm] GATEWAY $:ANS-018.02
From: UA9FBV@UA9FBV.PRM.RUS.AS
To : SAT@AMSAT
Preliminary Echo Keplerian Elements
AMSAT News Service Bulletin 018.02 From AMSAT HQ
SILVER SPRING, MD. January 18, 2004
To All RADIO AMATEURS
BID: $ANS-018.02
The following Preliminary Echo Keplerian Elements have been developed by
Stacey Mills W4SM, AMSAT Operations VP, in response to questions about the
nature of the planned Echo orbit. These elements can be used by orbit
prediction programs to show the type of orbit we can expect but it cannot be
used to predict passes because the times will be a function of the exact
date and time of launch. Stacy's comments follow:
"Launching at 1030 UTC on March 31st from Baikonur should give an RAAN of 42
degs. That sets the orbital plane nicely. For ArgP, I just plugged in 180
which is not correct for this high a latitude launch, but since the orbit is
close to circular it doesn't really matter. Mean motion was calculated from
the orbital period of 5996.2 seconds which equals 14.4091 orbits/day.
Eccentricity was obtained from the launch docs. I then adjusted mean
anomaly to put the [spacecraft] over Baikonour at the time of launch and
then adjusted back to present day so that the MA and orbit numbers don't
appear negative. If you track forward to launch day/time, the satellite
does appear over the launch site, so these are a pretty good, at least for
illustration purposes. The keps are in NASA 2-line format with correct
checksums. Orbit number is arbitrarily set at 0 today [15-Jan-04], and so
is meaningless."
ECHO
1 99999U 99999B 04015.44385708 .00000000 00000-0 00000-0 0 00013
2 99999 098.2700 042.0000 0072000 180.0000 226.0000 14.40910000000006
Rick
W2GPS
[ANS thanks Rick, W2GPS, for the above information.]
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