Mars Rover Update
24 Aug 2004
(Source: Jet Propulsion Laboratory)
SPIRIT UPDATE: Spirit probes deeper into 'Clovis' outcrop - sol 209-218, August 23, 2004
Spirit continued work over the past nine sols at a rock called "Clovis." The rover used its rock abrasion tool, microscopic imager, alpha particle X-ray spectrometer, and Mossbauer spectrometer to probe deeper into the history of this rock. Clovis is the most altered rock encountered by Spirit to date. It is part of a rock outcrop located on the "West Spur" of the "Columbia Hills," roughly 55 meters (180 feet) higher than Spirit's landing site about 3 kilometers (2 miles) away.
Spirit also successfully performed a couple of communications tests with the European Space Agency's Mars Express orbiter last week. The tests demonstrated the two spacecraft's ability to work together to transmit data collected by the rovers to Earth via the Mars Express communications relay. NASA's Mars Odyssey and Mars Global Surveyor orbiters also have this capability. More than 85 percent of the data from the rovers has been transmitted to Earth via the Odyssey orbiter.
On sol 209, Spirit experienced an unexpected reboot of the flight software. This incident was not a threat to the spacecraft. It is a known bug in the system that the rover team is working around.
On sol 210, Spirit drove up steep terrain to reach the exact spot on Clovis for work with the science instruments at the end of the robotic arm.
Between sols 211 and 216, Spirit completed an alpha particle X-ray spectrometer reading of a spot on Clovis called "Plano," which had been brushed off using the rock abrasion tool. Spirit then placed the rock abrasion tool on Plano again and drilled for 2.5 hours, creating a hole 8.9 millimeters (0.4 inch) deep, which is a new record! Spirit also continued a campaign to capture a color 360-degree panoramic camera image from this location. Spirit captured additional segments of the panorama on sols 217 and 218.
On sol 217, Spirit took microscopic images of the rock abrasion tool hole, and then placed the alpha particle X-ray spectrometer in the hole for an early morning observation.
On sol 218, Spirit placed the Mossbauer spectrometer in the rock abrasion tool hole and started a 48-hour observation. This is a longer than normal integration time, with a goal of resolving in more detail the makeup of this highly altered rock.
Spirit remains in excellent health.
OPPORTUNITY UPDATE: Opportunity Team Decides Against Dunes - sol 200-203, August 23, 2004
On sol 200 Opportunity was commanded to perform some remote sensing and some rock abrasion tool diagnostics in response to an activity that faulted out on sol 199. During these diagnostics on sol 200, the tool failed to respond as desired to a command to calibrate the grind motor. Analysis of this event suggests that there is a piece of debris (probably a rocky chunk of Mars) trapped between the grind bit and the brush bit. The rover team believes that it can be freed by turning the bits in reverse, but they are still evaluating the best approach to remedy the situation. There are several options available. The team decided to continue the investigation of this anomaly while pressing on with other objectives.
On sol 201 the rover was commanded to stow its arm and drive to a position about 12 meters (about 39 feet) clockwise around the crater. The intent is to head towards a dune tendril that reaches out of the bottom of the crater and may be accessible without having to drive into terrain that is too sandy for the rover to safely traverse. The drive went very well, and the rover ended up in the expected place.
On sol 202 the rover was commanded to proceed a little ways downslope. Team members were not able to command the drive the rover as far as they might have liked because they did not get all the data they hoped to get in the afternoon downlink pass on sol 201. The terrain around the rover is heavily coated with sand and dust, so each traverse requires careful evaluation to make sure there is enough rock material to drive on with confidence. From the images available, the team determined it could safely command only about a 1-meter (3.3-foot) drive. This drive proceeded as expected. At the end of the drive, panoramic camera images were acquired directly in front of the rover and out to the dune tendril. These images will be used to assess traversability to this sandy feature.
On sol 203 the team decided to scratch the approach to the dune tendril and, instead, headed the rover back towards "Axel Heiberg" and another target named "Ellesmere" for some soil observations. The terrain between the rover and the dune tendril did not present clear evidence of rocky plates to give the rover sufficient traction. Rather than spend more time in an attempt to scout further for an approach path, the decision was made to abandon the quest for the dune tendril. A drive of approximately 14 meters (46 feet) positioned the rover where it will be able to zero in on Ellesmere next. There was an apparent combination of slip or induced heading change, or both, due to the sandy terrain, which resulted in the rover ending up about 3 meters (about 10 feet) farther left than expected. This also caused Opportunity to unintentionally run over a patch of fine soil with some small dune-like ripples in it. The team will be assessing this traverse error, but it is par for the course when driving this far on such sandy, sloped terrain.