Battery? Doesn't the noise mean it has an internal combustion engine?
Well if we ever get off our asses and mine enough helium 3 to make it cheap and plentiful enough for the researchers who are working on the fusion reactor the size of a basketball without all the nasty radiation and very little waste to finish their work, these things will be quiet enough that breathing heavy may be louder.
The U.S. skipping the moon, ceding it to China and Japan, and going on to asteroids and Mars instead will go down as one of the biggest economic boondoggles of the past few centuries. Our oil companies have the revenue to fund an endeavor themselves, but are so near sighted and shareholder beholden that they are too stupid to look to future goals and revenues. And it isn't just them. Apple is expected to cross $170 billion in cash reserves this year. The cost for a manned mission to the moon and back again? Less than $1 billion and with a real effort, the cost could come down significantly. The thing is, you don't even have to do a bunch of flying back and forth. Set up an unmanned mining operation that gathers raw material, puts them into containers, strap them onto a rail and accelerate them off the moon and into the Pacific ocean for pickup and processing on Earth. You only need to send someone there for container resupply and maintenance, and it is likely that the containers themselves could be manufactured on the moon itself.
But I digress....killer robots are coming soon to planet Earth!