A big rocket to Mars? Wargaming it.

It is quite unlikely that a big enough rocket can be built and launched that could transport 100 people at a time to the planet Mars.  The payload's mass proposed for such a mission is 100 tons, soft-landed on the surface of the planet.

Let's examine this a little closer, shall we?

A hundred tons is 200,000 pounds.

If each person is 150 lbs, then 100 people would have the mass of 15,000 pounds.  That means 7.5% of the payload is the passengers.

As a point in comparison, the lunar lander in the Apollo Era had the mass of 5000 pounds (sans fuel) in the ascent stage.  The useful "payload" fraction actually landed was about 5 percent of the 100,000 pounds in lunar orbit.  If you exclude the ascent stage fuel, it doubles to 10,000 pounds, or 10 percent. Those numbers in the previous paragraph are roughly comparable to these lunar ascent module's numbers from the Apollo Era.

But the useful payload fraction that could be landed on the Moon was only 5000 pounds out of the 100,000 pounds in lunar orbit.  Let's say that a one way trip to the moon that only included the lunar lander would take that 35000 pounds and land softly on the moon.  Of that, about half is usable on the surface, or about 17,500 pounds.

What about the command module with the return capsule?  Since no return is available, that brings the useful payload to 50,000 pounds, at the most.  If it is one way, he doesn't need the return capsule and he doesn't need the ascent stage's fuel.  He doesn't need the trans-Earth injection burn, so he doesn't need that fuel.  All the fuel and hardware he needs is for landing.  He still needs an lunar orbital burn.   Maybe he gets 50,000 pounds on the moon, but I don't know for sure.   I suspect is it no more than that and is significantly less than that.   Half of the mass would be fuel to land the other half.  This is all guesswork.  I don't have the rocket equations handy on this netbook.  My recollection is that it takes about half of the mass to get to orbit from the moon.

So, the range of useful payload to the moon with a Saturn V class rocket is between 17,500 and 50,000 pounds.

This gives an idea of what Musk is suggesting that he can do.  He wants to land 200,000 pounds on Mars with a rocket about the size of the Saturn V.  Nope.  A much bigger rocket is needed, or multiple rocket launches.  His proposition would land 4 times as much mass on Mars as the Saturn V could put on the moon (at best).  He needs a lot more mass for the longer mission and the burn that would take him to Mars.  No rocket can do that now, nor is there likely to be one anytime soon.

Since the useful payload fractions being proposed are about equivalent, assuming that Musk can even achieve what he wants with mass delivered on Mars, what does that do for the Mars settlers?  Not much.  The lunar module had only the thinnest of walls- like aluminum foil.  It had only a few days of life support.  To survive the trip to Mars and to continue surviving, the colonists would need months of supplies.  No way they could generate as much shelter, food, and water that they would need in order to survive.

There is one possibility, and that is to do the life support functions in the vehicle itself.  It means growing food and replenishing supplies onboard instead of bringing them along and having to launch and warehouse them for the long flight.

How can you get 100 people to Mars?  Looking at the numbers in the first paragraphs, you may need up to 2500 pounds per person in the Apollo configuration just to get them there.  If you bump that up to 50,000 pounds landed, that allows up to 25000 pounds per person.  You could land maybe 8 people on Mars using those numbers and assuming you could do it all with comparable numbers to a moon landing using a Saturn V class rocket.

A big rocket isn't likely to do a hundred passengers unless there is much more tech invented.

Possibilities of that?  You would need the hardware to recycle all materials.  Nothing could be wasted.  Plasma waste converters could take the waste and make useful products from them again.  This includes ALL waste.  Number two and number one would have to be reused.  This introduces a significant YUCK factor.

You need to practice these skills somewhere in order to make them reliable.  You should practice them on the ground and in space in order to make them reliable in space.  You will need to be able to service them with the materials at hand.  Nothing could be shipped to you in two years at best.  You need to have the people trained so they could do this.  No Maytag repairmen up there.

An IronMan suit?  How would you manage that?  It could be powered like the Curiosity rover on Mars with a nuclear thermal device.  But the rover weighs about a ton.  If you have 25 thousand pounds per person, a ton isn't much.  The 2.5 kwh per day would have to power the recycling machine that processes the waste back into oxygen, water, and food.  Is that possible?  Probably nobody knows that yet.

It would make a lot more sense to take this step by step.  The Apollo program did it that way.  It succeeded.  Even then, they lost astronauts.  Space is dangerous and difficult.  Not kid stuff.

With respect to kids, you may want to speed up the colonization with biology instead.  How?  Manufacture an artificial womb and grow your own colonists!  Biological science can create artificial organs already, or will soon be able to do that.  Make the babies on Mars in artificial wombs.  Then you need only a few adults around to watch over them as they grow up.