Commands will be sent to Curiosity instructing the rover to collect a third scoop of soil from the "Rocknest" site of windblown Martian sand and dust.

Pending evaluation of this Sol 69 (Oct. 15, 2012) scooping, a sample from the scoopful is planned as the first sample for delivery - later this week - to one of the rover's internal analytical instruments, the Chemistry and Mineralogy (CheMin) instrument.

A later scoopful will become the first solid sample for delivery to the rover's other internal analytical instrument, the Sample Analysis at Mars (SAM) instrument.

The rover's second scoopful, collected on Sol 66 (Oct. 12), was intentionally discarded on Sol 67 due to concern about particles of bright material seen in the hole dug by the scooping.

Other small pieces of bright material in the Rocknest area have been assessed as debris from the spacecraft. The science team did not want to put spacecraft material into the rover's sample-processing mechanisms.

Confidence for going ahead with the third scooping was based on new assessment that other bright particles in the area are native Martian material.

One factor in that consideration is seeing some bright particles embedded in clods of Martian soil. Further investigations of the bright particles are planned, including some imaging in the Sol 69 plan.

Sol 69, in Mars local mean solar time at Gale Crater, will end at 5:01 a.m. Oct. 16, PDT (8:01 a.m., EDT).