Posted on by Nancy Atkinson

NASA May Drop Ares I-Y Test Flight

Artist concept of Ares I. Image Credit: NASA

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Just one week after the first test flight test of the Ares I-X rocket, NASA says it may decide to cancel a follow-up launch called Ares 1-Y, which wasn’t scheduled until 2014. Reportedly, program managers recommended dropping the flight because, currently, there isn’t the funding to get an upper stage engine ready in time. The test flight may be replaced with a new, still undefined test flight in 2012 or 2013. “It simply does not fit where we are headed,” said Jeff Hanley, Constellation Program manager was quoted in NASA’s Constellation Blog. “The test vehicle was intended to meet evolving needs but the current configuration is too different from what the program requires to certify the Ares/Orion vehicle systems.”

Depending on whether the Obama administration decides to continue the Ares I program, this decision may be moot. Earlier this week Sen. Bill Nelson said Obama may make a decision on NASA’s future path, based on the report by the Augustine Commission, by the end of November.

At a press conference last week Hanley said the team continually assesses their flight test program. This week managers met and decided that the Ares I-Y flight fell too late in the vehicle development phase to provide useful information and lacks key elements to make it a true validation of the flight vehicle’s systems.

Originally, the I-Y test was planned for 2012. It was to be a suborbital flight to test a five-segment booster, a flight production upper stage, a functional command module and launch abort system and a simulated encapsulated service module, but without a J-2X engine.

By fall 2008, program managers were already looking at changing direction for the Ares I-Y test to improve the overall program’s chances of flying a full test vehicle by 2014. Now, with the Constellation Program nearing its preliminary design review and with maturing vehicles and systems, managers agree the I-Y test objectives can be achieved through other tests already in the manifest.

NASA is now studying the costs and benefits of going ahead with a 2012 launch previously called “Ares I-X prime” that would flight-test a full five-segment Ares I solid-fuel first stage and the Orion crew exploration vehicle launch abort system at high altitude.

Stay tuned.

Sources: NASA Constellation Blog, Aviation Week

Posted on by Nancy Atkinson

Ares I-X Fully Stacked

Ares I-X in the VAB. Credit: NASA

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For the first time in more than a quarter-century, a new space vehicle stands ready in NASA’s Vehicle Assembly Building. But will it fly without violent vibrations, and what verdict will the Augustine Commission give the Constellation program? Only time will tell, but for now the Ares I-X is at its fully assembled height of 100 meters (327 feet) and is one of the largest rockets ever put together in the VAB’s High Bay 3. Ares I-X rivals the height of the Apollo Program’s 364-foot-tall Saturn V. The Ares I-X flight test currently is targeted for Oct. 31. Ares I-X consists of a four-segment first stage solid rocket motor, and a simulated upper stage that represents the weight and shape of the Ares 1 rocket and Orion crew vehicle. It will be launched in a suborbital arc into the Atlantic to collect data on its flight dynamics and parachute recovery performance.

The flight of the unpiloted Ares I-X will be an important step in confirming that the rocket design is safe and stable in flight before piloted flights of Ares I begin in the middle of the next decade.

But — even before the launch of Ares I-X — a critical series of ground tests will take place to confirm that the vehicle’s dynamic response will respond to launch loads and vibrations the way that computer analytical models have predicted it will respond.

“While we are confident in the predicted model results and simulations, these ground tests are critical because we have no experience launching rockets as long and slender as Ares I-X,” according to Paul Bartolotta, Ares I-X Modal Test Lead who is responsible for leading a NASA-wide Modal Test Team from his office at NASA’s Glenn Research Center, Cleveland, Ohio.

Saturn V, Ares I-X and Delta IV. Credit: NASA
Saturn V, Ares I-X and Delta IV. Credit: NASA

With its height and average diameter of approximately 4 meters (14 feet), Ares I-X has a high “slenderness ratio” compared to other launch vehicles. The similarly-shaped Delta IV, for instance, is about 5.2 meters (17 feet) in average diameter and 69 meters (225 feet) long. The Saturn V was about 10 meters (33 feet) in average diameter and 111 (363 feet) in length.

Due to its long slender shape, the Ares I-X is unique from a flight dynamics standpoint.

“We’re going to be shaking the vehicle to make sure our structural models match the actual vehicle characteristics,” said Kurt Detweiler, Ares I-X Lead Systems Engineer, based at NASA Langley. “This is important for determining how the vehicle will respond during flight. If the vehicle doesn’t match the analytical model, its guidance, navigation and control systems will be off,” he added.

A series of sensors strategically located throughout the stacks will measure the amount and direction of movement, as the shakers impose random loads to determine the rocket segment’s first several bending modes. A comparison will be made between predicted and measured mode shapes to verify the Ares I-X flight dynamics model.

Sources: NASA on Facebook, NASA