Sol 842: Trying again...18 December 2014
Unfortunately, the Sol 841 command sequences could not be sent to MSL because of a transmitter problem at the Deep Space Network (DSN) antenna. This reminded me not to take for granted communications between Earth and Mars, even though such problems are rare. Bad weather over a DSN station can prevent transmission or receipt of radio signals. Because of such risks, every bundle of command sequences sent to the Mars rovers includes a few sols' worth of "runout" sequences. These tell the rover what to do if new commands are not received. So MSL is safe and healthy, but not doing much on Sol 841 besides sending more data back to Earth (through the Mars orbiters, as usual).
As you might expect, the Sol 842 plan includes most of the observations planned for Sol 841. But the arm activities had to be moved earlier to ensure that the MAHLI images of the right front wheel will be received on Earth in time for weekend planning on Friday. These images should help determine whether it is safe to brush using the Dust Removal Tool. To make room for the arm activities before the critical MRO data relay, Mastcam observations of targets dubbed "Telescope Peak," "Fairview Valley," "Gem Hill," and "Juniper Hills" were moved later, after the MRO communications pass.
Dates of planned rover activities described in these reports are subject to change due to a variety of factors related to the Martian environment, communication relays and rover status.