If we look at jet aircraft, wear depends on the airframe and the engines, and the airframe seems to be the number of pressurize/depressurize cycles as well as the running hours. Engines get swapped out routinely but when the airframe has enough stress it's time to retire the aircraft lest it suffer catastrophic failure. Rockets are different in scale (much greater stresses) but we can expect the failure points due to age to be those two, with the addition of one main rocket-specific failure point: cryogenic tanks.

How long each will be reliable can be established using ground-based environmental testing. Nobody has the numbers for Falcon 9R yet.

Weight vs. reusable life will become a design decision in rocket design.

information revolution is a disappointment. Jobs get slashed, but there is no increase in the creation of actual wealth or value.

There has been an increase in wealth, but most of it has gone to the top 1%. Trickle-down is not simply not working anymore. Sorry, Republicans, but you have it all wrong. You are applying 1960 economics to the wrong era. Tax the wealthy to fix our rotting infrastructure; then we'll have jobs, consumers, and working roads and pipes.

Thank you, I'm quite flattered by the comparison.

I was thinking Spanish Inquisition, Crusades, vicious fights between Catholics and Protestants, Galileo, etc. True, that's more of a mid-point than a "start".

Christianity "matured". Islam seems to still be in the middle stage.

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That explains the No Smoking sign the probe found.

Then, on the day after Thanksgiving in 2013, methane readings shot up in Gale Crater and stayed high while Curiosity made three more measurements over the next 60 days.

Right after Thanksgiving? I suspect they did it Gilligan's Island-style and the probe really landed on Earth, in middle America.

You are making a strawman argument. Never did I suggest doing any such thing.

You can attempt to draw all the offensive comparisons you want while ignoring the fact it isn't a terribly challenging problem to solve when your wall isn't right through the middle of a major city and isn't easily climbable and isn't the only line of defense. Look at what happened when they put in a complex fencing system in the San Diego zone in the mid 90s: suddenly crossing attempts dropped by over 90%. Nobody got through there, so they all went into the mountains to go around the system.

Simply extend the San Diego system across the rest of the border and have heavy patrols. Anyone damaging the system is imprisoned for a period, then deported to their country of origin. Those who manage to make it through the system are quickly rounded up by the regular patrols and immediately deported to their country of origin. Most will stop trying. The few that remain will be far more easily managed.

Pardon me, but that's bullshit.

Let's just take the forces we already have today. We have 1.4 Million in active duty military personnel and 850,000 reserves. Obviously we can't take every single one, so let's take half: 1.1 Million people. Now stick them on a 3-man rotation minus 1/3 for duty rotations and leave and spread them out across the 1,954 mile border with Mexico. That puts 125 people plus their equipment per mile of border, plus all their R&D budget going into technologies to increase protection. Those personnel aren't just idle all day; they're building fences, digging trenches, laying sensor grids, and basically doing all the stuff that completely shut down the San Diego zone for crossings and they're doing it 24/7/365 at 125 per mile or one person every 14 yards.

I think that's all way overboard for what we'd need to actually secure (~99% reduction in successful unauthorized crossings) that border, but in any event, don't try to say it's impossible to do. Say we lack the political will. Say we choose not to do it. Say we just aren't interested enough in the problem to do what's necessary to solve it. But don't say it's impossible; that's absurd. I'm not even getting terribly creative here; just sticking boots on the ground and a whole lot more boots than we'd ever actually need at that.