DSPs and Milstars and Orions Oh my!

Philip Chien (kc4yer@amsat.org)
Fri, 7 May 1999 02:30:52 -0400 

Oy it's been a frustrating couple of weeks ...

Ignore media reports about this being the biggest string of rocket failures
since 1986.  1995 was a worse year with more failures.  However the current
trend does involve more established launchers and higher value satellites
as well as less proven rockets.


Ed Cannon <ecannon@mail.utexas.edu> said:

>If the really bright one (+1)
>that Sue and Mike and I observed was the Delta III, its intrinsic
>magnitude must be brighter than that of a Delta II!

They did and it is.

The Delta 3 second stage a) combines the functions of the Delta 2's second
and third stage (orbit injection and perigee burn) and b) does so for much
larger satellites.  Not surprisingly it's much larger than the Delta 2
second stage, although they do share some components (guidance, batteries,
etc.).  The Delta 3 upper stage is 4 meters in diameter and 19.1 meters
long (with engine).  The orange band you see in the vehicle photos is
actually the Spray On Foam Insulation (SOFI) for the hydrogen tank - the
same insulation used for the Shuttle's external tank.

Of course the Delta 3 second stage was not planned to be in such a low
orbit which also contributes to its brightness.  Indications are the
stage's second burn was only for about a second and then the engine
suddenly shut down.  Amazingly it recovered from an uncontrolled tumble and
stablized in the proper attitude for the spacecraft deployment.

I've had excellent geometry passes over the past two days, but the weather
hasn't been cooperating.  Maybe I need to have a talk with the Air Force
weather forecasters about aranging good weather for me for tonight.


Hughes is planning on raising Orion 3's perigee to a roughly 1300 km.
circular orbit and then deciding what to do with it.  For the life of me I
can't see any way of raising it to geostationary orbit unless there's a
warp drive engine installed.  Contrary to room temperature IQ television
reporters (Celsius) there is no thoughts of a shuttle retrieval - in fact
Hughes specifically said that they weren't considering a shuttle rescue
(and why).  But try to tell that to a TV reporter.  *sigh*


The Air Force has verified that Milstar 2 F1's appendages (payload truss
and solar arrays) have been deployed, so it should be an incredible sight -
possibly the first non one-dimensional artificial satellite to show as more
than a point of light to the naked eye.

Its Centaur is also in a much lower orbit than any typical Centaur stage
(even the ones about to reenter rarely have as low an orbit).  In addition
the wide-body Centaur used with the Titan IV is much larger than the
typical Centaurs used for Atlases.  The Namibia report does sound very much
like an observation of the Centaur stage, although I do have the same
reservations which Ted expressed.



Philip Chien, KC4YER
Earth News
world (in)famous writer, science fiction fan, ham radio operator,
all-around nice guy, etc.