re: New Flasher? DMSP 14

Philip Chien (kc4yer@amsat.org)
Fri, 18 Apr 1997 22:34:55 -0400

Ron Lee <ronlee@pcisys.net> said:

>
>There was a parade of the three objects from the 1997 012 launch.
>Object B (#24756) was due at 21:14 local, object A (#24753) one minute
>later, and Object C (#24765) at 21:17.
>
>I missed object B (clouds not a factor yet).  But at 21:15, I saw a
>nice flasher (maybe 3 flashes per second) and bright, followed closely
>by a likely steady, dimmer object.   Clouds precluded following them
>and also made sighting of the C piece unlikely.

1997 12A is a DMSP military weather satellite.  Previous satellites in this
series were launched with converted Atlas ICBMs, but they ran out of
Atlases and this one was launched with a Titan II.

I'm at a loss as to why there would be three objects cataloged from this
launch.  With many Titan II launches the upper stage is actually on a
ballistic trajectory which quickly reenters without completing a full orbit
(e.g. Landsat 6 launch).  So I wouldn't expect to see a Titan upper stage
in orbit.

Under this launch scenario the satellite's built in upper stage (A Star 37
class solid motor) is used to accelerate the spacecraft to orbital
velocity.  In some cases the solid kick stage is then ejected, in others it
remains with the satellite.

If the solid upper stage were to separate from the spacecraft it would
result in two objects from the mission, but I'm at a loss to understand why
there would be three.

These are just from my knowledge about the Titan II launch vehicle and DMSP
satellite.  I do not know this particular launch vehicle configuration
enough to verify if my assumptions are correct.

In any case, I believe other DMSP satellites have been reported as
flashers.  Here's a list of the previous satellites in the series -


1982 118A       DMSP  6 B5D2-1
1983 113A       DMSP  7 B5D2-2
1987  53A       DMSP  8 USA  26 B5D2-3
1988   6A       DMSP  9 USA  29 B5D2-4
1990 105A       DMSP 10 USA  68 B5D2-5
1991  82A       DMSP 11 USA  73 B5D2-6
1994  57A       DMSP 12 USA 106 B5D2-7
1995  15A       DMSP 13 USA 109 5D-3-F15

my notes indicate that DMSP 10 didn't reach the proper orbit due to a
faulty nozzle.



Philip Chien [M1959.05.31/31.145//KC4YER@amsat.org]