Re: Prelaunch Elset, Delta Iridium, 17 May 98

Bjoern Gimle (b_gimle@algonet.se)
Mon, 18 May 1998 02:51:30 +0200

>
>Prelaunch elset for the 17 May 98 launch (if it occurs) follows:
>
>Iridium, Delta, 5/17/98, 21:15:56 UT
>1 98765U 980XXA   98138.40157280 -.00378067  00000-0 -55178-1 0    12
>2 98765  86.5706 256.3573 0009801 264.3271  95.7271 14.78175419    89
>
>There still remains the unresolved issue about differences between my
>elset and data provided by another individual.   I am standing by my
>elset until proven wrong!
>
Thanks, Ron! After finding your messages while on the trip to Finland,
using only pen and pencil, I decided to stick to your elset(s).

I was rewarded as the string of five passed a star at RA 20:29:46,
decl.+49 02 (2000) above alp Cyg at 00:09:33.0 to 00:09:34.7 UT.

Just 4.3-6 seconds after Ron's elset. I was out late, so I missed the
predicted +4.2 peak magnitude, they were about +6 and fading.
I lost them after less than a minute.
I was also too late to look for the rocket.

Note that the elset assumes that they start climbing by decreasing MM
by 0.0075/day, and a similarly high B*. You may want to try

Iridium, Delta, 5/17/98, lower abs.ndot2/B*
1 98765U 980XXA   98138.40157280 -.00003780  00000-0 -55178-5 0    12
2 98765  86.5706 256.3573 0009801 264.3271  95.7271 14.78175419    89

so you won't have them pass before predictions.



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