Cunjo Carl

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About Cunjo Carl

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    Rocket Fancier

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  • Interests Science. All of it!

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  1. Eyes in the back of my head would be capital! There's actually ongoing research for that sort of stuff, I helped out a bit with research on biocompatible electrical interconnects to neurons about a decade back. It's a bit invasive for the general public to use, but technology-wise it's not that far out now. Spare hemispheres, maybe a little further... Albeit just as necessary in my case! CNS neuron coupling to nanoporous gold electrical interface, work by Dr. E. Seker et. al Also, technically a reuseable species, but it costs more to refurbish a unit than to just make a new one like on the STS . Being flippant, don't take too seriously, please!
  2. The ingredients for the glass typically come in the form of powders which can be blended, melted (1200C), and extruded to shape by pouring through a narrow opening. If poured vertically, the glass thins slightly as it falls, much as a stream of water flowing from the faucet does. Though glass in this thin-sheet form can be further drawn, no drawing is required for the ~200um size. As always, once solidified the glass needs to be either cooled very slowly or annealed to relieve internal stresses. Corning then often strengthens the surface of their glass by running it through an ion-exchange 'bath' of molten potassium nitrate (300C), which swaps out the glass' sodium ions for bigger potassium ions creating a uniform compressive stress . Edit: Willow glass is apparently Alkali free, so not a candidate for potassium ion exchange! Making this thin-sheet form factor is very common- The typical microscope cover slip (#1.5) is actually the same thickness as willow glass, but massively less flexible! I think the hard part of recreating willow glass would be finding the secret blend of 30 spices Corning uses to make their glass as tough and flexible as it is!
  3. Cunjo Carl

    SpaceX Discussion Thread

    NASA recently released their highlights real of the demonstration mission. The music is so very 80s
  4. Cunjo Carl

    Random Science Facts Thread!

    The zero-G crystalline plasma studies @kerbiloid just told us about were done up on the space station. In order to get the high vacuum required for their plasma chambers, ISS researchers simply opened a 2.5cm window to space... They call it their "Vacuum Resource". http://www.spaceref.com/iss/ops/ISS.User.Guide.R2.pdf
  5. Cunjo Carl

    NASA Commercial Crew Landers

    Apparently NASA's poised to be getting bushels of funding. In a recent talk Bridenstine was talking about their budget, and he sounded downright rosy about it. It's another high level talk about upcoming plans. A lot of it focuses on gateway, which has been talked about quite a bit in this thread, so I'll keep it going. If folks think I should do a new thread for this sort of stuff though, let me know. And, the overview of what they talk about: Beginning: We're goin' to the Moon! 6:30 We're getting lots of money (We hope) 7:00 Low boom flight demonstrator (X-59) 9:45 All electric plane (X-57) 11:00 Urban air mobility (flying delivery drones, flying cars) 12:30 Commercial crew 15:15 CLPS- Gotta go fast. Have 10 payloads ready to go. 16:15 Gateway Will be funded if the budget request goes through Gateway will use solar electric thrust for maneuvering Designed for access to all parts of the moon 18:45 Need SLS, Orion ESM, and reusability (tugs, etc) Want Orion to be mostly reusable by EM4 21:15 Funding for various projects 22:45 Tour of a full scale mockup of Orion 26:30 Announcing opening 3 pristine lunar samples 28:30 Gateway again Not crewed full time Canada will be helping with robotics (Canadarm returns?) ESA and JAXA are joining as well 32:15 Solar Electric Propulsion For moving gateway between orbits Hall thruster based (no surprise) Show and tell of their enormous vac chamber vf6 Getting prototypes this month 38:45 'Space directive 1' 39:30 Mars Recently found complex organic compounds Still looking for life Budget request has funding for Mars 2020, sample return and the helicopter 43:45 Osiris Rex, New Horizons 44:45 Helio physics, solar flares and the Parker probe 46:15 Earth science: funding and goals 48:15 Astrophysics & James Webb Space Telescope 52:45 Gateway yet again Radio telescopes on the far side of the moon are a possibility 54:00 Recap & closing statements Use of NASA research in agriculture, industry and disaster relief Talk about us on social media, please.
  6. Cunjo Carl

    For Questions That Don't Merit Their Own Thread

    There is! All jet airplane air intakes actually do this, and it's referred to as "inlet pressure recovery". In a rocket engine, the high pressure gas is choked at the de Laval nozzle throat, and allowed to expand through the nozzle where it trades its temperature and pressure energy for kinetic (flow) energy going out the back. It's an 'isentropic' process (ideally at least), meaning it can be reversed by reversing the situation. So if we instead start with a fast flowing gas (imagining the air around a supersonic airplane), and we intake that air through a nozzle and a choke it we'll get a high temperature and pressure gas. Unfortunately, we can't put enormous bell nozzles on front of our planes, so the real world pressure recoveries aren't that spectacular when traveling at high mach speeds. I wasn't aware before hand, but I just checked, and it appears that pressure recovery is quite good at lower speeds, especially sub mach. This, and the expanding tube diameter you mentioned are the only situations I'm aware of that increase pressure without moving parts or an external energy input. Edit: *All jet intakes except scramjets use inlet pressure recovery. On the other hand ramjets only use inlet pressure recovery with no moving parts to further boost the pressure like turbojets (the standard turbine engines) have.
  7. Cunjo Carl

    For Questions That Don't Merit Their Own Thread

    You can get the power requirement using any of the following formulas based on what information you have available for your electromagnet. Power = V2/R = I*V = I2*R With Power in Watts, nominal voltage "V" in Volts, current "I" in amps, and resistance "R" in ohms. 2 out of the 3 should be provided by the manufacturer. On the other hand, if you're looking to make your own and want to know more let me know! Separately, in regards to the planes @ARS asked about a while back, but a bit off topic...
  8. I looked around for a while and found some people who were able to roll with the punches, including this amazing work by Ryuhei Mori. Mori actually manages to make a rechargeable Aluminum-Air battery, completely bypassing the obnoxious Hydrogen gas production step we've been talking about. This battery sucks Oxygen right out of the air and ultimately combines it with Aluminum to make Al2O3 + Electricity. Then, if you push power back into the battery it reverses the reaction to recharge the battery. To put icing on the cake, Mori manages this with only simple, common materials. If I didn't see his results, I'd have called it impossible- it's really spectacular! https://pubs.rsc.org/en/content/getauthorversionpdf/C4RA02165G Of particular interest to us space-y people, Most of the mass involved in this battery can be sourced from the Moon. It's mostly just Aluminum, Aluminum Oxide and Water. It has some salt, some metal and some plastic binders as well, but they're a minority of the mass. I really love Mori's material choices, and production-wise it's all industrially feasible. All this said, we probably won't be seeing many of these batteries, at least for a while. The Aluminum battery's not without its drawbacks, and here on Earth there's little commercial drive for it. Electric cars and storage facilities are served almost as well by Lithium batteries, which are extremely well suited to their task and becoming cheaper by the day. Of particular note for Lithium is the roll-to-roll drycells recently developed by Maxwell, which are poised to make Lithium batteries even cheaper, lighter and more energetic. It's a very hard bar to beat. For sourcing on the Moon though, Aluminum-Oxygen, Aluminum-Glass and Aluminum flywheels are kinda the only three options that don't require a ton of refining. So for there, this is very interesting! Ryohei Mori's Aluminum Battery, ALFA, can store electricity by reversibly oxidizing Aluminum using only common materials.
  9. Cunjo Carl

    NASA Commercial Crew Landers

    NASA's Administrator Jim Bridenstine hopped on a soap box to talk about NASA's aspirations for the Moon at the end of a 3AM talk with SpaceX & NASA about commercial crew. It's a high level overview about the politics, goals and hopeful benefits of NASA's recent commercial programs. There's no real new information, but everything I've read so far has been fairly scattered, so it was nice to get this informal rundown ' right from the horse's mouth ' as it were. He's also surprisingly eloquent for 3AM! The other similar presentation I'd seen was a much stiffer request from industry, and included many more.... aspirational items. https://youtu.be/JN0OWlfGWhw?t=439
  10. That'd be nice! There may well be one, but catalysts for dehydration reactions of metal salts are unfortunately a little rare. I gave it a quick check, but all I could find for turning the hydroxide into alumina was the thermal decomposition. The reaction of Aluminum with water is very aggressive, so it would be hard to find a catalyst active enough to stop the initial production as well. As the standard solution, Aluminum Hydroxide can be neutralized using various acids, which would remove the gelling issue but add some new ones from the complexity. As an alternative, the medical industry seems to be leaning towards using surfactants (like soap) to help with similar issues in Aluminum Hydroxide gels, so those might be a way forward- though given our gas generation surfactants might even make more of a mess! Finally, the first option that popped into my head was something mechanical like sonication (using high frequency sound waves to stir). Aluminum Hydroxide is shear thinning, so if it can be kept constantly stirred, its viscosity can be kept lower. This would also help release the Hydrogen gas and break down the Aluminum chunks.
  11. Swinging back around to the Aluminum and water thing, I figured I'd chime in about an interesting wrinkle. I helped a neighboring lab develop this chemistry a while back for the purpose of very (very) very high purity Hydrogen production which is necessary for some fancy business in electronics fabrication. Unfortunately it would be very tricky to develop it for use in a battery though. Our desired reaction looks like this, all nice and clean... 2 Al + 3 H2O -> 3 H2 + Al2O3 But it's unfortunately pretty tricky to make work well in the real world, because also: 2 Al + 6 H2O -> 3 H2 + 2 Al(OH)3 (and a host of other related hydroxides) Now from one point of view this is no trouble because we make the same amount of Hydrogen with either reaction. But, unfortunately for a battery, Al(OH)3 is a terribly gloopy gel in these conditions. It pushes the Gallium away from the Aluminum surfaces, prevents stirring (important for mid-sized batteries because the reaction gets very hot), makes a spattery mess with the Hydrogen bubbles, and generally does all sorts of things that are obnoxious to deal with for a battery. In a lab or factory setting no troubles, but for a standalone battery it'd be a big pain!
  12. Cunjo Carl

    Launcher (the company)

    I have a couple random guesses. One of them is that if the chamber pressure is above 50 bar, the 'warm' compressed liquid Oxygen will have dramatically better viscosity than RP1, making it easier to pump through the channels, so the channel(s) can be made simpler/smaller. Also, when warmed, pressurized liquid Oxygen can go supercritical effectively removing its surface tension and probably allowing for simpler injectors and better propellant mixing in the chamber, and so better combustion efficiency in a smaller chamber. The downside is they're more constrained on materials choice... it looks like they originally tried an inconel chamber (expensive and chemically resistant) and now they're apparently trying Copper! As long as they're very careful to keep it Dry, copper can be surprisingly Oxygen resistant. I certainly wouldn't have guessed it though! That'd sure be awesome! They apparently line their chambers with copper, but the rest of the engine/throat is apparently an enormous single hunk of 3D printed inconel, which would be a good material for the job! Some more articles with interviews and pretty pictures: https://3dprintingindustry.com/news/launcher-space-race-largest-single-piece-3d-printed-rocket-engine-149500/ https://3dprint.com/220518/launcher-a-space-start-up-making-3d-printed-rocket-engines/ Edit: Image is a direct link from the 3dprint.com interview, which has a lot of juicy technical details on the fabrication of the engine: Launcher Inc.'s E-1 engine, and two injectors. Apparently all 3d printed
  13. Cunjo Carl

    Launcher (the company)

    Nice- It is in fact LOX/RP1! Also, they seem to be getting along well with their town officials and have good safety measures in place, which says at least to me that they intend to be trying at this long-term. https://riverheadlocal.com/2018/04/04/town-issues-violation-notice-to-rocket-engine-company-at-luminati-site/