The science team has been waiting quite a long time for this moment. Back in late March, nearly 180 Mars-days ago and when Curiosity was investigating the last stretches of the Bagnold Dunes before continuing towards Vera Rubin Ridge, Curiosity's scoop gathered a sample called "Ogunquit Beach." In order to quantitatively determine the mineral assemblage present in this sample of a sand dune, Curiosity would have to deliver the sample to the CheMin X-ray diffractometer instrument. However, because of the ongoing troubles with the arm's drill feed, Curiosity has been stuck with Ogunquit Beach in "storage" and unable to deliver the sample to CheMin - until this weekend! Tomorrow, at around 7:30am PDT, Curiosity will be given the "all clear" to deliver Ogunquit Beach to CheMin. Throughout the weekend, CheMin will analyze this sample, precisely measuring diffraction data for deriving its mineral assemblage, and will send the data back to Earth. The science team is very excited to be crossing this milestone, and we can't wait to compare Ogunquit Beach to the other measurements of the Bagnold Dunes acquired over the last few years.
In addition to this big achievement, Curiosity will also be investigating interesting science targets directly in front of her. The first task of the "weekend" on Mars will be to investigate three geologic targets of interest. First, the ChemCam laser system will be used to determine the chemistry of the targets "Katberg," "Normandien," and "Black Reef." Katberg is a relatively flat and benign piece of bedrock lying directly in front of the rover. Normandien is a bit further away from the rover, and is a darker rock sitting on top of the local bedrock, sand, and dust. Lastly, Black Reef is another darker rock (though slightly larger and more rounded than Normandien) that doesn't appear to be a piece of the local bedrock in the immediate rover surroundings. Following these measurements, Mastcam will document these three targets, as well as acquiring a few small mosaics of the local bedrock to the left and right of the rover and monitoring environmental conditions (e.g., atmospheric dust). The afternoon of this day is dedicated to delivering Ogunquit Beach to CheMin, with CheMin analyzing the sample overnight.
In the early Mars morning of the second day, Curiosity will make some additional atmospheric observations using Mastcam and Navcam. Later that afternoon, Curiosity's arm will swing into position, will brush away any dust or debris from the Katberg target, and will image Katberg with the high-resolution MAHLI camera. The APXS instrument will then be used to collect an overnight chemical analysis of Katberg. Midday on the third day, Curiosity will stow her arm and set off towards the east to continue making progress through Vera Rubin Ridge. After her drive, Curiosity will acquire some necessary post-drive images before returning them to Earth for the science team to analyze on Monday morning.
While most of this weekend's activities are fairly "normal" in the context of our recent scientific investigations, delivering Ogunquit Beach to CheMin marks an important milestone for utilizing this valuable rover asset. We hope that the results of these analyses will be just as valuable in our understanding of the mineral assemblages present in Martian sand dunes!