TheNorthrop Grumman and Boeing team competing to build NASA's new Crew ExplorationVehicle (CEV) unveiled a design Oct. 12 that echoesthe Apollo-like approach the agency adopted for its planned return to the Moon.
While theteam's CEV closely resembles the Apollo vehicle,Northrop and Boeing officials said they have made numerous modifications toincrease mission flexibility and safety as NASA gears up to replace the agingspace shuttle.
TheNorthrop/Boeing team is competing against Lockheed Martin to design and buildNASA's next-generation space vehicle, which is expected to transport astronautsto the international space station, the Moon and eventually Mars. NorthropGrumman officials estimate the winning team will need to construct three tofive CEVs in a year with different functionalitiesdepending on how frequently NASA wants to fly.
The agencyis expected to select a prime contractor by April 2006.
"To be safeand soon we have to go with proven methods," Doug Young, vice president ofspace systems at Northrop Grumman, said at an Oct. 12 news conference here,noting the capsule design to be one of the most reliable and safest for launchand re-entry.
TheNorthrop/Boeing team proposes using lightweight materials for the commandmodule to deliver twice the available interior volume Apollo astronauts had fortheir trips to the Moon. The new material will allow the 5.5-meter blunt bodycapsule to ferry as many as six passengers to the international space stationand take up to four astronauts to the Moon.
"The sizeand capacity of today's hardware will make this vehicle much different thanyour father's Apollo," said Leonard Nicholson, the CEVteam's deputy program manager. While there is more room for passengers and somecargo, Nicholson said the capsule will only weigh about 10 to 15 percent morethan Apollo because of the use of lightweight materials.
"It's avery large capsule, when you think about it, with a lot of capability," Youngsaid.
As outlinedin NASA's architecture plan, the Northrop/Boeing CEVis designed to launch into space atop a solid rocket booster like the onescurrently used to power the early phases of shuttle flights.
The designincludes a launch-abort system, a cylindrical structure that covers the top ofthe command module like an inverted funnel during liftoff. If all goessmoothly, the system will detach from the CEV oneminute into launch and burn up in the atmosphere. But in the case of anemergency, the system is equipped with a rocket engine that will ignite andpull the capsule away from the vehicle, either releasing the capsule toparachute back to Earth or taking it on to orbit if close enough to space. Fromthere, the capsule can plan normal re-entry operations.
Once inorbit for a Moon mission, the CEV would dock with thelunar lander and the Earth departure stage --- bothof which are planned to be launched prior to the CEVon a separate rocket --- then proceed to the Moon.
Their CEV module would have deployable solar arrays to gatherpower while traveling in space and would carry more fuel than Apollo, allowingastronauts to change orbit and land anywhere on the lunar surface rather thanbeing restricted by the positions of the Earth and the Moon as NASA was duringthe Apollo missions. "Now we can go to the polar areas of the Moon" when wecouldn't before, Nicholson said.
While thecrew is on the surface, the CEV will be able tooperate autonomously in lunar orbit while crew members on the surface remotelymonitor its status. The CEV could orbit the Moon forup to 180 days, Young said.
Once thecapsule returns to Earth, it is designed to touch down on land instead of inthe water like Apollo, but this process is still in the working stages,Nicholson said. Currently the team is working on developing parachutes todecelerate the vehicle, a small rocket to slow it down before impact,deployable airbags, and a crushable structure that can be installed on thebottom of the module to absorb the energy from landing.
The CEV also will have two-fault tolerant subsystems, Nicholsonsaid, which means the vehicle's critical components essentially will have twoback-ups. "On Apollo, there was only one-fault tolerance, so we had to starttalking abort right away" if a problem arose, he said.
While Youngwould not discuss cost estimates for the design, government and industrysources have said NASA's CEV is expected to cost $5.5billion to develop and the Crew Launch Vehicle another $3.2 billion. Flighttesting is expected to add another $2 billion to $3 billion to the price tag.
NASA hasbudgeted $1.8 billion for the CEV and Crew Launch Vehicledesign effort for 2006.
"Clearly,it's all going to come down to cost and getting those numbers down to a bareminimum that NASA is constricted by," Young said.