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Chandra X-ray ObservatorySaturday, July 24 1999 10:00 p.m. EDT
Media Relations Department
Marshall Space Flight Center
Spontaneous applause erupted in the Chandra X-ray Observatory Operations Control Center in Cambridge, Mass. at 9:16 p.m. EDT this evening as the observatory successfully completed the first firing of its Integral Propulsion System to begin raising its orbit.
The flight operations team commanded the observatory's liquid apogee engines to ignite at 9:11 p.m. EDT over the Atlantic Ocean off the coast of northwest Africa.
"The observatory has taken its first steps under its own power," said Craig Staresinich, TRW Chandra Program Manager from the control center. "Initial indications are that the burn went flawlessly," Staresinich reported.
The five-minute burn, adjusted the perigee or low point of Chandra's orbit upward by about 544 miles. Four more firings of the system's engines are planned over the next several days to place Chandra in its final operational orbit.
The firing was performed by a redundant set of two 105-pound-thrust liquid apogee engines, the highest performing space-qualified engines of this type in the industry. The engines are fueled by hydrazine and nitrogen tetroxide.
Chandra's new perigee is approximately 750 miles (1,200 kilometers) and its apogee is about 45,014 miles (72,023 kilometers). The observatory's new orbit is 24 hours, 38 minutes in duration, slightly longer than its earlier orbit of 24 hours, 17 minutes. The spacecraft velocity at perigee is now about 22,000 miles per hour (9.8 kilometers per second.)
Following the Integral Propulsion System burn sequence the Flight Operations Team began preparations for the activation of the observatory's Electron Proton Helium instrument, a radiation detection device.
Editor's Note: NASA's Marshall Space Flight Center in Huntsville, Ala., manages the Chandra X-ray Observatory for NASA's Office of Space Science, NASA Headquarters, Washington, D.C. The Smithsonian Astrophysical Observatory in Cambridge, Mass., manages the Chandra science program and controls the observatory for NASA. TRW Space and Electronics Group of Redondo Beach, Calif., leads the contractor team that built Chandra.