Planning Take Two: Sols 3885-3886

Planning Take Two: Sols 3885-3886
by Remington Free | Ops Engineer - JPL
Pasadena CA (JPL) Jul 12, 2023

Earth planning: Monday, July 10, 2023 This weekend, Curiosity went into runout and was unable to execute the Sols 3882-3884 plan that is detailed in last blog post. Nothing is actually wrong; runout refers to when the rover doesn't have anything to do as it hasn't received any new instructions. Runout is normally caused by an error in the uplink process - in this case, the transmitter at our DSN station went 'red' and was unable to send up our plan. DSN refers to the Deep Space Network, which is the ground-based collection of huge antenna dishes which we use to beam information at our rovers. They are hugely important for us to be able to communicate with Curiosity, but occasionally there are faults which prevent transmission. My tactical role is on downlink for the robotic arm, so it was an uneventful downlink assessment day with most teams not having any completed activities.

To check on the state of the rover during runout, we have created what is known as a "runout beep." When it doesn't have any normal planning instructions (in the form of a master sequence), Curiosity is able to recognize it is in runout and send a small "beep" transmission which lets us know that it is otherwise working normally and is healthy. We did successfully receive the runout beep, so we know she is doing just fine up there!

Current planning for sols 3885-3886 involves repeating a lot of the intended activities of the previous plan (sols 3882-3884). Due to runout, Curiosity actually had built up a lot more power than we would have had if the plan had uplinked correctly, so we were able to fit in additional science activities to take advantage of the extra power. An extra ~60 minutes of science time was added to the intended plan, which is exciting! The team discussed how best to use that extra power.

On sol 3885, we will perform APXS analysis of the "Planitero" target, which is a flat, less dusty area of bedrock surface, in order to determine its composition. On this sol, we also have a large science block, which will include Mastcam imaging of the "Kukenan" hill to document its stratigraphy (the layering of the rock), several cracked bedrock fractures, and the "Stokani" target, which is more dark planar bedrock surface. ChemCam will perform additional observation of "Stokani" using the LIBS instrument (see my previous blog post for a description of LIBS) and several ridge mosaics. Later on in the day, Mastcam will also document "Planitero." After the bulk of the science activities, Curiosity will perform a short drive, which is very similar to the previous drive planned.

After the drive, we performed a SPENDI (Shunt Prevention Environmental Navcam Drop-In). It is not preferable to fully charge the batteries, so when we have a lot of charge such as in this case caused by runout, we keep the rover awake longer and fill the extra time with Navcam use for opportunistic science activities. Otherwise, we would have to radiate the extra heat and power into the atmosphere, which would be a waste. Our SPENDI included a number of Navcam movies and a full dust devil survey. Post-SPENDI, Navcam will take a sky observation. Other remote sensing activities in sol 3886 of the plan included, Mastcam mosaics and tau (atmospheric opacity) observations. It's nice to be able to take advantage of unexpected situations like this; we were able to get some awesome pictures that we might not otherwise have time for.