Boys on Orion spaceship might be beached if bad vibrations not fixed on Ares

William Atkins
Wednesday, 09 April 2008 04:54

Science - Space

One fix to the problem is to counteract the vibrations using “tuned mass dampers” placed in the parachute region (between the Ares I first stage and the Orion space capsule) or in the aft skirt of the Ares I first stage.

These dampers generally consist of masses on spring devices that cancel out the spacecraft’s natural oscillations by moving in the opposite direction.

A second possible fix is to change the natural frequency of the crew launch vehicle (Ares I) so that it does not match the frequency of the solid rocket motor when it fires.

This change could be made so that the weight of the spacecraft is changed or the structure of the spacecraft is made less stiff (so it can tolerate the vibration better) or more stiff (so that it can resist the vibration more efficiently).

Announced on Thursday, April 3, 2008, NASA also is looking into the possibility of adding shock absorbers to (possibly) the top of the Ares’ first stage and (possibly) to the bottom of the rocket.

Shock absorbers could also be added to the astronauts’ seats so that the shaking force from the SRB on their bodies would be dampened and, thus, allow the astronauts to perform necessary activities during launch phase.

The forces of gravity (G) felt by the Orion astronauts during the first few minutes of powered flight is estimated to be much greater than what NASA woul like them to experience. NASA would like the astronauts to experiences G forces close to the forces felt by Gemini and Apollo astronauts in the 1960s and 1970s.

Later in 2008, a Preliminary Design Review (PDR) meeting will be conducted for the Ares I project by NASA officials. Further analysis will be conducted between now and then so, at this PDR meeting, NASA will have a better idea on how to deal with this perceived problem.