Being the closest planet to Earth—only 80 million kilometers away—Mars has always been looked at as the big red apple in space exploration. Yet, the small planet represents quite a challenge with its harsh topography, toxic atmosphere, and extreme climate. Mars was named after the ancient Roman god of war; it is the fourth planet from the Sun with half the size of the Earth, and it has two moons: Phobos and Deimos.
The first attempt to send a probe to the surface of Mars was carried out by the Soviet Union during the 1960s; however, the probe nicknamed MARSNIK 1 failed to reach Earth’s orbit and the mission was a failure. In 1993, NASA launched the Mars Exploration Program (MEP), seeking to achieve four ambitious goals: to determine if life ever existed on the Red Planet, study and characterize its geology and climate, and eventually prepare for human exploration on its surface.
Massive challenges have faced the program over the years, from entering the planet’s orbit, to descending and landing on the surface. One of the toughest challenges was developing technologies that can function properly in the hostile environment of Mars. Countless engineering maneuvers had to be applied to ensure that the rovers, balloons, and sampling systems could withstand and operate properly under the extreme environmental conditions of the Martian desert.
The basic strategy of the MEP was simply to seek signs of life in order to prove if Mars was, is, or can ever be a habitable environment for biological life forms. As water is the key to life, the earlier Mars missions—2001 Mars Odyssey, Mars Exploration Rovers, Mars Reconnaissance orbiter, and Mars Phoenix Lander—focused on discovering any signs of past or present existence of water. Images from rover expeditions suggested that water did exist on Mars; the sizes, shapes, and distribution of geological forms—such as sand, grit, and small rocks—strongly indicate they were shaped and moved by water in the ancient past.
Until now, the Curiosity rover performed all expeditions. The 899 kg car-sized piece of equipment was launched to Mars on 26 November 2011 from Cape Canaveral Air Force Station; it landed on 6 August 2012 on Aeolis Palus*. The initial goal of Curiosity was to spend 687 on Gale crater on Mars; yet, it has been persistently comping Martian soil for 1532 days—nearly four years—powered day and night, in all seasons, by its own set of Radioisotope Thermoelectric Generators (RTGs). Excess heat is channeled via internal warming system to keep the rover’s sensitive electronic sampling and analyzing equipment in normal operating temperatures protected from Martian frosty ambience.
As Earth’s first ambassador to Mars, Curiosity has been doing a great job studying Martian geology and climate, and investigating if the selected research field, Gale crater, has ever hosted any kind of microbial life. Curiosity is now providing information that, one day, will be the keystone for future human exploration on Mars.
However, sending humans to the surface of Mars will be a completely different challenge with an atmosphere 100 times thinner than that of Earth, and an average temperature of −63˚C. Descending and landing a human-carrying ship on the surface safely will be extremely difficult due to the uneven topography of the planet that is basically formed of mountainous terrains filled with rough rocky features as hills, craters and trenches. Landing locations must be selected carefully and landing thrusts must be designed to ensure soft and stable landings to avoid the danger of tipping off the vehicle.
The future of the MEP remains foggy. Due to the huge cost of previous missions and the unusually high failure rate, it became very difficult to rally enough public support to provide funds for any further missions. Nevertheless, scientists still hope that at some point in the near future there will be enough will and means to continue the Mars exploration marathon, and eventually collecting enough knowledge to enable the human race to finally visit its red shy neighbor.
References
marstech.jpl.nasa.gov
marsmobile.jpl.nasa.gov
This article was first published in print in SCIplanet, Winter 2017 issue.
Cover image by Freepik