NASA - National Aeronautics and Space Administration

Just as NASA's Mars rovers, Spirit and Opportunity, captured the imagination of old and young alike as they explored the Martian surface, a new space explorer is waiting in the wings to take center stage: the Mars lander called Phoenix.

Set for launch in August aboard a Delta II rocket, Phoenix's assignment is to dig through the Martian soil in the arctic region where water and ice exist and then use its onboard scientific instruments to analyze the samples it retrieves. Phoenix will look not only for water, but also for any signs that some form of life does or could exist.

Image at Left: The spacecraft undergoes illumination testing of its solar arrays in a clean room after arriving at NASA's Kennedy Space Center in Florida. Image credit: NASA/Kim Shiflett

As the Delta rocket is being assembled at Launch Pad 17A at Cape Canaveral Air Force Station in Florida, the Phoenix spacecraft is in an environmentally controlled "clean room" at the nearby Kennedy Space Center, where it's undergoing the final checks and preparations before being moved to the launch pad. It was delivered to the space center from Colorado, where it was built and extensively tested by Lockheed Martin Space Systems.

"We have, in essence, two vehicles that we have to verify," says Ed Sedivy, Phoenix program manager for Lockheed Martin. "There is the vehicle that gets us there and then there's the vehicle we operate on the surface of the planet. That's something that is unique about a lander."

Since the spacecraft's arrival at Kennedy, technicians have completed an illumination check of the solar arrays, and are continuing to perform other preflight tests and install final components like the descent parachute, flight radar and heat shield.

Once Phoenix is encapsulated in the third-stage fairing, the spacecraft will move to the launch pad in a protective canister and be hoisted atop the rocket about two weeks before liftoff. But the marriage between spacecraft and launch vehicle actually begins years before a mission is scheduled.

Image at Right: On Launch Pad 17-A at Cape Canaveral Air Force Station in Florida, a third solid rocket booster is raised from its transporter before being lifted into the mobile service tower. The booster is one of nine that will be attached to the Delta II rocket's first stage (background) to power the Phoenix launch. Image credit: NASA/Kim Shiflett

"Usually about three to five years before launch, we work with the spacecraft project, Lockheed in this case, to make sure the spacecraft design is compliant with the launch vehicle that the mission is going to launch on," says Ron Mueller, mission manager for Phoenix launch integration.

This will be the 326th flight of a Delta rocket, which also was the launch vehicle that carried the two Mars rovers on the first leg of their voyage.

The cruise phase of the journey to the red planet will take more than nine months. Once the spacecraft reaches its destination, landing isn't an easy task, employing both a parachute to first slow the vehicle, and hydrazine-powered engines on the underside to control the speed of the final descent to the surface.
+View artist's conception of Phoenix's descent to Mars (NASA-JPL/Corby Waste)

As the spacecraft hurls through the Martian atmosphere, the parachute is deployed by a mortar and slows the rate of descent from supersonic to subsonic. "We then drop down using propulsive engines," explains Barry Goldsetin, Phoenix project manager at NASA's Jet Propulsion Laboratory in California. "That takes us from 120 miles per hour to 5 miles per hour at touchdown."

Image at Left: With the spacecraft visible behind him in the clean room, Phoenix Program Manager Barry Goldstein briefs the news media. Image credit: NASA/Kim Shiflett

Once on the surface, the lander will wait about 30 minutes, allowing the dust kicked up by the landing to settle, before deploying its two circular solar arrays, robotic arm, weather mast and camera.
+View artist's conception of Phoenix working on Mars (NASA-JPL/Corby Waste)

Phoenix's scientific work will be directed by a group from the University of Arizona, led by Principal Investigator Peter Smith. What discoveries NASA and Smith's team will uncover is hard to predict but, once again, the mysteries of the red planet have the potential to captivate an Earth-bound audience.

Cheryl L. Mansfield
NASA's John F. Kennedy Space Center