The Planetary Report

June Solstice 2022

From Our Member Magazine

How The Planetary Society got to Mars

In December 1996, NASA’s Pathfinder spacecraft left Earth, carrying the names of thousands of Planetary Society members along with it. They became the very first names collected from the public to make it to the surface of Mars.

In a funny twist of fate, though, almost no one — not even Planetary Society members or staffers — knew the names had made it aboard. It was a historic moment that was both meticulously prepared and completely unexpected.

It all started with an idea Louis Friedman shared with his Planetary Society co-founders, Carl Sagan and Bruce Murray, sometime in the mid-’90s. They all agreed that sending members’ names to Mars was a crucial, tangible way for members to participate in scientific research.

“We didn’t just want to be cheerleaders,” Friedman said in a recent interview with us. “We wanted to give people a sense of involvement in planetary exploration.”

And so the Society collaborated with NASA’s Jet Propulsion Laboratory (JPL) to develop the project, which would send members’ names to Mars. They ultimately created a chip called MAPEX (microelectronics and photonics experiment) that contained the names.

Before Pathfinder launched, The Planetary Society was also working with NASA on a separate project: a contest to name the rover that would fly on the mission. The winner — a student from Bridgeport, Connecticut named Valerie Ambroise — chose the name Sojourner, after the abolitionist Sojourner Truth.

The Society had a hand in several ambitious projects around this time, but not all of them panned out. MAPEX flew on Russia’s Mars ‘96 mission, but regrettably, the mission failed shortly after launch. NASA had made extra copies of MAPEX in case it could be used on future missions, but no one knew where The Planetary Society members’ names would end up, if anywhere.

NASA finally found a suitable mission for them: Pathfinder. When the spacecraft landed on July 4, 1997, it was carrying copies of the documentation chip included in MAPEX. The Planetary Society had finally touched down on Mars.

Planetfest '97 Poster
Planetfest '97 Poster A poster for Planetfest ’97, the event where the Society announced that members’ names were on Mars, included in MAPEX.Image: The Planetary Society

Friedman said he heard the news just before the landing, which came as a “wonderful surprise.”

“I remember getting a call from JPL that was essentially, ‘Oh, by the way, Lou, we have MAPEX on the spacecraft,’” he said. “But it felt terrific. Getting to Mars was huge.” The Planetary Society announced the surprise news to its members during Planetfest 1997, a joyous event celebrating the touchdown of Pathfinder on Mars.

Since Pathfinder, many missions have sent names into space, including MAVEN, New Horizons and OSIRIS-REx. Planetary Society staff even helped collect and sort the names that flew on NASA’s Cassini mission to Saturn.

But gathering names from the public and sending them to Mars for the first time? It all started with us — and you. That legacy lives on in the cosmos forever.

Visions of Mars, on Mars
Visions of Mars, on Mars This image shows the DVD provided by The Planetary Society to the Phoenix mission, which contains 250,000 names of people who signed up to send their names to Mars. The DVD is mounted on the deck of the lander, which sits about one meter above the Martian surface, visible in the background. Image: NASA/JPL/University of ArizonaImage: NASA / JPL / U. Arizona

The Planetary Society has helped send names, messages, images and good wishes aboard more than a dozen spacecraft. To date, we’ve sent our members and supporters to the Moon, Venus, Mars, Saturn, asteroids, comets, Pluto and out of the solar system entirely.

In some cases, we built the hardware used to carry the names into space. In others, we partnered with other groups to collect names. See all missions that have carried or are carrying Planetary Society member names at

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The Planetary Report • June Solstice

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