So far in this brief series on in-band signaling, we looked at two of the common methods of providing control signals along with the main content of a transmission: DTMF for Touch-Tone dialing, and coded-squelch systems for two-way radio. For this installment, we’ll look at something that far fewer people have ever used, but almost everyone has heard: Quindar tones.
As a space-faring species, we’ve done a fair job of exploring and exploiting our local neighborhood. We’re pretty good at putting people and machines into orbit, but our galactic-scale signature is pretty tiny. Our radio signals are no more than 100 light-years away, and our farthest physical artifact isn’t even a light-day away from us 40 years after it launched.
Clearly we need to do a better job of getting out there, and that’s the goal of Breakthrough Initiatives’ Starshot program, which aims to launch a nano-spacecraft to Alpha Centauri and get it there fast. The program aims to build solar-powered credit card-sized spacecraft with sensors, cameras, communications, and even MEMS thrusters for attitude control. Motive power will come from solar sails catching laser light shined onto it from Earth, eventually accelerating the craft to 20% of the speed of light and reaching its destination within a generation.
The thought that we could start spreading ourselves out into the galaxy within the lifespan of most of the people on Earth is intoxicating. Sure, a wafer of silicon is a far cry from a sleek starship with powerful warp engines and all the finest appointments, or a gritty star freighter that can make the Kessel Run in less than 12 parsecs. But the laws of physics and the limits of engineering conspire to keep us mostly stuck at the bottom of a deep gravity well, and if this means sending fleets of nanobots across the galaxy in our stead, so be it.
And no matter what form our first galactic spacecraft take, you can bet that the Deep Space Network will be supporting the mission. For now, you can listen in on the program’s test satellites currently in orbit if you tune to 437.240 MHz.
Continue reading “Credit Card Sized Spacecraft Poised To Sail To Alpha Centauri”
There are times when a mechanism comes to your attention that you have to watch time and time again, to study its intricacies and marvel at the skill of its designer. Sometimes it can be a complex mechanism such as a musical automaton or a mechanical loom, but other times it can be a device whose apparent simplicity hides its underlying cleverness. Such a moment came for us today, and it’s one we have to share with you.
RainCube is a satellite, as its name suggests in the CubeSat form factor and carrying radar instruments to study Earthly precipitation. One of the demands of its radar system is a parabolic dish antenna, and even at its 37.5 GHz that antenna needs to be significantly larger than its 6U CubeSat chassis.
It is the JPL engineers’ solution to this problem that is the beautiful mechanism we want to show you. The parabola is folded within itself and tightly furled round the feedhorn within the body of the satellite. As the feedhorn emerges, first the inner sections unfurl and then the outer edge of the parabola springs out to form the dish antenna shape. Simultaneously a mechanism of simplicity, cleverness, and beauty, one we’d be very proud of if it were our creation.
There is nothing new in collapsible parabolas used in spacecraft antennas, petal and umbrella-like designs have been a feature of some of the most famous craft. But the way that this one has been fitted into such a small space (and so elegantly) makes it special, we hope you’ll agree.
[via space.com]
Name the countries that house a manned space program. In order of arrival in space, USSR/Russian Federation, United States of America, People’s Republic of China. And maybe one day, Denmark. OK, not the Danish government. But that doesn’t stop the country having a manned space program, in the form of Copenhagen Suborbitals. As the tagline on their website has it: “We’re 50 geeks building and flying our own rockets. One of us will fly into space“. If that doesn’t catch the attention of Hackaday readers, nothing will.
For their rocket testing they need a lot of video feeds, and for that they use cheap Chinese GoPro clones. The problem with these (and we suspect many other cameras) is that when subjected to the temperature and vibration of being strapped to a rocket, they cease to work. And since even nonprofit spaceflight engineers are experts at solving problems, they’ve ruggedized the cameras to protect them from vibration and provide adequate heatsinking.
The heat issue is addressed by removing the camera case and attaching its metal chassis directly to a heatsink that forms the end of an extruded aluminium case. Vibration was causing the camera SD cards to come loose, so these are soldered into their sockets. Power is provided by a pair of 18650 cells with a switching regulator to provide internal power, and another to allow the unit to be charged from a wide range of input voltages. A PCB houses both the regulators and sockets for cable distribution. There is even a socket on top of the case to allow a small monitor to be mounted as a viewfinder. Along the way they’ve created a ruggedized camera that we think could have many applications far beyond rocket testing. Maybe they should sell kits!
We’ve covered Copenhagen Suborbitals before quite a few times, from their earliest news back in 2010, through a look at their liquid-fueled engine, to a recent successful rocket launch. We want to eventually report on this project achieving its aim.
Thanks [Morten] for the tip.
