Pinning Tails On Satellites To Help Prevent Space Junk

Low Earth orbit was already relatively crowded when only the big players were launching satellites, but as access to space has gotten cheaper, more and more pieces of hardware have started whizzing around overhead. SpaceX alone has launched nearly 1,800 individual satellites as part of its Starlink network since 2019, and could loft as many as 40,000 more in the coming decades. They aren’t alone, either. While their ambitions might not be nearly as grand, companies such as Amazon and Samsung have announced plans to create satellite “mega-constellations” of their own in the near future.

At least on paper, there’s plenty of room for everyone. But what about when things go wrong? Should a satellite fail and become unresponsive, it’s no longer able to maneuver its way out of close calls with other objects in orbit. This is an especially troubling scenario as not everything in orbit around the Earth has the ability to move itself in the first place. Should two of these uncontrollable objects find themselves on a collision course, there’s nothing we can do on the ground but watch and hope for the best. The resulting hypervelocity impact can send shrapnel and debris flying for hundreds or even thousands of kilometers in all three dimensions, creating an extremely hazardous situation for other vehicles.

One way to mitigate the problem is to design satellites in such a way that they will quickly reenter the Earth’s atmosphere and burn up at the end of their mission. Ideally, the deorbit procedure could even activate automatically if the vehicle became unresponsive or suffered some serious malfunction. Naturally, to foster as wide adoption as possible, such a system would have to be cheap, lightweight, simple to integrate into arbitrary spacecraft designs, and as reliable as possible. A tall order, to be sure.

But perhaps not an impossible one. Boeing subsidiary Millennium Space Systems recently announced it had successfully deployed a promising deorbiting device developed by Tethers Unlimited. Known as the Terminator Tape, the compact unit is designed to rapidly slow down an orbiting satellite by increasing the amount of drag it experiences in the wispy upper atmosphere.

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Unconventional Homopolar Motor

As a hacker, chances are that you have built a homopolar motor, as you only need three things: a battery, a magnet and some copper wire. There are zillions of videos on YouTube. This time we want to show you [Electric Experiments Roobert33]´s version. Definitely a fresh twist on the ubiquitous design that you see everywhere. His design is a bit more complicated, but the result makes the effort worthwhile.

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Right hand rule for the Lorenz force. By Jfmelero, via Wikimedia Commons

The homopolar motor was the first electric motor ever built. Created  Michael Faraday in 1821, it works because of the Lorentz force. This force acts on any current-carrying conductor that is immersed in a magnetic field which is perpendicular to the current. These motors really have no practical applications, but are an excellent way to learn basic aspects of electromagnetism.

In this setup, there are two conductive rings placed above a wooden base, connected to the battery terminals. Neodymium magnets are connected by a conductive rod that pivots in the center of the rings, closing the circuit and allowing the flow of current. Then the Lorentz force makes its magic and pushes the rod and magnets in a circular motion.

Very clean and well-edited work, as are other videos by [Electric Experiments Roobert33]. You may want to replicate this nice motor, or you can also make the simpler version to start experimenting.

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24kJ Capacitor Bank

The Leyden jar capacitor posted the other day fails to compare to what [FastMHz], one of the members over at the 4HV.org forums, has been busy building, a 24kj capacitor discharge bank. This capacitor bank will be configured for 4500v @ 2400uF and can be charged up slowly using microwave oven transformers. It can then release all its stored energy in under a millisecond through a triggered spark gap. This allows for some pretty big sparks as seen in this video, we are not sure about the laughing in the video maybe the power has gone to his head? Continue reading “24kJ Capacitor Bank”