Every day, the United States Space Command (USSPACECOM)
monitors more than 8,000 man-made
objects orbiting the Earth
. The command supports manned space
flight with data from a worldwide Space
Surveillance Network (SSN)
of radar and optical sensors.
These provide extensive worldwide but not complete global
coverage. The sensors are able to monitor an object as small as a
baseball in Low Earth Orbit approximately 100 to 600 miles from
Earth and as small as a volleyball in Geosynchronous Orbit,
approximately 22,300 miles.

USSPACECOM supports manned missions like our Space Shuttle and
the International Space Station, comparing the orbits of
satellites and debris with the orbit of manned spacecraft 36
hours into the future. This support is also provided for
satellites which are to be deployed by the shuttle to conduct an
experiment or research and then retrieved by the shuttle. Prior
to the shuttle launch and any on-orbit maneuvers, the National Aeronautics and Space
Administration (NASA)
will inform the Space Control Center in
Cheyenne Mountain who will in turn check for any possible close
approaches in the new flight path 36 hours out. If the orbit of
any satellite or debris comes close to the predicted orbit of the
Shuttle or the ISS. USSPACECOM immediately notifies NASA. NASA
decides whether to maneuver the manned-space vehicle, to avoid
the satellite or debris.

Also closely supported by USSPACECOM are shuttle missions
involving space rendezvous. Prior to the launch, NASA and
USSPACECOM analyze the intended path of the shuttle and the
object with which it will rendezvous. After the shuttle is in
orbit, updated information about the other object’s orbit is
provided so a smooth and safe rendezvous can take place. Examples
of this would be the shuttle docking with the ISS or the shuttle
rendezvousing with the Hubble space telescope.