Curiosity: Paving the Way for Martian Exploration
Even though sending humans to Mars is a mission for the future, we can already send probes, satellites and rovers to explore the red planet. The largest space rover ever built, Curiosity, landed in Gale Crater on 6th August 2012. The Curiosity rover was built to search for evidence of whether Gale Crater might have been habitable in the past.
About the same size as an old Mini Cooper and weighing 900 kg, landing the rover safely was incredibly difficult, particularly due to the thin Martian atmosphere. The reduced air resistance on Mars meant engineers had to think carefully about how to slow the spacecraft down from 13 000 mph to 0 without it crashing into the surface of Mars. A parachute was used to slow its descent and then 4 retrorockets were fired when it was 20 metres above the surface and the rover was lowered safely to the ground by nylon ropes. The landing was called the ‘7 minutes of terror’ especially as the NASA team didn’t know if it had landed safely until an hour or so after it happened due to delays in signal transmission.
Curiosity was designed to investigate the crater for at least one Martian year. It cost 2.5 billion dollars (1.6 billion pounds) and involved 7000 people around the US. It will read the geological history of the crater by looking at the rocks there and it will also look for other basic ingredients of life: carbon, hydrogen, nitrogen, phosphorus, sulphur and oxygen. The rover has various scientific instruments on board. It is designed to carry out many different experiments to ascertain whether Gale Crater may have been habitable in the past. It will analyse a gas called methane (made up of carbon and hydrogen) and help determine whether the methane is biological or from other sources – high levels of methane could be an indicator of life. An important detector on board measures the level of radiation and particles arriving at the surface from the Sun and other stars – astronauts on the International Space Station can suffer from radiation sickness in space as a result of their exposure to this. If we send people up there we need to know how to protect them.
Curiosity has many cameras: some at the front and back of the rover to help it drive over the uneven Martian surface; one on the end of the robotic arm that can take close-up images of the rock and one on the mast that takes high-resolution images and videos. There was even a descent camera that took amazing pictures of the rover reaching the surface of Mars and ejecting its parachute and heat shield.
It made its first contact with a rock called Jake Matijevic with its 2.1 metre robotic arm and has also taken scoops of martian soil for analysis on board. The biggest discovery to date came when it found rounded gravel – evidence for an ancient stream that once flowed over the surface of the crater. It is currently on its way to an area called Glenelg which is the intersection of three types of terrain, after which it will drive to Mount Sharp. This extraordinary rover could pave the way for future human exploration of the planet and the continuing search for extraterrestrial life.
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