Composite hazcam camera image (left) shows the robotic arm in motion as NASA’s Mars Exploration Rover Opportunity places the tool turret on the target named “Private John Potts” on Sol 4234 to brush away obscuring dust. Rover is actively working on the southern side of “Marathon Valley” which slices through western rim of Endeavour Crater. On Sol 4259 (Jan. 16, 2016), Opportunity completed grinds with the Rock Abrasion Tool (RAT) to exposure rock interior for elemental analysis, as seen in mosaic (right) of four up close images taken by Microscopic Imager (MI). Credit: NASA/JPL/Cornell/Ken Kremer/kenkremer.com/Marco Di Lorenzo
Composite hazcam camera image (left) shows the robotic arm in motion as NASA’s Mars Exploration Rover Opportunity places the tool turret on the target named “Private John Potts” on Sol 4234 to brush away obscuring dust. Rover is actively working on the southern side of “Marathon Valley” which slices through western rim of Endeavour Crater. On Sol 4259 (Jan. 16, 2016), Opportunity completed grinds with the Rock Abrasion Tool (RAT) to exposure rock interior for elemental analysis, as seen in mosaic (right) of four up close images taken by Microscopic Imager (MI). Credit: NASA/JPL/Cornell/Ken Kremer/kenkremer.com/Marco Di Lorenzo
NASA’s world famous Mars Exploration RoverOpportunity continues blazing a daily trail of unprecedented science first’s, still swinging her robotic arm robustly into action at a Martian “Mining Zone” on the 12th anniversary of her hair-raising Red Planet touchdown this week, a top rover scientist told Universe Today.
Twelve Years Ago, Spirit Rover Lands on Mars. This mosaic image taken on Jan. 4, 2004, by the navigation camera on the Mars Exploration Rover Spirit, shows a 360 degree panoramic view of the rover on the surface of Mars. Spirit operated for more than six years after landing in January 2004 for what was planned as a three-month mission. Credit: NASA/JPL
Twelve Years Ago, Spirit Rover Lands on Mars . This mosaic image taken on Jan. 4, 2004, by the navigation camera on the Mars Exploration Rover Spirit, shows a 360 degree panoramic view of the rover on the surface of Mars. Spirit operated for more than six years after landing in January 2004 for what was planned as a three-month mission. Credit: NASA/JPL
Exactly 12 Years ago this week, NASA’s now famous Spirit rover touched down on the Red Planet, starting a spectacular years long campaign of then unimaginable science adventures that ended up revolutionizing our understanding of Mars due to her totally unexpected longevity.
Just how dangerous are the terrifying dust storms that swarm Mars?
Brave explorers trek across the red dunes of Mars when a dangerous dust storm blows in. In moments, our astronauts are blasted by gale force winds and driving sand, reducing visibility to zero. The brave heroes stumble desperately through the driving onslaught, searching in vain for shelter from the catastrophic conditions. One is blown into a ravine, or right to the edge of the cliff, requiring a dramatic rescue and likely a terrible terrible sacrifice and important parting words showing the true mettle of our heroes.
“Tell my Asuka… printed body pillow… I loved her…”
Will they make it? Why the heck would anyone land on that dusty irradiated death trap? Actually, a better question might be “Why do writers lean so hard on this trope?”. I’m looking at you Andy Weir.
Martian dust storms don’t just come from the fevered imagination of the same sci-fi writer who gave us a lush Venusian jungle, Saturnalian lava flats and Moon floor cheese. These dust storms are all too real and they drive at serious windspeeds.
NASA’s Viking landers clocked them at 100 km/h during dust storm season. Which is a thing on Mars. The landers sheltered enough from the big storms that they probably didn’t experience the greatest winds they’re capable of.
Scientists have seen evidence that sand is shifted around on the surface of Mars, and the regolith requires high wind speeds to pick it up and shove it around. Dust devils spin up across the surface, and rotate at hurricane speeds.
When the wind is above 65 km/h, it’s fast enough to pick up dust particles and carry them into the atmosphere encasing the planet in a huge, swirling, shroud. Freaked out yet? Is this dangerous? It sure sounds dangerous.
Apologies to all the fearmongering sci-fi writers, but actually, it’s not that dangerous. Here’s why.
First off, you’re not on Mars. It’s a book. Second, it’s a totally different experience on Earth. Here when you feel the wind blasting you in the face, or watch it dismantle a house during a tornado, it’s the momentum of the air particles hammering into it.
An illustration of a dust storm on Mars. Credit: Brian Grimm and Nilton Renno
That momentum comes from air particle density and their velocity. Sadly, the density of the atmosphere on Mars is a delicate 1% of what we’re used to. It’s got the velocity, but it just doesn’t have the density.
It’s the difference between getting hit by a garden hose and a firehose with the same nozzle speed. One would gets you soaked, the other can push you down the street and give you bruises.
To feel a slight breeze on Mars similar to Earth, you multiply the wind speed by 10. So, if the wind was going about 15 km/h here, you’d need to be hit by winds going about 150 km/h there to have the same experience.
It’s not impossible for winds to go that fast on Mars, but that’s still not enough wind to fly a kite. To get it off the ground your mission buddy holds the kite, and you run around in the dumb Martian sand like a try-hard ass.
It would fly for a second and then crash down. You’d wonder why you even brought a kite to Mars in the first place because it’s NEVER windy enough.
Boo hoo. Your Mars kite doesn’t work. Good news! You’re on Mars!
Bad news. It was a one way trip. Good news! A wizard has made you immortal!
Bad news. The wizard has brought to life the entire fictional cast of the Twilight series and they’re also there and immortal. Have fun brooding with your new dorky friends, FOR ETERNITY.
What I’m saying is you could stand on the red planet restaurant patio and laugh at anything the weather system could throw at you. That is unless, you’re solar powered.
Opportunity Rover. Credit: NASA
Mars gets regular dust storms. From time to time, they can get truly global. In 2001, a storm picked up enough dust to shroud the entire planet in a red haze. Temperatures went up as dust helped trap heat in the atmosphere. This storm lasted for 3 months before temperatures cooled, and the dust settled back down again.
During a storm in 2007, dust blocked 99% of the light reaching the solar panels of the Opportunity rover. This severely decreased the energy it had to power its instruments, and most importantly, the heaters. Ultimately, it was possible that the cold could kill the rover, if the dust hadn’t subsided quickly enough.
If you happen to see a movie or read a book about an astronaut on Mars dealing with a dangerous dust storm, don’t worry. They’ll be fine, the wind won’t shred them to pieces. Instead, focus on unbreathably thin atmosphere, the bone chilling cold, or the constant deadly radiation.
That and where’s their food come from again? Well, now you know dust storms aren’t a big issue. Want to travel to Mars? Tell us in the comments below.
If you haven’t checked it out yet, go read “The Martian”. Jay and I loved the pants off it and we can’t wait to see the film version.
A small drone helicopter currently being developed by engineers at NASA's Jet Propulsion Laboratory could serve as a reconnaissance scout for future Mars rovers, greatly enhancing their effectiveness. Credit NASA JPL
NASA’s Jet Propulsion Laboratory recently announced that it is developing a small drone helicopter to scout the way for future Mars rovers. Why would Mars rovers need such a robotic guide? The answer is that driving on Mars is really hard.
Here on Earth, robots exploring volcanic rims, or assisting rescuers, can be driven by remote control, with a joystick. This is because radio signals reach the robot from its control center almost instantly. Driving on the moon isn’t much harder. Radio signals traveling at the speed of light take about two and half seconds to make the round trip to the moon and back. This delay isn’t long enough to seriously interfere with remote control driving. In the 1970’s Soviet controllers drove the Lunokhod moon rovers this way, successfully exploring more than 40 km of lunar terrain.
Driving on Mars is much harder, because it is so much further away. Depending on its position with respect to Earth, signals can take between 8 and 42 minutes for the round trip. Pre-programmed instructions must be sent to the rover, which it then executes on its own. Each Martian drive takes hours of careful planning. Stereo images taken by the rover’s navigation cameras are carefully scrutinized by engineers. Images from spacecraft orbiting Mars sometimes provide additional information.
A rover can be programmed either to simply execute a list of driving commands sent from Earth, or it can use images taken by its navigation cameras and processed by its on-board computers to measure speed and detect obstacles or hazards by itself. It can even plot its own safe path to a specified goal. Drives based on instructions from the ground are the fastest.
The Mars Exploration Rovers Spirit and Opportunity could drive up to 124 meters in an hour this way. This corresponds to about the length of an American football field. But this mode was also the least safe.
When the rover actively guides itself with its cameras, progress is safer, but much slower because of all the image processing needed. It may progress by as little as 10 meters an hour, which is about the distance from the goal line to the 10 yard line on an American football field. This method must be used whenever the rover doesn’t have a clear view of the route ahead, which is often the case due to rough and hilly terrain.
As of early 2015, the farthest Curiosity has driven in a single day is 144 meters. Opportunity’s longest daily drive was 224 meters, a distance the length of two American football fields.
If ground controllers could get a better view of the path ahead, they could devise instructions allowing a future rover to safely drive much further in a day.
That’s where the idea of a drone helicopter comes in. The helicopter could fly out ahead of the rover every day. Images made from its aerial vantage point would be invaluable to ground controllers for identifying points of scientific interest, and planning driving routes to get there.
Flying a helicopter on Mars poses special challenges. One advantage is that Martian gravity is only 38% as strong as that of Earth, so that the helicopter wouldn’t need to generate as much lift as one of the same mass on Earth. A helicopter’s propeller blades generate lift by pushing air downward. This is harder to do on Mars than on Earth, because the Martian atmosphere is on hundred times thinner. To displace enough air, the propeller blades would need to spin very quickly, or to be very large.
The copter must be capable of flying on its own, using prior instructions, maintaining stable flight along a pre-specified route. It must land and take off repeatedly in rocky Martian terrain. Finally it must be capable of surviving the harsh conditions of Mars, where the temperature plummets to 100 degrees Fahrenheit or lower every night.
The JPL engineers designed a copter with a mass of 1 kilogram; a tiny fraction of the 900 kg mass of the Curiosity rover. Its propeller blades span 1.1 meters from blade tip to blade tip, and are capable of spinning at 3400 rotations per minute. The body is about the size of a tissue box.
The copter is solar powered, with a disk of solar cells gathering enough power every day to power a flight of two to three minutes and to heat the vehicle at night. It can fly about half a kilometer in that time, gathering images for transmission to ground control as it goes. Engineers expect that the reconnaissance that the drone copter gathers will be invaluable in planning a rover’s drives, tripling the distance that can be traveled in a day.
References and further reading:
Thanks to Mark Maimone of NASA Jet Propulsion Laboratory for information about the daily driving distances of Curiosity and Opportunity.
