OPPORTUNITY UPDATE: Finishing Up in 'Endurance' - sol 285-291, November 23, 2004
Opportunity has now reached the furthest point east in its travels inside "Endurance Crater." Rover drivers have determined that there is no safe path beyond the current position. Therefore, Opportunity is now in the midst of an intensive remote-sensing campaign, capturing a panorama of Burns Cliff plus super-resolution images and miniature thermal emission spectrometer observations of selected targets. When this campaign concludes, the rover will back away and head for a way out of Endurance Crater. Opportunity remains healthy and in an extremely advantageous solar array attitude.
The plan for 285 was to drive 1.5 meters (about 5 feet) east on firm rocky terrain ahead of the rover. The drive went as planned, covering 1.55 meters (5.1 feet). After integrating the results of this drive with an earlier study of Burns Cliff traversability, the team decided not to proceed farther. Opportunity has reached the easternmost point of its drive inside Endurance Crater. The rover is at the western edge of Burns Cliff and from this vantage point, it will perform super-high resolution imaging and other science observations.
Sol 286 was a restricted sol because the team did not know results of the sol 285 drive in time for planning sol 286. Opportunity recorded more than three hours of observations, took a nap, and then used afternoon and overnight communication sessions with Mars Odyssey. Solar exposure is excellent inside the crater, so Opportunity's power and battery state of charge continue to increase. The rover has not used deep-sleep mode in more than a week, and probably won't for the foreseeable future.
Sols 287 and 288 were planned together. Opportunity began super-high resolution imaging activities on sol 287. Starting at 11:15 local solar time, the rover performed the following activities: an hour of panoramic camera imaging, an hour of miniature thermal emissions spectrometer imaging and another hour of panoramic camera imaging. Sol 288 was almost exactly the same three-hour activity, but with the images targeted differently.
The Deep Space Network experienced a station transmitter problem on Saturday and Opportunity did not receive all of its two-sol uplink as planned. The rover received all except the last part of the sol 287 bundle, but none of the sol 288 bundle or data management bundle. Due to quick reaction by the weekend uplink team, bundles were successfully uplinked on Sunday, in time for execution of the sol 288 plan. The total effect of the missed Saturday uplink was a loss of about 30 minutes of science on the morning of sol 288.
Sols 289, 290 and 291 were very similar. Each was a continuation of the remote sensing campaign, with an additional panoramic camera observation. Sol 289 activities included observations of dunes and dust with the panoramic camera and miniature thermal emissions spectrometer. Also the panoramic camera was used for super-resolution imaging of "Whatanga," a contact boundary between two layers of rocks. For sol 290, in addition to the panoramic camera observation, Opportunity made several long-dwell observations of Burns Cliff targets with its miniature thermal emission spectrometer. Cloud observations on the morning of sol 290 produced a dramatic image. Sol 291 included a super-resolution observation of a target called "Bartlett."
The remote sensing campaign is generating a large volume of data at a time when, due to the rover's orientation, there is limited bandwidth available for downlink. As a consequence, Opportunity is operating with limited memory headroom, though still within planning guidelines. In order to improve the situation, the team took advantage of the Deep Space Network's 70-meter antenna availability and Opportunity's good energy state to plan a one-hour, direct-to-earth session in the middle of the day on sol 291. This resulted in the downlink of an extra 15 megabits of data.