For the past seven months, NASA’s newest Mars rover has been closing in on its final destination. As Perseverance eats up the distance and heads for the point in space that Mars will occupy on February 18, 2021, the rover has been more or less idle. Tucked safely into its aeroshell, we’ve heard little from the lonely space traveler lately, except for a single audio clip of the whirring of its cooling pumps.
Its placid journey across interplanetary space stands in marked contrast to what lies just ahead of it. Like its cousin and predecessor Curiosity, Perseverance has to successfully negotiate a gauntlet of orbital and aerodynamic challenges, and do so without any human intervention. NASA mission planners call it the Seven Minutes of Terror, since the whole process will take just over 400 seconds from the time it encounters the first wisps of the Martian atmosphere to when the rover is safely on the ground within Jezero Crater.
For that to happen, and for the two-billion-dollar mission to even have a chance at fulfilling its primary objective of searching for signs of ancient Martian life, every system on the spacecraft has to operate perfectly. It’s a complicated, high-energy ballet with high stakes, so it’s worth taking a look at the Seven Minutes of Terror, and what exactly will be happening, in detail.
As the name implies, here at Hackaday we strive to bring you interesting projects every single day. But that doesn’t necessarily mean a project only gets one day to grace these storied pages. Quite the opposite, in fact. We’re always happy to revisit a project and find out how far it’s evolved since we last crossed paths with it, especially when the creators themselves reach out to give us an update.
Which is exactly what happened when [Jakob Krantz] recently wrote in to get us up to speed on this incredible open source rover project. We first saw this 3D printed Curiosity inspired robot a little less than a year ago, and at that point it was essentially just a big box with the distinctive NASA rocker-bogie suspension bolted on. Now it not only looks a lot closer to the Martian rovers that inspired it, but it’s also learned a number of new tricks that really take this project to the next level.
The articulated head and grabber arm don’t just help sell the Curiosity look, they’re actually functional. [Jakob] notes that he doesn’t have kinematics integrated yet, so moving the arm around is more for show than practical application, but in the future it should be able to reach out and grab objects. With the new cameras in the head, he’ll even be able to get a first person view of what he’s picking up.
Last year [Jakob] was using a standard RC transmitter to drive the rover around, but he’s since put together a custom controller that’s truly a thing of beauty. It uses an ESP32 and LoRa module to communicate with matching hardware inside the rover, as well as a smartphone clipped onto the top that’s displaying telemetry and video over WiFi. The controller is actually its own separate project, so even if you aren’t in the market for a scaled down Mars rover, its controller could come in handy for your next robotics project.
While Mars may be significantly behind its sunward neighbor in terms of the number of motor vehicles crawling over its surface, it seems like we’re doing our best to close that gap. Over the last 23 years, humans have sent four successful rovers to the surface of the Red Planet, from the tiny Sojourner to the Volkswagen-sized Curiosity. These vehicles have all carved their six-wheeled tracks into the Martian dust, probing the soil and the atmosphere and taking pictures galore, all of which contribute mightily to our understanding of our (sometimes) nearest planetary neighbor.
You’d think then that sending still more rovers to Mars would yield diminishing returns, but it turns out there’s still plenty of science to do, especially if the dream of sending humans there to explore and perhaps live is to come true. And so the fleet of Martian rovers will be joined by two new vehicles over the next year or so, lead by the Mars 2020 program’s yet-to-be-named rover. Here’s a look at the next Martian buggy, and how it’s built for the job it’s intended to do.
More than a few hackers have put in the considerable time and effort required to build a rover inspired by NASA’s robotic Martian explorers, but unfortunately even the most well funded home tinkerer can’t afford the ticket to send their creation offworld. So most of these builds don’t journey through anything more exciting than a backyard sandbox. Not that we can blame their creators, we think a homebrew rover will look just as cool in your living room as it would traipsing through a rock quarry.
Beyond a few “real” bearings here and there, all of the key components for the rover are 3D printed. [Jakob] did borrow a couple existing designs, like a printable bearing he found on Thingiverse, but for the most part he’s been toiling away at the design in Fusion 360 and using images of the real Curiosity rover as his guide.
Right now, he’s controlling the rover with a standard 6 channel RC receiver. Four channels are mapped to the steering servos, and a fifth to the single electronic speed control that commands the six wheel motors. But he’s recently added an Arduino to the rover which will eventually be in charge of interpreting the RC commands. This will allow more complex maneuvers with fewer channels, such as the ability to rotate in place.
Everyone knows that space is an incredibly inhospitable place, but the surface of Mars isn’t a whole lot better. It’s a dim, cold, and dry world, with a wisp of an atmosphere that provides less than 1% of Earth’s barometric pressure. As the planet’s core no longer provides it with a magnetosphere, cosmic rays and intense solar flares bathe the surface in radiation. Human life on the surface without adequate environmental shielding is impossible, and as NASA’s fleet of rovers can attest, robotic visitors to the planet aren’t completely immune to the planet’s challenges.
As a planet-wide dust storm finally begins to settle, NASA is desperately trying to find out if the Red Planet has claimed yet another victim. The agency hasn’t heard from the Opportunity rover, which landed on Mars in 2004, since before the storm started on June 10th; and with each passing day the chances of reestablishing contact are diminished. While they haven’t completely given up hope, there’s no question this is the greatest threat the go-kart sized rover has faced in the nearly 15 years it has spent on the surface.
Opportunity was designed with several autonomous fail-safe systems that should have activated during the storm, protecting the rover as much as possible. But even with these systems in place, its twin Spirit succumbed to similar conditions in 2010. Will Opportunity make it through this latest challenge? Or has this global weather event brought the long-running mission to a dramatic close?
Few things build excitement like going to space. It captures the imagination of young and old alike. Teachers love to leverage the latest space news to raise interest in their students, and space agencies are happy to provide resources to help. The latest in a long line of educator resources released by NASA is an Open Source Rover designed at Jet Propulsion Laboratory.
JPL is the birthplace of Mars rovers Sojourner, Spirit, Opportunity, and Curiosity. They’ve been researching robotic explorers for decades, so it’s no surprise they have many rovers running around. The open source rover’s direct predecessor is ROV-E, whose construction process closely followed procedures for engineering space flight hardware. This gave a team of early career engineers experience in the process before they built equipment destined for space. In addition to learning various roles within a team, they also learned to work with JPL resources like submitting orders to the machine shop to make ROV-E parts.
Once completed, ROV-E became a fixture at JPL public events and occasionally visits nearby schools as part of educational outreach programs. And inevitably a teacher at the school would ask “The kids love ROV-E! Can we make our own rover?” Since most schools don’t have 5-axis CNC machines or autoclaves to cure carbon fiber composites, the answer used to be “No.”
Last week, Hackaday had the chance to tour NASA’s Jet Propulsion Laboratory (JPL) in Pasadena, California. Tours are given all the time at JPL, but ours was special. Steve Collins invited us, and acted as our tour guide, and a new friendship with Michelle Easter got us a look inside the labs where equipment for the 2020 Mars mission is being built.