Science

SpaceX BFR: Everything We Know About Elon Musk's Massive Mars-Bound Rocket

Yes, it's big.

SpaceX

The BFR is coming. SpaceX’s giant rocket is set to eclipse the Tesla Roadster-toting Falcon Heavy in a matter of months, with Elon Musk planning to use the new craft to power a manned mission to Mars. While the company has so far used a mix of Falcon family rockets to send satellites into space, the BFR has been designed for both large-scale exploration and smaller satellite missions.

“Essentially, we want to make our current vehicles redundant,” Musk said at the International Astronautical Congress in Adelaide, Australia last September. “We want to have one booster and ship that replaces Falcon 9, Falcon Heavy, and Dragon.”

Here’s what you need to know about SpaceX’s most ambitious rocket:

How Big is the SpaceX BFR?

It’s huge. Really huge. It has a height of 348 feet, 150 feet of which covers the ship, plus a total mass of 9.7 million pounds and a diameter of 30 feet. The Falcon 9, on the other hand, is 230 feet tall with a mass of 1.2 million pounds and a diameter of 12 feet.

YouTube channel Corridor Crew produced a video to show the BFR compared to landmarks like the Statue of Liberty:

BFR Specifications

Musk released a slew of details about the BFR at the International Astronautical Congress in Adelaide, Australia last September.

Musk's BFR slide in its whole.

The design consists of two key components: a first stage booster and a second stage ship. The whole configuration is designed to be fully reusable, unlike the Falcon 9 that only offers around 30 percent reusability. This means the company will be able to save money on round trips and bring humans back from Mars. The Space Review’s Sam Dinkin estimates the cost of the two Mars trips at around $73 million based on publicly-available information and other factors, but SpaceX has yet to give official figures.

The BFR’s Raptor Engine

The first stage booster uses 31 Raptor engines, SpaceX’s ambitious new system powered by liquid oxygen and methane. The engines will work together to create liftoff thrust of 5,400 tons. It sounds like a lot, but the engines need to lift a total vehicle mass of 4,400 tons.

On the ship itself, there’s the engine section:

BFR ship engine section.

The sea-level engines, with an exit diameter of 1.3 meters, will create a thrust of 1,700 kilonewtons. These configurations will offer a specific impulse of 330 seconds at sea level, rising to 356 seconds in a vacuum. The vacuum engines, with an exit diameter of 2.4 meters, will have a total thrust of 1,900 kilonewtons with a specific impulse of 375 seconds.

The engines are built for redundancy. The ship can land with either of the two center engines, so if either one fails the ship can still land.

The Raptor engines are a big change from the Merlin engines used in the Falcon 9 and Falcon Heavy, utilizing methane as a fuel source due to its easy harvesting on Mars. SpaceX has devised a plan to create a propellant plant for the red planet:

BFR propelant creation.

Thankfully, Musk’s recent comment suggest the company is making progress:

The BFR Ship

The ship is set to measure around 150 feet long, with a payload bay around eight stories tall. That’s enough to fit a stack of first-generation Falcon 1 rockets. The passengers are held in the cargo area with a pressurized volume of 825 cubic meters, larger than an Airbus A380 cabin. The area will likely consist of 40 cabins that could fit a maximum of six people for 240 passengers total, although two or three per cabin is a more comfortable number, which would mean between 80 and 120 passengers.

The BFR ship.

Beyond the cabins, the payload bay will hold large common areas, a solar storm shelter, a galley and central storage. These are vital to the mission: it will take somewhere around three to six months to get to Mars, and passengers will need comfort.

The fuel tanks in the booster hold 240 tons of methane and 860 tons of oxygen, with a common dome splitting the two. Methane and oxygen will be chilled below liquid point

Inter-Earth Transport System

Part of the plan for BFR is to use it to transport people around the world, point-to-point. At the conference Musk suggested it could transport cargo to anywhere on Earth in 45 minutes at most, with most places accessible within 25 minutes. Earlier this year, Musk suggested the spaceport could link up to the hyperloop to enable travel from the city center in under 10 minutes, dramatically reducing the time it takes to get from one side of the planet to the other.

Nobody knows for sure how much a ticket will cost, but Dinkin’s estimate places the cost of transport at just over $1 million to transport 853 passengers, or $1,200 per person.

Mars Mission

SpaceX plans to use the vehicles to complete humanity’s first ever Mars missions. In 2022, the company aims to send two cargo ships to Mars, confirming water resources and identifying hazards. They’ll place power, mining and lfie support infrastructure that will enable future missions to the planet. The ships will include the solar panels and life support needed to power the propellant plant and keep astronauts alive.

Two years later, the next time Earth and Mars are close enough, SpaceX will send four more ships to the planet. Two of these will be cargo ships, will the other two will be crew ships. The mission will be to set up the propellant plant and build a base for future expansion.

It could be the first step to a Mars that looks like this:

A Future BFR setup.

Next Steps

Documents suggest the company is planning to build the BFR near a Los Angeles wharf. WW Marine Composites LLC applied in March to utilize a vacant lot at Berth 240, which an anonymous source claims to Ars Technica will be used for the manufacturing of the rocket.

The company plans to use a private spaceport in Boca Chica Village, Texas, for future missions. SpaceX currently leases three facilities: two in Florida at Cape Canaveral Air Force Base and NASA’s Kennedy Space Center, and California’s Vandenberg Air Force Base. Using its own would give the company total control over the launch process, and SpaceX Senior Communication Manager James Gleeson said in March the company is targeting the site to be operational by the end of this year.

As for the first test flight? It could come as soon as the first half of next year, Musk revealed at the South by Southwest conference in Austin, Texas, in March.

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