How SpaceX plans to land its massive BFR spacecraft on Earth

The giant spacecraft of 100 passengers that SpaceX plans to charge with a billionaire and a handful of artists could one day go around the moon, perhaps as early as 2023.

But the ship must also land safely on Earth.

While presenting to the public Yusaku Maezawa, passionate about the telescope and future passionate SpaceX, CEO Elon Musk also showed a simulation of the fall of the Big Falcon Rocket, or BFR, as a rock in free fall. on earth.

"It's very counterintuitive," said Musk. "It's not like people know something, it's not like an airplane."

Indeed, compared to the way people expect a plane to land, a BFR landing would be radically different. But when it comes to landing such a large reusable spaceship, the plan is in many ways very sensible – although it is far from realized.

In fact, the WCR could follow in the footsteps of NASA's retired space shuttles, a 184-foot-long machine that conducted space missions for three decades until its retirement in 2011.

During most of their descent into the atmosphere, the shuttles did not show their nose like an airplane. Instead, they positioned their noses, using the wide underside of the shuttle to catch a lot of friction and slow down.

"The Space Shuttle did exactly the same thing," said Brad King, director of the Space Systems Research Group at Michigan Technological University and CEO of Orbion Space Systems.

As the shuttle fell into the atmosphere, she acted "like a great ram" when she collided with air masses to brake in the air, said King.

And that is Musk's plan for the BFR.

"What's interesting is that it uses the body of the vehicle to lose most of its speed," said Jonathan McDowell, an astrophysicist at the Harvard-Smithsonian Astrophysics Center. "He kills a lot of horizontal speed early."

And it brakes during this first descent at very high speed in the atmosphere that is really the most critical. SpaceX has already mastered the last part, which puts things in place – even two rocket boosters at the same time.

"It's not a hard landing," McDowell said. "It's the 18,000 mph horizontal speed that you have to kill."

Once the BFR brakes and loses its momentum, it will simply fall straight to its landing point.

"That's what a stone would do," King said. "He's just coming out of the sky."

Hitting the precise landing point, however, will be a challenge.

Unlike NASA shuttles, once the WCR slows down and loses its momentum, it also loses most of its ability to propel itself to a specific location. The shuttle could go around to get ready to land. The WCR does not have this capacity.

So as soon as the rocket leaves the space and begins to descend into the sky, it will be necessary to make the necessary adjustments to bring it back into the landing zone.

"The decisions he makes in the air are absolutely crucial for his land," King said.

However, the WCR – in its current form – will have a small steering power. He has three fins on the back, two of which can move. Thus, once SpaceX is close enough to its landing zone, it has the ability, albeit limited, to correct the final course of the spacecraft.

"It gives them the ability to control downward," McDowell said.

But, as McDowell and King pointed out, these fins are not wings. They do not provide lift like a plane. They simply allow the craft to move from left to right.

Landing a giant spaceship may seem like a fancy venture. But SpaceX engineers have accomplished unprecedented feats for years.

"It's a very interesting design and I'm looking forward to them developing it into reality," McDowell said.

"When Elon and SpaceX decided to do something, I would not bet against them," said Tommy Sanford, executive director of the Commercial Spaceflight Federation, in an interview. "It's a bit like NASA in the '60s – you would not bet against them."

If it works, the BFR is designed to go well beyond the moon, into the farthest solar system. And this is no longer the case either.

"I think it's feasible and it's time," King said. "As a space species, humans have been able to put a vehicle on Mars for a while."

Over the next five years, SpaceX could have a vehicle that would not only allow it to go and come back, but to land safely on land.

"I do not see any technology that requires a miracle," he said.