From the outside, NASA's
next-generation spacecraft Orion looks a lot like the Apollo spaceship that
first took humans to the moon.
Both are rounded cone-shaped
capsules, in contrast to the winged space shuttle. But in some ways, the
similarities are only skin-deep.
"Visually we are like Apollo,
but in terms of state of the art engineering, we are closer to shuttle,"
said Jim Geffre, a NASA engineer working on Orion, which the agency has tapped
to replace its aging space shuttle fleet. "So the reality is we've drawn
on a lot of different sources for inspiration."
One of the biggest differences
between the Orion
Crew Exploration Vehicle and the Apollo Command Module is the electronics
inside them.
"The computing power of modern
electronics just dwarfs what they had available," Geffre told SPACE.com.
"That allows us to do a lot more and build more automation into the
spacecraft. More performance that uses less power and less space allows us to
build in redundancy that Apollo didn't have."
NASA plans to retire its three space
shuttles in 2010 and begin the first operational Orion flights no earlier than
2015.
Roomy moonship
Another major distinction between the two crew
capsules is their size. Orion outstrips the Apollo module, which was only 12.8
feet (about 4 meters) in diameter, compared to Orion's 16.5 feet (5 meters).
That extra room will enable the
future spacecraft to carry more people to space. Where Apollo transported three
astronauts to the moon - one stayed in orbit while two went down to the surface
- Orion will carry four spaceflyers who will each be
able to descend to the moon.
Both the Apollo and Orion spacecraft
rely on separate lunar landers to ferry moonwalkers to the lunar surface.
The Apollo Lunar Module was launched
along with its Command and Service Module aboard a massive Saturn V rocket. The
future lunar vehicle, called Altair, is planned to be launched separately from
Orion atop an Ares V booster, while the crew capsule will fly on the smaller
Ares I rocket. The two new vehicles will rendezvous in low-Earth orbit and
travel on
to the moon together.
Some design changes have been made
to Orion to enable lengthier lunar excursions. While the longest Apollo visit
to the moon lasted about 72 hours, future moon trips are planned to last days
and even months. That means more supplies must be packed aboard the spacecraft.
"Orion will be more capable in
terms of what it can carry - more food, air and water," said John Olson,
director of NASA's Exploration Systems Mission Directorate Integration office.
"It is going to have updated environmental control and life support
systems."
One spaceship, different stops
Orion and Altair are designed to be more
versatile than the Apollo program's craft, which were built for one
purpose: to land on the moon and carry astronauts home.
"Orion is going to enable all
kinds of exciting missions," Olson said in a phone interview. "This
is our crew exploration vehicle. It'll get us to the space station, the moon
and back, and start building toward the missions to Mars."
But packing extra supplies aboard
Orion for extended trips means a lot of extra weight, which is difficult and
expensive to loft into space. A major challenge for the engineers developing
Orion is coming up with creative ways to keep the weight of the spacecraft low.
One way scientists plan to meet the
weight requirements is to construct Orion out of new, state-of-the art
materials. NASA plans to utilize many new composite materials, such as an
aluminum-lithium alloy, as well as modern lightweight titanium, to build the
craft.
The scientists working to plan NASA's
future on the moon are mindful of the need for modern technology and
improvements, though they recognize the debt they owe to earlier Apollo
engineers.
"Apollo I think was right for
its time," Geffre said. "It met its mission very well. But electronics,
materials, the costs of Apollo, those are all things that time and technology
have wanted us to improve upon. We are taking advantage of all the effort that
was put into designing that vehicle. Where it's appropriate and we can learn
lessons or incorporate similar design techniques, we are trying to do that. But
in other cases where we do want to improve upon it, we do that as well."
Forty years after astronauts first
set foot on the moon, SPACE.com examines what wešve done since and whether
America has the right stuff to get back to the moon by 2020 and reach beyond.
For exclusive interviews and analysis, visit SPACE.com daily through July 20,
the anniversary of the historic landing.
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