Ares I-X Engineers Discuss Flight Test Results
The Ares I-X flight test in 2009 met all its primary goals and provided a solid foundation for future rockets, the engineers who designed the rocket and oversaw the launch said during a recent presentation at NASA's Kennedy Space Center in Florida.
"The rocket just performed beautifully," Deputy Mission Manager Jon Cowart told a group that included engineers who will be counted on to develop future launch vehicles. "Certainly one of the coolest things I have done," he said.
Although the Ares I-X comprised a four-segment solid rocket booster as a first stage and was topped with a dummy fifth segment and upper stage, the results showed the design is solid, Ares I-X officials said.
"It wasn't just good for designing an Ares rocket," Cowart said, "it was good for designing rockets in general."
The launch on Oct. 28, 2009, from Kennedy's Launch Pad 39B answered a great deal of fundamental questions about the rocket's performance and aerodynamic design. For example, Chris Calfee of Marshall Space Flight Center said the telemetry gave engineers a good look at the thrust oscillations the booster would experience during ascent. Calfee served as the first stage Integrated Product Team leader for the Ares I-X.
"We're confident that's not the problem we first thought it would be," he said.
The rocket was lined with more than 700 sensors that gave engineers enough data to compare with predictions made by computer models.
Marshall Smith, chief of systems integration office for Ares I-X at Langley Research Center, said most of the flight results lined up easily with the computer forecasts, including heating predictions that were within three degrees of the actual temperatures. The results give engineers and designers more confidence to use the models in future rockets and show them where to polish the models.
While the I-X team looked over the data from the flight test for weeks, Cowart admitted slight nervousness on launch day because of a maneuver planned to tip the 327-foot-long rocket slightly away from the fixed service structure at the launch pad.
"We all knew that it was going to do that fly-away maneuver, but when that thing comes off the deck and that thing started to tilt . . . I just didn't think it was ever going to stop tilting," Cowart told the group, laughing throughout. "As soon as it flew away, stopped tilting, no one was happier."
The flight's only flaw came after the first stage burned through its fuel and separated from the dummy upper stage. One of the three main parachutes collapsed entirely during the fall to the ocean and a second partially collapsed, most likely because the device that cuts the reefing lines activated earlier than planned.
With 3 ½ years from concept to launch, Cowart held up the flight test as an example of quickly working through designs and building the rocket with a great deal of existing technology, such as the avionics of the Atlas V rocket.
With the I-X experience to draw on, the engineers said future rockets can incorporate a number of policies, techniques and models to move ahead quickly from a concept to an operational launcher.
"We helped rocket science in general," Smith said.
Steven Siceloff, Kennedy Space Center