WASHINGTON -- NASA's Ares 1 crew launch vehicle passed its preliminary design review Sept. 10, clearing the way for the detailed design work to begin on the two-stage rocket.

 

NASA has targeted March 2011 for completing an Ares 1 critical design review that sets the stage for manufacturing of the rocket to begin in earnest.

 

The Ares 1's intended payload, the Orion Crew Exploration Vehicle, remains months away from entering its detailed design phase. NASA recently announced that Orion's preliminary design review, previously planned for this fall, likely would be pushed off into next year.

 

The Ares preliminary design review highlighted several design challenges that still must be addressed, among them providing further assurance that Ares can fly through a variety of weather conditions and making sure the rocket's staging events will go off without a hitch.

 

Steve Cook, manager of the Ares program at NASA's Marshall Space Flight Center in Huntsville, Ala., said those issues would be addressed during the normal course of engineering.

 

NASA plans to hold a separate preliminary design review next summer to cement the technical solution it recently selected for a thrust oscillation problem Ares engineers have been wrestling with for the better part of the year.

 

NASA intends to outfit the rocket's aft skirt with so-called active reaction mass absorbers designed to muffle vibrations that might otherwise travel up the rocket and expose Orion's crew to unsafe levels of shaking on the space shuttle.