What is this world coming to when a weather satellite that was designed for a two-year mission starts to fail 21 years after launch? I mean, really — where’s the pride these days?
All kidding aside, it seems like NOAA-15, a satellite launched in 1998 to monitor surface temperatures and other meteorologic and climatologic parameters, has recently started showing its age. This is the way of things, and generally the decommissioning of a satellite is of little note to the general public, except possibly when it deorbits in a spectacular but brief display across the sky.
But NOAA-15 and her sister satellites have a keen following among a community of enthusiasts who spend their time teasing signals from them as they whiz overhead, using homemade antennas and cheap SDR receivers. It was these hobbyists who were among the first to notice NOAA-15’s woes, and over the past weeks they’ve been busy alternately lamenting and celebrating as the satellite’s signals come and go. Their on-again, off-again romance with the satellite is worth a look, as is the what exactly is going wrong with this bird in the first place.
For most of us, 3D printing means printing in plastic of some sort — either filament or photo resin. However, we have all wanted to print in other materials — especially more substantial materials. Metal printers exist but they aren’t cheap. However, it is possible to print molds and cast metal parts using them. [Amos Dudley] prints molds. But instead of metal, he casts parts out of glass.
[Amos] covers several techniques. The first is creating a relief (that is a 3D shape that grows out of a base). According to the post, this prevents difficult undercuts. He then casts a mold from silica and uses a kiln to melt glass into the mold. You might expect to do that with a full-size kiln, but you can actually get an inexpensive small kiln that fits in your microwave oven.
Second up on the surprise list is the badge maker himself. The design is a throwback to days of yore as Joe Grand steps up to the plate once again. Veterans know him as Kingpin, and his badge-making legacy runs deep. Let’s jump in and take a look.
Carburettors versus electronic fuel injection (EFI); automotive fans above a certain age will be well versed in the differences. While early EFI systems had their failings, the technology brought with it a new standard of reliability and control. By the early 1990s, the vast majority of vehicles were sold with EFI, and carburettors became a thing of the past.
The Mazda Miata was no exception. Shipping in 1989, it featured not only multiport fuel injection, but also a distributorless ignition system. Consisting of two coilpacks in a wasted spark configuration, with computer-controlled timing, the system was quite advanced for its time, especially for a budget sports car.
Despite the Miata’s technological credentials, those in the modified car scene tend to go their own way. A man by the name of Evan happened to be one such individual and decided to do just this — scrapping the EFI system and going with a retro carburetor setup. It was around this point that this I got involved, and mechanical tinkering ensued.
In the early 1990s, NASA experienced a sea change in the way it approached space exploration. Gone were the days when all their programs would be massive projects with audacious goals. The bulk of NASA’s projects would fall under the Discovery Project and hew to the mantra “faster, better, cheaper,” with narrowly focused goals and smaller budgets, with as much reuse of equipment as possible.
The idea for what would become the Mars InSight mission first appeared in 2010 and was designed to explore Mars in ways no prior mission had. Where Viking had scratched the surface in the 1970s looking for chemical signs of life and the rovers of the Explorer program had wandered about exploring surface geology, InSight was tasked with looking much, much deeper into the Red Planet.
Sadly, InSight’s primary means of looking at what lies beneath the regolith of Mars is currently stuck a few centimeters below the surface. NASA and JPL engineers are working on a fix, and while it’s far from certain that that they’ll succeed, things have started to look up for InSight lately. Here’s a quick look at what the problem is, and a potential solution that might get the mission back on track.
Paul Stoffregen did it again: the Teensy 4.0 has been released. The latest in the Teensy microcontroller development board line, the 4.0 returns to the smaller form-factor last seen with the 3.2, as opposed to the larger 3.5 and 3.6 boards.
Don’t let the smaller size fool you; the 4.0 is based on an ARM Cortex M7 running at 600 MHz (!), the fastest microcontroller you can get in 2019, and testing on real-world examples shows it executing code more than five times faster than the Teensy 3.6, and fifteen times faster than the Teensy 3.2. Of course, the new board is also packed with periperals, including two 480 Mbps USB ports, 3 digital audio interfaces, 3 CAN busses, and multiple SPI/I2C/serial interfaces backed with integrated FIFOs. Programming? Easy: there’s an add-on to the Arduino IDE called Teensyduino that “just works”. And it rings up at an MSRP of just $19.95; a welcomed price point, but not unexpected for a microcontroller breakout board.
The board launches today, but I had a chance to test drive a couple of them in one of the East Coast Hackaday labs over the past few days. So, let’s have a closer look.
It’s been fifty years since man first landed on the Moon, but despite all the incredible advancements in technology since Armstrong made that iconic first small step, we’ve yet to reach any farther into deep space than we did during the Apollo program. The giant leap that many assumed would naturally follow the Moon landing, such as a manned flyby of Venus, never came. We’ve been stuck in low Earth orbit (LEO) ever since, with a return to deep space perpetually promised to be just a few years away.
Falcon Heavy Payload Fairing
But why? The short answer is, of course, that space travel is monstrously expensive. It’s also dangerous and complex, but those issues pale in comparison to the mind-boggling bill that would be incurred by any nation that dares to send humans more than a few hundred kilometers above the surface of the Earth. If we’re going to have any chance of getting off this rock, the cost of putting a kilogram into orbit needs to get dramatically cheaper.
Luckily, we’re finally starting to see some positive development on that front. Commercial launch providers are currently slashing the cost of putting a payload into space. In its heyday, the Space Shuttle could carry 27,500 kg (60,600 lb) to LEO, at a cost of approximately $500 million per launch. Today, SpaceX’s Falcon Heavy can put 63,800 kg (140,700 lb) into the same orbit for less than $100 million. It’s still not pocket change, but you wouldn’t be completely out of line to call it revolutionary, either.
Unfortunately there’s a catch. The rockets being produced by SpaceX and other commercial companies are relatively small. The Falcon Heavy might be able to lift more than twice the mass as the Space Shuttle, but it has considerably less internal volume. That wouldn’t be a problem if we were trying to hurl lead blocks into space, but any spacecraft designed for human occupants will by necessity be fairly large and contain a considerable amount of empty space. As an example, the largest module of the International Space Station would be too long to physically fit inside the Falcon Heavy fairing, and yet it had a mass of only 15,900 kg (35,100 lb) at liftoff.
To maximize the capabilities of volume constrained boosters, there needs to be a paradigm shift in how we approach the design and construction of crewed spacecraft. Especially ones intended for long-duration missions. As it so happens, exciting research is being conducted to do exactly that. Rather than sending an assembled spacecraft into orbit, the hope is that we can eventually just send the raw materials and print it in space.
