Humans have been sailing various seas and oceans for thousands of years, and using boats for potentially even longer than that. But as a species we wouldn’t have made it very far if it was only possible to sail in the same direction the wind is blowing. There are a number of methods for sailing upwind, but generally only up to a certain angle. [rctestflight] wondered if there was some way of sailing straight upwind instead and built this rotary sail craft to test the idea.
Normally a boat sailing upwind will sail approximately 45° into it, then “tack” 90° across the wind until they’re at another 45° angle from the wind, this time facing the opposite direction. This back-and-forth nature is not the most efficient path, so this vessel uses a few propellers to bypass the traditional sail. The first iteration, built on a sleek catamaran hull, uses a large propeller to catch the wind’s energy, then transfers it mechanically through a set of shafts to an underwater prop.
It took a few tries to get the size and pitch of both propellers narrowed down to where the boat would move forward into the wind, but move it does. A second major iteration of the build uses a single shaft with no gears, with the trade-off that neither propeller is facing an ideal direction, but this has the added benefit of the boat naturally pointing itself upwind.
While none of the designs are speed demons, the concept is sound enough. It’s just that, in most cases, performing multiple tacks to get upwind is acceptable compared to the extreme efficiency losses and drag from propeller-driven sailing crafts like these. A more effective way of propelling a boat upwind, at least using modern technology, might be to trade sails for solar panels.
Continue reading “Sailing (Directly) Into The Wind”
When sending satellites into space, the idea is to place them into as stable an orbit as possible in order to maximize both the time the satellite is useful and the economics of sending it there in the first place. This tends to become rather untenable as the amount of space junk continues to pile up for all but the lowest of orbits, but a team at Brown University recently tested a satellite that might help solve this problem, at least for future satellite deployments.
The main test of this satellite was its drag sail, which increases its atmospheric drag significantly and reduces its spaceflight time to around five years. This might make it seem like a problem from an economics standpoint, as it’s quite expensive to build satellites and launch them into space, but this satellite solves these problems by being both extremely small to minimize launch costs, and also by being built out of off-the-shelf components not typically rated for spaceflight. For example, it gets its power solely from AA batteries and uses an Arduino for its operation and other research.
The satellite is currently in orbit, and has already descended from an altitude of 520 km to 470 km. While it won’t help reduce the existing amount of debris in orbit, the research team hopes to demonstrate that small satellites can be affordable and economically feasible without further contributing to the growing problem of space junk. If you’re looking to launch your own CubeSat one day, take a look at this primer which goes over most of the basics.
By the early 20th century, naval warfare was undergoing drastic technological changes. Ships were getting better and faster engines and were being outfitted with wireless communications, while naval aviation was coming into its own. The most dramatic changes were taking place below the surface of the ocean, though, as brave men stuffed themselves into steel tubes designed to sink and, usually, surface, and to attack by stealth and cunning rather than brute force. The submarine was becoming a major part of the world’s navies, albeit a feared and hated one.
For as much animosity as there was between sailors of surface vessels and those that chose the life of a submariner, and for as vastly different as a battleship or cruiser seems from a submarine, they all had one thing in common: the battle against the sea. Sailors and their ships are always on their own dealing with forces that can swat them out of existence in an instant. As a result, mariners have a long history of doing whatever it takes to get back to shore safely — even if that means turning a submarine into a sailboat.
Continue reading “Hacking When It Counts: Setting Sail In A Submarine”
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.
Thanks to [Andy] for the tip!
The Protei project aims to develop a robotic solution for oil-spill cleanup. [Cesar Harada] quit what he calls his dream job at MIT to work toward a solution to the ecological disasters that are oil spills. He had previously been working on Seaswarm, a swarm of robots that use conveyor belts of absorbent material to leech oil from seawater. But Protei doesn’t use legions of drones. It aims to use better design to improve the effectiveness of a small number of units.
The whole idea is well described in the video after the break. If a long trailing boom of absorbent material is towed in a serpentine pattern perpendicular to the flow, starting down current and moving upward, it can be quite effective at halting the spread of crude. Initial experiments have shown that a robotic vessel can do this efficiently with just a few improvements. First, to counteract the drag of the tail the rudder of the boat was moved to the bow. Secondly, the hull has been articulated as you can see above. This allows the robot to better utilize wind power to sail, making turns without losing the push of the wind.
The project is raising money through Kickstart as an open hardware project. Let’s hope this becomes a cheap and effective way to fix our costly drilling mishaps. Continue reading “Protei: Articulated, Backward Sailing Robots Clean Oil Spills”
This is the Pinta, an autonomous sailboat built to attempt an ocean crossing from Ireland to Martinique (in the Caribbean). A group of researchers at Aberystwyth University built her as part of the Microtransat Challenge.
To keep tabs on the vessel her creators included an Iridium short burst data modem with a backup system made from a SPOT satellite tracker using a PIC microcontroller to trigger a transmission every six hours. The sailing systems are a conglomeration of a Gumstix board, GPS, a windshield wiper motor to control the sail, and a tiller pilot for steering. A set of solar panels helps to top off the lead-acid batteries that power the system.
Unfortunately the old gal has encountered problems. You can see from the tracking data that, although it sailed 500 km in the last twelve days, she is still just off the coast of Ireland. The primary tracking system has failed, which could signal a system-wide computer failure. We hope the team will eventually recover the vessel as we’re interested in finding out what caused this unfortunate turn of events.