The space world was last week abuzz with the news of NASA’s Curiosity rover stuck in sandy ‘Hidden Valley’ on the Martian surface and was required to change its route to find out an alternative pathway to reach the 5.5 kilometres long mountain, Mount Sharp.
But what would have been the possible cause for the efficient Curiosity, which is exploring the Red planet in search of life, to abandon its plans and opt a ‘soft route’ to proceed towards the centre of Mars’ Gale Crater to reach its destination at the base of Aeolis Mons or Mount Sharp.
The reason is possibly the holes on the wheels of the Mars rover Curiosity. Scientists say some of them were intentional so as to facilitate the rover in its navigation on the harsh terrain of Mars but many of them are new developments following two Earth-years of its driving across the barren environment and rolling over the harsh rocky land.
Apart from the huge amount of dust accumulated on the rover’s body, there are dings, scratches and tears in its wheels that very well narrate the story about its survival and strength in such a harsh environmental condition.
Emily Lakdawala of the Planetary Society discussed the issue with the project leader, who is heading an investigating team on rover mission, and then posted in her blog on August 19, an in-depth report on the ongoing wheel problems of Mars Curiosity rover and NASA mission.
An investigating team called “Tiger Team” was formed to determine the reasons behind the more-than-anticipated damage and figure out the best possible ways to address the problem. The Tiger Team on August 7 met for a major review session to discuss the developments and future course of actions. Lakdawala had a detailed conversation with Project Manager Jim Erickson about the Mars mission’s status, the Curiosity and its wheels.
The main six questions Lakdawala has talked about in her post and were posed before Erickson were:
- What is the nature of the damage to the wheels?
- What is causing the damage to the wheels?
- What is the expected lifetime of the wheels, and how does that life end?
- How can they prolong the life of the wheels?
- Why didn’t they foresee this problem?
- What are they changing for Mars 2020?
In her blog post, the Planetary Society senior editor wrote:
… punctures, fissures, and ghastly tears. The holes in Curiosity’s wheels have become a major concern to the mission, affecting every day of mission operations and the choice of path to Mount Sharp. Yet mission managers say that, so far, the condition of the wheels has no effect on the rover’s ability to traverse Martian terrain.
Talking about the imminent design of the rover, she wrote:
“They designed Curiosity to handle all the challenges that Spirit and Opportunity had experienced, especially sand, which Curiosity traverses substantially better than her predecessors. They designed Curiosity to handle the sand traps, flat bedrock, and rocks-perched-on-sand landscapes seen by all the previous landers. They just didn’t imagine the possibility of the peculiar and never-before-seen terrain type that they found in Gale crater.”
Quoting Curiosity Project Manager Jim Erickson, she wrote:
“There are [places] on Earth that do have these sharp ventifacts, but we hadn’t seen them on Mars and we didn’t test against them.”
Mentioning about the rover’s encounter with Mount Sharp, Lakawalla wrote:
“It turns out that there are mechanical aspects of the mobility system that actively shove the wheels into pointy rocks. A wheel can resist the force of one-sixth of the rover’s weight pressing down on a pointy rock, but it can’t resist the rover’s weight plus the force imparted by five other wheels shoving the sixth wheel into a pointy rock. The forces are worse for the middle and front wheels than they are for the rear wheels …”
Talking about the fate of the Mars mission in the aftermath of the recent development, Lakdawala said that the wheel problems will not end the mission, however, it would affect the pace of the mission. In her post, she wrote:
“The biggest effect of the wheel damage problem is to slow the mission down. And that’s what will limit how much Curiosity accomplishes. By not traveling as fast, and by having to limit their path choices, the amount of exploration that they can do is necessarily less than if they could go gallivanting across the bedrock outcrops at will.”
Summing up the whole conversation between Erickson and akdawala, it is concluded that the wheel problem is a serious issue, but it has no effect on the capability of the rover, at least presently.