Also, Mars sucks. If you get anything out of any information the space agencies, it should be this. Mars sucks. The one good thing about Mars, is that the planetary mass provides a shield to half a sky of deadly radiation. We tend to forget that we live inside the atmosphere of the sun, and that shields us a little bit from the even more deadly cosmic radiation that would sleet through our tiny little bodies and french fry all our fun little genes and proteins in caramelized onion.
But still the sun's atmosphere itself is no Swiss picnic. Those solar flares, moving on up to Carrington events and probably beyond, play hob not just with our biological systems, but with all our little robot systems as well!
Good thing Earth has a magnetic field, and it's starting to look like that may be one of the most important requirements for complex life. So, and if you don't have a magnetic field? The next best thing would be dirt. On the Moon, a good two meters of lunar regolith cuts down on 99% of solar and cosmic radiation. Same for Mars. If you want to remain an ape-shaped denizen of Outer Space, you gotta be prepared to become a moleman. Which, guess what, still makes life in space a sucky experience.
That dirt comes in handy down here. Many did not appreciate digging in during the Civil War, or later during World War I, but it sure helped when it came to stopping bombs and artillery shells.
The use of concrete in WWII resulted in some (mainly Nazi) structures so indestructible that they remain in place as uneconomical or even infeasible to tear down.
Even during the Korean War, there was a stalemate that produced an old-fashioned trench warfare segment.
"We hated to dig," recalled A. Robert Abboud, First Marine Division Company commander at Outpost Bunker Hill. "The Chinese were wonderful diggers. They had tunnels they could drive trucks through. We couldn't get to them with our air power because they were underground all the time".Fast forward to the Vietnam War, and it wasn't just tunnels and warrens that stymied air power, the jungle cover itself was quite sufficient.
"the Jason* scientists calculated that use of tactical nuclear weapons to destroy the Ho Chi Minh trail would require at least ten a day, or 3,000 per year. The amount of downed trees would actually increase the cover provided to the enemy. The best alternative would be to seed choke points of the trail with highly radioactive waste, but radioactivity decays, and the window of impassibility would close. Besides, there was no reason the enemy could not forge new trails".As long as we steer clear of H-bombs (for which dirt is not so effective) it would appear dirt solves a lot of problems when it comes to countering offensive systems, whether human operated air power, or increasingly, autonomous unmanned air power.
Which kind of gets me to the current worry over artificial intelligence, and the coming prospect of autonomous hunter/killer robots. The likes Stephen Hawking, Elon Musk, and Bill Gates worry that this creates a doomsday scenario.
Oh, ho hum. Competing doomsdays are all around us. And they don't come from the future, they blossom from the past.
It's pretty evident that our own aggregate artificial intelligences have a rather ironic habit of producing incredibly primitive behaviors, despite our best minds strategizing outcomes. Look no further than the US and the Soviet Union during the Cold War, rarely rising above the invertebrate behavior of fiddler crabs on the beach. So, it doesn't take much intelligence to get extinction going.
But those HKs... don't even have to be that smart. Dragonflies are very effective killing machines. So, we don't even have to get to human level intelligence. And HKs are inevitable, even without the influence of the arms industry, which is considerable.
DARPA is heavily influenced by the Defense Science Board. Where DARPA goes, the Pentagon follows. And the Defense Science Board is is stacked with people who serve on the boards of corporations that manufacture robotic systems for DARPA and the Pentagon. Corporations and organizations like Raytheon, Boeing, General Dynamics, Northrop Grumman, Bechtel, Aerospace Corporation, Texas Instruments, IBM, Lawrence Livermore National Laboratories, Sandia National Laboratories, etc. etc. not even counting the small fry.
And all of these guys have a major hardon for autonomous hunter/killer robots. And not just robots. Robot systems. And not just robots systems, but systems of systems. Systems of systems on land, sea, air and outer space, like wheels within wheels within wheels.
Worried about the Chinese building air strip castles in the South China Sea? Worried about those hypersonic anti-ship missiles? Pheh! Too little, too late. So solly, Charlie. The US of A nimbly outmaneuvered and outspent the Chinese some twenty years ago.
Castles? Walls? Sorry guys. That arms race is done. Finito.
Dirt? Maybe if you got enough of it, if you dig down deep enough and clever enough, might help you out, but nowadays, it is no longer the cheap solution it once was.