The U.S.
Air Force Research Laboratory is planning a small experimental satellite that
would orbit in close proximity to a host spacecraft and keep tabs on their
surrounding space environment.
The
laboratory's space vehicles directorate, located at Kirtland Air Force Base in
New Mexico, plans to fly the experiment in 2009, according to a request for
information sent to industry Nov. 15.
Plans call
for awarding up to three study contracts for the Autonomous Nanosatellite
Guardian for Evaluating Local Space (Angels) this coming spring, said Tom
Caudill, the space surveillance technical area lead at the laboratory. A single
company likely would be chosen in 2007 to build the demonstration spacecraft,
he said.
Caudill
acknowledged the program's schedule and $20 million budget are challenging. But
he said those constraints were chosen deliberately to help stimulate designs
for relatively simple, low-cost satellites that can be built quickly, he said.
"We're
trying to change the paradigm--to push contractors to do this quicker and
cheaper," Caudill said, noting that the military is making a developmental push
in this direction with efforts like TacSat.
The Angels
satellite will be launched into a geostationary orbit for an experiment that is
expected to last about a year, according to the request for information. The
Air Force hopes to extend the mission for another two years, according to the
request for information.
Geostationary
orbit is a belt of space some 36,000 kilometers above the equator that hosts
most communications satellites. The Air Force chose that orbit because its
distance from Earth's surface makes it less visible and more difficult to
monitor than lower orbits, Caudill said.
The Angels
spacecraft would launch along with a yet-to-be-determined host satellite that
it would shadow in orbit, Caudill said. The launch likely will be arranged by
the Defense Department's Space Test Program, he said.
Caudill
said a full range of contractors, large and small, have expressed interest in
the Angels project. "The smaller firms are maybe a little more able to live
within the cost than the bigger ones, but even the big houses are looking
seriously at what they can do to make this work," he said.
Prospective
contractors will be given the chance to define much of the satellite's
capability, Caudill said. Those capabilities could include monitoring space
weather conditions, detecting anti-satellite weapons and diagnosing technical
problems with the host spacecraft, he said.
Bidders
must use relatively mature technology for the Angels program, Caudill said.
Individual component technologies must be proven by the time bids are submitted
in May 2007, and their ability to operate as part of an integrated system must
be demonstrated by December 2008, he said.
The Air
Force Research Laboratory's work on small orbit-rendezvous satellites such as
XSS-10 and XSS-11, as well as advances in component miniaturization, have
helped lay the groundwork for Angels, Caudill said.
Meanwhile,
the lab also is working on an experimental space-based optical telescope that
could monitor distant objects in space, according to the request for
information.
Caudill
said that effort is not as far along as Angels, but that the telescope would be
mounted on a significantly larger satellite, though one that is smaller than
most platforms used by the Air Force today.
Theresa
Hitchens, director of the Center for Defense Information, a think tank here,
said better space surveillance capabilities are urgently needed by the Air
Force.
"It needs
to be done and pronto," she said. Hitchens in the past has called for
improvements to U.S. space surveillance systems to help U.S. satellites avoid
collisions with other spacecraft as well as orbital debris.
But
Hitchens also sees potential problems with a mission in which one satellite
closely shadows another. If a spacecraft were to stray too far from its host it
could be viewed as a threat by other nations operating satellites in the area,
she said.
"If the
Chinese were doing this, you can bet that the U.S. Air Force would be
apoplectic," Hitchens said.
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