The Real Reason Blue Origin's Rocket Looks...Like That
You can't help but immediately laugh when you see the rocket ship Jeff Bezos built. Sure, it's puerile, but that doesn't make it any less funny, something the endless number of Internet memes, Saturday Night Live skits, and late-night talk show jabs prove. Jokes aside, there are several scientific reasons why Blue Origin's New Shepard rocket looks so much like... that.
During an interview with Slate, Daniel Ramspacher, a propulsion engineer at NASA Goddard Space Center, said most rockets are phallic-shaped because that's how they've always been designed. There's not much that comprises a sub-orbital rocket ship. You have the mushroom-shaped capsule at the top, followed by several fuel tanks stacked atop each another, with the engine at the bottom. Lucy Rogers, an inventor with a Ph.D. in mechanical engineering, backed up that claim in an interview with Inverse, saying the shape of a rocket has to be aerodynamic to reduce drag. She explains that other common projectiles like bullets are all basically the same shape because that particular shape helps reduce drag.
According to NASA, drag is the main force that slows down an object as it slices through the air, and an object's shape changes the amount of drag. Since round surfaces have less drag than flat ones, and narrow surfaces will typically have less drag than wider ones, rockets tend to look rather phallic for one simple reason: it's the best design choice. Period. But there are other reasons why New Shepard is a bit more extreme looking than others.
The New Shepard capsule has plenty of legroom and amazing views
This sub-orbital ship was only going to the Kármán line, a boundary some 62 miles above Earth's surface that has acted as the border between Earth's atmosphere and space for decades (via Business Insider). That's where the air is too thin for regular aircraft to maintain the lift generated by Earth's atmosphere, so ships need a propulsion system. All propulsion systems need fuel, of course, but a trip to the Kármán line requires far less than one to the moon or even the space station.
For that reason, the dimensions of the fuel tanks — that is, the rocket — can be significantly reduced. Lucy Rogers explained to Inverse that the ratio between the rocket's width and height is what determines how slender it is. That design can only be minimized to a certain degree before it weakens the entire structural integrity of the ship. Thus, rockets look the way they do.
There's also the question of the capsule's bulbous proportions. Bezos wanted his passengers to have the "biggest windows in space" so they can have the best experience possible — something that's not surprising considering how much they're paying to become space cowboys. According to Business Insider, optimizing cabin size so passengers could have some legroom, combined with the larger windows, all contributed to the capsule being so much bigger than normal. As for its fat-bottomed appearance, it was wider because it needed to remain stable on its descent to Earth after detaching from the New Shepard booster.
While the entirety of the ship, unfortunately, looks like it does, every design choice was made with the safety of the passengers in mind.