Curiosity Blog, Sols 4709-4715: Drilling High and Low in the Boxwork Unit
Written by Catherine O’Connell-Cooper, APXS Strategic Planner and Payload Uplink/Downlink Lead, University of New Brunswick, Canada
Date of the earthworks plan: Friday November 7, 2025
We are in the most intensive phase of the investigation into box structures: the drilling campaign. Campaign group Boxwork requested a pair of drilled targets – one in a trough (the topographic low) and one on an adjacent ridge, surrounding the trough.
As we noted in a previous blog, finding a drilling target in hollows has proven tricky, as hollow floors are often covered in sand and pebbles, with minimal bedrock exposed. But over the past two weeks, we have successfully drilled the rock target “Valle de la Luna” in a large trough called “Monte Grande”. We finished at Valle de la Luna on Monday and quickly moved up the ridge to reach our second target, about 10 meters (about 33 feet) away.
We wanted to name our targets to reflect the difference in location – from the topographic low point to the (relatively speaking) high point of the neighboring ridge. Our hollow target, Valle de la Luna, is named after an area of valleys in the Atacama Desert, Chile. This area is one of the driest on the planet, with a unique environment and an incredible landscape sculpted with geological formations that would not be out of place in Gale Crater.
Although there is only a 2 meter (about 6½ feet) difference in elevation between the hollow bottom and the top of the ridge, we decided to name our ridge target “Nevado Sajama”, which is an extinct volcano and the highest peak in Bolivia. Go big or go home!
Wednesday’s plan focused on our “Drill Sol Zero” activities. We use this day to fine-tune our drilling position with a little practice (we call this type of positioning practice a “bump” because it is usually within a few meters, or less than 6 feet) to the most suitable potential drilling target. On Wednesday we made very little progress on the workspace, and this morning (Friday) the best potential target for drilling was in the ideal location. Today we are conducting our Drill Sol 1 activities, which focus on sorting the Nevado Sajama bedrock block for drilling (the center of this Mastcam image; the bottom block in this Navcam image). The Rover Planners (RP) will test the coherence of the rock, to assess its resistance under drilling pressure. APXS and ChemCam will analyze brushed bedrock in the planned drilling area. We can compare this to the workspace targets very close to Wednesday (“Isluga Volcano” for APXS and “Luna Muerte” for ChemCam), to determine how homogeneous or heterogeneous this area is. MAHLI will image the bedrock here as well, and compare it again to Wednesday’s workspace targets (the Isluga Volcano and the MAHLI-only target “Sipe Sipe”, which was an area of freshly broken rock, shattered when we drove over it).
The drilling campaign for the caisson zone took two years of planning. Over the years, the Boxwork campaign focus group (including myself) held regular meetings, presentations, and brainstorming sessions. It’s so rewarding to finally be here, in the middle of this active drilling campaign.
