Frank

The power take-off would have to draw power from both turbines somehow. I'd like to see Pratt and Whitney develop this. I can think of a few applications where a 30% weight reduction would be extremely beneficial. The software used in the link I posted seems to be around $6,500 US, it could show the full cycle including the counter-rotating turbine side, not just the counter-rotating compressor. The AC engine companies probably have similar or even better software for simulations. Maybe try and get an internship position in exchange for some R&D time?

Zubrin's moon direct transport plan uses existing tech plus a redo of an Apollo-era Lunar Excursion Module. It also introduces (to me anyway) a microwave based ice melting and collection scheme. Basically, a trip to the lunar surface and back requires 2 Falcon heavy launches plus a Falcon-9 launch for crew. No BFR, no SLS needed. Moon Direct - Robert Zubrin - International Space Development Conference - Saturday, May 26, 2018 - YouTube: Discussion on redit: https://www.reddit.com/r/spacex/comments/8my4tf/moon_direct_robert_zubrin_international_space/

Huh. Seems regenerative braking isn't used on most e-bikes despite having the capability because of increased battery and motor wear vs limited range extension (5% to 10%), also a freewheeling issue. Might be worth doing on those e-scooters though because motors are more powerful and propel the full load. Why Don't More E Bikes Use Regenerative Braking?: https://www.evelo.com/blog/why-dont-more-bikes-use-regenerative-braking/ Electric Bike (eBike): Freewheel or Regenerative braking? - Bicycles Stack Exchange: https://bicycles.stackexchange.com/questions/31124/electric-bike-ebike-freewheel-or-regenerative-braking

This may be of interest: COMPARISON OF COUNTER–ROTATING AND TRADITIONAL AXIAL AIRCRAFT LOW-PRESSURE TURBINES INTEGAL AND DETAILED PERFORMANCES http://softinway.com/wp-content/uploads/2013/10/Comparison-of-Counter-rotating-and-Traditional-Axial-Aircraft-Low-pressure-Turbines-Integral-and-Detailed-Performances.pdf

Regenerative braking utilizes the fact that (most) motors can be used as generators (alternators). So every (most) e-bike has a built-in alternator. Adding an alternator to an e-bike just adds extra weight and cost.

Hi Stefan, why deleted? This may be of interest: http://softinway.com/wp-content/uploads/2013/10/Comparison-of-Counter-rotating-and-Traditional-Axial-Aircraft-Low-pressure-Turbines-Integral-and-Detailed-Performances.pdf

or this, skf make bearings, no personal experience though. http://www.skf.com/group/products/lubrication-solutions/lubricants/lubricant-selection/index.html and http://www.skf.com/binary/21-99598/13238EN_GreaseSelectionChart.pdf

Externet, It occurred to me, maybe you haven't done a patent search? Many new ideas, surprisingly, aren't new. Search here: Espacenet - Home page Not sure about google patents privacy, or any google search privacy for that matter... Also, I hear wayback machine (archive.com) is used for prior art time stamping, so if this forum is archived there, it would qualify. Backups are spotty though. Plus, a bunch of us could attest as to timeline should it come down to it...

Another possibility is that as you build the thing, some other problem or better way crops up which requires or constitutes some IP. Then selling that secret (and a working prototype) is a possibility. It happened to me after filing a patent application. This IP may never be disclosed unless I decide to build one, but it's a similar pickle. As the inventor, you have knowledge of the problem and it's solutions and non-solutions that others may not grasp even if explained. Sort of like the patent clerk who just didn't get it. Putting in an application, whether a patent is granted or not, certainly guarantees that should you ever choose to build your invention, it won't be encumbered.

Patent rules change and are different in different countries. Look at "first to file", US is such, VS "first to invent" VS "prior art". Ultimately, lawyers must get involved to defend rights/claims and it seems like deepest pockets win, esp. in US (my biased opinion).

Like this? Sweden's new electric highway works like a scaled-up slot car track: https://newatlas.com/eroadarlanda-sweden-electric-highway/54197/ eRoadArlanda: https://eroadarlanda.com/

"In Situ Heat Shield Fabrication at Phobos/Deimos for Earth-bound Mars Return Spacecraft and Mars EDL of Surface Exploration Craft" - Wow! If Mars' moons dust composition is similar to our moon's, it means that tech that works on the moon should work (if gravity isn't a factor) on other moons. So Oxygen production at Mars' moon should also be possible. Another reason to start a moon base, and another reason to start with oxygen from regolith once there. Regolith Derived Heat Shield for Planetary Body Entry and Descent System with In Situ Fabrication: https://www.nasa.gov/pdf/744615main_2011-Hogue-Final-Report.pdf

Right, the vapour pressure doesn't increase with tire pressure, so even with water available in the tire, vapour pressure is limited and condensing water vapour doesn't change pressure very much at all. Also, as the tire heats up, it's pressure increases limiting the effect of water vapour compared to free air temperature vapour pressure increase. Based on the example given, compressing the air to 8 bar isothermically would remove moisture from the tire to 0.19/1.7 to about 11% that of saturated air. Keeping water out would help (though not very significantly) by limiting the amount of extra water available in the tire to create extra vapour pressure. Consumer report showed the diffusion rate, 3.5 psi loss for air over 1 year and 2.2 psi for nitrogen: Nitrogen in tires - Q&A: https://www.consumerreports.org/cro/news/2007/10/nitrogen-in-tires-q-a/index.htm Conclusion: Not worth paying extra for nitrogen, check air pressure regularly.

Well, nitrogen or other gases will also change pressure with temperature, but the water vapour claim I'm still unclear on. Why would it increase with increasing pressure? I understand that the upper bound of vapour pressure in a tire is already in the 1% region, but now I wonder what the effect of compressing the air to 8 bar for example, and letting it cool to standard temperature would be. I know from experience that water will condense, so even less moisture/water vapour will get into the tire. I haven't found the formula to calculate this effect. Also, "température de l'air ambiant" seems a better translation to ambient temperature since "température ambiante" seems to translate directly to room temperature. Being francophone in an anglophone area, the anglicized "température de la pièce" version seems more accurate. BTW, I +1 bender's previous post for illustrating the size of helium tire needed and showing that condensation of water vapour is insignificant next to gas pressure change due to temperature. Found charts here: Compressed Air and Water Content: https://www.engineeringtoolbox.com/water-content-compressed-air-d_1275.html

I would have gone with the literal "température de la pièce", but google used "ambiante" which it translated back to température ambiante -> ambient temperature "room temperature" in french - Google Search: https://www.google.com/search?q="room+temperature"+in+french Curiosity got the better of me. To me, ambient temperature is dependent on (external and unknown) conditions, whereas room temperature is a fairly specific range.

It might be an even better ratio if relative mass is considered. At 150w/kg, ~113 kg of mass for the solar PV panels must be accelerated, so the heat engine thruster might be even smaller. How heavy are telecom satellites?

lcd panel to block out the "red" beam as needed?

Finally found the quote for FH partly reusable: Elon Musk on Twitter: "Side boosters landing on droneships & center expended is only ~10% performance penalty vs fully expended. Cost is only slightly higher than an expended F9, so around $95M.… https://t.co/Wx1Q0nS5dr So $95 million/(63.5*0.9) = $1.66 million/t Placing payload into LEO is for the closest refuelling point. Either propellant launched as extra ballast when possible, or ferried from the moon (only works under special circumstances). I'm thinking meet in the middle as much as possible, maybe (also) a propellant depot at EML-1 or EML-2.

Adding communication equipment to the list, of course. This Robert Zubrin op-ed - How to build a moonbase in four years - should really get the discussion going Op-ed | Moon Direct: How to build a moonbase in four years - SpaceNews.com: http://spacenews.com/op-ed-moon-direct-how-to-build-a-moonbase-in-four-years/

If I can't create an image without distortion, I'm going to say we're left with arrays of lasers and/or fibre-optic guiding. Fresnel magnifier might fit into the mix, advantage being they're relatively cheap and large, but introduce distortion. Just some ideas... Maybe arrays of pico projectors and a Fresnel magnifier array screen.

Yes, I would expect so, as do lenses, but perhaps minor enough for the application (which we know nothing about).

Hi Wosoka, Maybe combine with a parabolic mirror to make the beam parallel once its angle is changed?

Maybe the mirror is not glass and the plastic got melted, maybe a combination of sunlight and light absorbing material or chemical reaction that melts plastic? Or a protective film over the mirror that can be removed since it's a new truck?

Hey KIVALO, nice diagram and explanation. I say no. But more stuff will get squeezed between the lugs and more stuff might get kicked up, which could slow things down. Because the track speed is dependent on on the final gear moving the track along, the radius between the track and the "driver" gear sets the speed. Making the lugs longer means the end speed of the lugs around the gear will be faster, but the lugs will also come together faster. The only way it could go faster is if the track got pulled up under the gear height or the surface travelled on was curving up. If the thought is the speed is proportional to the lug length, that doesn't hold IMHO.

Top picture is right handed, bottom is left-handed (goofy in snowboarding talk). Tool goes in the dominant hand. I didn't know they sold them the other way without labels, that's weird.