Most of us first spot them as children—the white lines in the blue sky that are the telltale sign of a flight overhead. Contrails are an instant visual reminder of air travel, and a source of much controversy in recent decades. Put aside the overblown conspiracies, though, and there are some genuine scientific concerns to explore.
See, those white streaks planes leave in the sky aren’t just eye-catching. It seems they may also be having a notable impact on our climate. Recent research shows their warming effect is comparable to the impact of aviation’s CO2 emissions. The question is then simple—how do we stop these icy lines from heating our precious Earth?
Disappointing news this week for those longing for same-hour Amazon delivery as the retail giant tapped the brakes on its Prime Air drone deliveries. The pause is partially blamed on a December incident at the company’s Pendleton, Oregon test facility, where two MK30 delivery drones collided in midair during light rain conditions. A Bloomberg report states that the crash, which resulted in one of the drones catching fire on the ground, was due to a software error related to the weather. As a result, they decided to ground their entire fleet, which provides 60-minute delivery to test markets in Arizona and Texas, until a software update can be issued.
I was looking at the periodic table of the elements the other day, as one does, when my eye fell upon the right-hand side of the chart. Right next to the noble gases at the extreme edge of the table is a column of elements with similar and interesting properties: the halogens. Almost all of these reactive elements are pretty familiar, especially chlorine, which most of us eat by the gram every day in the form of table salt. As the neighborhoods of the periodic table go, Group 17 is pretty familiar territory.
But for some reason, one member of this group caught my attention: iodine. I realized I had no idea where we get iodine, which led to the realization that apart from chlorine, I really didn’t know where any of the halogens came from. And as usual, that meant I needed to dig in and learn a little bit about the mining and refining of the halogens. At least most of them; as interesting as they may be, we’ll be skipping the naturally occurring but rare and highly radioactive halogen astatine, as well as the synthetic halogen tennessine, which lives just below it in the group.
You know (or maybe you didn’t), I get super excited when y’all use the links at the bottom of this round-up we call Keebin’ to communicate with your old pal Kristina about your various labors of love. So just remember that.
Case in point: I was typing up this very issue when I heard from [Jay Crutti] and [Marcel Erz]. Both are out there making replacement keyboards for TRS-80s — [Jay] for Models 3 and 4, and [Marcel] for the Model 1. Oooh, I said to myself. This is going at the top.
A TRS-80 Model 4. Image by [Jay Crutti] via JayCrutti.comRelevant tangent time: I remember in the 90s having a pile of computers in my parents’ basement of various vintages, a TRS-80 Model 2 among them. (Did I ever tell you about the time I got pulled over for speeding with a bunch of different computers in the backseat? I was like no, officer, first of all, those are old machines that no one would really want, and I swear I didn’t steal them.)
I think the TRS-80 is probably the one I miss the most. If I still had it, you can bet I would be using [Jay] and [Marcel]’s work to build my own replacement keyboard, which the 40-year-old machine would likely need at this point if the Model 4 is any indication with its failing keyboard contacts.
To create the replacements, [Jay] used Keyboard Layout Editor (KLE), Plate & Case Builder, and EasyEDA. Using the schematic from the maintenance manual, he matched the row/column wiring of the original matrix with Cherry MX footprints. Be sure to check out [Jay]’s site for a link to the project files, or to purchase parts or an assembled keyboard. On the hunt for TRS-80 parts in general? Look no further than [Marcel]’s site. Continue reading “Keebin’ With Kristina: The One With The Hardware-Layered Keyboard”→
With the right conditions, this tiny sensor can measure 12 meters
If you need to measure a distance, it is tempting to reach for the ubiquitous ultrasonic module like an HC-SR04. These work well, and they are reasonably easy to use. However, they aren’t without their problems. So maybe try an IR time of flight sensor. These also work well, are reasonably easy to use, and have a different set of problems. I recently had a project where I needed such a sensor, and I picked up a TF-MiniS, which is a popular IR distance sensor. They aren’t very expensive, and they work serial or I2C. So how did it do?
The unit itself is tiny and has good specifications. You can fit the 42 x 15 x 16 mm module anywhere. It only weighs about five grams — as the manufacturer points out, less than two ping-pong balls. It needs 5 V but communicates using 3.3 V, so integration isn’t much of a problem.
At first glance, the range is impressive. You can read things as close as 10 cm and as far away as 12 m. I found this was a bit optimistic, though. Although the product sometimes gets the name of LiDAR, it doesn’t use a laser. It just uses an IR LED and some fancy optics.
This week, we witnessed a couple of space oopsies as both Starship and New Glenn suffered in-flight mishaps on the same day. SpaceX’s Starship was the more spectacular, with the upper stage of the seventh test flight of the full stack experiencing a “rapid unscheduled disassembly” thanks to a fire developing in the aft section of the stage somewhere over the Turks and Caicos islands, about eight and a half minutes after takeoff from Boca Chica. The good news is that the RUD happened after first-stage separation, and that the Super Heavy booster was not only able to safely return to the pad but also made another successful “chopsticks” landing on the tower. Sorry, that’s just never going to get old.
On the Bezos side of the billionaire rocket club, the maiden flight of Blue Origin’s New Glenn ended with the opposite problem. The upper stage reached orbit, but the reusable booster didn’t make it back to the landing barge parked off the Bahamas. What exactly happened isn’t clear yet, but judging by the telemetry the booster was coming in mighty fast, which may indicate that the engines didn’t restart fully and the thing just broke up when it got into the denser part of the atmosphere.
