– NASA wants the Orion Crew Exploration Vehicle to shed about 1,350 kilograms by the time it weighs in again this spring even though the spacecraft is still light enough to be lifted by its Ares 1 rocket.
Scott Horowitz, NASA’s associate administrator for exploration systems, told reporters during a Jan. 25 briefing here that the preliminary designs for Ares 1 show that the two-stage rocket has “more than sufficient performance” to put the 22,800-kilogram Orion spacecraft into orbit.
He acknowledged, however, that Orion’s six-person crew module gained some weight between September and December as Lockheed Martin Space Systems, the spacecraft’s Denver-based prime contractor, made some changes to its winning design – at NASA’s request. He said the design changes ate into an 3,600-kilogram-to-4,500-kilogram reserve NASA would like to keep largely intact at least until a formal preliminary design review slated for April 2008.
Horowitz said such weight growth is not unusual in the early stages of spacecraft design as engineers try to build as much margin into their systems as they can. “They’ve added things and the weight has grown, which is a normal process in many of these big projects.”
Orion nominally consists of a 9,525-kilogram crew module, a service module that weighs about 12,000-kilograms fully fueled, and a 500-kilogram spacecraft adapter that connects the stack to the Ares 1. Orion is also equipped with a powerful but heavy launch abort system designed to rapidly whisk the crew module away from the rocket in the event of an emergency. The launch abort system weighs over 6,000 kilograms, pushing Orion’s gross lift-off weight to over 28,000 kilograms – more than what Ares 1 can carry to orbit. But because the launch abort system is jettisoned well before Orion reaches orbit, Horowitz explained, it only contributes about 760 kilograms to Orion’s effective payload weight.
Horowitz said NASA’s Orion Project Manager Skip Hatfield is going back over the designs to find ways to get the crew module back down to 9,525 kilograms. Areas that might yield a good share of the desired weight savings include the capsule’s heat shields and avionics systems and even setting limits on how big individual crew members can be, he said.
Horowitz said NASA would keep a close eye on Orion’s weight as it goes through its next cycle of system-level design reviews this spring.
Meanwhile, NASA is gearing up to select the contractors that will help it develop the Ares 1 cryogenic upper stage. Marshall Space Flight Center released a draft request for proposal Jan. 4 for the Ares 1 upper stage production contract.
Doug Cooke, NASA deputy associate administrator for exploration systems, said a final request for proposals is due out Feb. 23 with a contract award expected later this year. Cooke said NASA also intends to release soon a draft solicitation for the Ares 1 avionics system. Cooke said NASA intends to keep both procurements on track despite the possibility that it will have to do so within a flat budget.
Congress is due to take up a joint spending resolution soon expected to fund most government agencies at their 2006 levels. For NASA, that would mean getting about $500 million less than it requested for 2007. NASA supporters in the House and Senate, however, plan to push a raise for NASA when the spending resolution moves through committee.
Horowitz declined to comment on the potential impact to his programs since the spending resolution was far from finalized. But he did say that keeping Ares and Orion on track are his top priorities.
“I have been told, and I agree, they are my primary objectives,” Horowitz said. “They get first bid.”