- Passengers take off from Earth in a tightly packed space-plane, like a 747. This is size and mass efficient, and it can be re-used the next day or week to fly another load of passengers, spreading out its cost among many thousands of passengers. It might look something like the BFS renders you've seen, but will lack the long-term amenities. It might also be used for point-to-point travel on Earth.
- Once in LEO they'll transfer to a roomier, inflated habitat that cannot land but has the necessary elbow room 100 people will need if they're going to live for months at time there. This habitat will have a BFC engine attached to one end, pre-fueled by BFTs, and it will accelerate towards whatever destination the people want--Mars, the Moon, Venus, Ceres, or some deep space Lagrange point.
- Once at destination the craft will decelerate into a circular orbit, at which point a local space-plane (which will be adapted to operate in the local environment) will taxi the passengers down.
- All of the above will probably be fueled from in-space fuel resources.
Thursday, February 8, 2018
The Falcon Heavy has flown, and the mission was a near-complete success. It was far more successful than anyone could have realistically expected it to be. The loss of the core booster at sea was unfortunate, but holy cow. Seeing the two side boosters fly back to the landing zone and land in formation was break-taking, and the pictures of Starman and the Roadster in space are ones for the history books. I fully expect those will be alongside the pictures taken by the Apollo astronauts.
As an exercise, I'm now going to prognosticate and make some predictions about the future prospects of the Falcon Heavy and the likely development path of the BFR.
Falcon Heavy won't fly much. The FH took a long time to develop, and in the interim the Falcon 9 more than doubled its performance. The F9 is now capable of flying the missions the FH was originally intended for, at a 33% discount relative to the FH. With a payload to LEO of 22 tons, the F9 is more than capable of taking the lion's share of the commercial and military market. The only rocket even slightly comparable to FH (by performance; it's more than 4x as expensive) is the Delta IV Heavy, and it only flies once a year at most. There just aren't too many customers for that sort of tonnage.
The price advantage of FH compared to the Delta IV Heavy ($90 vs $400 million per launch) may grow the heavy lift pie over time, as new customers come forward with bigger cargos. But that wouldn't happen immediately.
The Falcon Heavy might help kill SLS. The Space Launch System has a ton of political support (especially from Sen. Richard Shelby of Alabama), but there is no way to deny that it is a budgetary pelican around NASA's neck. It costs billions every year in development costs and will cost at least $1 billion per launch. And it isn't scheduled to fly until December 2019, while the Falcon Heavy is available today. And the Block 1 spec for the SLS doesn't deliver much performance advantage over FH--SLS B1 puts 70 tons in LEO, compared to the FH's 64. Moreover, Elon Musk said during his post-launch press interviews that the Falcon Heavy could be scaled up to 100 tons by adding two more side boosters.
This is a direct shot at the SLS, and considering that SpaceX was able to develop and fly the Falcon Heavy for under $1 billion, the Congressional budget office has to be asking itself what exactly they're getting in return for the seemingly endless money-pit that is SLS development. The business-minded and frugal Trump Administration will also see it this way. But expect the political fight for this to be absolutely massive, as there are huge vested interests in the SLS gravy train.
SpaceX might be its own best customer. SpaceX is developing a satellite constellation it hopes will deliver global broadband internet to every corner of the world (and generate fat wads of cash to fund further rocket development). This will be an absolutely massive constellation, numbering in the thousands of satellites when complete. Which means SpaceX will have an almost unlimited internal demand for space launch. If the Falcon Heavy flies more than the odd NRO mission every year or two, it'll probably be for SpaceX itself.
BFR will not take as long as FH. The "technology behind the technology" of FH is not the rocket itself, but the software-based models and testing SpaceX used to develop the Falcon Heavy and allow it to be as successful as it was on its very first flight. These models and testing systems are probably generic and adaptable to BFR's development, and will speed up the process of development. Don't expect another six-year delay in BFR's road to flight like FH experienced.
BFF, BFC, and BFT before BFS. The same is not true of BFS. The Big Falcon Ship (BFR's upper stage) is enormously more complex than the BFR booster. Just look at Dragon 2 development and you'll see that BFS will not be straightforward. More importantly, think about SpaceX's cash flow situation. They need to make money along the way, and there is no near-term customer for a ship that can keep 100 people alive for months at a time in space. Elon's dreams notwithstanding, SpaceX doesn't have the richest man in the world funding it with unlimited quantities of AMZN stock sales. SpaceX's approach to Mars will have be organic and self-funding. Even if Elon hates it, Gwynne Shotwell will force this approach.
So what does organic and self-funding look like? First ask yourself-who are the customers?
Elon has said that the immediate business case for BFR is to replace F9 and FH and use BFR for 100% of their local launch business. That makes sense; since BFR is fully reusable it's cheaper to fly than both of the current Falcon rockets, so it doesn't even matter than it has way more performance than is necessary to launch GEO satellites. At current launch prices they can fly it mostly empty and still make money.
But BFS is overly complicated for that, and will add years of delays to the project. A much easier project (relatively speaking) will be designing a Big Falcon Fairing (BFF). Basically, picture the current SpaceX fairing joined to the current second stage, and then scaled up to BFR size and fully reusable. That's what you need to serve the satellite market and could be designed much faster and at less expense than BFS.
SpaceX will also want a piece of the new Administration's plans for the Moon, as well as any deep space science missions NASA (and other national space agencies) has in mind--and you don't need a BFS for that either. What you need is a simpler on-orbit tugboat or semi-truck (choose your analogy, but call it Big Falcon Cargo (BFC)) to deliver payloads to the Moon or outer planets. This BFC will stay in orbit and lack all the life support systems, pressure hull, or heat shields necessary for Martian aerobraking.
Lastly, both the BFF and BFC will only really deliver on their performance capabilities if they can refuel in orbit. Elon already suggested they would develop a specialized upper Big Falcon Tanker (BFT) for taking fuel to the BFS, but I expect it will fly many years before BFS does.
BFS in 2026 or never. BFS will only be developed when SpaceX has some customers who want to land on Mars. Maybe that's NASA, maybe it's Mormons. Who knows. But the need to develop BFR upper stages that serve the markets that exist today (satellites and deep space science) will divert resources away from BFS. They'll miss the 2022 launch window for sure, and maybe the 2024 one. In the interim they'll learn a lot about refueling in orbit and landing on the Moon. This will in turn inform their designs for an eventual Martian lander. What I expect they'll learn is that a singe ship that can "do it all" is overly complicated and expensive. The eventual system that gets people to the surface of Mars will grow more organically from the infrastructure built up to service Cis-Lunar activity. It might look something like this.