 When we think about rovers on Mars, we think of curiosity, taking selfies and zapping rocks with its lasers. But long before curiosity, and long before even the tiny rover Sojourner, was the prop M Soviet rover that sadly never touched Martian soil. Mars 3 was a Soviet mission to the Red Planet that launched on May 28th of 1971, and it made the first successful landing on the planet on December 2nd of that year. Once it landed, as designed, the lander opened like a flower to reveal the sweet of scientific instruments including a camera, and it did send back the first ever picture of the surface of Mars, this grainy mess that we see right here. Then, after 14 seconds, Mars 3 went silent and never came back online. Scientists lost all communication with the first ever landed payload on Mars, and no one really knows what happened. There's speculation it succumbed to a dust storm, but we'll never really know unless we can go and find it. And it's a real shame because Mars 3 also had a teeny tiny squat box of rover on board, the prop M rover. The prop M's, which weighed just 10 pounds on Earth, were designed to be lifted out of the lander payload and placed onto the surface by a mechanical arm. Prop M was basically a tiny little box with skis sticking at the bottom of it. They were designed to lift the carriage of the rover up off the surface slightly, but it didn't exactly give it a lot of clearance for rocks. And, likely inspired by harsh Russian winters and not knowing too much about the surface environment on Mars, they didn't have rover wheels, they actually had skis, these little rovers. So they were designed not to roll across the surface, but to kind of step like cross-country skis. Basically, it would move by shifting one ski in front of the other, shuffling along the surface. And it wasn't exactly a free-range rover by design. It was connected to the Mars 3 lander by a 50-foot long or 15-meter cable, so it could only go as far as that cable or tether would allow. But even though they were tethered, the rovers were designed to have some autonomy. Sticking out the front of the box were two arms, a sort of very rudimentary hazard avoidance system. Basically, as the rover shuffled across the surface, if it hit a rock, it would depress one of the bars. Depressing the bar would send a signal to the rover that it had to turn to avoid a hazard, and then it would turn and go about its way. And, of course, the rovers were designed to do some science as well. The rover was equipped with instruments to test soil density and depth. And it would also be watched by the lander's camera eyes. Every five feet, the rover would stop so the camera could take a picture. And scientists would ideally be able to analyze the soil disrupted by the skis as it moved across the surface. This is actually a very important data point that scientists still use in rover images today. When Mars 3 went silent, there was no way of salvaging the mission to see if the Prop M rover could actually successfully ski across the surface of Mars. And it wasn't the only loss for Prop M. Mars 3's predecessor mission, Mars 2, also had a Prop M on board. But it crashed into the Martian surface on November 27th of that year. After two failed rover attempts on Mars in 1971, it wouldn't be until 1997 that NASA landed the Pathfinder rover on Mars and deployed the little Sojourner rover onto the surface that we would start actually roving and exploring the surface of the Red Planet. So what do you guys think about early Soviet and Russian exploration of Mars? Are there missions you would like to know more about? Leave me any of your thoughts, comments, and just topics you'd like to see covered in future episodes down in the comment section below. Be sure to give this video a like and, of course, be sure to follow me on Twitter and on Instagram for my daily vintage space content. And with new videos going up right here every single week, be sure to subscribe so you never miss an episode.