Elon Musk, founder of SpaceX, gave a presentation last Friday at the International Astronautical Congress in Adelaide, Australia titled “Making Life Multiplanetary.”
Musk began by giving the reasons for SpaceX’s mission and his own interest in space, saying:
You want to be inspired by things. You want to wake up in the morning and think the future is going to be great, and that’s what being a space-faring civlization is all about. It’s about believing in the future and thinking that the future will be better than the past. And I can’t think of anything more exciting than going out there and being among the stars.
In the nearly 45 minute talk, Musk reviewed the history of SpaceX and its progeny of existing launch vehicles, from the Falcon 1, Falcon 9, Falcon Heavy, and the Dragon cargo/crew capsule. He then proceeded to introduce the new vehicle which SpaceX is working on, called the “BFR,” which has been interpreted as “Big ‘Freaking’ Rocket” or “Big Falcon Rocket.”
SpaceX’s plan is to phase out its existing rockets and eventually go-forward with just the BFR as an all-purpose platform for cargo and crewed missions. This will streamline development and maintenance for the company and reduce overall costs. Musk said, “We want to make our current vehicles redundant.” To that end, Musk stated that SpaceX plans to build up a stock of Falcon 9 and Falcon Heavy rockets to use for upcoming missions and then shift all resources to development of the BFR (he said that work has already begun).
The BFR consists of two stages: a first booster stage and an upper crew/cargo ship. The booster stage has 31 of SpaceX’s Raptor engines, generating a combined liftoff thrust of 5400 tons to lift a vehicle weighing 4400 tons.
The upper ship consists of three sections: engine, propellant, and payload. It is 48 meters long and 9 meters in diameter.
The engine area has a total of 6 engines, all of which can gimble to control thrust direction. Four are vacuum engines and are situated around the circumference. The inner two are sea-level engines used for landing; only one engine is actually required to allow for redundancy (Musk says that he wants to eliminate the “pucker factor” of landing). On the outside of the engine area is a small delta wing with a split flap to control pitch and roll; this allows for stable landing with various atmospheric conditions and payloads.
The propellant area has tanks for liquid methane (CH4) and Oxygen (O2).
The payload area is meant for crew and/or cargo. It has a pressurized volume of 825 square meters, which Musk notes is greater than an Airbus A380. Musk gave details on what a Mars Transit Configuration might look like. It would have 40 cabins (2 to 3 people per cabin for about 100 people on a flight to Mars), large common areas, entertainment areas, central storage, a galley/kitchen, and a solar storm shelter.
The BFR can lift 150 tons to low earth orbit (LEO). The ship can also be refueled in orbit by another ship by mating the two at the rear, connecting the fill lines of both ships, accelerating in the direction of the ship which will be emptied, and then undocking and returning the emptied ship. This would allow the refueled ship to cary 150 tons to Mars.
To reduce launch costs, Musk’s plan is for the entire BFR to be reusable. He showed a slide comparing the carbo lift capacity of various rockets, with smallest on the left and greatest on the right. The BFR has the greatest capacity, beating even the Saturn V’s 135 tons. Then, he showed a followup slide which ordered the rockets based on launch cost, with lowest cost on the left and largest on the right. The BFR was the lowest cost.
Again, Musk attributed this low launch cost to reusability, drawing an analogy with aircraft. He said that you could buy a small turboprop for about $1 to $2 million and fly it to Australia, crashing it. Or, you could charter an airliner for about $500 thousand. The airliner is cheaper because it is designed to make the trip many times; the only marginal cost is fuel. Similarly, the BFR is designed to be reused many times, with fuel being the major cost factor in launches.
Regarding lift capacity and cost, Musk also noted:
Often I’ll be told, “But, you would get more payload if you made it expendable.” I say, “Yes, you could also get more payload from an aircraft if you got rid of the landing gear and the flaps, and just parachuted out when you got to your destination. But, that would be crazy and you would sell zero aircraft.”
The target market of the BFR is satellite launches (due to its size, it can launch very large satellites or even multiple satellites at once), ISS servicing, Moon missions, and Mars missions. Musk mentioned building a base on both the Moon and Mars.
Regarding Mars, his “aspirational” plan is to launch 2 cargo ships in 2022 to find water and place resources for the next mission. Then, in 2024 he wants to launch 2 cargo ships and 2 crewed ships to begin building a base and to construct a propellant plant (to extract methane and oxygen from Mars). Then, he wants to start building a city there, showing an artist’s rendition during his presentation.
Finally, Musk proposed the idea of using the BFR to travel to points on earth, taking off and landing vertically. Any spot on Earth could be reached in under an hour, with most places only requiring 30 minutes of travel time.
Musk’s presentation elicited applause from the audience, with one member yelling “Good job, Elon!” While Musk is involved in many other enterprises, it is obvious that SpaceX is where his passion lies.