Searching for Past Life

Curiosity: a compelling desire to learn something new, a characteristic of any astronomer, and the most recent rover launched toward Mars. Its goal is to search for evidence that the planet may once have held microscopic life and to help plan human exploration of Mars in the future. This long-awaited mission is currently on a 570 million kilometer journey to the red planet.

It took nearly a decade before Curiosity even reached the launch pad. NASA began planning the mission in 2003 with a launch planned for 2009. When the rover reached its deadline however it wasn’t quite ready and the launch had to wait another two years before Mars passed close to Earth again.

The Launch and Landing

An Atlas V-451 rocket lifts off into space Saturday morning at the Kennedy Space Center carrying Curiosity.

More than 13,000 peered into the distance at the Kennedy Space Center as the rover launched into a cloudy sky on Saturday morning. It was NASA’s first launch to Mars in four years, and the first launching of a Martian rover in eight years. Curiosity is the world’s biggest extraterrestrial explorer. The rover weighs 1 ton, is 10 feet long, 9 feet wide, and 7 feet tall. In total it is 10 times more massive than previous Mars rovers.

Curiosity separated from the Atlas V rocket 44 minutes into the mission. Just six minutes after the spacecraft separation officials on the ground received a signal letting them know that all had gone well.  The spacecraft is now free of the Atlas V-541 rocket and is headed toward Mars. In August 2012 Curiosity will reach Mars and the mission team is prepared for its landing.

Both Spirit and Opportunity used air bags to land on Mars.  Curiosity is much too large. During the three minutes before touchdown, it will slow its descent with a parachute.  During the final few seconds it will be lowered on a tether to the surface. It is a landing system maneuver which has never been tried before, but is expected be highly accurate.

The rover will then spend two years in the Gale Crater, which is 154 kilometers in diameter and holds a mountain that is higher than Mount Rainier in Seattle.  This site is not only a visually dramatic landscape but is expected to hold a plethora of minerals that were once formed in water. Curiosity will land at a specific location which was most likely formed by water-carried sentiments. It will also explore the layers at the base of the mountain, which contain clays and sulfates, both of which form in water. The rover will spend one Martian year and two Earth years exploring this crater.

A great video that will help make sense of the landing and what Curiosity will do on Mars can be found here.

Curiosity Itself

The explorer holds 10 science instruments. Impressively these instruments are designed to sample the material collected and delivered by the rover’s arm themselves. Curiosity’s 7 foot arm will drill into the ground (a feat that has never been done before) while the instruments inside the 7-foot mast will analyze the red rock. Following is a list of these 10 instruments and their goal:

1.) The Mars Science Laboratory Mast Camera (MastCam) will be used to capture high-resolution color pictures and videos of the Martian landscape. These images will help the mission team drive and operate Curiosity.

2.) The Mars Hand Lens Imager (MAHLI) will take images allowing us to see features as small as 12.5 microns. This instrument is mounted on Curiosity’s arm and will also be able to focus on out-of-reach objects.

3.) The Mars Descent Imager (MARDI), a small camera, will be used to record the astonishing video of the rover’s decent to the surface. This video will provide information on Curiosity’s surroundings and allow the NASA team to plan where the rover will work.

4.) The Sample Analysis at Mars (SAM) instrument weights 38-kilograms and took up half of the mission’s budget. Needless to say it’s crucial to the mission. It is actually a group of three separate instruments: a mass spectrometer, a gas chromatograph, and a laser spectrometer. SAM will search for carbon-containing compounds – the mission’s primary goal. The rover’s robotic arm will drop samples into SAM, located in Curiosity’s main body.

5.) The Chemistry and Mineralogy (CheMin) instrument will identify different types of minerals and note their abundance. It will do so by shining an X-ray beam through the sample and noting how the beam is diffracted based on the crystalline structures. Knowing the mineral makeup of Marks will help the mission team better understand past environmental conditions on Mars.

6.) The Chemistry and Camera (ChemCam) instrument will use laser pulses to vaporize thin layers of material in the Martian rocks and soil. A spectrometer will then analyze the composition of the vaporized pieces by observing the types of atoms excited by the beam. This will allow Curiosity to study the rocks that are out of reach of its robotic arm and allow the mission team to determine whether or not to send Curiosity there in order to investigate further.

7.) The Alpha Particle X-ray Spectrometer (APXS) mounted on Curiosity’s arm will measure the abundance of chemical elements in the soil. It will do so by shooting X-rays and alpha particles (helium nuclei) at the samples and analyzing the released X-rays.   The energies of these X-rays will allow the team to identify the exact elements in the soil.

8.) The Dynamic Albedo of Neutrons (DAN) instrument provided by Russia’s Federal Space Agency will allow Curiosity to search for ice and water up to one meter beneath the surface. The instrument will shoot a beam of neutrons at the ground and then measure the speed at which these neutrons reflect back. Hydrogen atoms slow neutrons down. Thus slower neutrons will signify underground water.

9.) The Radiation Assessment Detector (RAD) will measure high-energy radiation. A secondary goal of the rover is to measure the radiation on Mars. This will play a useful role in determining whether it is safe to send astronauts to Mars in the near future.

10.) The Rover Environmental Monitoring Station (REMS) provided by Spain’s Ministry of Education and Science will act like a weather station. It will monitor the atmospheric pressure, humidity, wind, and temperature. Researchers will have a daily weather update.

Curiosity will work for 23 months after landing. Unlike Spirit and Opportunity its power source is 10.6 pounds of radioactive plutonium. It was simply too much work for a set of solar panels to power. So it’s a mobile, nuclear-powered laboratory. A key benefit to using this power source is that Curiosity will be able to work when it’s cloudy and at night.

The world has launched more than three-dozen missions to Mars. Half of them have succeeded. This $2.5 billion mission is of a much larger scale than past missions and a success will not only reveal more about the red planet but also help us plan future missions. Also known as the Mars Science Laboratory you can find updates on the mission’s homepage.

About Shannon Hall

While writing for astrobites I was a graduate student at the University of Wyoming working on exoplanet research. Previously, I graduated from Whitman College with two degrees: one in physics-astronomy and one in philosophy. I am now working toward my career goals in science journalism and education. Feel free to visit my website.

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