Daily Updates - September 9, 2004
Spirit Status at end of sol 239 - 242
Spirit is in safe place to continue daily science observations automatically throughout the solar conjunction period when engineers and scientists will be unable to send commands reliably to the rover. An 18-day period began a transition into solar conjunction on sol 241, when the Sun partially obscured the communications path between Earth and Mars, making communications sessions unreliable. Engineers were able to successfully command Spirit on sol 241, and they had partial commanding success on sol 242.
Engineers will attempt to command Spirit on sol 243 also. From sol 244 through sol 255, sequences already safely on board will perform a set of science activities on a daily basis. On sols 256 through 258, the last three days of conjunction, the rover team will attempt normal operations again.
On sol 242, engineers sent Spirit a set of coordinated commands to use the miniature thermal emission spectrometer and panoramic camera for observations of possible future science targets. A new set of 12 conjunction master sequences was also transmitted successfully to Spirit. This new set of conjunction master sequences will use less energy than previous sequences.
For the conjunction period, the rover team has placed the Moessbauer spectrometer on one of the two magnets on the rover deck. Spirit will activate the Moessbauer instrument every day during conjunction in order to characterize the dust that has collected on the magnet. However, a wrinkle has developed in this plan. Before placing the Moessbauer spectrometer on the magnet, Spirit placed it on the soil in front of its current location. That soil touch was done to leave a soil impression that would be studied after conjunction for changes. Images taken after the touch indicate that Spirit inadvertently picked up some soil and likely sandwiched that soil onto the magnet with the Moessbauer. It's the team's first inadvertent sample acquisition!
Engineers and scientists decided to leave the Moessbauer in place on the magnet and will evaluate the status and effect of the dirt clod after conjunction. The dirt does not pose any threat to the rover from an engineering perspective.
Since Spirit arrived at its solar-conjunction resting place, its science activities have focused on gathering data from the surrounding area for use in planning post-conjunction sols. Navigation camera images in Spirit's drive direction have been used to develop traverse maps. These maps show areas that allow Spirit to maintain a north-facing tilt; these areas will provide significantly more solar energy and will therefore be favored as the team plans the traverse to Spirit's next science target.
During conjunction, Spirit will transmit five-minute "beep" tones, and engineers will send "No-operation" commands to the rover to characterize effects that the conjunction has on radio transmissions between Mars and Earth.
Spirit Daily Update Archive