A normal camera uses a lens to bend light so that it hits a sensor. A pinhole camera doesn’t have a lens, but the tiny hole serves the same function. Now two researchers from the University of Utah. have used software to recreate images from scattered unfocused light. The quality isn’t great, but there’s no lens — not even a pinhole — involved. You can see a video, below.
The camera has a sensor on the edge of a piece of a transparent window. The images could resolve .1 line-pairs/mm at a distance of 150 mm and had a depth of field of about 10 mm. This may seem like a solution that needs a problem, but think about the applications where a camera could see through a windshield or a pair of glasses without having a conventional camera in the way.
Scientists don’t know exactly what fast radio bursts (FRBs) are. What they do know is that they come from a long way away. In fact, one that occurs regularly comes from a galaxy 3 billion light years away. They could form from neutron stars or they could be extraterrestrials phoning home. The other thing is — thanks to machine learning — we now know about a lot more of them. You can see a video from Berkeley, below. and find more technical information, raw data, and [Danielle Futselaar’s] killer project graphic seen above from at their site.
The first FRB came to the attention of [Duncan Lorimer] and [David Narkevic] in 2007 while sifting through data from 2001. These broadband bursts are hard to identify since they last a matter of milliseconds. Researchers at Berkeley trained software using previously known FRBs. They then gave the software 5 hours of recordings of activity from one part of the sky and found 72 previously unknown FRBs.
Space elevators belong to that class of technology that we all want to see become a reality within our lifetimes, but deep-down doubt we’ll ever get to witness firsthand. Like cold fusion, or faster than light travel, we understand the principles that should make these concepts possible, but they’re so far beyond our technical understanding that they might as well be fantasy.
Except, maybe not. When Japan Aerospace Exploration Agency (JAXA) launches their seventh Kounotori H-II Transfer Vehicle towards the International Space Station, riding along with the experiments and supplies for the astronauts, will be a very special pair of CubeSats. They make up the world’s first practical test of space elevator technology, and with any luck, will be one of many small steps that precedes the giant leap which access to space at a fraction of the cost will be.
Of course, they won’t be testing a fully functional space elevator; even the most aggressive of timelines put us a few decades out from that. This will simply be a small scale test of some of the concepts that are central to building a space elevator, as we need to learn to crawl before we can walk. But even if we aren’t around to see the first practical space elevator make it to the top, at least we can say we were there on the ground floor.
You normally think of HP as producing inkjet and laser printers. But they’ve been quietly building 3D printers aimed at commercial customers. Now they are moving out with metal printers called — predictably — the HP Metal Jet. The video (see below) is a little glitzy, but the basic idea is that print bars lay down powder on a 21-micron grid. A binding agent prints on the powder, presumably in a similar way to a conventional inkjet printer. A heat source then evaporates the liquid from the binder.
The process repeats for each layer until you remove the part and then sinter it using a third-party oven-like device. According to HP, their technique has more uniform material properties than fusing the powder on the bed with a laser. They also claim to be much faster than metal injection molding.
French Defense Minister Florence Parly took a page out of Little Red Riding Hood when she recently called out a Russian satellite for having “big ears”. While she stopped short of giving any concrete details, it was a rare and not terribly veiled accusation that Russia is using their Luch-Olymp spacecraft to perform orbital espionage.
Luch satellite conceptual drawing from NASA
At a speech in Toulouse, Parly was quoted as saying: “It got close. A bit too close. So close that one really could believe that it was trying to capture our communications.” and “this little Stars Wars didn’t happen a long time ago in a galaxy far away. It happened a year ago, 36,000 kilometers above our heads.”
The target of this potential act of space piracy is the Athena-Fidus satellite, a joint venture between France and Italy to provide secure communication for the military and emergency services of both countries. Launched in 2014, it provides 3 Gbit/s throughput via the Ka-band for mobile receivers on the ground and in drones.
This isn’t the first time Russia’s Luch class of vehicles has been the subject of scrutiny. In 2015 it was reported that one such craft maneuvered to within 10 kilometers of the Intelsat 7 and Intelsat 901 geostationary communications satellites, prompting classified meetings at the United States Defense Department. As geostationary satellites orbit the Earth at 3.07 km/s, a 10 km approach is exceptionally dangerous. Even a slight miscalculation could cause an impact within seconds.
Could Stealth Satellites Be In Our Future?
Much to the chagrin of shadowy spy agencies everywhere, this sort of orbital cat and mouse is easily detectable from the ground. When spy planes became easy to detect using radar, the next step was to evade that detection. Are we on a path to satellites that are transparent to radar?
Gregory Charvat, author of Small and Short-Range Radar Systems and occasional contributor here at Hackaday, tells us that building a stealth satellite is no easy task. “Just like how we had to re-invent the aircraft to make the first stealth aircraft, to make a stealth satellite one would have to fundamentally re-invent the satellite as we know it today.”
Likening it to the immense cost and effort it took to develop stealth aircraft like the Lockheed F-117 Nighthawk, Gregory says developing a satellite which could hide from radar would likely be more trouble than it’s worth for most applications. Space is already hard enough. “Maintaining that special shape that reflects radar away from your aircraft and including all of these essential peripherals is a big challenge” Gregory says, which results in “compromise and high maintenance costs.”
Beyond attempting to eavesdrop on communications, military insiders say that these close passes by Luch satellites could also be “dry-runs” for anti-satellite operations; either by using a directed energy weapon to disable the target spacecraft, or simply running into it. With events like these, and the commitment by the United States to establish a Space Force in the coming years, efforts to militarize space seem to be on the rise.
Do you have a couple of minutes? Literally and precisely, two minutes. That’s how long these ten songs play. So what? A short song is not new, but these ten songs are part of a campaign to encourage residents of Cape Town, South Africa to cap their showers at one-hundred-twenty seconds. Some of us do not have to worry about droughts or water bills, but most of us are concerned about one or both of those, and this ingenious campaign alerted people to the problem, gave them the means to time themselves, and made it pleasant, not oppressive. The songs are freely available, and one might even pique your listening tastes from the biggest stars in South Africa.
So, where is the hack? Some of us have experimented with egg timers on the towel rack, timers on the showerhead, servos on the faucet knobs, or occupancy sensors, but those are strong-arm techniques or only for measuring, not regulating water use. These songs attack the most viable vector, the showerer. Or is it showeree? Telling people there is a drought is one thing, but giving them the ability to regulate themselves in such a way that they comply is a hacker’s approach. The songs on the site do not autoplay so there will be no hanging out under the water spray to find the best song. Which is your favorite?
Sailboats have been traversing the Atlantic Ocean since before 1592, sailing through sunshine, wind, and rain. The one thing that they’ve all had in common has been a captain to pilot the ship across this vast watery expanse, at least until now. A company called Offshore Sensing has sailed an unmanned vessel all the way from Canada to Ireland.
The ship, called the Sailbuoy, attempted the journey last year as well but only made it about halfway before the mission was abandoned. This year, however, the voyage was finally completed, and this craft is officially the first unmanned ship to cross the Atlantic Ocean. The journey took about 80 days using sails and a small set of solar panels to drive the control electronics.
Using this technology, the company can investigate wave activity in specific areas of the ocean without having to send out a manned vessel to install a permanent buoy. The sailbuoy simply uses its autonomy to stay in a particular patch of ocean. There have been other missions that the sailbuoy has been tasked with as well, such as investigating the aftermath of the Deepwater Horizon oil spill in the Gulf of Mexico. With a reliable craft like this, it becomes much easier, safer, and less expensive to explore the ocean’s surface.
