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SpaceX Makes Aerospace History With Successful Launch, Landing of a Used Rocket (theverge.com)
Eloking quotes a report from The Verge: After more than two years of landing its rockets after launch, SpaceX finally sent one of its used Falcon 9s back into space. The rocket took off from Cape Canaveral, Florida, this evening, sending a communications satellite into orbit, and then landed on one of SpaceX's drone ships floating in the Atlantic Ocean. It was round two for this particular rocket, which already launched and landed during a mission in April of last year. But the Falcon 9's relaunch marks the first time an orbital rocket has launched to space for a second time. SpaceX CEO Elon Musk appeared on the company's live stream shortly after the landing and spoke about the accomplishment. "It means you can fly and refly an orbital class booster, which is the most expensive part of the rocket. This is going to be, ultimately, a huge revolution in spaceflight," he said. "It's been 15 years to get to this point, it's taken us a long time," Musk said. "A lot of difficult steps along the way, but I'm just incredibly proud of the SpaceX for being able to achieve this incredible milestone in the history of space."
Actually, the next milestone is rapid reuse :) Tweet from Musk this evening:
SpaceX has a backlog. It'll be nice to see if they can really up their launch rate and clear it all out.
Kneel Before Christ!
Excellent advice when you have an author looking after your interests who will ensure things work out in the end. But in real life, if you believe that, you should get to work on your perpetual motion machine now.
Post may contain irony: discontinue use if experiencing mood swings, nausea or elevated blood pressure.
Baby steps man. Baby steps. The future isn't coming overnight.
Funny. Ancient Athens did not have lawyers. They still had trials and courts and arbitration. Each side of a case represented himself. You don't need lawyers when the law is simple and short enough for the common citizen to understand.
F9 boosters are only travelling at about 2,300 m/s (64km AMSL) at MECO, compared to the space shuttle's 8,200 m/s (120km ASML) during reentry, so it's understandable that more work needed to be done to get the space shuttle flying again. Personally, I think you should be comparing the F9 booster rebuild to the SRB recovery and rebuild - what SpaceX are doing there is order of magnitude more complex.
That said, there's no real point in comparing the two - they don't have much in common apart from the fact they're both launch systems.
I disagree. Given a mould that can be heated to high temperatures, you can cast regolith into whatever form you want (we do this sort of thing all the time on Earth, it's not complicated). Even large random natural asteroids can survive entry and landing with minimal erosion if they enter on a good trajectory (see the Hoba meteorite for an example); if you're customizing the trajectory and casting to a perfect entry shape, you have a natural ablator; whatever doesn't ablate is your recovery.
As for getting it to Earth, you need a launch system - but this doesn't mean propellant. Asteroid material contains iron, so you can accelerate it with a coilgun. The biggest challenge is the length of the coilgun needed. However, collapsible and rollable booms have been advancing very well; you can pack very long objects into very small spaces nowadays. Check out Roccor's rollable trusses - they're my favorites. It's like a composite truss appearing out of nowhere. And electronics can be embedded into them.
You have several systems that need to be developed. First, reconnaissance satellites - a couple hundred million a pop in small quantities, a couple dozen million a pop in large quantities (or less if launch costs go down). The mining system, power system, sintering system and launch systems are each probably in the $750M-2B range for design/development/testing/launch costs. Maybe $5B total just for starters. But you have no overburden to to remove and ore concentrations matching the best mines on Earth. As for entry sites and recoveries, there's different strategies. You can eject to direct aerocapture-to-entry, but you'll have a pretty large landing ellipse (whether you go for a shallow water or desert/wasteland recovery environment), since we're talking something that's unguided - the ellipse would be in the rough ballpark of tens of thousands of square kilometers. The area of course doesn't need to be empty all of the time, only during brief windows each synodic period when returns will be arriving; it can be fine for fishing, grazing, agriculture, etc during the mean time. If you want to shrink the landing ellipse, you can have them aerocapture to orbit. From there you can have a "space tug" of any sort inject them into a precise entry trajectory, with a landing ellipse of just a couple to a couple dozen square kilometers. Alternatively you should ship small, reusable guidance stages (just a couple dozen m/s dV) to be attached to each sintered return to ensure that they arrive on a precise trajectory to land in a narrow ellipse; this would require periodic resupply of such stages to the mine. Of course, no mine can operate indefinitely without any kind of resupply regardless; things wear and break down.
Each new mine gets a lot cheaper than the last, of course, as you're building it on what you've learned from the last attempt.
Kneel Before Christ!