/sci/ - Science & Math

>>15556791
Yup, and an open cycle lift effect engine that relies on pushing the vessel along external pressure gradients without propeller or jet effects is called a sail. So technically a QI drive is an aether sail.

>>15493306
Yes.

>>15418357
>I didn't entirely agree with the z-pitch guy or the mag sail guy but they're like geniuses in comparison to these people, fuck
We're still around, we just don't constantly refight spacecraft propulsion console wars in the absence of new data. SpaceX working on lower launch costs, and Starship in particular, are the focus for now because flying test vehicles is still the bottleneck once you've proven a technique in a vacuum chamber on the ground.

>>15035593
Jeff Greason is trying to raise $50M to build a plasma magnet sail demo mission and yeet it out of the magnetosphere.
Mike McCulloch has been doing lab work on QI thrusters with an assistant.
The QVT/EM drive guys in Nebraska claim to have been able to use their space warp thruster to push on a non-ferrous ball through a solid insulating wall.
Hermeus demonstrated turbojet to ramjet mode transition in an engine, which is necessary for either SSTO HTOL spaceplanes or hypersonic air launch.
BE-4 has still not flown.

I've been thinking about Quantized Inertia and I think it's possible to keep the more fun parts (Unruh radiation, meme thrusters, etc.) without tossing GR or even dark matter. I think what QI offers, if only accidentally, is a quantum gravity theory that doesn't require a graviton particle to exist at all.

>>14806047
>2m/s^2 acceleration
>6U cubesat is by definition max 8kg
>2x8=16N of thrust
>let's be really, really generous and say a 6U cubesat has a 100W@1AU power supply
>plasma magnet sails scale thrust with the third or fourth power of input wattage (I forget which) based on the original John Slough paper
Holy BALLS. This thing is a torch drive as long as it's a few hundred kilometers away from other ships and accelerating antisunward. The hard part is going to be finding some other plasma trick to brake into orbit without exploding or melting the spacecraft.

>>14556382
>>14556387
Earth having its own Trojans at Solar L2 as well as L4/L5 would be pretty cool. How did we never see the roggs before?

First for plasma magnet sails and L2 spaceports creating Treasure Planet irl.

OC COMING THROUGH

After weeks of shouting back and forth in circles with other anons about the Plasma Magnet Sail, I decided to email Jeff Greason, the guy who gave the TVIW talk about interplanetary and interstellar missions the sail enabled, about some of the questions raised. The answers are below.

>The anomalously high 0.5g acceleration for one of the ship designs
It turns out that the 0.5g number was a complete misinterpretation by the Centauri Dreams article writer, and that the reference 2500kg ship / 10cm sail accelerates at 0.5m/s^2 rather than 0.5g. That's still enough to get you up to 20km/s in 40000s, or less than 11.5 hours of thrust, which is perfectly doable for a fast Mars mission, and you might actually be able to brake at the end without nuking yourself Orion style or burning up in the Martian atmosphere.

>scaling up
The 30m sail-coil math -does- work out, which means you can get truly excellent payload fractions at larger ship masses. With a 1000 metric ton (one gigagram) ship you can get over 90% payload by mass and accelerate at 0.006017m/s^2, which is about 519.87 m/s of delta-V every day, so you can hit that same 20km/s "go anywhere in the solar system" velocity in 40 days of continuous power.

>materials
Superconductors are required to get anything like the described efficiencies out of the plasma magnet sail, since the current is time-varying to produce the rotating field. However, he did say that existing superconductors would be enough to carry the 90kA current needed for the full sized sail.

>why Neptune
The reason Neptune works better for braking is because its magnetosphere is physically larger than Jupiter's without carrying the same

>>11804680
>>tfw treasure planet was real
We even get the moon as a spaceport. It's got low gravity and is outside Earth's magnetosphere, so all you need is a cheapass reusable ISRU Al-LOX rocket "pilot boat" booster or a mass driver to launch your payloads to lunar orbit. Then the plasma magnet sail is unfurled and off you go.