In July of 2020, NASA will place an unnamed rover (currently known as Mars 2020) on top an Atlas V rocket in Cape Canaveral, Florida. This car sized rover will be blasted off Earth and shot towards our neighbouring planet, Mars. It will travel through deep space for six months before arriving at the red planet. It will break through Mars’ thin atmosphere and land in a region known as Jeziro crater in February 2021. Mars 2020 will join a suite of spacecraft already at Mars including its predecessor Curiosity and six orbiting satellites. In recent years, Mars has been a favourable target for exploration, with discoveries of seasonal water flows and spikes of methane piquing scientists’ interest in the search for life beyond Earth. This neighbouring world has captivated our imagination for millennia, and we are now closer than ever to answering whether life once existed on Mars…or potentially even exists there today.
Mars was once thought to be an Earth-like world before the first spacecraft provided us with a close-up view. Observations by astronomers in the 1800s reportedly showed ‘canals’ on Mars, believed to have been constructed by life forms to transport water across the planet for irrigation and agriculture. Newspapers at the time even went as far as speculating about Martian life as if it has been proven. This idea was the inspiration behind H.G. Wells novel War of the Worlds, telling of an invasion of Earth by aliens who were fleeing Mars. The idea bordered on fantasy, but it quickly fell out of favour when further examination of the planet in 1909 during a planetary opposition with Earth showed that there were no canals to be seen anywhere on the planet; it was merely an optical illusion of different surface features. After the space race in the 1960s, both the USA and then Soviet Union quickly turned their gaze towards Mars. Both began sending probes to fly-by the red planet, with many failures in the beginning. The American Mariner 4 probe conducted the first successful fly-by in 1965, beaming back the first ever close-up images of the Martian surface. It showed us Mars was a heavily cratered, dry, and seemingly dead world. This confirmed what many scientists had begun speculating over the years; life on Mars was seemingly impossible.
Although the first images did not depict a lush, water-laden world as scientists had once hoped, many missions continued to be sent to Mars as we began to discover more about this foreign world. The first surface missions like Viking were stationary landers that did not move and were confined to studying the area directly around them. Sojourner became the first successful rover after landing in 1997. Although a proof of concept that did not travel far, this mission showed us that rovers were a viable means of exploration, meaning we could explore larger areas and direct rovers to specific areas of interest for scientists. The hugely successful Spirit and Opportunity rovers followed, both landing in 2004. These twin rovers far outlived their designed lifespans and gave us a wealth of new information on Mars. Opportunity lasted an incredible 14 years despite being designed to last three months and travelled over 45km across the Martian surface. NASA’s latest rover to the red planet is Curiosity, which landed in 2012. It too has outlived its expected life span of two years as it continues to explore to this day. Curiosity is the most complex rover ever sent to Mars with a suite of scientific instruments including 17 cameras and a laser used to vaporise rock. In recent years, Curiosity has detected peaks of methane in the Martian air, alluding to the possibility that this could be caused by organic and biological processes like here on Earth. We know that Mars today is not the water-world we hoped it was, but decades of successful Mars missions have shown us it was once very Earth-like with oceans of liquid water. This makes it the most likely candidate to find evidence of past or present life in our Solar System.
The new rover
The design of Mars 2020 is based largely on the already successful design of Curiosity. It will use the same EDL systems (Entry, Descent, Landing) that Curiosity did in 2012, as well as looking visually very similar. Mars 2020 is designed to specifically search for astrobiology and signs of past habitability on Mars and will carry more complex instruments to search for signs of possible life. One instrument called Mars Oxygen ISRU Experiment (or MOXIE) is a technology demonstration that will produce oxygen on the Martian surface for the first time. This is essential for the eventual humans who will soon follow. Mars 2020 will also carry a small helicopter known as MHS. This will be the first ever helicopter to fly on another world, and it will scout out areas for the rover to explore in advance.
Landing any spacecraft on another planet is no easy task, and the engineers who worked on this mission will be watching nervously as Mars 2020 begins the process of landing in 2021. Tens of thousands of people watched with excitement when Curiosity landed in 2012, and it’s no doubt that Mars 2020 will bring in even more anticipation as we send off our latest robotic pioneer to its new home.
Spacecraft play a vital role in our exploration of cosmos in our search for life beyond Earth. These robots do the hard work for us by scouting out the conditions, finding clues about past life, and pointing us in the right direction. We are closer than ever before in answering the question of whether we are alone or not. The Mars 2020 rover may not be able answer the question point blank, but it will tell us where to look when we finally take our first steps on another planet ourselves in the near future.
Images: TOP: Curiosity watches a sunset on Mars while exploring Gale crater; ABOVE LEFT: The Curiosity rover and its parachute seen descending towards Mars, taken from the orbiter MRO; ABOVE RIGHT: Mars 2020 carries a suite of complex scientific instruments including the first ever helicopter to fly on another world.
Josh Kirkley, Astronomy Educator