10 ms·

That was a very dense an informative presentation last night, but I think the main take away is that rapid reusability is a game changer. In fact, game-changer

That was a very dense an informative presentation last night, but I think the main take away is that rapid reusability is a game changer. In fact, game-changer is probably an understatement, basically every intuition and rule-of-thumb we have about space launches and travel will have to be rethought. And this will be true even of SpaceX falls well short of meeting their stated targets (2020 orbit, 150t capability, multiple refights per day, etc. Musk stated (I think he just did some mental napkin math at one point) that if they meet their goals, the world's launch capacity will be expanded by two orders of magnitude. How often does any new development in any field bring about two orders of extra capacity? How does this incredible capacity change how you use this thing? First consider prices. A launch would cost fuel + support operations + amortized cost of rocket. The last two will tend towards zero as they can be increasingly automated and will be a small fixed cost. IIRC, fuel costs roughly $60-100 per kilo to LEO, a 100kg person with 100kg of supplies and life-support equipment can reasonably expect to get to LEO for $20000 in fuel costs. Ok, so you need to "rent" the rocket (you want to stay there at least a few days), pay operations, SpaceX margin, R&D etc. Even then, imagine weekend LEO launches for $50,000 in the late 2020s. That's astounding. Given millenials' propensity for "experiences", they're going to have hoards of people buying this. But what about risk? They've been trying to launch Crew Dragon for many years and still haven't. Well, with expandable rockets, you have to establish a safety record, it takes multiple flights, it's extremely expensive, you need a new rocket for each one. With fully reusable rockets, you can literally establish a safety record for an individual rocket within a matter of weeks, not years. Even launching once every three days (ie, far from their daily targets), it would take only a year to do more launches than Falcon or Arienne 5 have made in decades. Also, people are far more willing to take risks than organizations like NASA. Consider a thought experiment: SpaceX does 100 launches of Starship and establishes a safety record of 99% (1 blew up). They then start selling tickets, will people still buy, fully signing away any liability? Yes, you'll still have hoards of people lining up for a chance. Finally, this is going to change science as well. Today, sending a 1 ton rover to the surface of Mars is a Really Big Deal. Hence, probes are made very carefully, very expensively and very very slowly. Not just design and build (it takes a decade), but operations as well (Curiosity traveled only 20km in the last 8 years). Everything is essentially super-low bandwidth. But once you know you can get a cheap ride to Mars (of anywhere else) any time, you don't have to go to such extremes. You can easily send more rovers, more radio relays, they can travel further, experiment more, take more risks and if you lose one, it's just not a big deal anymore!

hwillis 7y ago
SpaceX is completely changing the opportunities of getting to space. The reduction in price has been nuts. According to NASA the space shuttle was ~$450 million per launch, or $16,364 per kg to LEO. The Delta 4 Heavy is $12,156 per kg. For some launches it's even higher- the Air Force paid $15,109 per kg for four launches. The Falcon 9 is $62 million, or $2,719 per kg to LEO. The Falcon Heavy is $2,351 per kg when expendable or $1,411 when reused. The BFR is supposed to have 2.5x the payload for 8% of the cost: $46 per kilogram. Even fully expendable it's $2,233 per kg. That's INSANE. It's space elevator money: > For a space elevator, the cost varies according to the design. Bradley C. Edwards received funding from NIAC from 2001 to 2003 to write a paper, describing a space elevator design. In it he stated that: "The first space elevator would reduce lift costs immediately to $100 per pound" ($220/kg).[1] If the BFR actually becomes reality it turns a journey to orbit into an airplane ride. A $10,000 airplane ride that will shake your fillings loose, but make no mistake: that completely changes everything about space. It makes putting satellites in orbit around Jupiter as hard as visiting the north pole. Fucking TV hosts will be able to go for a quick jaunt around the moon. If the BFR happens, we'll have a mars base just because it would be so cheap it's a no-brainer. Building a new ISS would be about as hard as building a new Sealab. [1]: https://en.wikipedia.org/wiki/Space_elevator_economics https://en.wikipedia.org/wiki/Space_elevator_economics
- Mountain_Skies 7y ago
  $100/lbs is pretty inexpensive but still high enough to cause some to spend some time with Jenny Craig before their flight.
  - hwillis 7y ago
    $46/kg, or $21/lb. Probably not worth a gym membership, but it would be the most money I ever saved taking a dump.
- DennisP 7y ago
  It's the dawn of the true space age. And though Musk isn't a fan, this could even make solar power satellites economical. The monolithic designs from the 1970s would be absurdly expensive, but modern designs like SPS-Alpha get economies of scale by using lots of small identical parts that self-assemble in orbit. According to the book The Case for Space Solar Power, a 2GW satellite would deliver electricity at 15 cents/kWh at pre-SpaceX launch costs. I plugged BFR's $50/kg into its cost breakdown and got 4 cents/kWh, which is pretty good for zero-carbon baseload. Ground solar is cheaper by itself, but probably not after including storage. The basic idea is geosynchronous orbit, microwave power transmission with a phased array device that requires a reference signal from the target location, and a wire mesh collector several miles wide. Over 24 hours, a solar panel in geosynch collects 5.4 times as much light as one on Earth. At the time the book was written, the power transmission had been tested over a couple dozen miles, and was 40% efficient. Longer-term, if we collect fuel from the moon to go from LEO to GEO, we could make it even cheaper.

hwillis 7y ago

SpaceX is completely changing the opportunities of getting to space. The reduction in price has been nuts. According to NASA the space shuttle was ~$450 million per launch, or $16,364 per kg to LEO. The Delta 4 Heavy is $12,156 per kg. For some launches it's even higher- the Air Force paid $15,109 per kg for four launches. The Falcon 9 is $62 million, or $2,719 per kg to LEO. The Falcon Heavy is $2,351 per kg when expendable or $1,411 when reused. The BFR is supposed to have 2.5x the payload for 8% of the cost: $46 per kilogram. Even fully expendable it's $2,233 per kg. That's INSANE. It's space elevator money: > For a space elevator, the cost varies according to the design. Bradley C. Edwards received funding from NIAC from 2001 to 2003 to write a paper, describing a space elevator design. In it he stated that: "The first space elevator would reduce lift costs immediately to $100 per pound" ($220/kg).[1] If the BFR actually becomes reality it turns a journey to orbit into an airplane ride. A $10,000 airplane ride that will shake your fillings loose, but make no mistake: that completely changes everything about space. It makes putting satellites in orbit around Jupiter as hard as visiting the north pole. Fucking TV hosts will be able to go for a quick jaunt around the moon. If the BFR happens, we'll have a mars base just because it would be so cheap it's a no-brainer. Building a new ISS would be about as hard as building a new Sealab. [1]: https://en.wikipedia.org/wiki/Space_elevator_economics https://en.wikipedia.org/wiki/Space_elevator_economics

Mountain_Skies 7y ago
$100/lbs is pretty inexpensive but still high enough to cause some to spend some time with Jenny Craig before their flight.
- hwillis 7y ago
  $46/kg, or $21/lb. Probably not worth a gym membership, but it would be the most money I ever saved taking a dump.
DennisP 7y ago
It's the dawn of the true space age. And though Musk isn't a fan, this could even make solar power satellites economical. The monolithic designs from the 1970s would be absurdly expensive, but modern designs like SPS-Alpha get economies of scale by using lots of small identical parts that self-assemble in orbit. According to the book The Case for Space Solar Power, a 2GW satellite would deliver electricity at 15 cents/kWh at pre-SpaceX launch costs. I plugged BFR's $50/kg into its cost breakdown and got 4 cents/kWh, which is pretty good for zero-carbon baseload. Ground solar is cheaper by itself, but probably not after including storage. The basic idea is geosynchronous orbit, microwave power transmission with a phased array device that requires a reference signal from the target location, and a wire mesh collector several miles wide. Over 24 hours, a solar panel in geosynch collects 5.4 times as much light as one on Earth. At the time the book was written, the power transmission had been tested over a couple dozen miles, and was 40% efficient. Longer-term, if we collect fuel from the moon to go from LEO to GEO, we could make it even cheaper.