NASA Mars Exploration Rovers Spirit Update: Serious but Stable

sol 1730-1736, November 14 – November 20, 2008:

Spirit’s condition has improved during the past week, though skies remain fairly dusty after the recent Martian dust storm. Since sol 1730 (Nov. 14, 2008), solar-array energy has averaged 169 watt-hours (100 watt-hours is the amount of energy needed to light a 100-watt bulb for 1 hour). The latest measurement of atmospheric darkness caused by dust, known as Tau, is 0.858. The dust factor, representing the portion of sunlight penetrating the coating of dust on the solar panels, is 0.2912.

Spirit performed a cursory check of the health of the miniature thermal emission spectrometer. After three nights with the spectrometer’s heaters disabled, the instrument appeared to be undamaged as of sol 1730. Power is not yet sufficient to re-enable those heaters, though Spirit will continue to monitor the spectrometer while waiting for power to improve. For the most part, Spirit is limiting activities to those necessary for maintaining engineering health and safety.

Spirit endured another challenge when new commands from Earth for sol 1734 (Nov. 18, 2008) did not arrive. At that point, Spirit began to execute a backup set of activities known as a runout plan. On Earth, engineers created a new sequence of commands for sol 1736 (Nov. 20, 2008) to manage communications and preserve power. Meanwhile, they are investigating why Spirit did not receive their previous commands.

According to the latest Martian weather report for Nov. 15 (sol 1731), skies are expected to continue to clear during the next couple of weeks. No other storms have been identified within a couple of thousand kilometers of Spirit’s location.

Spirit is preparing for solar conjunction, where the Sun is between Earth and Mars, preventing communications. This period begins Nov. 29th. Before and during solar conjunction, Spirit’s activities will remain conservative as the rover waits for the skies to clear and for the power situation to improve.

Sol-by-sol summary

In addition to measuring dust-related changes in atmospheric opacity with the panoramic camera, Spirit completed the following activities:

Sol 1730 (Nov. 14, 2008): Spirit observed the sky briefly with the miniature thermal emission spectrometer.

Sol 1731: Spirit rested and soaked up the Sun’s rays to recharge the batteries.

Sol 1732: Spirit rested and soaked up the Sun’s rays to recharge the batteries.

Sol 1733: Spirit rested and soaked up the Sun’s rays to recharge the batteries.

Sol 1734: Spirit completed basic activities in the runout plan.

Sol 1735: Spirit completed basic activities in the runout plan.

Sol 1736 (Nov. 20, 2008): Spirit completed basic activities in the runout plan.

Odometry:

As of sol 1736 (Nov. 20, 2008), Spirits total odometry was 7,529.02 meters (4.68 miles).