Just send already-dead astronauts. You will need to launch a lot less consumables, life support, shielding, and soft-landing equipment. The science return will be impacted, but not by much.

Deccelerating something from orbital velocity is just as difficult as accelerating it to orbital velocity in the first place, except you've expended all your fuel already. Much easier to use the atmosphere.

Mining water from an extraterrestrial body, with or without humans, is science fiction at the moment. I don't see how you can make 10 year plans that involve this.

As to passenger-less travel, I'm all for it. It's so much cheaper, faster, safer, and efficient that I don't see why anyone bothers with people.

That adds a huge amount to the fuel load.

Let's list them
- getting a large enough can to space (Apollo and Dragon are too small for an 8 month voyage with all the consumables needed)
- protecting the humans from radiation during the 8 month voyage
- slowing down (can be done with fuel, but increases launch costs a LOT)
- landing (can be done with fuel, but increases launch costs a LOT)
- generating fuel and consumables on Mars
- handling contingencies

Submarines that are capable of 8 month voyages mass 10,000 tons. Fancy lifting that into space?b

SpaceX got one thing right: it's conservative.

It's using proven technology with no exotic materials that they had to develop themselves. They're not even using the more efficient Hydrogen as fuel - they're using the less efficient but much more reasonable kerosene. This is what allowed them to develop a reasonable launcher for better-than-reasonable prices.

However, it's a far cry from round trips to Mars. That needs a lot of exotic development and is in uncharted territory, unlike everything else that SpaceX has done before. Musk's promises are worthless here unless he can see into the future.

This isn't science, it's PR.

This is wrong, you can move more than one unit of energy with a heat pump per unit of energy invested. In fact it is more efficient to heat with an air conditioner than with an electric heater.

Yet religions are the only ones to claim divine sponsorship of their ideas, and to try to enforce them. The only organizations that come close are states, and they tend to interfere a lot less in their citizen's private lives.

This "Love God" rule is completely pointless.

No, it's "religion".

Try deleting one of the other and seeing whether the statement still holds.

And also the other way around:

      Religion breeds fear and ignorance.

It's so beautifully symmetric.

Well, Curiosity uses a parachute, so it's probably not too heavy for it.

A small rover or lander can only carry a small amount of instruments. If you want to do serious science, you need a reasonable number of those.

It's too large for airbags.