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Comment Re:Mars isn't going anywhere. (Score 2) 168

the atmosphere really is .... too thick to light a retro rocket at high speed.

SpaceX claims that their SuperDraco thrusters are capable of igniting during Mars EDL, at supersonic speeds. Of course, we won't know for sure until they actually do it, but given their accomplishments to date, I see no reason to doubt them.

Comment Re:Mars isn't going anywhere. (Score 1) 168

Bub Zubrin's Mars Direct plan is the most likely scenario, at least in the next few decades. Eventually someone will build large-scale cyclers as you describe, but not until mining of asteroids and the moon gets underway, making materials available in space. Judging by his past statements, Elon intends to land people on Mars before that is likely to happen, which most likely means he intends to do it with the Falcon Heavy, at least for those first few 'flags & footprints' missions. If that is so, then they'll most likely use some variation on Zubrin's architecture. In fact, Zubrin himself has outlined a mission (which calls the 'Trans-Orbital Railroad') using Falcon Heavies.

We know very little about SpaceX's upcoming Mars Colonial Transporter, except that it is intended to transport 100 people to Mars with each flight. It's highly unlikely that they'll make that their first trip to Mars, which means they'll do it with Falcon Heavy first, and that means Mars Direct.

As for when...? I reckon they'll get boots on the ground sometime in the late 2020's.

Comment Re:2050-2065+ (Score 1) 278

Hm.. Let's see. First private company to send a capsule to orbit and return it safely to earth. First private company to deliver cargo to the ISS. First (and only) private company to down-mass cargo from the ISS. First use of integrated abort thrusters (instead of a "tower"), making their capsule the first to offer abort capability all the way to orbit, as well as the first to be capable of controlled, propulsive landing on land instead of parachuting into the ocean. First use of 3D-printed rocket engines in a production vehicle (which happen to be the first rockets capable of ignition in atmosphere at supersonic speeds). First entity, government or private, to even attempt to recover a booster stage (and judging by their progress in previous attempts, they stand a good chance of nailing that too, in a few weeks). Cheapest ride to orbit, bar none -- not even the Chinese can match their price, let alone beat it.

Yeah, I guess you're right. They haven't really done that much. What was I thinking?

Comment Re:2050-2065+ (Score 2) 278

it's more like half as rapid

Your math is off a bit. Elon has said he expects to land the first humans on Mars in 10 to 12 years, or 2025~27. So if you double that, you'd get a window around 2035~39.

I voted on "before 2035" because I think SpaceX is likely to pull it off in that time frame. But of course, none of us really knows, because we don't know what they're working on behind the scenes, or how far along they are. There have been hints and rumors that they have some amazing projects in the pipeline, and that some of these will be revealed in the next few months, but for now, all we can do is speculate. What will their Mars Ascent Vehicle look like? What kind of hab modules will they use in transit and on the surface? If Musk can say with a straight face that he expects to put humans on Mars in 10 or 12 years, they must be working on all these things already. But thus far, we know nothing.

I'll hold off judgment until we see more of what they're doing to reach that goal.

Comment Re:Heinlein quote. (Score 2) 378

You'll have to ask Freeman Dyson about that, but IMO, after a couple of generations of humanity living in "spinning donuts" in orbit, perhaps the cultural norms would change, and some people would be drawn to the frontiers, as has been our experience for many centuries. Why did Shackleton go to Antarctica? Why did Hillary climb Everest? Because it's there.

150 years ago, a gold-pan and a shovel (and a mule) was all you needed to trek west and find your fortune. Who knows what the equivalent of that kit will be in forty or fifty years? There could be abundant reasons for making that trip. We'll just have to wait and see.

Comment Re:Heinlein quote. (Score 1) 378

Fair enough, and I alluded to that with my EM-Drive comment. But that brings up the "leapfrog" problem: "popsicles" might wake up after 20 years en route only to be greeted at their destination by people who arrived five years earlier with the newly-discovered "magic carpet" propulsion system. And as TFA points out, by the time we even get close to thinking about such decisions, our robotic exploration tech will have advanced to the point where sending humans out there for pure science would be a needless waste of resources.

Relativistic travel is an interesting issue, especially for travel within the solar system. For example, let's say you're traveling from Earth to the Kuiper Belt, a distance of roughly four or five light-hours, and you make the trip at 2% of C (including acceleration and deceleration at either end), giving you a (subjective) trip time of a few months. How much 'objective' time would have passed back home? A year maybe? That would probably be acceptable to most people, especially if you could still send messages back and forth along the way. (It would be weird to watch weeks go by in days, but I reckon folks could adjust to that.)

Ultimately, we're not arguing against each other here. I acknowledge the fact that technological advances will (most likely) extend our reach exponentially in the coming decades. But I still think TFA is largely correct in framing the next century or so squarely in the Earth-Mars neighborhood.

Comment Re:Heinlein quote. (Score 1) 378

Those are all things that the settlers would have been doing on their original island.

Most of the tech needed for a colony in the Kuiper Belt will have been perfected decades earlier in Earth orbit, on the moon, Mars, and the main-belt asteroids. The definition of "habitable" in this context simply means having enough of the raw materials available from the periodic table, and the knowledge and tools to create a functioning ecosystem capable of sustaining human life.

Obviously, no one would dream of building a colony that far out unless there were already hundreds of similar ones already thriving in what TFA calls "home" (ie: the space between Earth and Mars).

Comment Re:Heinlein quote. (Score 4, Interesting) 378

Freeman Dyson gave an interesting talk a couple of years ago, speculating about the next few centuries of exploration and settlement. He envisions colonies in the Kuiper Belt in a couple hundred years, but not much beyond Mars for the next 50 or so. And he anticipates an "island hopping" model of interstellar expansion, similar to the Polynesian settlement of the Pacific. Anyway, it's an interesting talk. (34 min)

Comment Re:Heinlein quote. (Score 2) 378

It's a stretch to claim that humans will never travel beyond Mars, but human settlement beyond Mars is a different argument with a much better case to be made, at least until we come up with radical improvements in propulsion. People may be willing to spend months in a tin can to get somewhere, but years is another matter. Some explorers might visit the orbit of Jupiter or Saturn, but anything farther out would be an entire career in one trip. And there's not much in the way of useful resources out there that can't be found in the much more convenient asteroid belt.

Then again, maybe they'll crack the secret of the EM Drive, next week, and we'll be zipping around the solar system by 2030. That would be cool, but I'm not holding my breath...

Comment Re:Blinders Much (Score 2) 103

Nostalgia is just that.

Nostalgia is a huge market. (Surely you've seen Pawn Stars? American Pickers?) A few years ago, one of my employees, a 20-year-old, bought a Nikon FM2. I said, "What are you doing with a film camera in this day and age?" She just wanted to "go retro" and learn photography the old fashioned way.

People spend money for lots of weird reasons...

Comment Re:Blinders Much (Score 1) 103

You seem to be conflating my two queries. I don't wan't VHS-quality video, I want 35mm film-quality stills from the lenses and bodies currently residing in my basement. As others have noted, there have been medium- and large-format image sensors available for decades, but they cost many thousands of dollars. I ought to be able to get a 35mm "consumer" version for a few hundred bucks. As long as it had 1080p resolution or better, I would buy it. And I'm sure there are a lot of other old-timers like me who would buy it too.

Long computations which yield zero are probably all for naught.