No. Batteries are around 85% recovery of stored energy, while electrolysis, fuel tank, and fuel cell might get you around 40% return. Fuel cells are expensive. Compressed hydrogen tanks are expensive, and have a limited lifetime before you have embrittlement issues and you have to replace it.

Minutemens are solids. It takes a bit of effort to light one off. You can’t just bang into it.

You can make a robot that will quickly lay bricks, in a straight line, on level ground. If the ground changes, or the wall isn’t straight, that’s changing environment.

They are not good when the environment is constantly changing and is hard to define. So we’ll still need people in construction and janitorial for example, although they will be assisted by robots.

I suppose you’re right. That’s a gas turbine in a tank, not a car.

Looks like a backpack.

No. It’s called having a power turbine separate from the core, and can be run that way indefinitely, rather than burning out a clutch in short order.

In your first example there is zero torque while the engine is not moving.

Sure it can. Some engines are designed to stop with one or more pistons in an appropriate position to let them autostart. There’s no compression, so there’s not a whole lot of torque, but there’s enough to crank the engine and get it running. Some even used explosive charges to turn over.

Ow! Ow! Frozen balls! Ow!

States with higher electrical prices tend to have higher gas prices, so I’ll just use middle ground values for both: $0.15/kWh and $2.50/gal. Ill also use a ballpark value for economy of 250Wh/mile (they claim 227). So, that means a little under $0.04/mi, and it will cost more than any gasoline vehicle that achieves…

I stand corrected. Looks like it’s only GE that does composite fans, but they’ve been doing them for over 20 years now. Not sure why Rolls and Pratt haven’t yet followed suit.

The vehicle is to be a lifting body, and will perform a gliding re-entry and flight to the landing pad. It will likely not flip engines down until its already subsonic.

That 11.6Gs was a ballistic entry with a narrow vehicle that punched well into the atmosphere before slowing down. Nearly every manned vehicle since has performed a gliding entry, where the body is oriented in such a manner as to produce lift, allowing the vehicle to slow down gradually in the upper atmosphere. Most…

GE made the HP bits. The LP bits are Pratt’s.

They’re usually composites these days.