Mars group > Research > Missions > Phoenix > CalTarget/iSweep

The combined CalTarget and iSweep experiment

iSweep

The improved sensitivity sweep magnet experiment (iSweep) is an improved version of the sweep magnet experiment on the Mars Exploration Rovers. The iSweep experiment has enhanced sensitivity to detect non-magnetic dust particles in the Martian atmosphere if they exist.

The sweep magnet on the rovers was designed to allow only non-magnetic particles to settle in the center and (essentially) no particles have been detected there for the entire mission. 

The Phoenix lander carries three identical iSweep experiments placed on different locations on the lander deck and each consisting of six identical sweep magnets covered with silicone chips of different colors.
The different contrasts provided by the various background colors enhance the ability to detect any non-magnetic particles that might settle in the center of these magnets. 

CalTarget

In addition the three iSweeps serve as calibration targets for the cameras on Phoenix (the Surface Stereo Imager and the Robotic Arm Camera). The iSweep magnets are expected to keep their colored centers clean of magnetic dust and thereby provide virtually constant color references for the cameras during the entire mission.

Fiducial points

There are three fiducial points on the lander deck covered with the same colored material as the iSweeps. The primary function of the fiducial points is to serve as orientation markers for the SSI and thus assist in the operation of the Robotic Arm.
But since the fiducial points are far away from the influence of any magnets and are covered in the same colored material as the iSweeps, they will also serve as references for the iSweep experiment providing dust sedimentation in zero magnetic field.
 

We also have the MECA magnets on Phoenix