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ISS Comm
- Subject: [sarex] ISS Comm
- From: K6due@xxxxxxx
- Date: Sun, 5 Nov 2000 09:04:23 EST
(Note: This story, from Florida Today, shows that the writer did not know
of our ARISS amateur radio, which soon will, be in place. That will serve
for emergency comm, as well as school and personal contacts. Roy, K6DUE)
November 5, 2000
Contact limited with crew, station
By Steven Siceloff
FLORIDA TODAY
SPACE CENTER, Houston - Communicating with people in space has never been
easy.
In the 1960s, NASA had to build small outposts with big dish antennas around
the globe to keep track of its spacecraft. It also outfitted ships with
similar equipment to provide more voice access to the orbiting crews.
NASA has since changed its ways and now relies on a constellation of large
communications satellites to relay voices, pictures and crucial information
from shuttles to ground controllers in Houston.
So when American Bill Shepherd and Russians Yuri Gidzenko and Sergei Krikalev
moved into Space Station Alpha last week, it was dj vu for the American space
agency. Ground controllers again had to wait for the spacecraft to pass over
ground stations before they could talk to their crew. Complicating the
matter, the brief time to talk, usually 10 minutes, but sometimes 20, had to
be split with Russian controllers outside Moscow who also want to know how
their guys are doing.
Communications gear on two Russian station modules can work only with Russian
equipment on the ground, meaning the crew was limited to a few communications
sessions a day with ground controllers.
But that pressure has been alleviated somewhat by a computer system and small
camera the station astronauts have activated, a kind of digital tin can and
string from space.
The system, called Orbital Communications Adapter, is a laptop computer with
a tiny camera built into it. The computer is mounted on a special base that
allows the images and voices to be sent down to Earth through antennas on the
American Unity space station module to the same satellites the shuttle uses
and then down to Mission Control in Houston.
The signal also works the other way, allowing the station crew to see the
astronauts they are talking to on the ground.
The system is far from clear and resembles the movies Internet users watch.
The biggest advantage is that it allows ground controllers and astronauts to
talk almost anytime. That would come in handy particularly in an emergency,
but it also is critical in permitting the crew to talk to family members, for
instance.
The Russian space station Mir had no such ability, and when a fire broke out
on the station in 1997, controllers in Moscow did not find out about it until
Mir passed over Russia long after the fire was extinguished.
But while the ability is there now to talk to the crew often, station flight
director Jeff Hanley said NASA will use the equipment sparingly.
"The down side is that we give up command and telemetry (information from the
station) when we switch to the system," he said. We also need to leave (the
crew) alone to do their work."
The Orbital Communications Adapter is a stop-gap method for the station until
the U.S. Destiny Laboratory Module and its host of computers is carried to
the station in January. The computers are needed to control American antennas
and electronics already on the station to allow communications virtually
anytime, including clear television images.
The current crew will not get to enjoy the advanced system long. They are to
return to Earth in February.
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