The Phoenix Mars Lander is currently undergoing final testing and assembly in preparation for its August 2007 launch. Spacecraft assembly is occurring at Lockheed Martin Space Systems in Littleton, Colorado. Integrating all the subsystems (e.g., thermal, electrical, mechanical, and communications) onto the lander's structure is the first step in the assembly process. Science instruments are then installed onto the lander deck and electrically integrated to the spacecraft. Software codes that operate these subsystems and instruments for remote operations are also integrated. Testing to ensure proper operation of all the subsystems, scientific instruments, and software occurs during this assembly step. Assembly and initial performance testing occurs from April to October 2006.

Engineers are assembling the Phoenix spacecraft at the Lockheed Martin Space Systems facility in Littleton, Colorado. In this image, the bottom of the spacecraft is easily seen, including the hexagonally shaped hazard avoidance radar and the spherical hydrazine fuel tanks. (Image Credit: NASA/LMSS)

From November 2006 through March 2007, the lander will be shaken, baked, frozen, zapped, and asphyxiated; to assure the entire system can survive its expected environmental conditions. Packaged into its protective capsule and bolted to a large speaker coil, Phoenix will be bombarded with strong sound vibrations simulating extreme launch stresses. The thermal and vacuum test will lay the spacecraft bare to a severe cold and airless environment similar to outer space. The spacecraft will be pelted with electromagnetic radiation to simulate the exposed conditions of outer space and the Martian surface where there is no atmosphere to protect the spacecraft from the Sun's energetics. Phoenix will also undergo a series of tests to ensure that the spacecraft properly transforms from rocket passenger to deep space traveler to Martian surface dweller. These include practice jettisons of the cruise solar panels, aeroshell, and capsule top, as well as deployments of the parachute, legs, and science instruments.

The flight descent thrusters, which are crucial to Phoenix safely landing on Mars, are being installed on the spacecraft. (Image Credit: NASA/LMSS)
While the spacecraft is being assembled in Colorado, a parallel test effort will be occurring at the Phoenix Science Operations (SOC) Center, Tucson, Arizona. The SOC houses the Payload Interoperability Testbed (PIT), a full mock up of the lander on the surface of Mars. The PIT will feature the ability to test the landed operation sequences for digging and sample delivery to the science instruments under many different types of soil compositions and densities (hard ice through loose sand). This will provide detailed data on the digging rate, energy, time, and amount of sample that can be expected in various soil conditions that can be encountered on the surface of Mars.

In May 2007, Phoenix will undergo final assembly and shipment to Kennedy Space Center. At the cape, the spacecraft will undergo its final checkout, explosives used to support jettisons will be loaded, and hydrazine propellant will be pumped into the fuel tanks. The spacecraft will then be mated to the upper stage of the Delta II launch vehicle ready to be launched in August 2007.