Radar tracking data gathered during the Delta II launch
of the MESSENGER spacecraft earlier this month has provided
promising results that may benefit NASA’s Space Shuttle
Program and Discovery’s Return to Flight.

A pair of radars installed at NASA’s Kennedy Space Center,
Fla., tracked the launch of the Delta II. They tracked
separation of the nine solid rocket boosters and jettison of
the first stage and the payload fairing, the “nose” of the
rocket that protected the MESSENGER spacecraft during launch.

“This test was quite successful for us in proving a concept,”
said NASA project manager Tony Griffith. “The use of high-
resolution wide-band and Doppler radars allows us to observe
almost any possible debris during ascent, and means we can
observe the Space Shuttle without regard to limitations of
visibility, cloud cover and darkness,” he added.

More importantly, the tandem radars “saw” — in significant
detail — normal Delta launch events, such as ice shedding
from the Delta first stage, ejection of the solid rocket
booster nozzle throat plugs, and contents of their exhaust.
For the Space Shuttle Program, the test showed that the
radars, working together, were effective in visualizing the
vehicle elements in high resolution and the ability to attain
speedy interpretation of the images for initial data analysis
after a Shuttle launch.

The antennas have been on loan to NASA from the USNS
Pathfinder, a U.S. Navy instrumentation ship. The 30-foot-
diameter C-band wide-band radar antenna and the smaller X-
band Doppler radar worked together to image the Delta in
flight. The Navy operated the radars for NASA during the
MESSENGER launch. NASA was responsible for analyzing the
imagery.

“This turned out to be a successful and mutually beneficial
partnership with the Navy that we will pursue,” Griffith
said.

Later this fall, a 50-foot-diameter C-band wide-band radar
will be installed on this site for a similar Return-to-Flight
application and for use by the Navy. The radar is being
relocated to KSC from the Roosevelt Roads Naval Station in
Puerto Rico.

The radars used for the test are being returned to the USNS
Pathfinder, though the C-band radar used in this test could
return as a backup for Return to Flight, if available from
the Navy. NASA is evaluating the procurement of two X-band
Doppler radars for use on ships downrange, including one of
the solid rocket booster retrieval ships.