RE: Upcoming Titan-4/NUS Launch from VAFB

Ted Molczan (
Wed, 8 May 1996 00:04:24 -0400

John Pike wrote:

>A Titan 4 no-upper stage is currently scheduled for launch from Vandenberg
>Air Force Base on Sunday 12 May, with a window announced as between noon and
>4 PM Pacific time. Based on an earlier announcement, subsequently withdrawn,
>of a launch window between 3-7 PM Pacific, local observers are anticipating
>a launch at around 3 PM Pacific.

and Stu Huston wrote:

>On 1 May Ted Molczan wrote:
>>Why the transfer? The Titan IV awaiting launch
>>on 12 May'96 from Vandenberg AFB could offer a 
>>clue. USA 33 is very old, even by recent KH-11 
>>standards, so it is reasonable to expect it to be 
>>replaced soon, certainly sometime this year.
>>If the May launch turns out to be USA 33's 
>>replacement, then it would not surprise me to
>>find it in a standard 14.77 rev/d orbit, with RAAN
>>spaced about 48.9 deg west of USA 116. At about
>>that time, USA 116 would drop its perigee to
>>the standard altitude, and resume its sun-synch,
>>14.77 rev/d operation.
>If we assume this scenario, would that allow us to make a more accurate estimate 
>of the launch time?

and Ron Lee asked:

>A Titan IV is due to be launched from Vandenberg AFB, CA
>on May 12 or 15.   Could someone provide search elements?

Well, if this turns out to be LEO launch, which seems likely, given the lack
of an upper stage, then this will add to the Kh constellation, or the NOSS
constellation, or the Lacrosse constellation, or something entirely
new. Let's look at the possibilities for the existing LEOs:

To replace the Kh-11 known as 88099A (USA 33), launch would have to
occur about 11:06 PDT, but that is outside the launch window.

To replace the Kh-11 known as 95066A (USA 116), launch would have
to occur about 14:22 PDT. This is inside the launch window, but seems
very unlikely, given that 95066A is only 6 months old.

To replace Lacrosse 1 (88106B) in its present plane, would require launch 
at about 09:03 PDT, but that is outside the launch window. Although
88106B is quite old, and could be a candidate for replacement, its orbit
probably is not standard, given that it is in a 57 deg inclination, instead of
the 68 deg of Lacrosse 2. Lacrosse 1 was launched on a shuttle, and
its orbit probably is a compromise, due to launch from KSC, from which a
68 deg inclination cannot be safely reached. So if this is Lacrosse 3, it
makes more sense to look at the constellation building opportunities with
Lacrosse 2.

To replace Lacrosse 2 (91017A) in its present plane, would require launch
at about 04:42 PDT, but that is outside the launch window. The only possibility 
that makes intuitive sense, and that fits the window, is to launch at 12:40 PDT,
placing the spacecraft 120 deg east of Lacrosse 2.

To replace the NOSS 2-1 cluster (90050C, D, E), launch would have to
occur about 04:16 PDT, but this is outside the launch window.

To replace the NOSS 2-2 cluster (91076C, D, E), launch would have to
occur about 20:21 PDT, but this is outside the launch window.

To bisect the NOSS 2-1 and NOSS 2-2 planes, creating three planes spaced 
equally about 120 deg in longitude, launch would have to occur about
12:18 PDT. This is within the launch window. The Titan IV launched from
VAFB on 2 Aug 93, which blew up, launched at a time that would have placed
it nearly 150 deg east of NOSS 2-1, and 90 deg west of NOSS 2-2. On 12 May,
a launch at 14:29 PDT would duplicate this spacing. Of course the ultimate
spacing could have been quite different. NOSS 2-1 lingered for about 12 days
in a 61 deg, 300 km orbit, and a later a 61 deg, 455 km orbit, before manoeuvring 
to the NOSS 63.4 deg, 1100 km orbit. In that case, the desired plane was the
NOSS 1-8 plane, so it appears that the low orbit was designed to permit the
NOSS 2-1 plane to catch up to NOSS 1-8 plane, perhaps due to a late launch.
The apparent catch-up was about 17 deg, relative to NOSS 1-8. Another
possible explanation is that the fourth payload 90050A, had to placed in a
different plane than the NOSSs.

In summary, almost everything is possible, so we have the usual confusing mess!

A few days before launch, VAFB will issue a notice to sailors and pilots to avoid 
the area were the SRBs are expected to fall. The location of that area will provide
a good clue as the launch azimuth, sufficient to at least distinguish between Kh and

Time permitting, I will issue Lacrosse and NOSS search elements shortly before

bye for now