In the wee hours of Saturday, a type of rocket that did not exist five years ago sat on the launch pad at Cape Canaveral counting down to launch. Its mission: Sending what is arguably the most advanced spacecraft ever built, Dragon, on a multi-day unmanned shakeout mission to deliver cargo to the International Space Station at unprecedentedly low cost, and with the eventual promise of becoming America's new manned spaceship. The countdown was aborted with half a second to spare due to a faulty part not much bigger than bicycle gears, and ironically my diary about that planned launch faced a similar fate - it became (and remains) inaccessible because I embedded a livestream that turned out to contain an automatic redirect triggered even when I try to edit that diary. But the part has been replaced, SpaceX is planning to launch tonight about three hours from now, and this time I know better than to embed a livestream (but I will update periodically when new info comes out).

In the first diary, I went through an extensive spiel explaining how important this launch is - important enough that even a failure would be a success because someone is actually trying and has the resources to commit. As a commenter in a space forum I frequent had reminded me - and I think it worth spreading this information far and wide - this mission is basically trying to recreate every achievement of the entire Gemini program in a few days minus the crew: It will attempt to launch a pressurized capsule into Earth orbit, execute precision maneuvers, safely rendezvous with another spacecraft (the ISS), then return to Earth intact.
Everything about this mission is bold and experimental: The Falcon 9 rocket type on which it is being launched has only launched twice before, and is several times cheaper to build than any competitor in its class; it has the most advanced software and most efficient ground operations procedures ever devised for a launch vehicle; and if not for the severely narrow launch windows for reaching ISS, SpaceX could have tried to launch again within hours of the initial scrub - an unprecedented capability. Even with the faulty part, SpaceX says that the rocket would have launched successfully according to its simulations. In fact, even the way the company is being paid by NASA is radical - they're being paid for achievements and services, not mere activity, so failures and cost overruns would come entirely out of the corporate end rather than NASA.
SpaceX is causing the lazy, expensive, entitled Big Aerospace corporations and their wholly-owned Republican politician subsidiaries (and a handful of Democrats, but it's mainly a GOP phenomenon) to become worried and pissed off. The teabagger Congress has repeatedly slashed funding for this extraordinarily successful type of program the more powerful it proves its potential to be, and meanwhile keeps insisting on pouring billions into pursuing highly expensive, unreliable status-quo systems that no one actually wants and SpaceX has already more or less rendered obsolete, and on timelines that keep receding. They've done this because the money basically goes directly into the pockets of these large, traditional contractors who get paid no matter how little they deliver and how much it ends up costing, and the contractors in turn fund campaigns.
Once dividends, stock prices, and Republican payola are taken care of, it's anyone's guess how much actually goes toward advancing spaceflight in this corrupt system, but there's no arguing with the fact that these companies haven't produced dick in decades, and can't be bothered to risk their own resources trying anything new. They basically exist to be sponges, soaking up whatever money comes their way via the people they put in Congress, and it appears that the less they deliver, the more of that money they end up keeping. It's the same across every field they're involved in - from aviation to military projects to civilian space - the costs just keep increasing, and so do their stock prices, but what they deliver keeps being ever more humble. And then habitual boat-rocker Elon Musk started SpaceX and now things are getting interesting. That's why Rep. Frank Wolf (R - VA) desperately called for commercial programs to be ended so he could hand his favored contractor, Boeing, the business SpaceX was busily snatching away from them with every passing day.
SpaceX has built an entirely new family of rocket vehicles, several launch facilities, and a spacecraft on the kind of money that disappears in Boeing's couch cushions, and the industry and its toys in Congress are furious. This is not a space-flavored hedge fund the way the traditional industry is set up, but an actual space company with billions of dollars worth of commercial contracts committing its own resources to opening up the solar system to humankind. Unlike NASA, it is explicitly committed to this goal and doesn't depend on political whims to pursue them. The Dragon spacecraft you see here...

...will most likely be America's next manned spacecraft, and given the economics involved, probably the basis of worldwide human spaceflight for the next decade. Variants are being designed as not only crew and cargo transport to Earth orbit, but as orbital laboratories and landers capable of landing on Mars (albeit initially unmanned). It's been designed from the beginning to comfortably carry 7 astronauts with more room to spare than a three-person Soyuz. Meanwhile the Falcon 9 is being steadily evolved into a mass-production rocket with the potential capability to become not only reusable, but rapidly reusable - i.e., they'll seek to make it so stages fly back and land on their own power and are reused within a short period of time in subsequent launches. The Falcon 9 slated to launch tonight is expendable, so not really part of that project, but it all contributes. SpaceX projects that cost reductions by a factor of 100 are possible if reusability is achieved, putting the cost to orbit within the hundreds of dollars per kg rather than the $10,000 of the Space Shuttle.
There are many long, arduous, and perilous steps between here and there - not the least achieving the objectives of this mission, if not tonight, then on a subsequent launch. Once it achieves those, then it has to reliably repeat the performance as part of its contract to deliver cargo to the station, and meanwhile start launching Falcon 9's extensive manifest of commercial satellites whose owners were attracted to its unprecedentedly low prices. The production chain also has two consecutive new versions of the Merlin engine that powers the rocket awaiting implementation - first the Merlin 1D, and then the Merlin 2, which (as I understand it) vastly increases the power and efficiency of the engine. Meanwhile, SpaceX is developing the SuperDraco thruster for the Dragon spacecraft that can be used not only as a Launch Escape System (LES) for manned missions in the event of an emergency abort, but can be used for powered landing both back on Earth...and potentially on other surfaces.
Here are the landing legs for a prototype flyback reusable stage under construction, called the Grasshopper:

Even with the impressive stats, it may seem like a retread to be repeating the Gemini program, but in truth SpaceX is bringing us into truly uncharted territory of both low cost and capability. A few years of effort and a few hundred million dollars - chump change in NASA or its usual contractors' terms - have brought about a factor of about three reduction in cost, before anything even resembling high-volume flight has been achieved. I think it's safe to make this generalization: This is a lot harder than we think and will involve far more complexities than even the intrepid geniuses at SpaceX imagine, but they will also discover possibilities and ideas that had never been seriously considered before. And once things get going, they really won't stop. Ever.
I can't stress this enough: There is a threshold, and on one side of this threshold is life slowly struggling to evolve and succeed on one planet, and on the other side of the threshold is an explosion of life into new domains that will make the Cambrian Era pale in comparison. Humanity will definitely have to struggle for some time to come to realize its dreams in space, and keep running into frustrations and complications, and then...suddenly the door will open and we'll just...keep...going. Onward and outward, near and far, forever and ever. We don't know where that line is, but it seems like Elon Musk and his people at SpaceX have the scent and are driven by it. They crave the future with a hunter's passion, and it shows in their work. One day you may wake up and it will be Tomorrow. And maybe Tomorrow will literally begin tomorrow.

Falcon 9 is on the pad right now, cleared for launch at 12:44 AM PST / 3:44 AM EST with high probability of acceptable weather.
Mon May 21, 2012 at 11:07 PM PT: It seems I underestimated how tired I was. Sorry, folks - I'll have to sleep and then report on whatever happens well after the fact.
8:20 AM PT: Launch successful! Dragon in orbit. Solar arrays deployed. Navigation bay doors opened successfully. Quoth Elon Musk: “Dragon spaceship opens the navigation pod bay door without hesitation. So much nicer than HAL9000.” Video of the launch:
1:05 PM PT: CBS News is reporting the Falcon 9 second stage carried cremated ashes for Celestis Inc. - a company that sells spaceflights for families of the departed hoping to send their loved one's remains into space. Reportedly some of the ashes belonged to James Doohan (Scotty of Star Trek fame) and Gordon Cooper, one of the Mercury 7 astronauts.
Also, here's inspiring footage of SpaceX employees cheering Elon Musk - I assume it's from this launch since the video was just uploaded, but there is no time code:
1:06 PM PT: Woops. I guess Vimeo embeds don't work here.
1:08 PM PT: Several hours ago, it was reported that the star tracker is successfully activated.
1:11 PM PT: Spooky-inspiring image of the launch from spectator bleachers:

1:53 PM PT: Laser-ranging system on the Dragon is reportedly operating as expected.
4:00 PM PT: Here's a pretty awesome video of the launch from way out in the swamp - at one point when the main engine cuts off and emits smoke, it actually kind of looks like a dragon in flight:
8:36 PM PT: Not quite on topic, but Tesla Motors just announced June 22nd delivery date for the first Model S reservations. Elon Musk is kicking ass and taking names.