Lockheed Shares Satellite Connectivity Options

March 17, 2018 by 12 Comments

In an unusual turn of events, Lockheed Martin has released technical “payload accommodation information” for three of their satellite busses. In layperson’s terms, if you wanted to build a satellite and weren’t sure what guidelines to follow these documents may help you learn if Lockheed Martin has a platform to help you build it.

An opportunity to check out once-confidential information about satellites sounds like a perfect excuse to dig through some juicy documentation, though unfortunately this may not be the bonanza of technical tidbits the Hackaday reader is looking for. Past the slick diagrams of typical satellites in rocket fairings, the three documents in question primarily provide broad guidance. There are notes about maximum power ratings, mass and volume guidelines, available orbits, and the like. Communication bus options are varied; there aren’t 1000BASE-T Ethernet drops but multiply redundant MIL-STD-1553B might come standard, plus telemetry options for analog, serial, and other data sources up to 100 Mbps. Somewhat more usual (compared to your average PIC32 datasheet) are specifications for radiation shielding and it’s effectiveness.

In the press release EVP [Rick Ambrose] says “we’re sharing details about the kinds of payloads we can fly…” and that’s exactly what these documents give us. Physical ballpark and general guidelines about what general types of thing Lockheed has capability to build launch. Hopefully the spirit of openness will lead to the hoped-for increase in space utilization.

If you take Lockheed up on their offer of satellite development, don’t forget to drop us a tip!

[Via the Washington Post]

Stephen Hawking’s Legacy Includes Making His Work Widely Approachable

March 14, 2018 by 38 Comments

We are saddened by the passing of physicist Stephen Hawking. One of the great minds of our time, Hawking’s work to apply quantum theory to black holes launched his career and led to his best known theoretical discovery that black holes emit radiation, aptly known as Hawking radiation.

Thinking back on Stephen Hawking’s contributions to humanity, it strikes us that one of his most important is his embrace of pop culture. While his scientific discoveries and writings are what will stand the test of time, in our own age it is remarkable that Stephen Hawking is a household name around the world.

Hawking’s first book, A Brief History of Time, has sold more than 10 million copies and for many readers was their introduction into the way physicists view space and time. It was written for general consumption and not reserved for those who were already bathed in the jargon of theoretical physics. It sent the message that contemplating science is something that is fun to do in your spare time. This work continued with his more recent mini-series Into the Universe with Stephen Hawking created for the Discovery Channel.

A fan of the series, Hawking appeared in an episode of Star Trek: The Next Generation in 1993 and made subsequent, often repeat, appearances on The Simpsons, Futurama, and The Big Bang Theory. This was great fun for all science geeks who knew of his work, but it has a far more profound effect of normalizing interaction with a world-class scientist. Appearing on these shows told the story that the pursuit of knowledge is cool.

Having scientists in the public light is crucial to research and advancement. It lets the general public know what kind of frontiers are being pursued, and why that matters. This trickles both up and down, inspiring the next generation of scientists by introducing deep topics at an early age, and ensuring funding and opportunities for this upcoming wave of researchers has widespread support.

Stephen Hawking showed us some incredibly complicated secrets of the cosmos both through his discovery, and through his ambassadorship of scientific knowledge. He will be greatly missed but leaves behind an admirable legacy which we can all strive to live up to.

[Main image by Martin Pope via The Telegraph]

Lost In Space: How Materials Degrade In Space

March 12, 2018 by 31 Comments

Hackaday readers are well aware of the problems caused by materials left exposed to the environment over time, whether that be oxidized contact pads on circuit boards or plastics made brittle from long exposure to the sun’s UV rays.

Now consider the perils faced by materials on the International Space Station (ISS), launched beginning in 1998 and planned to be used until 2028. That’s a total of 30 years in an environment of unfiltered sunlight, extreme temperatures, micrometeoroids, and even problems caused by oxygen. What about the exposure faced by the newly launched Tesla Roadster, an entirely non-space hardened vehicle on a million-year orbit around the sun? How are the materials which make up the ISS and the Roadster affected by the harsh space environment?

Fortunately, we’ve been doing experiments since the 1970s in Earth orbit which can give us answers. The missions and experiments themselves are as interesting as the results so let’s look at how we put materials into orbit to be tested against the rigors of space.

Continue reading “Lost In Space: How Materials Degrade In Space” →

The UA723 As A Switch Mode Regulator

February 15, 2018 by 37 Comments

If you are an electronic engineer or received an education in electronics that went beyond the very basics, there is a good chance that you will be familiar with the Fairchild μA723. This chip designed by the legendary Bob Widlar and released in 1967 is a kit-of-parts for building all sorts of voltage regulators. Aside from being a very useful device, it may owe some of its long life to appearing as a teaching example in Paul Horowitz and Winfield Hill’s seminal text, The Art Of Electronics. It’s a favourite chip of mine, and I have written about it extensively both on these pages and elsewhere.

The Fairchild switching regulator circuit. From the μA723 data sheet in their 1973 linear IC databook, page 194 onwards.
The Fairchild switching regulator circuit. From the μA723 data sheet in their 1973 linear IC databook, page 194 onwards.

For all my experimenting with a μA723 over the decades there is one intriguing circuit on its data sheet that I have never had the opportunity to build. Figure 9 on the original Fairchild data sheet is a switching regulator, a buck converter using a pair of PNP transistors along with the diode and inductor you would expect. Its performance will almost certainly be eclipsed by a multitude of more recent dedicated converter chips, but it remains the one μA723 circuit I have never built. Clearly something must be done to rectify this situation.

Continue reading “The UA723 As A Switch Mode Regulator” →

Harvesting Energy From The Earth With Quantum Tunneling

February 14, 2018 by 117 Comments

More energy hits the earth in sunlight every day than humanity could use in about 16,000 years or so, but that hasn’t stopped us from trying to tap into other sources of energy too. One source that shows promise is geothermal, but these methods have been hindered by large startup costs and other engineering challenges. A new way to tap into this energy source has been found however, which relies on capturing the infrared radiation that the Earth continuously gives off rather than digging large holes and using heat exchangers.

This energy is the thermal radiation that virtually everything gives off in some form or another. The challenge in harvesting this energy is that since the energy is in the infrared range, exceptionally tiny antennas are needed which will resonate at that frequency. It isn’t just fancy antennas, either; a new type of diode had to be manufactured which uses quantum tunneling to convert the energy into DC electricity.

While the scientists involved in this new concept point out that this is just a prototype at this point, it shows promise and could be a game-changer since it would allow clean energy to be harvested whenever needed, and wouldn’t rely on the prevailing weather. While many clean-energy-promising projects often seem like pipe dreams, we can’t say it’s the most unlikely candidate for future widespread adoption we’ve ever seen.

Search For Military Satellite Finds One NASA Lost Instead

January 25, 2018 by 26 Comments

[Scott Tilley] was searching for radio signals from the Air Force’s top-secret ZUMA satellite. He found something that is — we think — much more interesting. He found NASA’s lost satellite called IMAGE. You are probably wondering why it is interesting that someone listening for one satellite found another one. You see, NASA declared IMAGE dead in 2005. It went silent unexpectedly and did not complete its mission to image the magnetosphere.

NASA did a failure review and concluded that in all likelihood a single event upset caused a power controller to trip. A single event upset, or SEU, is a radiation event and should have been automatically recovered. However, there was a design flaw that failed to report certain types of power controller failures, including this one.

The report mentioned that it might be possible to reset the controller at a specific time in 2007, but given that NASA thought the satellite was out of commission that either never occurred or didn’t work. However, something apparently woke the satellite up from its sleep.

[Scott] did a lot of number crunching to determine that the satellite’s spin rate had only decreased a little from its operational value and that the doppler data matched what he expected. [Scott] can’t read or command the telemetry, so he doesn’t know how healthy the satellite is, but it is at least operational to some degree. It’s really neat to see members of the team that worked on IMAGE leaving comments congratulating [Scott] on the find. They are working to get him data formatting information to see if more sense can be made of the incoming transmissions.

Who knew listening to satellites could be so exciting? If you want to build your own ground station, you might be interested in this antenna mount. If you need to know what’s overhead, this can help.

34C3: Vintage Verification, Stop Nuclear War With A 6502

January 10, 2018 by 11 Comments

Our better-traveled colleagues having provided ample coverage of the 34C3 event in Leipzig just after Christmas, it is left to the rest of us to pick over the carcass as though it was the last remnant of a once-magnificent Christmas turkey.  There are plenty of talks to sit and watch online, and of course the odd gem that passed the others by.

It probably doesn’t get much worse than nuclear conflagration, when it comes to risks facing the planet. Countries nervously peering at each other, each jealously guarding their stocks of warheads. It seems an unlikely place to find a 34C3 talk about 6502 microprocessors, but that’s what [Moritz Kütt] and [Alex Glaser] managed to deliver.

Policing any peace treaty is a tricky business, and one involving nuclear disarmament is especially so. There is a problem of trust, with so much at stake no party is anxious to reveal all but the most basic information about their arsenals and neither do they trust verification instruments manufactured by a state agency from another player. Thus the instruments used by the inspectors are unable to harvest too much information on what they are inspecting and can only store something analogous to a hash of the data they do acquire, and they must be of a design open enough to be verified. This last point becomes especially difficult when the hardware in question is a modern high-performance microprocessor board, an object of such complexity could easily have been compromised by a nuclear player attempting to game the system.

We are taken through the design of a nuclear weapon verification instrument in detail, with some examples and the design problems they highlight. Something as innocuous as an ATtiny microcontroller seeing to the timing of an analogue board takes on a sinister possibility, as it becomes evident that with compromised code it could store unauthorised information or try to fool the inspectors. They show us their first model of detector using a Red Pitaya FPGA board, but make the point that this has a level of complexity that makes it unverifiable.

The gamma ray energy spectrum of a cobalt-60 source as seen from an Apple II.
The gamma ray energy spectrum of a cobalt-60 source as seen from an Apple II.

Then comes the radical idea, if the technology used in this field is too complex for its integrity to be verified, what technology exists at a level that can be verified? Their answer brings us to the 6502, a processor in continuous production for over 40 years and whose internal structures are so well understood as to be de facto in the public domain. In particular they settle upon the Apple II home computer as a 6502 platform, because of its ready availability and the expandability of [Steve Wozniak]’s original design. All parties can both source and inspect the instruments involved.

If you’ve never examined a nuclear warhead verification device, the details of the system are fascinating. We’re shown the scintillation detector for measuring the energies present in the incident radiation, and the custom Apple II ADC board which uses only op-amps, an Analog Devices flash ADC chip, and easily verifiable 74-series logic. It’s not intentional but pleasing from a retro computing perspective that everything except perhaps the blue LED indicator could well have been bought for an Apple II peripheral back in the 1980s. They then wrap up the talk with an examination of ways a genuine 6502 system could be made verifiable through non-destructive means.

It is not likely that nuclear inspectors will turn up to the silos with an Apple II in hand, but this does show a solution to some of the problems facing them in their work and might provide pointers towards future instruments. You can read more about their work on their web site.