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Fredaspace. That websites pretty great. Thanks. With some guesstimation on their prices (dunno whay shipping to the us would be if i were launching the thing) but for 400-500£ can get the balloon and gps and everything for the launch but jeb and the camera. When i get off the job im on for the next couple weeks i can order the gps and all myself (cause assuming they dont break, i can reuse them) and then do up a kickstarter for a few balloons and gas (since those are the expended parts)

SO like really, If anyone can get the balloon, and a weight limit that balloon can lift. And I can get a sensors/gps setup picked out and set up. Honestly I probably have most of the sensors already, just no GPS chip thats not already built into anything or a GPRS board to send the coords to a phone or something. And as long as the thing doesn't smash on the ground and we pick the thing up when the projects done, its not like it'll cost me anything in the long run cause I can reclaim those sensors after the project (or leave them, and shoot for a higher altitude with a subsequent project) The biggest monetary loss on this project is definitely the guy who gets the balloon, and the gas for the balloon. Honestly though if someone could link me to good sites about getting the balloon, I doubt that those are super expensive either. Hell sounds like a great geocaching adventure anyways when the thing comes down, depending on where it lands.

Could always try to do the balloon project inside the 10cm form factor of a cubesat. Or a 20x10x10 (less need of custom pcbs for the electronics) dunno though what people would want this rig to do though? Like what is the actual design goal of this project?

20 grams... lesse an ATmega chip off of an arduino weighs in the ballpark of 2g... So basically you're putting an unprotected PCB in space with some sensors on it and a couple tiny solar cells, and calling it a satellite. (Though theres always those ping pong ball "sats")

Honestly a while ago i built a temp data logger for some ovens for a company using 32 spi temp sensors (8 per oven, in different spots). Needed 3 pins for the spi, and then for the trigger lines to the different sensors, i had 4 shift registers set up in series (3 more pins), they'd just kick out a single 1, followed by 31 0s and as the 1 would get shifted through, and trigger 1 of them at a time. Set it up just right with your data logger program, and you never need more than 6 pins to control "infinite" amounts of spi chips (you will run into clockspeed problems with the shift registers though) Also as far as this balloon project, most of it could be hand prototyped on a small board oneself, or if you want a full sensor package. The 100-200 of a several sensors in 1 shield, might actually save you money and time in the long run. (3in1 sensor chips are always helpful too. Could rig up your sensors on a prototyping shield easy enough, and then youd just throw an sd datalogger shield on top to save the data)

Honestly both are almost the same price (35-40 for rpi vs 20-30 for arduino) i can point out though that the arduino is much less power hungry than the rpi. Ive messed with both units extensively. When it comes to interfacing with other chips (accelerometers, gyros, gps) i can certainly say that its significantly easier to do with an arduino than an rpi. In any rpi projects that ive done that need to read or control other things, especially screens, i have the rpi stream the commands into the arduino for execution because its easier to control things directly from the arduino. Honestly if you gave me a list of the kinds of sensors you wanted to use, i could probably throw together a base datalogging program for them in an afternoon on arduino. But sensors themselves can get kinda expensive. On the note of only being able to use 2 digital inputs, this is incorrect. However i am guessing that you are meaning theres 1 I2C bus and 1 SPI. Yes you can only read from 2 chips at any particular instant. But in many cases you can read and store values from several sensors several times a second. Many drones that run off of arduino are pulling from a gyro, compass, barometer, accelerometer, and sometimes the gps chip, all with the same spi wires (just with a different control line) Also on the note of gps shutting off at an altitude... i cant really help with that part, ive never tried to get an unlocked gps chip. But at the same time, do you need full gps tracking? Or only when it starts to come back down?

Resilience to what? Blacking out? Fairly sure that if you shifted to a 1.2g environment, a healthy person would feel much heavier, but it likely wouldn't just be like "2 days gone by, time up time to pass out". Anything below 2Gs would probably be manageable to live in, and even perhaps might be beneficial in some applications. Someone for example who lived on a station simulating 1.5Gs for a couple years, moving around and going about their business, then going down to earth and only seeing 1G, might almost feel superhuman in strength. While a person coming from earth might have a lot of trouble adapting to life in a 1.5g. But you know, given a year to build up the strength, then they'd be just like the person coming down. Although, it'd be much more effective if the gravity were adjusted over time rather than a sudden jolt change. On the note of mars. Well any majorly different gravity would have major changes on development. Someone raised on mars wouldn't need to be as strong, or have anywhere near the bone density or heart strength. Likely if someone lived there for 10 years and adapted to that environment, they might find that they're unable to return to earth simply because to them, earth would be ~ "3gs". But hey there hasn't been much experimentation on that yet. Id say forget messing with Mars and instead go for a moon base to get the first major test data of people living extended lives in a different gravity (besides, on the moon, they're literally a couple days flight away encase anything happens, and they might have some actual work to do while they're there). Rotating space station might also be a good way (but much better for testing the higher G situations). I honestly do wonder though. The Human body is amazingly adaptable, and even in my own state, between summer and winter I get vast differences in my own physical fitness level (start of spring, I can probably do a 20 minute mile, and then flop on the ground and be done for the day. Winter bear fat and all that. End of summer, I'll have often gotten down to a 8min mile, while carrying ~50lbs total of airsoft gear, my shield, and occasionally a forest stormtrooper costume for the lulz, and I'll have run 3-4 marathons or half marathons. Sometimes I wonder what I could be like if I kept the same activity level through winter, but I tried the gym thing and it really wasn't for me.) Trained soldiers also baffle me in their endurance and conditioning. Hell people do ultra-marathons. They just run, 50 damn miles... for FUN. Put 1 of them on mars, and watch them go. Don't even need rovers, they could just run, jump, maybe fire a little compressed gas thruster for a little vertical boost to slow their decent. Cover a football field in 2-3 jumps. I would hope to see in my lifetime, a large enough station with a rotating gravity block large enough for people to live for years. Start it off at 1G, and gradually speed it up by .5Gs a year, while studying the people living on it. Could a person survive sustained 1.5-2Gs? Probably, but you'd probably have major back problems. Andre the giant was literally too heavy for his bones and heart to support towards the end of his life. And a 200lb person at 2Gs would basically feel like him.

Probably the closest to a "high" orbit over earth that you could assume would be either sitting in an earth-moon Lagrange point, or an earth-sun Lagrange point. While technically not in "orbit" they are places far enough from earth where you'd be able to sit in roughly the same area.

Actually in all truth, the GPS chip has accuracy within a 35ft diameter sphere (I coulda bought a better 1, didn't was cheap) And as it compares notes between the 2 altitude values. If the barometer shows up within the vertical error of the GPS chip, it uses the barometer value. If it shows that its outside of the GPS altitude on the barometer, it sends me a little alarm to tell me that somethings may be wrong (hasn't happened ever though except right at startup while its still using the stored values of its last flight for calibration, then it runs calibration and it goes away.) Mainly its there encase we get a notable pressure change that would be throwing the barometer readings off from what their current altitude settings are. Have been having thoughts of building some kind of laser rangefinder into it so it could have a 3rd setpoint for altitude since of checks, since well, the ground is the most dangerous to the health of the craft. SO its been a couple days though, hows the box working, got any vids of launching?

Well see theres the thing, a lot of people don't really understand "serving size" 6-11 grains a day generally equates to ~ 3-7 slices of bread, and such (I think 1 ear of corn counts as 2servings, or ~1/4th lb cooked rice, or 2 cups of cereal) And even then its considered in a range. I'm sure most people could handle 4 slices of bread, an apple, an orange, 5 minutes of raiding a veggie tray (really you wanna get kids to eat their veggies? Cut them up into small easy to eat chunks, and keep them on hand, its easy. Veggie plates are godly for this) or a couple small salads. A couple glasses of milk and a small piece of meat (a serving of meat is roughly the size of a deck of cards, or a small hamburger patty) Honestly I hit the whole food pyramid almost each meal (although right now I'm doing a bit more meat because I'm working out more and need moar protein) but I'm a fairly large-built person... Perhaps I do eat a little too much, but its generally burned off when the weekend comes and we get a game of streethockey going on or such.

Well the Ford class carrier... no solid info has come out about its top speed but it'd probably be capable of the upper 40kts. Assuming 45, thats 51mph or 81kph. (a full 15mph faster than the stall speed on my fathers supercub, and faster than the stall speed on that "flying flapjack" plane by chance vought) Into a headwind which on the sea, finding a 20-30mph wind is certainly easy enough. Shuttle landed on a regular runway at 215mph, so its relative speed to a carrier could actually be about 135. We could probably manage a spaceplane design that's a bit more aerodynamic and could land at that kind of relative speed. At the same time I really don't know about that upper 40kts. The power plant is gonna be making quite a bit more than previous ships, and the hull profile is a bit better designed. Entirely possible that if they cranked up to flank speed they might break into the 50kt range

Cool Don't worry they're super easy to use, and it has one of the most helpful support forums I've been on. And on the note of altitude you can get a barometer board the size of a quarter for ~$10 and they're a dozen guides on setting them up. And at least going off the 1 that runs on my drone. It uses GPS/compass for its main positional info, but keeps accelerometer/gyro/barometer to keep a second "where it think's it is" without GPS. (you know, encase a cloud comes by jsut right and loses signal, it'll be smart enough to fly itself back to where I launched it from, pop out a chute and land without crashing) The barometers are pretty accurate too. 1 I use is within .4m in altitude after calibrating it on the ground, though the drone never gets above about 100m (don't even think I'm supposed to have it that high) the barometer is rated to ~9000m. Don't think you'll be having any rockets hitting that altitude anytime soon. (if you do tell us, and film it, I'm sure we'd all enjoy)

Very well made, good job sir. I especially like the continuity feedback loops. Save many a "why didn't it fire, were the leads hooked up right" problems. I also like the usage of RJ-45 as your cabling (using stuff thats readily available to get the job done) I might be worried in the future about the wiring surviving the 1.8amps for the couple seconds while the igniter runs however. RJ45 isn't the highest amperage rated cabling there is. You might consider doubling or tripling the gnd/18V lines. You've currently got 1gnd, 1-18V, and 2 signal LEDs, that should live 4 extra wires in the cable doing nothing. Add 2 of those to the 18V circuit, and 2 to the gnd to spread the amperage. Less risk of damage if you find later on that its having problems putting that much power down 1 tiny wire. Advice on straighter hole drilling. My suggestion to you in the future if you continue down the path is to get a nail and a hammer and tap a little dot for the tip of the drill to rest in while starting the holes. Less drill walking around, and your holes end up straighter and more even. That or a center punch, can probably pick 1 up at your local hardware store. But hey, not hating on you or anything, I have about 80 project boxes with holes all over the place for LEDs and crap myself (took till about my 40th electrical wingding before I stopped using tupperware boxes/altoids tins and actually buying project enclosures that have the lines on the inside to help line up where you want things) I'm not one heavy into the rocketry myself (I've stuck to RC planes because the local police don't get so upset about them) though I've got more than 1 RC plane capable of firing 2-4 rockets that it can carry. If you plan to go a little farther down the electrical path (maybe make a rocket that keeps itself vertical as long as possible via onboard electronics, or tries to hold an angled trajectory... or even more, the skys the limit) I can give you tips on a lot of that stuff if you need it.

Can't hate the religious guy, I say if we ever get a moon space program going again, we give him and a dozen of his peers a free round trip to the moon and back. See his argument after that.

Also dont forget that the game would have to be doing all these gravitational computations on top of the already rather straining (to some machines) inter-part forces within a craft itself. (this might be passed over perhaps if there were a mod that after "building" your ship locked it in as a rigid structure, but then thats kinda ruining the fun of the game) In an extreme case, adding in full n-body physics would also being to cause tidal forces within your ship structure. (ship is a certain semi rigid shape moving at a constant speed. The parts of the ship closer the planet are moving faster when referenced from the planet than the parts farther out, and this could induce forces in the ship, at least I think it would. Don't really remember the rules for that, but I'm pretty sure the net effect would be your ship spinning wonkily, although on the scale of the game and by extension IRL it's not too much of a problem for anything we've built yet).

Well from my terrible videogaem coding experience. (My end year project for the class was a "asteroids" type game, where you were in orbit. You had to keep the asteroids from hitting the planet or lose points. If you tried hard though you could use a tractor beam and redirect the roids into orbit themselves and tell them to get mined for extra points, and later turn them into little defense platforms that would help shoot down roids (they'd wait and only fire at where your mouse was pointed). All in all it was a fun little derp made for a project. In that I did have n-body gravity dragging you around so you could get yourself in a semi orbit around an asteroid and such. I had planned to do more with it, but then I got a job and all that stuff ended. Now the n-body worked just fine because there were basically no graphics or anything to work with. But as you started shooting stuff up and the asteroid count climbed, well on the school computers it started getting laggy around ~70 objects (cause remember, thats 70 objects interacting with eachother every frame, and lots and LOTS of math going down) After that I patched out the N body and just made them all check gravity to the planet, so then you could easily have hundreds of asteroids about without any lag. (ofcourse I'm sure there were countless things I could have done to streamline it more.) Game didn't bother at any point trying to track your own orbital path though. Just kinda had to speed stuff up until you were happy and then hope they didn't crash.

Well that was part of my argument for a flying boat type spaceplane... MAYBE its a ginormous mega-carrer spaceplane????????? Jk, never gonna happen.

What if we're trying to land on a planet with rougly earthlike characteristics however is covered mostly by water?

The whole floatplanes vs flying boats is really semantics and I'm pretty sure that most people understood the intent, since I pointed out the spruce goose, catalina PBY as examples, and nto a Cessna 172 with a floatkit on it. But at the same time I do still have a bit of a point on them. A, well we've already done controlled landing with craft of assorted shapes and sizes, I'm sure we can design 1 that would work. B, Done that too, haven't landed 1 on water, but again, I'm sure we could manage it. C, why can't the heat shield be built into the floating fuselage itself? If the craft lands at a moderately low speed it shouldn't be damaged much by the landing. It wouldn't be excessively more weight than the fuselage itself, just a slight bit more bulk and perhaps some floats that are extend out of the wings for stability on the water. Some weight is saved on traditional landing gear that needs to pop out of the heat shield, so the heat shield itself could almost be 1 large cast piece layered on (instead of individual tiles like the shuttle, or could be a throwaway piece like on the early capsules. Land it, tow the craft to a place to refit it for launch, snap a new heat shield on) D, decent speed and airspeed isn't so damaging as you'd think, especially if they did a nice flare right before landing, and if landing on calm enough water the right shape hull would just skim across with help from residual lift to a landing while slowing to a nice stop, after all we've done jet boats that go at over 300mph last I checked. Remember, stress from this type of landing is spread across the hull much more evenly than traditional landing gear where its focused into 3 points. Who craft would have more internal structure probably, but less focused around a few points. (might work, might not) I'd assume they'd land with a heavy flare dropping the tail in the water first and dragging the rest of the craft down as the speed drops off. E, that open ocean would be the biggest problem I can see honestly, and there's not a lot of large bodies of fresh water I'd be fine with shooting a landing on. Unless ofcourse the craft is a real spaceplane and can fly under its own power in the atmosphere for a length of time to get to suitably calm water (but why bother then when you can go for a suitable runway) F, dunno about how buoyant the space shuttle would have been. After landing it could pop out a couple of inflatable floats until it can be collected? G, corrosion on the ocean can generally be fought off with zincs on boats, but along as the thing doesn't sit in the water for extended times there shouldn't be too much problem. And even then, if we're talking a craft that uses a plastic ablative heat shield like the capsules of the 60s and 70s, who really cares if that corrodes cause well, its garbage now. Well the shuttle had poor glide ability, but at the same time we're talking hypotheticals, the shuttle is also mostly late 70s tech, and we've got much better materials now that we couldn't work with before. To be a spaceplane, it would probably have atmospheric flight engines and wouldn't need to glide to a landing. Who knows though. Onto the C-130. Yeah landing the thing on the Forrestal was kinda BS. Unassisted takeofs and landings, while only doing it on a carrier ~1000ft long. Though looking at videos I get the feeling they were very worried about the wing clipping the conning tower. Although there is always that operation credible sport idea. Yep guys, so the specs of the aircraft say it needs about 1500ft to take off, and land normally. We want you to do it in ~350, twice. Then get back up and go land on a carrier that the plane isn't designed to land on either.

Is it possible... yeah maybe, you might need to step away from a design like the previous shuttle into something with a better maneuverability. And something with an air-breathing engine to help it have more control would be nice. You'd probably need a bigger carrier though, try for more than 4 layers of cables to hit, also the landing strip would be better if it were straight with the forward motion of the ship. But by that point why bother landing on the carrier? Why not buildit so you have a floating hull and just land on the water like a floatplane (spruce goose, catalina PBY, other... floatplanes) Maybe even build in some ground effect aerodynamics to the craft (the russians did a bit with the concept, I think there was a low altitude "plane" for hauling cruise missiles)

I have to agree with that. After all, last year when I was subbing in a physics teacher towards the end of the year and we were getting into the short little "astrophysics" part of the class. Thats when I came across KSP myself and good lord, threw that on my laptop, brought it into school and put it up on the projector. "So kids, how do i get this thing to the mun?" single best teaching aid for that part of the class ever. Because its childish, and any kid can pick it up and get to the mun within their first hour of play. Spent over a week doing explanations of newtons laws and how basic orbit works with no kids understanding any of it. 10 minutes of flying a little probe around in orbit, and now I have some kids who... may not know the math perfectly, but they understood the concept.

On the plane I took my initial flight lessons on (Cessna 182 I believe) its "autopilot" was a wing leveler/VOR homing system (VORs are beacons all around the country that are logged on maps, turn the system to the right frequency and itll tell you what direction you are from the beacon itself, then they do some stuff to figure out how far you are from them and stuff, but its all depressingly simple electronics) that since it didn't have a laser or radar altimeter, a pressure based one instead. If you set it to a certain altitude, the plane would climb and descend "randomly" following the pressure gradient. Actually was kinda nice because some of the mountains in NH the system will automatically bring you right up over them without input because of the pressure changes (though its a small plane, hands on the stick all the time)

Well you could work with nonrubber wheels, could probably go outside with soem scrap and make up a paddle-type wheel that you see on older tractors, but the argument still stands. The biggest thing about the modern age is our ability to move crap, and thats really all thats helped us become so advanced. On the note of knowledge... I don't really think that "knowledge for daily life" is a good term. Because what is required for daily life? If your talking about trades, food and materials production. These are the things that even though people don't think about much, they atleast have some idea of how it works. Just many of these things are no part in the... first world lifestyle. Lack of a library doesn't really mean you'd be held back so much. Heck by just going and taking a tally of the skills of everyone in say your apartment building, you might be surprised what everyone knows about or has done before. Yes ultimately there is a limit to what a small group can do. But assuming you don't go full ...... (like very post apocalyptic movie and such likes to show) and instead work with other neighboring groups, trading knowledge and resources as needed. And even then, just look at the books people may have around their houses. Most people who work in some kind of trade have at least some books relating to what they do around that can be learned from, even a lot of "office workers" often have some more useful hobby outside of their job.

Also, if you wanna draw police attention, get a few people together in a "public RC park" with control line fighters and do streamer fights with them. Cops start coming out of the woodwork when people start hearing the weedwackers from 1/2mi away, and then if you get a good 150v150mph head on collision while maneuvering, those little things sound like a car accident happened. Especially if you use metal spars for the wings.

Well I was meaning if you were planning on doing a controllable rocket... but if thats not what you're going for. Model rocket motors are great, and I've made them based off of this little guide before, and they worked kinda well. http://balloons.space.edu/ndra/nickle.html Musta shot off about 500 rockets of varying size based off that. But make sure that whenever you're doing anything with these rockets you keep a fire extinguisher handy, and safety is always the #1 priority. Worked great for little rockets, though we did some larger ones. Pay special attention to the "coring" part of the guide because if you don't get a fast burn... you just get a smokey flamey mess. Couple other things, before trying your plane thing out, try for just some rockets. Get some papertowel tubes, or make rocket bodies with some craft paper. We had done a couple "rocketplanes" a while ago that launched via 1 of these, but had full RC pitch and roll controls and you'd just kinda fly them on the way down, they worked great.