Alex Zaharov-Reutt
Sunday, 25 May 2008 15:05
Science -
Space
Page 2 of 3
According to the Phoenix Mars Mission website, we are now in stage four of the mission, entitled “
Entry, Descent and Landing”.
The Phoenix website explains:
“At 125 km (78 miles) above the surface, Phoenix will enter the thin martian atmosphere. It will slow itself down by using friction. A heat shield will protect the lander from the extreme temperatures generated during entry. Antennas located on the back of the shell which encases the lander will be used to communicate with one of three spacecraft currently orbiting Mars. These orbiters will then relay signals and landing info to Earth.”
“After the lander has decelerated to Mach 1.7 (1.7 times the speed of sound), the parachute is deployed. Shortly after the parachute is deployed, the heat shield is jettisoned, the landing radar is activated, and the lander legs are extended.”
“The lander continues through the Martian atmosphere until it comes within 1 km (.6 miles) of the Martian surface. At this point, the lander separates itself from the parachute. It then throttles up its landing thrusters and decelerates.”
“When Phoenix is either at an altitude of 12 m (39 ft) or traveling at 2.4 m/s (7.9 ft/s), the spacecraft begins traveling at a constant velocity. The landing engines are turned off when sensors located on the footpads of the lander detect touchdown.”
Once the lander successfully touches down on Mars – due to happen within 15 hours – the
5th stage of the mission can begin.
The site explains that:
“Surface operations are planned in relation to martian days, which are known as sols. Because Mars rotates slightly slower than Earth, sol is 40 minutes longer than our planet's 24-hour day. A strategic plan is created that outlines operations two weeks into the future.”
“This strategic plan is used to create a more detailed tactical plan which decides surface activities that will take place for the next two sols. Daily science and engineering data is used to assess the status of the strategic and tactical plans, and the plans are updated as necessary.”
“Immediately after Phoenix touches down on the surface of Mars (sol 0), critical instruments such as the solar arrays and SSI mast are deployed. Later in the afternoon of sol 0, EDL data and MARDI images are sent to Earth. On sol 1, TEGA, MECA and RAC are turned on and checked out, and the RA is deployed. SSI begins taking images of the landing site and the area where the robotic arm will be digging, and MET begins to sample the weather at the landing site.”
See the Phoenix site for details on all the
acronyms used above, all of which are suitably linked.
Please read on to page 3 for final details of the mission on Mars once the landing is complete.
