Mission Overview

Mars Science Laboratory/Curiosity

National Aeronautics and Space Administration

NASA’s Mars Science Laboratory mission set down a large, 

mobile laboratory — the rover Curiosity — at Gale Crater, using 

precision landing technology that makes many of Mars’ most 

intriguing regions viable destinations for the first time. During the 

23 months after landing, Curiosity will analyze dozens of samples 

drilled from rocks or scooped from the ground as it explores with 

greater range than any previous Mars rover.

Curiosity carries the most advanced payload of scientific gear 

ever used on Mars’ surface, a payload more than 10 times as 

massive as those of earlier Mars rovers. Its assignment: Investigate whether conditions have been favorable for microbial life and 

for preserving clues in the rocks about possible past life.

The Mars Science Laboratory spacecraft launched from Cape 

Canaveral Air Force Station, Florida, on Nov. 26, 2011. Mars 

rover Curiosity landed successfully on the floor of Gale Crater on 

Aug. 6, 2012, Universal Time (evening of Aug. 5, Pacific Time). 

Engineers designed the spacecraft to steer itself during descent 

through Mars’ atmosphere with a series of S-curve maneuvers 

similar to those used by astronauts piloting NASA space shuttles. 

During the three minutes before touchdown, the spacecraft 

slowed its descent with a parachute, then used retrorockets 

mounted around the rim of an upper stage. In the final seconds, 

the upper stage acted as a sky crane, lowering the upright rover 

on a tether to the surface.

Curiosity is about twice as long (about 3 meters or 10 feet) and 

five times as heavy as NASA’s twin Mars Exploration Rovers, 

Spirit and Opportunity, launched in 2003. It inherited many design 

elements from them, including six-wheel drive, a rocker-bogie 

suspension system and cameras mounted on a mast to help the 

mission’s team on Earth select exploration targets and driving 

routes. Unlike earlier rovers, Curiosity carries equipment to gather 

samples of rocks and soil, process them and distribute them to 

onboard test chambers inside analytical instruments.

NASA’s Jet Propulsion Laboratory (JPL), Pasadena, Calif., builder 

of the Mars Science Laboratory, engineered Curiosity to roll over 

obstacles up to 65 centimeters (25 inches) high and to travel up 

to about 200 meters (660 feet) per day on Martian terrain.

The rover’s electrical power is supplied by a U.S. Department of 

Energy radioisotope power generator. The multimission radioisotope thermoelectric generator produces electricity from the heat 

of plutonium-238’s radioactive decay. This long-lived power supply gives the mission an operating lifespan on Mars’ surface of a 

full Mars year (687 Earth days) or more. At launch, the generator provided about 110 watts of electrical power to operate the 

rover’s instruments, robotic arm, wheels, computers and radio. 

Warm fluids heated by the generator’s excess heat are plumbed 

throughout the rover to keep electronics and other systems at 

acceptable operating temperatures.

The mission uses radio relays via Mars orbiters as the principal 

means of communication between Curiosity and the Deep Space 

Network of antennas on Earth. 

The overarching science goal of the mission is to assess whether 

the landing area has ever had or still has environmental conditions 

favorable to microbial life, both its habitability and its preservation.

Curiosity landed near the foot of a layered mountain inside Gale 

Crater. Layers of this mountain contain minerals that form in water 

and may also preserve organics, the chemical building blocks of 

life. The portion of the crater floor where Curiosity landed has an 

alluvial fan likely formed by water-carried sediments. Selection of 

Gale Crater followed consideration of more than 30 Martian locations by more than 100 scientists participating in a series of open 

workshops.

Selection of a landing site of prime scientific interest benefited 

from examining candidate sites with NASA’s Mars Reconnaissance Orbiter since 2006, from earlier orbiters’ observations, 

and from a capability of landing within a target area only about 

20 kilometers (12 miles) long. That precision, about a five-fold 

improvement on earlier Mars landings, makes feasible sites that 

would otherwise be excluded for encompassing nearby unsuitable 

terrain. The Gale Crater landing site is so close to the crater wall 

that it would not have been considered safe if the mission were 

not using this improved precision.

Advancing the technologies for precision landing of a heavy payload yields research benefits beyond the returns from Mars Science Laboratory itself. Those same capabilities would be important for later missions, both to pick up rocks on Mars and bring 

them back to Earth and to conduct extensive surface exploration 

for Martian life.
JPL 400-1491 8/12 NASA Facts

National Aeronautics and Space Administration

Jet Propulsion Laboratory

California Institute of Technology

Pasadena, California

www.nasa.gov

For more information about MSL/Curiosity, go to: 

www.nasa.gov/msl

mars.jpl.nasa.gov/msl

Science Payload

In April 2004, NASA solicited proposals for specific instruments and investigations to be carried by Mars Science Laboratory. The agency selected eight of the 

proposals later that year and also reached agreements with Russia and Spain for 

carrying instruments those nations provided.

A suite of instruments named Sample Analysis at Mars analyzes samples of 

material collected and delivered by the rover’s arm, plus atmospheric samples. It 

includes a gas chromatograph, a mass spectrometer and a tunable laser spectrometer with combined capabilities to identify a wide range of organic (carboncontaining) compounds and determine the ratios of different isotopes of key elements. Isotope ratios are clues to understanding the history of Mars’ atmosphere 

and water. The principal investigator is Paul Mahaffy of NASA’s Goddard Space 

Flight Center, Greenbelt, Md.

An X-ray diffraction and fluorescence instrument called CheMin also examines 

samples gathered by the robotic arm. It is designed to identify and quantify the 

minerals in rocks and soils, and to measure bulk composition. The principal investigator is David Blake of NASA’s Ames Research Center, Moffett Field, Calif.

Mounted on the arm, the Mars Hand Lens Imager takes extreme close-up pictures of rocks, soil and, if present, ice, revealing details smaller than the width 

of a human hair. It can also focus on hard-to-reach objects more than an arm’s 

length away. The principal investigator is Kenneth Edgett of Malin Space Science 

Systems, San Diego.

Also on the arm, the Alpha Particle X-ray Spectrometer for Mars Science Laboratory determines the relative abundances of different elements in rocks and soils. 

Dr. Ralf Gellert of the University of Guelph, Ontario, Canada, is principal investigator for this instrument, which was provided by the Canadian Space Agency.

The Mars Science Laboratory Mast Camera, mounted at about human-eye 

height, images the rover’s surroundings in high-resolution stereo and color, with 

the capability to take and store high-definition video sequences. It can also be 

used for viewing materials collected or treated by the arm. The principal investigator is Michael Malin of Malin Space Science Systems.

An instrument named ChemCam uses laser pulses to vaporize thin layers of material from Martian rocks or soil targets up to 7 meters (23 feet) away. It includes 

both a spectrometer to identify the types of atoms excited by the beam, and a 

telescope to capture detailed images of the area illuminated by the beam. The 

laser and telescope sit on the rover’s mast and share with the Mast Camera the 

role of informing researchers’ choices about which objects in the area make the 

best targets for approaching to examine with other instruments. Roger Wiens of 

Los Alamos National Laboratory, Los Alamos, N.M., is the principal investigator.

The rover’s Radiation Assessment Detector characterizes the radiation environment at the surface of Mars. This information is necessary for planning human 

exploration of Mars and is relevant to assessing the planet’s ability to harbor life. 

The principal investigator is Donald Hassler of Southwest Research Institute, 

Boulder, Colo.

In the two minutes before landing, the Mars Descent Imager captured color, 

high-definition video of the landing region to provide geological context for the 

investigations on the ground and to aid precise determination of the landing site. 

Pointed toward the ground, it can also be used for surface imaging as the rover 

explores. Michael Malin is principal investigator.

Spain’s Ministry of Education and Science provided the Rover Environmental 

Monitoring Station to measure atmospheric pressure, temperature, humidity, 

winds, plus ultraviolet radiation levels. The principal investigator is Javier GómezElvira of the Center for Astrobiology, Madrid, an international partner of the NASA 

Astrobiology Institute.

Russia’s Federal Space Agency provided the Dynamic Albedo of Neutrons instrument to measure subsurface hydrogen up to 1 meter (3 feet) below the surface. 

Detections of hydrogen may indicate the presence of water in the form of ice or 

bound in minerals. Igor Mitrofanov of the Space Research Institute, Moscow, is 

the principal investigator.

In addition to the science payload, equipment of the rover’s engineering infrastructure contributes to scientific observations. Like the Mars Exploration Rovers, Curiosity has a stereo navigation camera on its mast and low-slung, stereo 

hazard-avoidance cameras. Equipment called the Sample Acquisition/Sample 

Preparation and Handling System includes tools to remove dust from rock surfaces, scoop up soil, drill into rocks and collect powdered samples from rocks’ 

interiors, sort samples by particle size with sieves, and deliver samples to laboratory instruments.

The Mars Science Laboratory Entry, Descent and Landing Instrument Suite is a 

set of engineering sensors designed to measure atmospheric conditions and performance of the spacecraft during the arrival-day plunge through the atmosphere, 

to aid in design of future missions.

Program/Project Management

The Mars Science Laboratory is managed for NASA’s Science Mission Directorate, Washington, D.C., by JPL, a division of the California Institute of Technology 

in Pasadena. At NASA Headquarters, David Lavery is the Mars Science Laboratory program executive and Michael Meyer is program scientist. In Pasadena, 

Peter Theisinger of JPL is project manager and John Grotzinger of Caltech is 

project scientist.