In a key experiment, the two American astronauts now circling the earth used a rendezvous radar system aboard their GT-5 spacecraft to track a radar transponder device at Cape Kennedy on Tuesday (24 August).
In a key experiment, the two American astronauts now circling the earth used a rendezvous radar system aboard their GT-5 spacecraft to track a radar transponder device at Cape Kennedy on Tuesday (24 August). In future flights, the transponder will be aboard an Agnea target rocket and will be vital to attempts at rendezvous.
The astronauts sent radar "queries" to the transponder device - located in the Kennedy spaceport on Merritt Island - and received answers. The capsule radar picked up the transponder when the capsule was 400 miles away, and continued in touch with it until it was 500 miles beyond.
The astronauts ejected a radar transponder satellite early in the GT-5 mission, but a planned attempt to rendezvous with it had to be cancelled, when the radar pod ran out of electrical power before the difficulties with the GT-5 fuel cells could be resolved. Tuesday's experiment was a partial replacement, and proved the ability of the spacecraft's onboard radar equipment to contact a transponder similar to those to be actually used in rendezvous attempts.
The transponder at Merritt Island is mounted on a simulated GT-5 capsule atop a small building full of radar equipment. The simulated capsule was maneuvered into various attitudes as part of the test.
A transponder is a device which will receive radar signals from the spacecraft, simplify them, and send them back. This exchange of signals permits the capsule's computer to locate the transponder precisely in space and assist the astronauts in guiding the capsule towards it.