NASA Mars Rover Spirit: Warming Up on Mars
sol 1669-1677, September 12-20, 2008:
With Martian winter on the wane, Spirit is using significantly less energy to stay warm. During the winter solstice, Spirit needed 90 watt-hours to run the heater. Now, the rover uses between 30 and 40 watt-hours. The reduced demand for power, more than the slow increase in solar-array input, has freed up energy for other things. In particular, Spirit has added more images to the 360-degree view of its winter surroundings, known as the “Bonestell panorama.” The top tier, one of three tiers needed for the final image mosaic, is almost complete.
Plans called for Spirit to use the miniature thermal emission spectrometer for the first time in several months. The last time the rover used the instrument was on Martian day, or sol, 1558 (May 21, 2008). On sol 1675 (Sept. 18, 2008), Spirit’s schedule of activities included calibrating the spectometer and using it to observe the sky and ground. Normally, scientists use the observations to measure temperatures at different heights and create a temperature profile of the ground and atmosphere. In this case, the purpose of the measurements is to verify that the spectrometer is still working after a long, cold period of disuse. The measurements will also enable scientists to estimate the amount of dust on the optics. They may or may not provide a useful temperature profile.
Spirit is healthy and all subsystems are performing as expected as of the most recent report from NASA’s Odyssey orbiter on sol 1674 (Sept. 17, 2008). Solar-array energy has inched upward to 255 watt-hours (100 watt-hours is the amount of energy needed to light a 100-watt bulb for one hour). Skies are clearer than last week, with tau, a measure of the amount of sunlight blocked by atmospheric dust, dropping to 0.141.
Sol-by-sol summary
In addition to taking daily measurements of dust-related changes in atmospheric opacity (tau), Spirit completed the following activities:
Sol 1669 (Sept. 12, 2008): Spirit recharged the batteries.
Sol 1670: Spirit received new instructions directly from Earth sent at X-band frequencies to the rover’s high-gain antenna. The rover relayed data to NASA’s Odyssey orbiter to be transmitted to Earth.
Sol 1671: Spirit acquired column 20, part 1 and column 21, part 1 of the full-color Bonestell panorama, using all 13 color filters of the panoramic camera. The rover took spot images of the sky for calibration purposes with the panoramic camera.
Sol 1672: Spirit recharged the batteries.
Sol 1673: Spirit recharged the batteries.
Sol 1674: Spirit received new instructions from Earth via the rover’s high-gain antenna. The rover relayed data to Odyssey to be sent to Earth.
Sol 1675: Plans called for Spirit to acquire column 22, part 1 and column 23, part 1 of the Bonestell panorama and then verify that the miniature thermal emission spectrometer was still functional. This involved warming up the actuator, calibrating the instrument, measuring ground temperature, and measuring atmospheric temperatures at different heights. Plans also called for Spirit to calibrate the panoramic camera by taking images in darkness while the instrument was warm.
Sol 1676: Plans called for Spirit to recharge the batteries.
Sol 1677 (Sept. 20, 2008): Plans called for Spirit to recharge the batteries.
Odometry:
As of sol 1674 (Sept. 17, 2008), Spirit’s total odometry remained at 7,528.0 meters (4.7 miles).
