Re: Globalstars and Delta Burns Observed
Ron Lee (ronlee@pcisys.net)
Sat, 10 Jul 1999 09:51:45 -0600
GLOBALSTAR MO32 1378 x 1351 km
1 25851U 99037A 99191.43302173 -.00000107 00000-0 00000-0 0 14
2 25851 52.0103 315.9533 0017926 245.9263 114.0701 12.74308640 08
This is very close to the prelaunch elset provided.
The Delta second stage was observed in binoculars just after 10:32 UT
on 10 Jul 99. As it rose in elevation , I could see one fainter
object on either side of the second stage. If the direction of motion
is 12 o'clock, right from the satellite is 3 o'clock (southeast or to
the lower left from my perspective). then the two sets of Globalstars
were at about 2 and 8 o'clock. Since the objects were moving from
the SSW to NE, they appeared almost parallel to the horizon from my
vantage point.
At 10:33:56 UT I noticed the burn. The burn was oriented to the NW
or about 10 o'clock from the clock positioning I described. It was not
very impressive. However, at about 10:34:30 UT I did notice a definite
separation of the second stage to the SE away from the satellites.
Times are plus or minus a second or so since I transcribed the times from
a tape recorder. Several sources of error since I was not concerned
with absolute time accuracy.
After closing the shutter on the camera, I was unable to reacquire
the satellites. No problem. I had wisely (for a change), created
a second Skymap chart showing the depletion burn region. After
finding the appropriate stars, I waited. On time at 10:41:27 UT
the depletion burn started. This one was AWESOME. Soon after the
burn started, I made a note that it was turning. I believe the initial
plume direction was to the NE from my perspective or about 1 o'clock
from its direction of motion perspective.
At 10:41:56 UT it went between two target stars and I observed the
plume easily with the naked eye. The size was not measured accurately
but was perhaps two-three degrees in length. At 10:42:25 UT, the
outgassing from the rocket was still visible although the main plume
was now very faint. At 10:42:49 UT the outgassing continues and by
10:43:10 UT I felt it was over.
During the time, my impression is that it corkscrewed perhaps one full
turn. I suspect that the main plume was caused by the actual burn
scheduled to last for seven seconds and that the remainder of the
outgassing I saw was residual propellant/pressurant dumping.
The elset I have show that the satellites were above (trajectory wise)
the second stage during the depletion burn. The burn orientation would
have been away from the satellite and in a direction to lower the
perigee.
I am curious if the poor showing of the evasive burn was because it
was to the south (sun rising in the NE) while the depletion burn
was "over" the rising sun?
This would have been a great event to videotape. Does anyone here
have details on a suitable videocamera that would record under these
conditions?
Ron Lee