Canaveral Titan 4 search elements

Ted Molczan (molczan@fox.nstn.ca)
Tue, 2 Jul 1996 15:37:42 -0400

The U.S. Coast Guard has announced that the tonight's Titan 4
launch will follow an azimuth of 40.5 deg, from Pad 40, located
at 28.55 N, 80.57 W. That indicates a launch inclination of 
55.2 deg; however, I suspect that the actual orbital inclination 
will be at least 57 deg.

The only other Titan IV NUS (No Upper Stage) to launch from
Cape Canaveral entered a low 61 deg parking orbit. That one was 
rather unusual because the announced launch inclination was 52 deg.
The U.S. Coast Guard's off-limits boundaries, located about 285 km 
from the launch site, suggested an azimuth of about 43 deg, 
consistent with a 54 deg inclination. So it seems clear that the
launch inclination was indeed somewhat less than the orbital
inclination.

That suggests that a "dog-leg" manoeuvre was executed, most likely 
to take the vehicle out to a safe distance east of the U.S. 
northeast coastline, before taking a more northerly azimuth into 
the 61 deg orbit. The orbital elements of the Titan 4 2nd stage 
support this, because they reveal that its plane would have been
about 4.5 deg east of the launch site at lift-off.

The azimuth of tonight's launch is close enough to that of the
June 1990 launch, that I cannot rule out that it too will enter
a 61 deg orbit, or perhaps even slightly higher. I believe the
highest inclination parking orbit from Cape Canaveral was 62 deg,
on STS 36, in Feb 1990. That mission carried a large Kh-like
payload, which later manoeuvred to a 65 deg, 800 km orbit.

Below are search elements based on 57 deg and 61 deg orbits,
ranging between 300 km and 450 km altitude. They are based on
a launch at the start of the launch period, 3 July, 0 h UTC.
If the launch is delayed, then the epoch and the RAAN will have
to be adjusted accordingly. For example, a 30 minute delay, 
would require the addition of 30/1440 = 0.02083333 to the epoch,
and 30/60*15.041 = 7.52 deg to the RAAN.

I suggest producing ephemerides for all four elsets, to improve 
the probability of seeing the payload and rocket body. If you have 
the time to search for higher or lower orbits, then you can modify
the mean motion accordingly. A range between say, 16.1 and 14.5
rev/day would be adequate.

The rocket almost certainly will be flashing, if it has deployed its
payload. The payload may or may not be flashing also. Accurate 
positional and time observations should have the highest priority 
until  accurate orbits have been determined. Rough estimates of the
flash period will suffice.

99500A          15.0  4.0  0.0  4.2
1 99500U 99500  A 96185.00000000  .00000000  00000-0  00000-0 0    08
2 99500  57.0000 180.1700 0000001   0.0000  18.9000 15.90000000    08
99501A          15.0  4.0  0.0  4.2
1 99501U 99501  A 96185.00000000  .00000000  00000-0  00000-0 0    00
2 99501  57.0000 180.1700 0000001   0.0000  18.9000 15.40000000    04
99502A          15.0  4.0  0.0  4.2
1 99502U 99502  A 96185.00000000  .00000000  00000-0  00000-0 0    02
2 99502  61.0000 183.2000 0000001   0.0000  17.5000 15.90000000    07
99503A          15.0  4.0  0.0  4.2
1 99503U 99503  A 96185.00000000  .00000000  00000-0  00000-0 0    04
2 99503  61.0000 183.2000 0000001   0.0000  17.5000 15.40000000