Core Sample
Perseverance spots Santa Cruz on Mars
This image shows an artist concept of NASA Mars Atmosphere and Volatile Evolution MAVEN mission.

Mars Exploration Program

The Mars Exploration Program is a science-driven program that seeks to understand whether Mars was, is, or can be, a habitable world. To find out, we need to understand how geologic, climatic, and other processes have worked to shape Mars and its environment over time, as well as how they interact today.

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Four Science Goals for Mars Exploration

The key to understanding the past, present or future potential for life on Mars can be found in the four broad, overarching goals for Mars Exploration:

  • Goal 1: Determine if life ever arose on Mars.
  • Goal 2: Characterize the climate of Mars.
  • Goal 3: Characterize the geology of Mars.
  • Goal 4: Prepare for human exploration of Mars.

Our Exploration Strategy: Follow the Water!

To discover the possibilities for life on Mars--past, present or our own in the future--the Mars Program has developed an exploration strategy known as "Follow the Water."

Following the water begins with an understanding of the current environment on Mars. We want to explore observed features like dry riverbeds, ice in the polar caps and rock types that only form when water is present. We want to look for hot springs, hydrothermal vents or subsurface water reserves. We want to understand if ancient Mars once held a vast ocean in the northern hemisphere as some scientists believe and how Mars may have transitioned from a more watery environment to the dry and dusty climate it has today. Searching for these answers means delving into the planet's geologic and climate history to find out how, when and why Mars underwent dramatic changes to become the forbidding, yet promising, planet we observe today.

Future Missions

To pursue these goals, all of our future missions will be driven by rigorous scientific questions that will continuously evolve as we make new discoveries.

New technologies will enable us to explore Mars in ways we never have before, resulting in higher-resolution images, precision landings, longer-ranging surface mobility and even the return of Martian soil and rock samples for studies in laboratories on Earth.

Missions Supporting this Program

Perseverance Selfie with Ingenuity

Mars 2020: Perseverance Rover

The Mars 2020 mission Perseverance rover is the first step of a roundtrip journey to return Mars samples to Earth. (2020-present)

Rovers, helicopters, and rockets on Mars showing the robots that would collect and return a Mars sample

Mars Sample Return

NASA and ESA are planning ways to bring the first samples of Mars material back to Earth for detailed study. (Launching NET 2027)

Rover on Mars.

EXOMars Rover (ESA/Roscosmos)

NASA is providing critical elements to the astrobiology instrument on the ESA-led ExoMars rover, to explore whether life ever existed on Mars. (Launch suspended)



InSight was the first space robotic explorer to study in-depth the "inner space" of Mars: its crust, mantle, and core. (2018-2022)

Artist's concept of ESA's Trace Gas Orbiter.

ExoMars 2016 (ESA/Roscosmos)

NASA contributed communications relay and navigation aid to the ESA-led ExoMars Trace Gas Orbiter, to study the Martian atmosphere. (2016-present)

artist's concept of MAVEN and Mars


MAVEN is obtaining critical measurements of Mars' atmosphere to help understand dramatic climate change over the planet's history. (2013-present)

Illustration of Mars Reconnaissance Orbiter over Mars.

Mars Reconnaissance Orbiter

MRO studies the planet's atmosphere and terrain from orbit and serves as a key data relay station for other Mars missions. (2005-present)

Mars Curiosity Rover Selfie

Curiosity Rover

Curiosity is investigating Mars to determine whether the Red Planet ever was habitable to microbial life. (2011-present)

Photo of surface of Mars with Phoenix scoop

Mars Phoenix

Phoenix carried a complex suite of instruments to look for signs of water-ice in a region farther north than any previous mission. (2007-2008)

Opportunity rover on Mars

Mars Exploration Rover: Opportunity

One of two rovers that landed on opposite sides of Mars, finding traces of past wet and habitable environments. (2003-2019)

Sprit rover on Mars, artist rendition

Mars Exploration Rover: Spirit

One of a pair of Mars rovers that used field geology and atmospheric observations as they looked for signs of ancient water activity. (2003-2010)

Spacecraft flying over Mars

Mars Express (ESA)

NASA is contributing advanced radar and radio relay systems to this ESA-ASI mission searching for sub-surface water from Mars orbit. (2003-present)

Mars Odyssey orbiter over the north polar region

2001 Mars Odyssey

NASA's longest-lasting spacecraft at Mars is making the first global map of the amount and distribution of chemical elements and minerals that make up the Martian surface. (2001-present)

Spacecraft lander on Mars.

Mars Polar Lander/Deep Space 2

Mars Polar Lander's mission was to dig for water ice near the edge of the south polar cap and deploy two small surface probes, but all spacecraft were lost on arrival. (1999)

Spacecraft in orbit over Mars.

Mars Climate Orbiter

Designed to function as an interplanetary weather satellite and a communications relay for Mars Polar Lander, Mars Climate Orbiter was lost on arrival after entering the atmosphere too low. (1999-1999)

Mars Global Surveyor's Articulated High Gain Antenna.

Mars Global Surveyor

Mars Global Surveyor studied the entire Martian surface, atmosphere, and interior, discovering repeatable weather patterns, gully formation, new boulder tracks, and recent impact craters. (1996-2006)

Mars Pathfinder and Sojourner rover on Mars in 1997.

Mars Pathfinder

Mars Pathfinder demonstrated a new way to deliver an instrumented lander, and the first robotic rover, to the planet's surface, from which it returned data long past its primary design life. (1996-1997)

Artist's image of a spacecraft in orbit over Mars

Mars Observer

Mars Observer was designed to study the geology, geophysics and climate of Mars, but contact with the spacecraft was lost shortly before it was set to enter orbit around the planet. (1992-1993)

U.S. flag visible on Viking lander with Martian terrain on horizon

Viking 1

The first U.S. mission to land a spacecraft safely on Mars and return images of the surface, Viking 1 was part of a pair of probes seeking signs of life on Mars. (1975-1982 )

White lander with extended probe arm

Viking 2

The second of twin probes conducting experiments to look for signs of life on Mars, Viking 2 analyzed a second site during its mission until its power source ran out. (1975-1980)

Mariner 9 spacecraft

Mariner 9

NASA's Mariner 9, launched days after Mariner 8, was the first spacecraft to orbit another planet and to orbit Mars, mapping 85% of the surface. (1971-1972)

Mariner 8 spacecraft

Mariner 8

Mariner 8 was the first of two spacecraft in the Mariner Mars 71 project, but its launch vehicle failed, and it reentered Earth's atmosphere north of Puerto Rico. (1971)

An artist's concept of NASA's Mariner 7 spacecraft.

Mariner 7

Mariner 7 made a close flyby of Mars five days after its twin, Mariner 6, taking scans of the planet's south pole, despite losing several telemetry channels. (1969-1971)

An artist's concept of NASA's Mariner 7 spacecraft.

Mariner 6

Mariner 6, with its twin spacecraft Mariner 7, was designed to make a close flyby of Mars to look for signs of life and to develop technology for future missions. (1969-1971)

Mariner 4

A great early success of the U.S. space program, Mariner 4 took the first photos of another planet from deep space. (1964-1967)

Mariner 3

Mariner 3 lost power eight hours after launch, its solar panels never unfurled, and it failed to achieve the correct Mars trajectory. (1964)

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