Hams in Space!

Number 12 on your FHdbICk n rc!
Hams in Space!
SAREX II, the nextgeneration.
by Philip Chien
A
II :4 1a.m. on December 2, the night sky
lit up over Florida with a spectacular
display of flame and smoke as the Space
Shuttle Col umbia headed for orbit. After a
series of delays (caused mainly by a pcrstsra
nt hyd rogen fuel leak). STS-35 and
SA REX 11 -0 1 was finally o n its way!
STS ·35's primary miss ion was 10 carry
NASA's Astro-t spacelab with three ultraviolet
telescopes to observe the universe
in ways never viewed befo
re . Operating NASA's own
Goddard Spaceflight Cente r 's
Ultraviolet Imaging Telescope
CU lT) was payload specialist Ron
Parise WA4SIR. In 1978 un asrronomcr
Ron, a ham since 1962,
was completing his grad uate studies
at the University of Florida,
and by 1980 he was pan ofthe UIT
learn. Little did Ron realize then
that he 'd be flying with the UIT
instrument he helped develop.
The UIT is best described as a
so phistica ted tel ephoto camera
with super-sensitive film and a violet
filter. Imagine a telephoto ca m­
era with a field of view 2S% wider
than the full moon with ultra-lowlight
film with an effective ISO
(ASAI o f a couple ofhu ndred thou ­
sand (in compariso n with the 100­
400 film you'd normally purchase).
It has a filte r so violet the
human eye can't see it. further into
ultraviolet than Hubble 's capabilities
. Also, instead of an 18 or 36
exposure roll of film , you ha ve a
film pack with over J()(X) exposures
of 70mm fil m~ That's one
heck o f a telephoto camera!
SAREX II
Photo B. Mission commander Vance Brand talks withfamify mem-
hers via the SAREX 2 meter link. Photo courtesy ofNASA.
The launch of the Astra I mission
marked the beginning ofa new
se ries of SAREX (Shuttle Amateur
Radio EXperiment) nights .
The primary m issio n o f thi s
SA REX was to communicate with
a number o f classrooms across the
U.S., as well as to pro vide hams
worldw ide a way of directly con-
54 73 Amateuf Radio Today . March, 1991
necting up to the shuttle via a packet radio
robot.
In addition, Ron recommended trying shipto-ship
contact between Columbia and the
Soviet space station Mir . He said, " The idea
came to me some time ago, just because he re
was Mir ope rating 2 meters and we were
going to be operating 2 meters. and we ought
to talk to each other...
Any Columbia-to-Mi r contact would be
Photo A. Ron Parise WA4SIR working the world from the SAREX
operating position onboard STS-35. Phoro courtesy ofNASA.
much eas ier from the Sov iet side than from
the U.S. because Mir 's ham shack includes a
25 watt transceiver and an outside antenna,
while the Columbia has an inside antenna and
5 walt transceiver .
Contact between the IWO vehicles is complicated
by two factors. The most obvious
problem, the Doppler shift, actually turns out
to be fairly insignificant. More complicated
is the motion of the two spacecraft. Since the
spacecraft are in different orb its at
different altitudes. and traveling in
different di rections, the range between
the spacecraft and the line of
sight angle changes quickly: One
minute you ' re several thousand
kilometers fro m each other, the
next you' re right next to each other,
and then you' re several thou ­
sand miles away again.
Low Inclination
Unlike the earl ier ham radio
shuttle nights, Astra was launched
into an orbit with an inclination of
28 .5 deg rees , the typical orbit for
most shutt le fli ghts . Spacecraft
lau nched to the east gai n ex tra payload
capacity due to the Earth 's rotation:
A spacecra ft launched due
east can carry the most payload; the
orbit is inclined to the equator at the
same angle as the latitude of the
launch site . The end result is that
Astro flew no further north of the
equator than the KSC launch site,
and at the same latitude to the
south, 28 .5 degrees. The Spacelab
I m ission w ith O wen Garriott
W5LFL and Spacelab 2 with Tony
England W00RE flew into higher
incli nation orbi ts for better Earth
observation capabilities, the tradeoff
being less payload.
The iro ny is that the Sov iet space
statio n Mir is in a 51.6 degree
orbit, halfway between the Spacelab
2 and Spacelab 1 orbits. Had
Astra been launched into a higher
inclined orbit, longer opportu nities
for Mir contacts cou ld have been
possible.