On the 24th of January 2004, the Opportunity rover touched down on the surface of Mars. Opportunity rover was one of two rovers tasked with discovering ancient evidence of water on the Martian surface. After travelling 45km over the incredible Martian landscape, it did precisely that. Despite a life expectancy of just 90 days, Opportunity rover ended up engaged on Mars for an incredible 14 years earlier than succumbing to an enormous dust storm in 2018.
Although Opportunity’s rover time has come to an end, its incredible scientific discoveries live on in NASA’s ‘Curiosity’ rover. After a 6 month journey through space, Curiosity rover finally made Mars it’s home when it touched down on the 6th of August 2012. Armed with an array of advanced instruments, Curiosity rover looked to make new discoveries about the Martian climate and the geological processes that shaped Mars over its lifetime.
Since arriving on Mars, Curiosity’s important focus has been on Gale crater, which had been an area of high interest for scientists. Almost right away, Curiosity rover discovered strong evidence that this crater was once filled with water. In the past, rivers of liquid water would have flown into the crater carrying sand, silt and gravel together with it. Over time, these layers would build up and compress into rock – leaving a snapshot in time for Curiosity rover to discover. In order to further examine these ancient formations, Curiosity rover drilled into the lake bed and discovered a number of types of natural compounds.
These are chemical compounds that contain carbon, one of the most common components found in present in life on Earth. Although there is a lot of carbon in our solar system that doesn’t originate from life, this was a great sign that microbial life might have existed on Mars billions of years ago.
Curiosity rover continues to journey around Gale crater, discovering interesting formations and analyzing rock samples. So far, Curiosity rover has travelled 22km across the Martian surface – but it has not all been smooth sailing. Over the past 7 years, the rough Martian terrain has caused a significant amount of harm to Curiosity’s rover wheels. This is just one of the many problems that threaten Curiosity rover on the Martian surface.
In order to reduce tyre wear, the engineers that control the rover have started to re-route Curiosity rover on its journey, to avoid the harshest of terrain. Curiosity remains in close communication with Earth via the Deep Space Network, which consists of antenna complexes at three locations around the world. The rover uses a steerable high-gain antenna which can be pointed immediately towards Earth.
The data rates when talking directly to Earth are slow, so Curiosity rover often sends its data through the Mars Reconnaissance Orbiter. This orbiter passes over the Curiosity rover for around 8 minutes each day. In that short period of time, Curiosity can send around 30 megabytes of data up to the orbiter which can then pass it onto Earth. If Curiosity was to send the same amount of data directly to Earth, it might take 20 hours.
Communicating directly with Earth also uses a lot of energy from the spacecraft’s batteries, so sending data can only be done for a few hours per day. Curiosity rover is powered by a radioactive thermoelectric generator. This works by converting heat from radioactive isotopes into electricity. This electricity charges two lithium-ion batteries, allowing Curiosity to hold high energy tasks each day.
The RTG is anticipated to fully power Curiosity rover until at least 2026. After that, the power will decrease and the quantity of movement and science it can perform Although Curiosity rover will continue to limp on, it’s entirely possible that mechanical failure or the Martian climate might stop Curiosity’s rovers exploration before its power runs out. A Martian dust storm, much like the one which silenced Opportunity, might also be the end of Nasa Curiosity’s mission.
Dust storms on Mars form clouds which may reach as much as 100km above the surface of the mars. The dust particles which circulate during these storms are small and slightly electrostatic, so they can often stick to the rover’s surfaces and interfere with electrical parts. Curiosity is just one of many rovers which will, in time, come to discover the endless bounds of space. The Mars 2020 rover is set to launch later this year and is anticipated to land on Mars in early 2021.
While Curiosity rover was sent to Mars to discover habitable conditions, the 2020 mission takes things a step further and hopes to find real proof of mars microbial life. Mars rovers are becoming more complex, more intelligent and more useful. And whereas Curiosity rovers may have many years left to roam, its electrical energy weakens each day and the threat of dust storms could easily be the end for Curiosity mission.
Over time, engineers will slowly start shutting off instruments to preserve power, until Curiosity sends its last bit of information and disappears silently into the Martian landscape. Either way, we can appreciate the enormous amount of data that Curiosity has collected on Mars and the unimaginable journey it’s been on to get there.