Mission to make solar flicks postponed

A drawing of HESSI

(CNN) -- NASA has again postponed the launch of a spacecraft designed to make movies of solar flares.

There is no problem with the High Energy Solar Spectroscopic Imager, or HESSI, according to Susan Hendrix, a spokeswoman for the Goddard Space Flight Center. But the launch has been delayed indefinitely because of ongoing concerns about the satellite's launch vehicle -- a Pegasus rocket.

A similar Pegasus rocket is blamed for dooming the test flight earlier this month of NASA's X-43A, an experimental plane designed to attain speeds as high as Mach 10.

Moments after the X-43A and its Pegasus booster rocket were released from the wing of a carrier aircraft, the combo went off course and was deliberately blown up. The debris fell into the Pacific off the coast of California.

The investigation into the test flight mishap still is in the works, so NASA is holding off on the $85 million HESSI mission, Hendrix told CNN.com on Tuesday.

Instead, she said the spacecraft will be loaded onto the Stargazer, a modified Lockheed L-1011, and ferried from its Cape Canaveral, Florida, launch site to Vandenberg Air Force Base in California within the next few days to have its battery replaced.

When HESSI is launched, the Stargazer will fly it out of Cape Canaveral Air Force Station to a height of about 39,000 feet over the Atlantic. The spacecraft and its Pegasus rocket will be dropped from the plane and the Pegasus then will boost HESSI to a circular orbit 373 miles (600 kilometers) above the Earth.

The satellite is equipped with an imaging spectrometer that can create X-ray and gamma ray movies of solar flares, which can disrupt communications and equipment on Earth. HESSI has a new kind of X-ray vision that will create the first high-fidelity color movies of solar flares in their highest energy emissions, according to NASA.

HESSI will join a team other solar observing satellites including SOHO, the Solar and Heliospheric Observatory; GOES, the Geostationary Operational Environmental Satellite; TRACE, the Transitional Regional and Coronal Explorer; and ACE, the Advanced Composition Explorer.

The HESSI mission is expected to last two to three years.

HESSI previously was set to launch last July but suffered damage during testing in March.