Mars Rover Curiosity is the latest in a robotic chain of explorers created by scientists and engineers, with each new iteration building on past Mars rovers’ successes and failures. Mars Rover Curiosity is similar to rovers that have gone before. But it’s the most advanced rover ever, and the instruments it carries to analyze Mars will give us more insight than we’ve ever had.

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There’s still a lot for us to learn. The existence of life (or past evidence of it), deposits of water, the components of its surface–the mysteries of the red planet are still many, and the chance to explore it is a rare one. So scientists and engineers have spared no expense ensuring that Curiosity will have the equipment it needs to educate us about our planetary neighbor.

When it lands on August 5, the rover will shoot neutrons into the rocky surface of Mars, monitor every movement of the wind, vaporize and analyze samples, and otherwise use the best space-age technology available to uncover the planet’s secrets.


Radiation Assessment Detector

Curiosity itself doesn’t mind radiation all that much. But the human explorers we plan to one day send to Mars might be a little more picky about the stuff. So as one of the few tools sent to Mars to prepare for human exploration, the Radiation Assessment Detector (RAD) has an important job. About the size of a small toaster, the device will look into the Martian atmosphere and use a stack of silicon detectors and a crystal of cesium iodide to measure cosmic rays and solar particles. As high-energy charged particles from the atmosphere head through the detectors, they produce electron or light pulses, allowing the RAD to determine their energy. The process could also tell us more about how radiation might have once hindered the development of life on Mars.

Mastcam Camera

The Mast Camera, also known as the Mastcam, isn’t the first camera ever strapped to a rover, but it could easily be the most advanced. On board Curiosity, it’ll take color images and video, and be able to stitch the images together to create beautiful panoramas of the red planet’s canyon-scapes. It features high-resolution lenses and will be able to take HD video at 10 frames per second, while a monochromatic setting can take single-color images to help analyze light patterns in different portions of the electromagnetic spectrum. It’s a lot of information, but it comes packaged with an internal data buffer that can store thousands of images–or hours of HD video–to send back to Earth.


Engineers have a lot to worry about during Curiosity’s descent through the atmosphere–as advertised by their “seven minutes of terror” video. But during that descent, Curiosity will already be working, gathering data for the next set of missions to Mars. The MSL Entry, Descent and Landing Instrumentation (MEDLI) will monitor the heat and pressure it undergoes upon entry. It’s actually made up of two kinds of instruments: MISP (MEDLI Integrated Sensor Plugs) and MEADS (Mars Entry Atmospheric Data System). Seven of each type sit on Curiosity’s heat shield. (The system is the black box in the left of the photo.) MISP will measure just how hot things get when it’s burning through the atmosphere. (Short answer: really hot. Slightly less short answer: three times hotter than a space shuttle going through Earth’s atmosphere.) Curiosity’s thermal protection system will actually burn off, and MISP will measure the rate of burning, known as “recession.” MEADS will take a measurement of the atmospheric pressure during descent. Arranged in a cross pattern, the seven sensors will allow engineers to determine Curiosity’s orientation as a function of time. Once they know that, they can grade Curiosity’s descent against their predictions, then improve them for next time.


Maybe the most futuristic of Curiosity’s tools, the ChemCam is an analyzing laser. By pointing it at areas as small as 1 millimeter, Curiosity will be able to determine the elemental composition of vaporized materials. A spectrograph will monitor the plasma created from zapping rocks and soil, then analyze its geological structure. It can be used in another handy way, too: the laser can clear away dust, allowing for much more detailed photographs, and if Curiosity can’t get close enough to take a closer look at a piece of Mars, ChemCham can do it from 23 feet away. From that distance, it’s still able to learn the type of rock in a sample, the composition of soil, if a sample contains chemicals harmful to humans, and if it contains water or ice.

Mars Hand Lens Imager

Sometimes, the tech of mere mortals can stand up to an uber geologist like Curiosity. The hand lens, for example, is an important, commonly used geological tool. And the Mars rover will be carrying its own robotic version on board. The Mars Hand Lens Imager (MAHLI) will help give an extremely close view of samples to scientists back at home. Extremely close: MAHLI will be able to take color images as small as 12.5 micrometers (less than human hair size). A traditionally white, flashlight-type light source and an ultraviolet, black light source will allow it to work day and night. The UV light also has an ulterior function: it can light up samples to detect carbonate and evaporite minerals, which would be evidence that water helped form Mars.

The Rover Environmental Monitoring Station

In addition to being a great geologist, The Rover Environmental Monitoring Station (REMS) will make Mars Rover Curiosity into a great cosmic meteorologist. In daily and seasonal reports, REMS will send scientists information on atmospheric pressure, humidity, UV radiation, wind speed and direction, air temperature, and ground temperature. Two booms will monitor wind speed, helping us to understand how breezes and one of the biggest weather phenomena on Mars, dust, operate. An inner sensor exposed to the atmosphere will catalogue changes in pressure caused by changes in the weather, and a filter keeps all the unwanted dust out.

Alpha Particle X-Ray Spectrometer

To get an accurate analysis of samples on Mars, the Alpha Particle X-Ray Spectrometer (APXS) works up close. When it makes contact with a rock or soil sample, it’ll bombard it with alpha particles and X-rays emitted as the element curium, placed inside, decays. The rays knock electrons from the sample out of orbit, and the energy released can be measured by sensors. This much energy, you’ve got sodium. Count again, and you’ve got something else. It works day and night, but can take a little while to get a thorough analysis: as long as two to three hours to determine all of the elements that a sample contains, although 10 minutes is enough to see the major elements at a glance.

Chemistry and Mineralogy X-Ray Diffraction Instrument

Mars Rover Curiosity’s mission isn’t just one that represents the future of space tech; it’s also about uncovering the history of Mars. Minerals can be a strong indication of what the planet looked like as it was forming. Certain minerals, for example, may indicate that lava once flowed near a certain area. The chemistry and Mineralogy X-Ray Diffraction Instrument (CheMin) will be able to find and analyze those and a whole lot more. Curiosity will be able to drill into rocks and collect a powder, then store it internally. CheMin will shoot tiny X-rays at the rock or soil sample; when they interact with it, some are absorbed and re-emitted at different energies. By calculating those energies, CheMin will be able to determine the atoms present in the sample. What minerals they discover might also hint at how much of a role water played in forming the planet’s minerals. Certain minerals contain water, and CheMin can tell the difference between those and the waterless variety. It might even clue scientists in on if Mars could have once supported life.

The Sample Analysis at Mars Instrument

The Sample Analysis at Mars (SAM) instrument is the technology behemoth of the Mars Rover Curiosity mission. A suite of three instruments, it makes up more than half of the scientific payload of Curiosity, and focuses on striking gold by finding evidence of life on Mars. The mass spectrometer, gas chromatograph, and tunable laser spectrometer inside can find compounds of carbon, such as methane, while also searching for lighter elements that might also indicate life, like hydrogen, oxygen, and nitrogen. The mass spectrometer will separate elements by mass, the gas chromatograph will vaporize samples using heat to analyze them, and the laser spectrometer will measure how much of various isotopes are in the samples. Accurate to within 10 parts per thousand, it may be the best chance Curiosity has of discovering life–past or present.

Dynamic Albedo of Neutrons

Even if Curiosity doesn’t, say, run into a puddle, there are still ways for it to discover water on Mars. Cosmic rays constantly hit the planet’s surface, knocking neutrons out of orbit. Hydrogen atoms in water or ice will slow those neutrons down, and that can be detected. A pulsing neutron generator called the Dynamic Albedo of Neutrons (DAN) can detect water content as small as one-tenth of 1 percent. DAN will send a beam of neutrons into the surface, three to six feet into the ground; if it detects a large amount of slower neutrons, that’s decent evidence there’s water underneath.