Shpaget

I'm the first to admit that I don't like filling, sanding and painting, but that sure looks like second grade job around the hatch.

https://www.youtube.com/watch?v=3ZEnDFIkq_E&feature=emb_title

Those space suits could easily pass as props for everyday wear in a SciFi tv series. They look much more flexible and easy to move around in than the thing used in Shuttle launches, for example.

Some news on this front: https://theconversation.com/why-astronomers-now-doubt-there-is-an-undiscovered-9th-planet-in-our-solar-system-127598 tl;dr, These guys think there might not be a planet nine considering the new data and reinterpretation of the old. They made more observation and found new Kuiper belt objects that indicate strong bias in previous observations. Supplemented with data from newly found objects, there is no longer the indication of a big object out there.

Even the cheap electric scooter I rode the other day was fly by wire. Probably for the best, since otherwise it likely would have offloaded me as soon as I cranked the throttle.

Why? Did the civilization suddenly forget about computers?

You could store it to an SD card in CVS format and once you have that, you can use whatever you want. I suggested Excel, because I had a mental image of conditional formatting background color and the image just appearing out of the empty cells. One more thing that occurred to me, depending on how fast your acquisition is and resolution you're after, you may want to track the sky on top of scanning it. Mount the entire thing on an equatorial mount, or for hard mode, combine the alt az tracking with the scanning. Even if it takes only one second to take a measurement, it will take a while to scan even a 100x100 pixel image, and the Earth will swing away.

Do you plan on automating the scanning motion? If you're into spreadsheets, you can have Arduino output directly into Excel and look at your image appear in front of you.

That's corporate logic. It makes perfect sense from the bean counting perspective.

The episode in question aired on September 7, 2001, so I suppose they didn't invent it, but that's where I heard it first and I don't think I've heard it any other place.

It's a line in Grim Adventures of Billy and Mandy, one of my favorite cartoons.

Is that a Mandy quote (while she is swapped with Billy)?

Not exactly SLS related, but... Doug Loverro, NASA's head honcho for human spacefligh, resigned. Ken Bowersox to take the seat, at least until permanent replacement is found. https://www.nasaspaceflight.com/2020/05/loverro-resigns-bowersox-acting-heo-lead/

I was taught to always return a tool in better shape than it was in when I borrowed it. Corollary, a tool you lend someone will be returned broken, if at all. Our company is a small one, so not many folks here, but stuff like that still happens, so, finances permitting, when I buy myself a nice new thingy that proves to be very good, I get a couple more of them to spread around. Lowers the chance of me not finding my own when I need it. Costs more, but saves a lot of aggravation in the long run. Examples: screwdriver set, exacto knives, mechanical pencils, steel rulers, magnetizer/demagnetizer, etc.

That would seriously mess me up.

Peter Hadfield, aka potholer54, gives his analysis of data available and online blogosphere. As usual for his videos, check the video description for links to sources.

So I got around to installing these boards and realized that instead of four inputs I designed the board around, I need five. Back to the drawing board, right? Well, not quite, but let me make the short story long. The project in question uses 4 hall sensors (they sense magnetic fields) to toggle two bistable relays. Not much to it, really, but hall sensor has inverted logic compared to what I need, namely, when there is no magnet close to the sensor it outputs 5V, when a magnet comes close, the output is 0V. I need it to behave the other way around, so before the signal gets to the MOFSET which powers the relay coil it needs to be inverted. A simple 7404 (NOT gate/inverter) did the job in my second go at it. Perfectly fine choice of IC, right? Well, not if you need to have 5 inputs control 4 outputs. But as I mentioned earlier, that was the second time I was making this PCB. The first time around I was not able to find the 7404 in my parts drawers, so I opted for the next best thing - a 7400 NAND gate, and just short one of the inputs on each gate to 5V. That makes the NAND gate effectively an inverter. And here comes my accidental genius. With a NAND gate, I can actually use two hall sensors on input to trigger one output, thus the PCB is still usable, and needs to have only one short trace Dremelled out and one additional resistor. Of course, this works because of the specific topography and desired function, but still, it meant that the fix took 5 minutes instead of several of hours to a day to redesign the PCB, etch it, drill it, and solder all the components. HA! In your face Mr. Alzheimer!

Time to build an island in the Atlantic, for all those landing needs.

Well, the choice between Arduino and RPi is simple. RPi is a huge overkill for this. You don't need a full blown computer to control one motor and a few LEDs. The power requirements alone would be a deal breaker here. Arduino is more than enough for this. Bluetooth for Arduino https://www.ebay.com/itm/HC-06-Wireless-Bluetooth-Arduino-PI-JY-MCU-Serial-RF-5V-Transeiver-Module-AU/272770538949?hash=item3f82641dc5:g:CtoAAOSwTCZZcU7B Note it's 3,3V device so you'll need a level shifter to bring it to 5V if you're using some 5V Arduino. Something like this: https://www.sparkfun.com/products/12009 As for a mobile app, perhaps check this: A forum that specializes in Arduinos is official Arduino forum https://forum.arduino.cc (it throws a 504 error at the moment, but the link should be fine). Unfortunately, the community there is a little weird. There certainly are knowledgeable guys there, but sometimes you keep getting cryptic answers that require an already existing knowledge of some (to newbies) obscure component behavior/characteristic which makes the answer practically unusable. Some of the guys there expect you to know a lot of theory before they are willing to help you, and just point you towards a (very) general direction, which I suppose is somewhat fine (noone should be doing your homework), but directing a newbie that asks about using a MOSFET to read up on transistor doping, is ridiculous, and doesn't help at all since the guy asking will not only fail to understand it, but has no need for it anyway. Better community is eevblog.com/forum/ but they are oriented towards more professional aspects of electronics, so a lot of them might not be interested in meddling with Arduinos. There are some that will help you there. Alternatively, why not stay here? There are a handful of us here that like to play with magic smoke.

Well, you don't need to own a 3d printer to benefit from them. There are services that will print whatever you design for a small fee (it would be a couple of bucks for what you need). You could probably find a maker space, college, high school or even a library that has one for public use. Edit, for a long time I refused to buy one, but then about half a year ago, the company I work for got a commission and we bought ourselves an Elegoo Mars (UV resin printer). It paid for itself on that first job, so it was financially justified, however, even though I did manage to find a couple of uses for it afterwards, I still don't think it would be worthwhile if it wasn't for that commission. 3D printing services are everywhere.

Those front wheels on model steam engines are a nightmare even on brand new locos of modern construction. Getting them to perform well in curves and slopes is an ongoing battle for us.

Exactly. The price drop Elon promises, if delivered, will bring about a paradigm shift in space hardware design. I can't help but compare it to relatively recent changes in electronics hobby scene. It used to be all about analog circuits, 555s and opamps to maybe get a half arsed AM radio. Now, you slap an Arduino in a Tupperware box and presto! You have have a data logging, wifi enabled, internet connected, RFID triggered, video call supported, lullaby singing, laser pointer swinging cat food dispenser. 20 years ago that would be a multimillion dollar project that would require a team of skilled engineers to pull off, now it's just a few clicks on ebay and a few more on github. Soldering iron optional. I expect similar change in space hardware too. If $ to LEO drops to sub three digit ballpark, you can expect to see sats built from "household" items. Need a solar panel? Why spend tens of thousands on superthin gallium arsenide cells when you can climb to your roof and take the much bigger polycrystalline silicon stuff for a fraction of the price and more output. Who cares if they have 5 mm thick glass on them and are mounted in steel frame? Launching that extra mass is basically free. Grab the lead acid battery from your car, while you're at it. No need to splurge on li-ion stuff.

Spent two days designing two PCBs for a project, completely done with one, started on the other when I had a deja vu. Went into my electronics folder and deja vu indeed. I've already done those things two months ago and the fully functional and tested boards have been sitting on my desk the whole time. Should I be worried?

Is there a failure mode where main engines can't be shut down? I suppose there is a conceivable scenario, but if the computer that is supposed to turn off the engines locks up, can they still be shut down? If not, can Dragon still get away if abort needs to happen near the end of the first stage burn (max acceleration)?

I wouldn't be surprised if SS started proving that before SLS kicks off properly. And let's not forget the New Glenn sleeper.