By Mary O’KEEFE

“Pathfinder was the first successful mission to the surface [of Mars],” said John Callus, project manager for MER at Jet Propulsion Laboratory.

Now landing on Mars seems easy, right? With each successful landing, rovers have become larger and have more equipment. It seems like a walk in the park – well, it’s not. It is extremely complicated with “what if” scenarios that could fill volumes, but scientists and engineers from NASA’s JPL make it seem easy because they have done it so many times. But back in 1997, when the little Sojourner rover was placed in Pathfinder, going to Mars was not that easy and landing was a Herculean event.

“This was our return to Mars after a long hiatus. It was two decades since the Viking, and then there was the Mars Observer,” Callus said.

Mars Observer was going to be the introduction back into Mars exploration after Voyager 17 years earlier, but as it was to enter the red planet’s orbit in August 1993, contact with the spacecraft was lost. So Pathfinder had a lot riding on its success.

The successful landing on July 4th, 1997 was picture- perfect. Callus said one of its most valuable contributions was its entry descent and landing system.

The Pathfinder was assisted by a parachute that slowed its descent through the Martian atmosphere, which is thinner than Earth’s. Then a system of airbags was used to cushion the impact when it landed. Even if the spacecraft landed with the rover upside down, it was designed to right itself.

“The [original] mission was to last seven days for the rover, and one month for the lander,” Callus said.

But the mission lasted about 84 days.

During that time Sojourner sent back breathtaking images and laid the foundation for future rovers like Spirit and Opportunity.

The total distance Sojourner traveled was less than a football field. One of the reasons it didn’t go farther was because it could not be too far from the lander, which kept its communications system working.

In addition to launching a new exploration frontier era on Mars, Pathfinder made space really cool again.

 “It was, at that time, the coolest remote controlled car in the solar system,” Callus said. “Every kid wanted one.”

There were all kinds of Martian toys manufactured, including a Hot Wheels Sojourner that Callus still has on his shelf at work.

“It was incredibly inspirational,” he said.

So this 4th of July there will be several recognition ceremonies for the littlest of the rovers, Sojourner and Pathfinder. After 20 years it’s still the coolest of all Martian remote controlled cars.

  Mary Okeefe