"We didn't know then what we know now, which is how tough it really is to land on Mars." - Viking mission planning director Gentry Lee (1942–present) on getting to Mars

The most significant engineering challenge was slowing the Viking lander, which would move through space at nearly 29,000 kilometers per hour before reaching Mars. This required the invention of supersonic parachute technology, which is still used today.

NASA’s Viking 1 and 2 missions tested soils for signs of life, captured images, and studied the Martian atmosphere, revealing evidence of ancient water flow, volcanic soil, and a thin carbon dioxide atmosphere.

NASA's Viking 1 and 2 missions revealed Mars' geological activity and potential for past life through their evidence of past surface water. Viking 1 held the record for the longest Mars surface operation until the Opportunity rover surpassed it in 2010.

NASA's proposed Voyager missions to Mars and Venus in the 1970s were canceled due to budget cuts and the Apollo 1 fire. The Viking program's smaller scope—focused on data collection—was the economically viable alternative to manned Mars mission proposals.

Three experiments on the Viking 1 and 2 landers searched for signs of metabolic activity in soil samples, indicating the presence of microorganisms. No definitive evidence of life was found in any experiment or lander imaging.

This collection includes original mission bulletins, engineering and planning documents, and interview segments from more than 80 Viking team members who made the historic exploration of Mars’ surface by a lander possible.

Terraforming the thin atmosphere, toxic dust, extreme cold, and lack of magnetic field is infeasible, given limitations to the size of what can be sent to Mars. NASA and SpaceX are instead exploring creating underground shelters.

Mars remains the most viable interplanetary destination due to its relatively habitable orbit. There are many challenges, however, including the huge distance to Mars, the need for advanced propulsion systems, uncertainty over the impacts of long-duration space travel on astronauts, and the need for safe landing techniques and equipment to handle Martian conditions. Human-manned missions to Mars are not likely to occur until the 2030s at the earliest.

The disk-band-gap parachute design was first developed for the Viking Project in the 1970s. Since then, it has been reinforced and uses stronger materials to handle larger payloads—including the 2020 Perseverance rover—landing it a world record.

Analog missions in volcanic terrains and craters mimic Martian and lunar environments. Crew members operating in these missions, including at sites in Utah, Nevada, Arizona, and Hawai'i, test suits and specialized space instruments under simulated conditions.

The Lunar and Planetary Institute provides assorted resources about the red planet, Mars. Review this basic 101 level introduction and get to know our solar system neighbor. Learn about Mars' planet-wide dust storms, staggeringly high mountains (six of which dwarf Mount Everest), and whether there's water there below the surface.

The US has conducted the most missions (23) and has the highest success rate (74%), followed by Russia (18 missions at 5%). The first successful orbiter was Mariner 4, while Viking 1 was the first successful lander.

Because conditions on Mars are pretty extreme for humanity, we tend not to think about living there, since everywhere on Mars feels a bit threatening. This imaginative essay uses current geographical knowledge of Mars to visualize what it would look like if humanity could alter its climate to make it widely habitable, a process known to sci-fi readers as terraforming. Given that transformation, where would the hottest neighborhoods be located?

-Apollo 14 astronaut Edgar Mitchell, in "The Way of the Explorer"

While reviewing designs for instruments to be carried by future Mars rovers, Nye suggested adapting the function of a calibration tool, which would be used by the Spirit and Opportunity rovers to help calibrate the brightness and color of their panoramic cameras on the Martian surface.

As telescope technology advanced, astronomers became able to observe the surfaces of objects in our solar system with greater detail. The dips, valleys, and lines crisscrossing Mars, particularly, captured onlookers' imagination, leading some to speculate that the seemingly organized features could only have been created by an intelligent civilization.

Sending humans to Mars in the following decades poses significant challenges, from the vast distance covered to get materials there to powering technology during weekslong dust storms. Research is ongoing to develop life support systems that can regenerate or recycle consumables.

Simulate a visit to the red planet with the Mars 2020 Perseverance Rover. This 3D interactive experience lets you explore various locations on the martian surface. See closeup images the rover has taken and view key points of interest. It's the next best thing to being there and certainly far safer!

- Astronaut John Glenn (1921–2016)

The twin machines were tasked with studying the geology of Mars to identify evidence of past water activity, determine the composition of minerals, rocks, and soils, and perform "ground truth" experiments to calibrate and validate observations made by Mars orbiters.

Nuclear rocket technology might be the fastest, safest way to get to the red planet. But if NASA wants to go, it should start development now.

In 2020, the Perseverance Rover landed on Mars, sending a message for the folks back home on its parachute. It took fewer than six hours for the Internet's collective forces to decode the secret slogan hidden in the parachute's colors and patterns, as well as the geographic coordinates of the earth-bound place where rocketry was perfected.

Conceived in the early 1960s, the Sea Dragon was an audacious ocean-launched rocket design that would have dwarfed the Saturn V in both scale and payload—but its extreme engineering challenges kept it firmly on the drawing board.

The Space Analog for the Moon and Mars combines the Test Module greenhouse with a workshop, kitchen, common area, sleeping quarters, and a yard that mimics lunar and Martian surfaces. A blind crew member in SAM’s first mission, Inclusion I, helped assess accessibility in potential future space habitats.

Evidence suggests that Mars has had a thicker atmosphere, which included greenhouse gases, and a magnetic field in its past, resembling Earth's current composition. After losing its magnetic field—the protection from solar wind—the atmosphere and its associated atmospheric phenomena gradually disappeared.

- Radio inventor Guglielmo Marconi

Unlike Earth, Mars lacks geological activity and oceans, though geological evidence suggests they both existed in the past. Its northern regions have far fewer craters than the southern ones, indicating that the rock in the north formed more recently.

Radically reducing the cost of rockets and innovating totally new space vehicles originated in the singular force of Elon Musk's vision. In this podcast, Founders creator David Senra shares what he learned reading a book about SpaceX's beginnings, highlighting Musk's audacious refusal to follow industry conventions and promotion of a culture of action and speed. Learn more insights from the founder here.

Planned for a 2027 launch, NASA Gateway is a lunar-orbiting space station meant to support Artemis lunar missions and future Mars travel. This resource includes an interactive 3D model of the proposed station's modules and layout.

Spacecraft have been taking pictures of Mars from space since 1965, when the Mariner 4 probe became the first to beam back an image of a planet other than our own. The technology has significantly evolved since then, with ultra-high definition resolutions revealing previously unseen surface features.

- Astronaut Buzz Aldrin (1930-present)

Engineer Bob Ebeling and four of his colleagues presented data to NASA officials and managers at NASA contractor Morton Thiokol the night before the launch about how cold temperatures could cause O-ring failure. Ebeling claims to have told his wife then that, "[Challenger is] going to blow up."

In April 2021, the solar-powered helicopter Ingenuity—attached to NASA’s Perseverance Mars rover—flew in what became the first controlled flight on a planet other than Earth. Carried with it was a piece of fabric from the famous 1903 Wright Flyer, a symbol of Ingenuity’s continuation of the Wright tradition.

When Neil Armstrong stepped onto the moon on July 20, 1969, his first words, transmitted across the globe, became legendary. Decades later, historians still debate whether he meant to say "one small step for a man," and where the phrasing may have originated.

After 50 years, NASA is heading back to the moon. Artemis missions will push beyond Apollo, landing astronauts on the moon's south pole by 2027. But why the long wait? Budget cuts, shifting priorities, and outdated tech stalled lunar exploration—until now. With new goals and modern tech, NASA is ready to return.

Combining science, diplomacy, and logistics, the Corps of Discovery created a model for later expeditions—from charting the Arctic to NASA’s space missions.

In 1997, NASA's Mars Pathfinder mission landed on the red planet. Its rover was named Sojourner in Truth's honor—a name selected by a 12-year-old student in a nationwide essay contest about a historical hero.

A network of interconnected, airtight bubbles would require several orders of magnitude fewer materials than those required to re-establish the entire planet's atmosphere to resemble Earth. However, the whole network would be compromised by a single micrometeor impact that destroys the air seal.

This podcast series explores Apollo 11 through firsthand stories from the engineers, mission controllers, and astronauts who made the moon landing possible, culminating in 13 minutes of NASA archive audio leading up to the landing.

Originally built for a four-year mission, Voyagers 1 and 2 used a rare planetary alignment and gravity assists to reach interstellar space. With limited power and aging systems, they will continue to send data until the mid-2030s.

Launched in 2004, the Rosetta spacecraft performed three flybys of Earth and one of Mars as gravitational slingshots to gain the necessary velocity to successfully place the Philae lander module on comet 67P/Churyumov-Gerasimenko. Philae achieved a soft landing only after bouncing twice from failed deployments of its anchoring harpoons.

From recovering and reusing rocket components to launching a mannequin and Tesla into orbit to the tune of David Bowie's "Starman," Elon Musk drove public interest and government contracts to his company as he transformed space launches into spectacles.

Mars continues to reveal itself through the Mars Curiosity Rover, which continues to ramble and roll across the red planet's surface. Here is NASA’s real-time portal for Mars exploration, featuring the latest news, images, and discoveries from the Red Planet. See evidence of the ancient rivers that once ran through the martian landscape, and see how Curiosity is setting the scene for possible future exploration by humans.

The attempts with Falcon 1 endangered the company's future but provided valuable information from which to iterate and follow up with the successful first privately funded orbital launch in history and multiple ISS resupply missions.