There Are Very Solid Engineering Reasons Why Jeff Bezos' Rocket Looks Exactly Like, You Know, That The suborbital rocket has a domed, wide capsule on top for passengers - giving it a phallic profile.

Blue Origin founder Jeff Bezos flew to the edge of space Tuesday in a company rocket that had a bulbous passenger capsule sitting atop a tall, narrow booster shaft.

The New Shepard rocket's tumescent shape was low-hanging fruit to social-media users who were quick to point out the craft's phallic design and wonder whether that design meant its billionaire passenger was compensating for something.

But experts say this suborbital sausage fest was anything but accidental. New Shepard's characteristic shape was designed to optimize cabin space for up to six passengers and maximize the rocket's stability when coming back to Earth, according to Pedro Llanos, an engineer and professor of spaceflight operations at Embry-Riddle Aeronautical University.

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"The main reason the design looks like this is because Jeff's first goal is to send people to space, so everything revolves around having four to six people in the cabin and so maximizing cabin volume," Llanos told Insider. His group at Embry-Riddle has sent cargo up on previous New Shepard launches in 2017 and 2019.

"Jeff also wanted to have the biggest windows in space so people could have an awesome experience," Llanos said, which further increased the size of the capsule.

While most spacecraft resemble, in part, male genitalia, New Shepard's wide mushroom-like capsule — and the skinny girth of the booster underneath — are the driving source of recent innuendo.

Blue Origin declined Insider's request for comment.

The capsule shape helps reduce drag on the rocket and keep passengers safe

According to Llanos, Blue Origin engineers tested more than 100 configurations for the capsule shape before settling on one that starts wide at the base and tapers — a bit like a muffin top.

Given that the capsule is the first thing to cut through the air as New Shepard ascends skyward (scientists call this forward-most part the nose cone), it's rounded to reduce drag, Llanos said.

Drag is the force that slows an object down as it moves through the air. The shape of a rocket affects how much drag it experiences, NASA said: "Most round surfaces have less drag than flat ones."

The capsule needed to stay stable on descent, too — it detached from the New Shepard booster in the atmosphere and fell for four minutes before deploying parachutes and delivering Bezos and three others safely to the ground. That's why engineers had to make the bottom so wide.

"The more base it has, the better it's going to land," Jonathan McDowell, an astronomer at the Harvard-Smithsonian Center for Astrophysics, told Insider. A capsule shape with a narrower base would have been less stable during reentry.

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A skinnier design helps the rocket reach suborbit

Like most rockets, New Shepard has a propellant-filled booster that helps blast its capsule toward space.

The higher in space a rocket's objective is, the more propellant it needs to hold in order to power its journey. So a booster carrying a spacecraft bound for the orbiting International Space Station, like SpaceX's Falcon 9 rocket, is going to be taller and larger than a booster for a rocket like New Shepard that's designed to go only to the very edge of space.

"You don't need as much fuel to go suborbital; everything on Jeff's rocket is optimized to go suborbital," Llanos said. "If it had gone orbital the design would've been much different."

Since Bezos' rocket was only aiming for the Kármán line — an imaginary boundary 62 miles above sea level, where many experts say space begins — its engineers cut down the height and girth of New Shepard's booster. (Narrower surfaces usually have less drag too, NASA said.)

The move reinforced the rocket's phallic profile.

McDowell said there are other rockets that have capsules wider than their boosters — known as "hammerhead" rockets.

Notably, he said, United Launch Alliance's Atlas V rocket, which will fly NASA and Boeing's CST-100 Starliner spacecraft to the space station on July 30, has a similar profile.

Future rockets might not have this phallic design

It's hard to predict whether future commercial space missions will sport a similar design, Llanos said.

Certainly, Blue Origin's next rocket — named New Glenn — looks more like a bullet than a penis.

"It's more elongated and longer to accommodate a much larger payload," Llanos said.

But New Glenn is designed to go into orbit and back. And unlike its suborbital predecessor, the rocket won't have a rotund nose cone, meaning New Shepard will likely be the only craft of its kind put out by Blue Origin.

"This is probably the most phallic-looking spacecraft you're going to see, if I had to guess," Daniel Ramspacher, a propulsion engineer at NASA Goddard Space Center, told Slate.

Morgan McFall-Johnsen contributed reporting.