The Northrop Grumman and Boeing team competing to build NASA's new Crew Exploration Vehicle (CEV) unveiled a design Oct. 12 that echoes the Apollo-like approach the agency adopted for its planned return to the Moon.

While the team's CEV closely resembles the Apollo vehicle, Northrop and Boeing officials said they have made numerous modifications to increase mission flexibility and safety as NASA gears up to replace the aging space shuttle.

The Northrop/Boeing team is competing against Lockheed Martin to design and build NASA's next-generation space vehicle, which is expected to transport astronauts to the international space station, the Moon and eventually Mars. Northrop Grumman officials estimate the winning team will need to construct three to five CEVs in a year with different functionalities depending on how frequently NASA wants to fly.

The agency is expected to select a prime contractor by April 2006.

"To be safe and soon we have to go with proven methods," Doug Young, vice president of space 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 launch and re-entry.

The Northrop/Boeing team proposes using lightweight materials for the command module to deliver twice the available interior volume Apollo astronauts had for their trips to the Moon. The new material will allow the 5.5-meter blunt body capsule to ferry as many as six passengers to the international space station and take up to four astronauts to the Moon.

"The size and capacity of today's hardware will make this vehicle much different than your father's Apollo," said Leonard Nicholson, the CEV team's deputy program manager. While there is more room for passengers and some cargo, Nicholson said the capsule will only weigh about 10 to 15 percent more than Apollo because of the use of lightweight materials.

"It's a very large capsule, when you think about it, with a lot of capability," Young said.

As outlined in NASA's architecture plan, the Northrop/Boeing CEV is designed to launch into space atop a solid rocket booster like the ones currently used to power the early phases of shuttle flights.

The design includes a launch-abort system, a cylindrical structure that covers the top of the command module like an inverted funnel during liftoff. If all goes smoothly, the system will detach from the CEV one minute into launch and burn up in the atmosphere. But in the case of an emergency, the system is equipped with a rocket engine that will ignite and pull the capsule away from the vehicle, either releasing the capsule to parachute back to Earth or taking it on to orbit if close enough to space. From there, the capsule can plan normal re-entry operations.

Once in orbit for a Moon mission, the CEV would dock with the lunar lander and the Earth departure stage --- both of which are planned to be launched prior to the CEV on a separate rocket --- then proceed to the Moon.

Their CEV module would have deployable solar arrays to gather power while traveling in space and would carry more fuel than Apollo, allowing astronauts to change orbit and land anywhere on the lunar surface rather than being restricted by the positions of the Earth and the Moon as NASA was during the Apollo missions. "Now we can go to the polar areas of the Moon" when we couldn't before, Nicholson said.

While the crew is on the surface, the CEV will be able to operate autonomously in lunar orbit while crew members on the surface remotely monitor its status. The CEV could orbit the Moon for up to 180 days, Young said.

Once the capsule returns to Earth, it is designed to touch down on land instead of in the water like Apollo, but this process is still in the working stages, Nicholson said. Currently the team is working on developing parachutes to decelerate the vehicle, a small rocket to slow it down before impact, deployable airbags, and a crushable structure that can be installed on the bottom of the module to absorb the energy from landing.

The CEV also will have two-fault tolerant subsystems, Nicholson said, which means the vehicle's critical components essentially will have two back-ups. "On Apollo, there was only one-fault tolerance, so we had to start talking abort right away" if a problem arose, he said.

While Young would not discuss cost estimates for the design, government and industry sources have said NASA's CEV is expected to cost $5.5 billion to develop and the Crew Launch Vehicle another $3.2 billion. Flight testing is expected to add another $2 billion to $3 billion to the price tag.

NASA has budgeted $1.8 billion for the CEV and Crew Launch Vehicle design effort for 2006.

"Clearly, it's all going to come down to cost and getting those numbers down to a bare minimum that NASA is constricted by," Young said.