CAPE CANAVERAL, Fla. – United Launch Alliance’s Atlas V rocket returned to action Friday after a close call three months ago, when its main engine quit firing six seconds too soon.
The early shutdown imperiled a launch of International Space Station supplies that reached orbit safely thanks to an extra minute of work by the rocket’s upper stage, News 6 partner Florida Today reported.
ULA fixed a valve problem that restricted fuel flow on that March 22 flight, leaving a significant amount unused.
The Atlas V rocket blasted off from Cape Canaveral Air Force Station’s Launch Complex 41 with a large, military communications satellite.
The 15,000-pound satellite, which was built by Lockheed Martin, will complete the space-based portion of the $7.7 billion MUOS program, which also includes four ground stations and software still being integrated with Army and Navy radios that will be deployed on the ground, at sea and in aircraft.
“This launch is a significant event for the entire MUOS team, because it will complete the five-satellite constellation,” said Navy Capt. Joe Kan, the program manager.
ULA and the Air Force would not discuss in detail the last Atlas V mission's engine issue, citing proprietary supplier information. They also would not say how close the launch came to failure.
They said investigation and testing resulted in a minor hardware change to the valve system that controls the mixture of kerosene fuel and liquid oxygen flowing through the Russian-made RD-180 engine.
“We’re very confident that we have the likely cause,” said Walt Lauderdale, the Air Force mission director. “Looking forward, we have high confidence for future missions.”
This launch had been planned for early May before the engine glitch occurred.
The fifth MUOS satellite, like the first four, will bolster a constellation of six older satellites providing a network critical to forces from every service who are on the move and working in difficult terrain, from mountains to forests to dense city streets.
The new constellation eventually promises to expand the network’s capacity by 10 times and to deliver smartphone-like features. Mobile troops will be able to make clearer calls while simultaneously sending emails, texts or mission data, even when the users are not located beneath the same satellite.
But those improvements, which may start to be rolled out later this year, won’t be widely available until user radios are ready and deployed over the next year or two.
For those advanced features, the satellite that is launching Friday will serve as a spare in case another MUOS spacecraft runs into trouble.
“If anything were to happen to one of the four satellites in orbit, we will be prepared to maintain coverage around the world,” said Kan.