TechTheDay

Landing the Opportunity rover or the Mars Exploration Rover – B (MER-B) on Mars was a big deal. It is one notable Martian exploration mission.  This robotic rover in the Red Planet is the exploration vehicle with the most distance traveled on Martian soil, at 25 miles or 40 kilometers. It has set the new greatest “off-world” travel record in 2014, having surpassed the record logged by the Lunokhod 2 rover of the Soviet Union (24 miles or 39 kilometers but on the Moon).

But why does the Opportunity rover need a memory wipe? The following are the details you would want to know about this space technology that has already done quite a significant contribution to the Martian exploration efforts of NASA.

Opportunity Rover – an Overview

Launched in July 7, 2003 as a part of NASA’s Mars Exploration Rover Mission, Opportunity landed on Martian soil in a space travel that took less than a year, arriving on Meridiani Planum (an area in Mars) on January 25, 2004. It reached Mars around three weeks after its twin rover, Spirit (aka MER-A), which landed on the other side of the planet. Since its Mars landing, Opportunity has been active with its exploration journey and continues to send data to Earth. Notably, it has already surpassed its estimated useful deployment by more than 10 years. It has exceeded its designed lifespan by more than 40 times as it continues to report valuable information gathered in Mars.

Opportunity was designed for a 90 sol duration of activity. Sol refers to a Martian day, which is slightly longer than an Earth day. It is equivalent to 24 hours, 39 minutes, and 35.244 seconds on Earth. Opportunity lists as its highlight accomplishments the finding of extra-Martian meteorites such as Heat Shield Rock and the two-year investigation on Mars’ Victoria crater. The rover also managed to reach Endeavour crater in 2011, or years after its designed mission period.

Reasons for the Memory Wipe Need

In recent months, however, Opportunity already showed major signs of degradation. According to NASA’s Jet Propulsion Laboratory, last month, the rover had to do a system reset several times due to memory problems. One of the major culprits identified is the “worn-out cells in the flash memory.” After several years of operating on alien grounds, the flash memory cell degradation was only expected. A memory reformatting, nevertheless, can still extend the life of Opportunity’s flash memory and allow it to continue with its exploration activities.

Opportunity is currently suffering from “amnesia events” similar to what Spirit, its twin rover, suffered before. By the way, Spirit only stayed operational for six years, sending its last data transmission to Earth on March 22, 2010. Opportunity has outlived Spirit but may soon suffer the same fate if the problems are not adequately addressed.

The Remote Memory Wipe Process

The remote flash reformatting is a low risk process according to NASA’s Mars Exploration Rover Project manager John Callas in an interview with Ars Technica. It is similar to what is being done by IT administrators for the systems they maintain on Earth. It can even be likened to the memory wiping that is now possible in smartphones and tablets.

The memory wiping or reformatting process for opportunity follow the typical steps. First, all the data currently stored on Opportunity’s flash memory will have to be downloaded (backup creation). Next, Opportunity’s system will be switched to a “safe mode” to make it independent from the flash memory. Under “safe mode,” Opportunity will be using a slower but more reliable communication and data transfer system. Memory wiping will then proceed.

Hopefully, Opportunity’s useful life gets extended after the reformatting. It’s already impressive that it has operated 10 years beyond its intended use but it will always be better to see it continue working for a couple more years.

Opportunity uses flash memory technology developed decades ago so it is expected that its memory isn’t going to be as reliable and fast as the flash memory units in current use. Still, it would be excellent for Opportunity to continue being operational since most of its other parts are still suitable for exploration work. It takes billions of dollars to send rovers to Mars so having machines that last longer than expected are definitely a boon to Earth’s space research efforts.

There have already been follow-up exploration vehicles sent to Mars by NASA after Spirit and Opportunity. The latest one is the much publicized Curiosity that landed on Martial soil in August 2012. NASA plans to send another rover to Mars in 2020 and even humans by 2030. By then, our storage media technologies shall have vastly improved that they may last longer than the units used on the Spirit and Opportunity rovers.