<html><body style="word-wrap: break-word; -webkit-nbsp-mode: space; -webkit-line-break: after-white-space; "><head><meta http-equiv="Content-Type" content="text/html charset=iso-8859-1"><meta http-equiv="Content-Type" content="text/html charset=iso-8859-1"><meta http-equiv="Content-Type" content="text/html charset=us-ascii"></head><meta http-equiv="Content-Type" content="text/html charset=iso-8859-1"><meta http-equiv="Content-Type" content="text/html charset=us-ascii"><meta http-equiv="Content-Type" content="text/html charset=iso-8859-1"><div style="margin: 0px; font-size: 12px; font-family: Arial; "><span style="font-family: Helvetica; "></span></div><div style="margin: 0px; font-size: 12px; font-family: Arial; "><span style="letter-spacing: 0.0px"><b>* Mars Exploration Rover Mission (Spirit and Opportunity) - December 18, 2012</b></span></div><div style="margin: 0px; font-size: 12px; font-family: Arial; min-height: 14px; "><span style="letter-spacing: 0.0px"></span><br></div><div style="margin: 0px; font-size: 12px; font-family: Arial; "><span style="letter-spacing: 0.0px"><b>SPIRIT UPDATE: Spirit Remains Silent at Troy - <i>sols 2621-2627, May 18-24, 2011</i>:</b></span></div><div style="margin: 0px; font-size: 12px; font-family: Arial; min-height: 14px; "><span style="letter-spacing: 0.0px"></span><br></div><div style="margin: 0px; font-size: 12px; font-family: Arial; min-height: 14px; "><span style="letter-spacing: 0.0px"></span><br></div><div style="margin: 0px; font-size: 12px; font-family: Arial; "><span style="letter-spacing: 0.0px">"No communication has been received from Spirit since Sol 2210 (March 22, 2010).</span></div><div style="margin: 0px; font-size: 12px; font-family: Arial; min-height: 14px; "><span style="letter-spacing: 0.0px"></span><br></div><div style="margin: 0px; font-size: 12px; font-family: Arial; "><span style="letter-spacing: 0.0px">More than 1,300 commands were radiated to Spirit as part of the recovery effort in an attempt to elicit a response from the rover. No communication has been received from Spirit since Sol 2210 (March 22, 2010). The project concluded the Spirit recovery efforts on May 25, 2011. The remaining, pre-sequenced ultra-high frequency (UHF) relay passes scheduled for Spirit on board the Odyssey orbiter will complete on June 8, 2011.</span></div><div style="margin: 0px; font-size: 12px; font-family: Arial; min-height: 14px; "><span style="letter-spacing: 0.0px"></span><br></div><div style="margin: 0px; font-size: 12px; font-family: Arial; "><span style="letter-spacing: 0.0px">Total odometry is unchanged at 7,730.50 meters (4.80 miles)."</span></div><div style="margin: 0px; font-size: 12px; font-family: Arial; min-height: 14px; "><span style="letter-spacing: 0.0px"></span><br></div><div style="margin: 0px; font-size: 12px; font-family: Arial; "><span style="letter-spacing: 0.0px"><b>OPPORTUNITY UPDATE: Shoulder Work At 'Copper Cliff' - <i>sols 3159-3165, Dec. 12, 2012-Dec. 18, 2012</i>:</b></span></div><div style="margin: 0px; font-size: 12px; font-family: Arial; min-height: 14px; "><span style="letter-spacing: 0.0px"></span><br></div><div style="margin: 0px; font-size: 12px; font-family: Arial; "><span style="letter-spacing: 0.0px">"Opportunity is working at "Matijevic Hillî (named in honor of Jake Matijevic) at the inboard edge of "Cape York" on the rim of Endeavour Crater. There, the rover has been conducting in-situ (contact) science measurements at a location called "Copper Cliff."</span></div><div style="margin: 0px; font-size: 12px; font-family: Arial; min-height: 14px; "><span style="letter-spacing: 0.0px"></span><br></div><div style="margin: 0px; font-size: 12px; font-family: Arial; "><span style="letter-spacing: 0.0px">On Sol 3160 (Dec. 13, 2012), Opportunity began taking images with its Microscopic Imager (MI) for a mosaic of a surface target. Partway through the activity, the rover's robotic arm experienced a stall in the shoulder azimuth joint. This has been seen a few times before when the arm is commanded to move at a slow rate, but not the slowest rate. Magnetic detents normally hold the motor armature when unpowered, and under certain slow-rate conditions they are able to restrain the armature from spinning. At higher rates, the armature has enough momentum to keep spinning, while at the slowest rates a higher stall threshold is used. Activities on Sol 3162 (Dec. 15, 2012) confirmed the joint is OK, and an offset placement of the Alpha Particle X-ray Spectrometer (APXS) was completed.</span></div><div style="margin: 0px; font-size: 12px; font-family: Arial; min-height: 14px; "><span style="letter-spacing: 0.0px"></span><br></div><div style="margin: 0px; font-size: 12px; font-family: Arial; "><span style="letter-spacing: 0.0px">On Sol 3165 (Dec. 18, 2012), Opportunity bumped about 18 feet (5.5 meters) to the west to reach a new set of surface targets in this Copper Cliff area. The rover will likely continue in-situ investigations in the area through the coming holiday. </span></div><div style="margin: 0px; font-size: 12px; font-family: Arial; min-height: 14px; "><span style="letter-spacing: 0.0px"></span><br></div><div style="margin: 0px; font-size: 12px; font-family: Arial; "><span style="letter-spacing: 0.0px">As of Sol 3165, the solar array energy production was 533 watt-hours with an increased atmospheric opacity (Tau) of 0.955 and a solar array dust factor of 0.607.</span></div><div style="margin: 0px; font-size: 12px; font-family: Arial; min-height: 14px; "><span style="letter-spacing: 0.0px"></span><br></div><div style="margin: 0px; font-size: 12px; font-family: Arial; "><span style="letter-spacing: 0.0px">Total odometry is 22.02 miles (35438.37 meters)."</span></div><div style="margin: 0px; font-size: 12px; font-family: Arial; min-height: 14px; "><span style="letter-spacing: 0.0px"></span><br></div><div style="margin: 0px; font-size: 12px; font-family: Arial; color: rgb(4, 51, 255); "><span style="letter-spacing: 0.0px; color: #000000">Landing sites link - <a href="http://marsoweb.nas.nasa.gov/landingsites/"><span style="letter-spacing: 0px; ">http://marsoweb.nas.nasa.gov/landingsites/</span></a> </span></div><div style="margin: 0px; font-size: 12px; font-family: Arial; min-height: 14px; "><span style="letter-spacing: 0.0px"></span><br></div><div style="margin: 0px; font-size: 12px; font-family: Arial; "><span style="letter-spacing: 0.0px">Visit the Mars Exploration Rover page at</span></div><div style="margin: 0px; font-size: 12px; font-family: Arial; color: rgb(4, 51, 255); "><span style="letter-spacing: 0.0px; color: #000000"> <a href="http://marsrovers.jpl.nasa.gov/home/index.html"><span style="letter-spacing: 0px; ">http://marsrovers.jpl.nasa.gov/home/index.html</span></a>.</span></div><div style="margin: 0px; font-size: 12px; font-family: Arial; min-height: 14px; "><span style="letter-spacing: 0.0px"></span><br></div><div style="margin: 0px; font-size: 12px; font-family: Arial; "><span style="font-family: Helvetica; "></span></div></body></html>