Leonard David's INSIDE OUTER SPACE

Ireson Hill as imaged by Curiosity’s Navcam Left B om Sol 1608, February 13, 2017.
Credit: NASA/JPL-Caltech

NASA’s Curiosity rover is carrying out Sol 1609 duties on Mars, driving over 30 feet (9 meters) on Sol 1608.

That drive has placed the robot closer to Ireson Hill, making it possible to image dark blocks that have tumbled down from the top of the hill.

Dark blocks

“Two of these blocks are within reach of the arm, but both are challenging targets,” reports Ken Herkenhoff of the USGS Astrogeology Science Center. Even the name chosen for the dark block is difficult: “Passagassawakeag.”

Curiosity Front Hazcam Right B image taken on Sol 1608, February 13, 2017.
Credit: NASA/JPL-Caltech

Herkenhoff  adds that this block is pointier than scientists would like for contact science, and the other dark block, dubbed “Perry” is close enough to the rover that there is a risk of collision with the arm.

Arm action

Complicating the plan further, Herkenhoff points out, is that the best time to take Mars Hand Lens Imager (MAHLI) images of these targets is late in the afternoon, when they won’t be shadowed by the arm.

However, the last chance to send data to Earth in time to make them available for planning is earlier in the afternoon, making it difficult to return all of the data needed to respond to a possible arm fault.

Safe distance

“Therefore, we decided to acquire a single MAHLI image of Passagassawakeag from a safe distance of 5 centimeters before the critical communications opportunity, and send it in case the full suite of MAHLI images of Perry planned later in the afternoon is not successful,” Herkenhoff says. Doing so, science teams would be better able to plan contact science on Perry in the near-term, if necessary.

Curiosity Mastcam Left image taken on Sol 1608, February 13, 2017.
Credit: NASA/JPL-Caltech/MSSS

According to the Sol 1609 plan, it was to start with Chemistry & Camera (ChemCam) and Right Mastcam observation of Passagassawakeag, a typical Murray bedrock exposure named “Spurwink,” and a more distant dark block called “Wassataquoik.”

Then the plan schedules Curiosity’s Right Mastcam to acquire a 3×1 mosaic of the Perry area, single images of rocks near the top of the hill named “Gonic,” “Kineo,” and “Edmunds,” followed by an 8×4-frame mosaic of the right side of the hill.

Complicated plan

Prior to the MAHLI imaging of Perry, a full suite of MAHLI images, plus extra stereo frames, is planned on Spurwink.

After all of the MAHLI activities have been completed, Herkenhoff says, the robot’s Alpha Particle X-Ray Spectrometer (APXS) is to be placed on Perry for a pair of short integrations, then placed on Spurwink for an overnight integration.

Concludes Herkenhoff: “Of course we are hoping that this complicated plan goes well!”