Oscar 10 sightings possible?

Ryan Rudnicki (RR03@swt.edu)
Mon, 10 Feb 1997 04:18:43 -0600 (CST)

Saw the notice below and wondered if any SeeSaters might be able to help?
AO-10 has NASA id# 14129; also known as 83-58B.  With its Molniya orbit,
even at perigee it's some 3800km up there; difficult to see.


Ryan Rudnicki

*****************************************************************

Date: Sun, 09 Feb 1997 12:21:40 -0600
From: BJ Arts <bjarts@uslink.net>
Subject: ANS-040 WEEKLY BULLETINS


[snip]


SB SAT @ AMSAT  $ANS-040.04
AO-10 KEP INFO

HR AMSAT NEWS SERVICE BULLETIN 040.04 FROM AMSAT HQ
SILVER SPRING, MD, FEBRUARY 09, 1997
TO ALL RADIO AMATEURS BT
BID: $ANS-040.04

There are no new keps for AO-10.  NORAD says, via Ken
Ernandes, that the satellite is in an orbit that is difficult to track with
their optical/video trackers (GEODSS), and it won't be until spring or
early summer before it is visible at these sites in the night sky (they
can't track during the day with this technique). Efforts are being made to
persuade them track it with other techniques (long range radar) or from
other sites, but so far no results.

 The current keps seem to be late according to Stacey Mills, W4SM, i.e. the

satellite appears before the keps predict. Mills found that if you can
figure 
out the time difference at perigee (when does AO-10 appear vs. when the
keps 
predict), then subtract (or add) that fraction of a day from the epoch
time. This will give a close prediction.. Of course more than just the
time/MA is changing, but that's a major factor, and this correction makes
the keps usable.  Others have done the same thing by adjusting the drag
factor.  Mills subtracted 0.02 days from Epoch time over the weekend and
this was a definite improvement, but he didn't have perigee data to really
tweak the correction. 

There is a beginning movement by the P3 command stations and others to
resurrect some older amateur ranging and orbital calculation techniques and
algorithms used on AO-10/13, update them to newer computers and rangers for
use on P3D and test them on AO-10, but this will take a while and 
new NORAD keps are expected before then. 

Until AMSAT receives new keps, try pointing at a predicted perigee AOS 
azimuth about 30 or so minutes earlier than predicted, listen to the beacon

freq., note the time of AOS, subtract this time as a fraction of a day from

Epoch time, and see if the new keps don't work a lot better, if you get a
good set, let ANS know what your adjustment factor was. Send the
information 
to wt0n@amsat.org. To be clear(er), assuming AOS is earlier than expected, 
subtract the difference between predicted AOS and actual AOS, expressed as 
a decimal fraction of a day, from EPOCH time. (If AOS is later than 
expected, add the difference to EPOCH time).

[ANS thanks  Stacey E. Mills, W4SM, for this information.]

/EX


[snip]


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BJ Arts  
WT0N in EN-37,  ARMY MARS AAR5EL
Hibbing, Minnesota. U.S.A.
e-mail bjarts@uslink.net or wt0n@amsat.org
Amsat News Service Bulletin Editor