System tested on Delta Mercury probe launch last month will augment cameras to observe return to flight missions

NASA is adding to its ability to image and track the Space Shuttle on the return to flight (RTF) missions planned for next year. In addition to using two Martin WB-57 Canberras for airborne imaging of the ascent, to augment improved ground-based cameras, the space agency plans to use radar to detect and track any debris shed by the external tank.

A proof-of-concept test of ascent debris radar tracking was conducted during last month's Delta II launch of NASA's Messenger Mercury probe. A C-band wideband radar and X-band Doppler radar on loan from the US Navy tracked the launch vehicle to separation of its payload fairing and were able to see ice shedding from the first stage and ejection of the solid-rocket-booster nozzle throat plugs, says NASA.

A larger US Navy C-band radar will be relocated from Puerto Rico to Cape Canaveral this year to support the first RTF mission, still planned for launch in March-April next year, NASA is also evaluating the procurement of two X-band radars for installation on ships down-range of the Shuttle launch site.

The radars, like the WB-57s, will be used experimentally during the two RTF missions, STS 114/Discovery and STS 121/Atlantis, before NASA decides whether to use them for all remaining Shuttle flights. Reliance on ground-based optical imaging limits NASA to daylight launches. "Our expectation and hope is that [the radars] will allow a return to night operations later," says Bill Readdy, associate administrator for space operations.

The NASA-operated WB-57s will be equipped with a nose-mounted ball turret housing high-definition television and infrared cameras. Flying at 60,000ft (18,000m), the aircraft will be able to image the Shuttle ascent over a 650km (400 miles) track. A Lockheed Martin P-3 will be used to image the orbiter's re-entry.


Source: Flight International