The popular press was recently abuzz with sad news from the planet Mars: Opportunity, the little rover that could, could do no more. It took an astonishing 15 years for it to give up the ghost, and it took a planet-wide dust storm that blotted out the sun and plunged the rover into apocalyptically dark and cold conditions to finally kill the machine. It lived 37 times longer than its 90-sol design life, producing mountains of data that will take another 15 years or more to fully digest.
Entire careers were unexpectedly built around Opportunity – officially but bloodlessly dubbed “Mars Exploration Rover-B”, or MER-B – as it stubbornly extended its mission and overcame obstacles both figurative and literal. But “Oppy” is far from the only long-duration success that NASA can boast about. Now that Opportunity has sent its last data, it seems only fitting to celebrate the achievement with a look at exactly how machines and missions can survive and thrive so long in the harshest possible conditions.
Continue reading “Engineering for the Long Haul, the NASA Way”
On the face of it, powering most spacecraft would appear to be a straightforward engineering problem. After all, with no clouds to obscure the sun, adorning a satellite with enough solar panels to supply its electrical needs seems like a no-brainer. Finding a way to support photovoltaic (PV) arrays of the proper size and making sure they’re properly oriented to maximize the amount of power harvested can be tricky, but having essentially unlimited energy streaming out from the sun greatly simplifies the overall problem.
Unfortunately, this really only holds for spacecraft operating relatively close to the sun. The tyranny of the inverse square law can’t be escaped, and out much beyond the orbit of Mars, the size that a PV array needs to be to capture useful amounts of the sun’s energy starts to make them prohibitive. That’s where radioisotope thermoelectric generators (RTGs) begin to make sense.
RTGs use the heat of decaying radioisotopes to generate electricity with thermocouples, and have powered spacecraft on missions to deep space for decades. Plutonium-238 has long been the fuel of choice for RTGs, but in the early 1990s, the Cold War-era stockpile of fuel was being depleted faster than it could be replenished. The lack of Pu-238 severely limited the number of deep space and planetary missions that NASA was able to support. Thankfully, recent developments at the Oak Ridge National Laboratory (ORNL) appear to have broken the bottleneck that had limited Pu-238 production. If it pays off, the deep space energy crisis may finally be over, and science far in the dark recesses of the solar system and beyond may be back on the table.
Continue reading “The Deep Space Energy Crisis Could Soon Be Over”
[Matt] created an animated gif of New Horizon’s Pluto flyby. The source images were taken from the the raw LORRI images, modified so the background star field could be seen, and assembled with OpenCV. Because Pluto and Charon orbit each other around a point above Pluto’s surface, simply putting Pluto in the center of each frame wouldn’t work. It’s the best visual explanation of this weird arrangement yet, all brought to you by the magic of OpenCV and Python.
On the subject of Kickstarter creators that don’t understand the conservation of energy, I present this.
We don’t know exactly what’s going on with this one, but here’s a swimming pool covered with RGB LEDs. It’s controlled by two Rainbowduinos, and looks like the coolest disco floor you’ve ever seen.
[Frank]’s 2011 Hundai Santa Fe wasn’t cool enough, so he added an F16 flight stick to his shift knob. The choice of joystick is paramount here: Saitek joysticks look too techy, Logitech ones are too expensive, and the Warthog H.O.T.A.S costs $400. Joysticks are extremely niche peripherals these days, it seems. He ended up strapping an old F16 joystick from the 90s on his shift knob, and it looks close enough to the real thing.
Two bodgers are stuffing the engine from a Toyota Celica into a 1980 Mini, and they’re trying to make it look stock. We’ve seen their project before, and now there’s a new episode. In this episode: the pedal box, the steering wheel, and figuring out how to make the car drive straight.