1 week Ago By Haygen Warren
In August, NASA’s Perseverance Mars rover began its fifth science campaign — the rover’s most ambitious yet. The campaign has seen Perseverance climb the western rim of Jezero Crater and face its steepest and most challenging terrain yet, all the while continuing to take surface samples and look for signs of ancient microbial life. Currently, Perseverance is expected to crest over the crater rim in early December.
However, teams have faced many challenges with navigating up the crater rim. Much of the terrain Perseverance has been driving over is much more slippery than initially thought, which has slowed the rover’s progress up the crater rim. More specifically, the crater rim terrain has been found to be loosely packed dust and sand with thin and brittle crusts, leading to the rover’s wheels slipping significantly.
On many days, Perseverance has only covered half the distance it would’ve covered on non-slippery terrain. In fact, during one day of climbing, the terrain was so steep and slippery that the rover was only able to drive 20% of the planned route. While previous rovers like Curiosity , Opportunity , and Spirit have faced steep and slippery terrain, none have faced terrain as extreme as this.
Mosaic image taken by Perseverance during its climb to the crater rim. Different locations the rover has visited are highlighted. (Credit: NASA/JPL-Caltech/ASU/MSSS) “Mars rovers have driven over steeper terrain, and they’ve driven over more slippery terrain, but this is the first time one had to handle both — and on this scale.
For every two steps forward Perseverance takes, we were taking at least one step back. The rover planners saw this was trending toward a long, hard slog, so we got together to think up some options,” said rover route planner Camden Miller of NASA’s Jet Propulsion Laboratory (JPL) in California. See Also Perseverance Updates Mars Missions Section Space Science Coverage Click here to Join L2 Teams have been working over the last several weeks to determine ways to reduce the amount of slippage Perseverance’s wheels experience.
On Oct. 3, the team sent commands to the rover to test some of these strategies, which included having the rover drive up a slope backward, as testing on Earth has revealed that the rover’s suspension system maintains better traction when driving backward. Additionally, the team had Perseverance attempt cross-slope (or switchback) driving and driving toward the northern edge of the crater.
All of these attempts were made as Perseverance was making its way up “Summerland Trail,” the name of the route Perseverance is taking up the crater rim. While all three attempts increased Perseverance’s traction while climbing the crater rim, the team determined that driving the rover toward the northern edge of the crater rim was the most beneficial due to the presence of larger rocks closer to the surface. “That’s the plan right now, but we may have to change things up the road.
No Mars rover mission has tried to climb up a mountain this big this fast. The science team wants to get to the top of the crater rim as soon as possible because of the scientific opportunities up there. It’s up to us rover planners to figure out a way to get them there,” Miller said.
Image showing the steep and slippery terrain Perseverance has encountered on its climb to the crater rim. (Credit: NASA/JPL-Caltech) As mentioned, Perseverance is expected to crest the crater rim in early December, and the site at which it will crest is known as “Lookout Hill.” After cresting the crater rim at Lookout Hill, the rover will continue driving another 450 m to another location, named “Witch Hazel Hill.
” Current data from orbital spacecraft around Mars has shown that Witch Hazel Hill likely contains light-toned layered bedrock, which the team will compare to the “Bright Angel” location Perseverance previously investigated. Along its travels up the crater rim, and throughout the rover’s four previous science campaigns, Perseverance has been collecting samples of the Martian surface, rocks, and other surface features. Once collected, the samples are dropped into one of 43 total sample tubes and subsequently dropped onto the Martian surface for collection by another mission at a later date.
Thus far, Perseverance has collected, sealed, and deposited 24 sample tubes, as well as one atmospheric sample tube and three “witness” tubes, which are sample tubes that have been preloaded with materials that can capture contaminants around sample collection sites. In the planning stages of Perseverance’s mission, teams required the rover to collect and cache 31 sample tubes at minimum. In subsequent planning and design meetings, 12 additional tubes were added in anticipation of issues with other sample tubes while on Mars, bringing the total number of tubes to 43.
The Summerland Trail route Perseverance is taking to the top of the crater rim. (Credit: NASA/JPL-Caltech/University of Arizona) Now nearing four years into its mission on the Martian surface, Perseverance has 11 empty sample tubes available for sample collection events, as well as two empty witness tubes. Recently, NASA and Perseverance’s teams decided to retire two empty sample tubes due to their location on the rover.
Perseverance accesses the sample tubes using a small internal robotic arm, and accessing these two tubes posed a risk to the arm due to a wire harness potentially getting caught onto a fastener on the rover’s frame. Following Perseverance’s cresting of the crater rim in December, the rover’s fifth science campaign will begin to conclude, and teams will begin to prepare for the sixth science campaign. (Lead image: Selfie of Perseverance looking at a deposited sample tube.
Credit: NASA/JPL-Caltech/MSSS).
