A View from Brittany Sauser
Analyzing the Flight of Ares I-X
NASA reports on the performance of its historic test flight rocket, including why the parachutes failed.
In late October NASA conducted the first test flight of its next-generation rocket, Ares. In a press conference at Johnson Space Center (JSC) in Houston this afternoon, project managers and engineers reported their preliminary findings.
The flight was successful in many ways, said Bob Ess, project manager of Ares I-X. For instance, it demonstrated the viability of the guidance, navigation and control systems. “The algorithms were perfect and performed flawlessly; a key result for validating our [predictive] models.”
Marshall Smith, manager of systems engineering and integration for the rocket, added that Ares I-X, the tallest rocket ever to be flown, shows that “[NASA] can push forward with the design of Ares I.”
The rocket’s flight lasted–from liftoff to splash down–approximately six minutes, enough time for engineers to gather data on the performance of the rocket’s avionic systems, accelerations and vibrations experienced, roll torque and thrust oscillation, as well as the separation of its stages.
One key problem during the flight was the malfunction of the parachutes designed to carry the rockets solid rocket booster back to earth. At an altitude of 45 kilometers the rocket’s two stages separated. The first stage, composed of four solid rocket boosters and a dummy fifth segment, were dropped into the Atlantic Ocean via three large parachutes. (The mock second stage broke apart and was not recovered.) But the main parachute failed and a second parachute partially failed causing the booster to splash down hard into the ocean, leaving a nice dent in its side.
The main parachute failed at inflation, said Smith. The parachutes are supposed to open in three stages, and at each stage there is a cable that keeps the chutes from opening too far. The engineers believe that one of the cables opened too far putting too much force on the lines causing them to shear. The engineers are still investigating the partial failure of the second chute. They plan to give two more Ares I-X performance reports–one in January and the other late February 2010.
The engineers now want to do additional tests flights in 2012 or 2013. “Each time we can make it more like Ares I, so the next [test rocket] will have a full five segment solid rocket booster,” said Jon Cowart, deputy project manager. But any future test flights will be contingent on the Obama administration’s decision on the future of human spaceflight.
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