Proton's return-to-flight mission set for launch Sunday
BY STEPHEN CLARK
Posted: September 28, 2013
A Russian Proton rocket is poised for flight on the steppes of Kazakhstan, ready to blast off Sunday on the heavy-lift launcher's first mission since a July 2 failure moments after leaving the launch pad.
Rollout of the Proton rocket with ASTRA 2E. Credit: Roscosmos
The return-to-flight mission is managed by International Launch Services, the U.S.-based firm responsible for commercial sales of Proton rocket flights.
Russian investigators blamed the fiery mishap on improperly installed yaw angular rate sensors, which feed attitude data to the Proton rocket's guidance system. Evidence from debris recovered near the Proton's impact crater, located less than 2 miles from the launch pad, showed technicians installed the sensors upside down.
The sensors fed bad information to the Proton's computers, and the 19-story booster almost immediately flew off course moments after liftoff July 2. It gyrated wildly as it ascended from the launch pad, then tilted over and broke apart before exploding in a fireball upon impact with the ground at the Baikonur Cosmodrome in Kazakhstan.
The accident destroyed three Russian Glonass navigation satellites. Russian media reported the mission was insured for about $200 million.
Officials ordered a design change to prevent the sensors from being installed down on future missions. A review board also recommended the Proton's prime contractor - Khrunichev State Research and Production Space Center - improve quality control measures in its factory.
The successful resumption of Proton flights will be good news to satellite operators waiting to launch payloads. After the launch of ASTRA 2E, ILS plans the launch of a new satellite for Sirius XM Radio and the launch of the Inmarsat 5 F1 spacecraft to inaugurate the London-based firm's Global Xpress service, which promises to deliver mobile users with broadband connectivity of up to 50 megabits per second.
ASTRA 2E was already at the Baikonur Cosmodrome when the July 2 failure occurred, and officials suspended launch preparations while investigators probed the mishap.
The 13,271-pound spacecraft, built by Astrium Satellites in France and based on the Eurostar E3000 platform, is designed to beam next-generation broadcast, direct-to-home and broadband services over Europe, the Middle East and Africa for a 15-year mission. It carries 60 Ku-band and four wideband Ka-band transponders to do the job.
The Proton's three core hydrazine-fueled stages will boost ASTRA 2E and a Breeze M upper stage on a suborbital trajectory in less than 10 minutes, then the Breeze M's main engine will fire five times over the next 9 hours to raise its orbit and position ASTRA 2E for deployment.
The mission is targeting an orbit with a high point of 22,205 miles, a low point of 2,611 miles and an inclination of 23 degrees.
ASTRA 2E's on-board propulsion system will finish the task of placing the satellite into a circular 22,300-mile-high orbit over the equator, and ultimately an operating post at 28.2 degrees east longitude.