Estimated Orion EFT-1 Elements

From: daryl bahls via Seesat-l <seesat-l_at_satobs.org>
Date: Sat, 29 Nov 2014 16:59:29 -0500
I've taken a cut at estimating the orbit elements for this Thursday's Orion EFT-1. The TLEs below assume an on-time launch at 4 Dec 12:05:00 UTC (7:05 EST).  The launch window is 2 hours 39 minutes long.  As near as I can tell similar launch windows exist for the next two days, opening ~5 minutes later each day.

Most of the reference data for this estimate came from the Orion Flight Text 1 Press Kit located here:
http://www.nasa.gov/sites/default/files/files/orion_flight_test_press_kit(1).pdf

There are two orbits.  An initial low altitude orbit for one rev and then the final high apogee orbit to approximate entry conditions from lunar distances.

EFT-1 Initial Orbit: Valid from: 4 Dec 2014 12:22:39 UTC to 14:00:26 UTC

1 99000U 14100A   14338.51572917 -.00000000  00000-0 -00000-4 0   010
2 99000 028.8000 075.9199 0509717 149.6600 356.5000 15.15120000000010

Initial Orbit visibility opportunities are in Western & Northwestern Australia and parts of Indonesia (about 12:57 to 13:04 UTC eclipse entry) and Southwestern US & Northwestern Mexico (13:40 eclipse exit to about 13:48 UTC).  Eastern parts of the US and Mexico visibility areas will be approaching dawn so the skies may be bright.  The stack should be fairly bright as the second stage is still attached at this point.

EFT-1 Final Orbit: Valid from: 4 Dec 2014 14:05:09 UTC to 16:18:35 UTC

1 99001U 14100A   14338.58690972 -.00000000  00000-0 -00000-4 0   010
2 99001 028.8000 075.2610 3154860 140.3900 021.9900  9.73703000000010

Final Orbit visibility opportunities are much more widespread due to the much higher 5800 km apogee altitude, although at much, much longer range.  Australia; South, Southeast and Far East Asia (from ~14:40 to 15:26 UTC eclipse entry), ranges vary from 6500 to 8000 km).  Hawaii will also have visibility as the spacecraft plunges back toward Earth (16:03 eclipse exit to 16:14 UTC, range ~3500-1100 km).

 

Daryl



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Received on Sat Nov 29 2014 - 16:00:17 UTC

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