Crews begin assembling next commercial Atlas 5 rocket
BY JUSTIN RAY
Posted: March 2, 2006
Another Atlas 5 launch campaign has commenced at Cape Canaveral for a commercial satellite deployment mission slated for blastoff April 20.
One Aerojet strap-on solid rocket booster will be added to the side of the first stage on Friday. The white motor is packed with solid propellant to give the Atlas 5 extra thrust for the first minute-and-a-half of flight.
The Centaur upper stage is scheduled to be mounted atop the rocket next week. The single Pratt & Whitney-built RL10 engine is fed with cryogenic liquid hydrogen and liquid oxygen.
It will be the eighth flight of Atlas 5 but the first to employ the 411 vehicle configuration distinguished by with four-meter nose cone, one solid booster and one Centaur engine. Previous Atlas 5 missions has used either multiple strap-on solids or none; a cargo's weight dictates the number of boosters needed.
The payload for this mission is the ASTRA 1KR direct-to-home television broadcast satellite that will serve millions of homes across Europe from geostationary orbit 22,300 miles above the planet.
Built by Lockheed Martin, the spacecraft will arrive at the Cape later this month for final testing and fueling at the Astrotech processing facility in Titusville. The rocket's two-piece nose cone will be slid around the satellite before being moved to the Vertical Integration Facility for mating with the Atlas 5 in early April.
The fully assembled Atlas 5 will roll to the launch pad on its 1.4-million pound mobile platform the day prior to liftoff.
The ASTRA system, operated by SES ASTRA of Betzdorf, Luxembourg, includes over a dozen satellites relaying more than 1,400 TV and radio channels to 103 million households.
ASTRA 1KR will join the seven satellites co-positioned at the system's prime orbital slot at 19.2 degrees East longitude to operate as a replacement spacecraft.
Launch on April 20 is targeted for 4:27 p.m. EDT (2027 GMT). The day's window to get the rocket airborne extends almost three hours to 7:16 p.m. EDT (2316 GMT).
The mission is managed by International Launch Services -- the joint U.S.-Russian venture that markets Atlas and Proton rockets.
"It is the first time that SES ASTRA has chosen an Atlas rocket for the launch of a new satellite," Martin Halliwell, the company's chief technology officer, said in announcing the launch order in December. "Thanks to the great experience that other SES companies have had with Atlas and our own long term relationship with the ILS team, we are confident that the launch of ASTRA 1KR will be successful."