At more than 60 years into the Space Age, fictional spaceships appear on our screens at a far greater frequency than the real things launch in real life. But that doesn't mean they'll actually fly.
When it comes to imagining interstellar travel, the history of spaceflight up until now hasn't given science-fiction designers a whole lot to work with. All we've seen are basic rockets (useful for escaping Earth's gravity well), plane-like space shuttles (useful for re-entering it), Moon modules (the lunar lander), and modular orbital tubes (the International Space Station).
On the uncrewed side, we've got satellites, deep space probes and Martian rovers — all designed for a very narrow range of jobs just within our solar system.
When that job is transporting humans between stars, in theory, spacecraft will have fewer design constraints. But does that mean they'll appear in all the weird and wonderful shapes and styles we've seen in on-screen science fiction?
Here's what he had to say on a variety of well-known spacecraft — starting with the most famous fictional spaceship of all.
The USS Enterprise (original vs. Next Generation models)
Ferdowsi grew up on the original Star Trek. It served both as a way to bond with his Iranian-American family and a vision of future space that would contain people from a diverse array of backgrounds. It's no exaggeration to say that Trek led him directly to launching real-life space missions.
"I wanted to make that version of the future a reality," he said in an interview.
He loves Next Generation too, but the upgraded 1990s version of the Enterprise interior strikes Ferdowsi as less realistic than the original. Why? One word: carpets.
"If you look at spacecraft today, there's a bare bones aesthetic," he said.
Every gram of extraneous equipment is another gram of mass you're going to have to spend fuel to lift off a planet — or turn on a dime in the middle of a space battle, say.
"And you're going to add another 10 kilograms of carpeting?"
Maybe the 23rd century's bountiful energy supply, in the form of dilithium crystals, has made spacecraft designers careless about how much mass they need to move around. Maybe all that corridor carpeting is just part of a ploy by Big Dilithium to get Starfleet to use more of its product.
Still, the original Star Trek — and the 2000s prequel series Enterprise — offered a more believable bare-bones aesthetic.
"That's probably the reality of where we're going," Ferdowsi says. "The more it looks like [1980s submarine movie] Das Boot, the more it looks like space exploration."
Which isn't to say the original series Enterprise interior had it all right. For one thing, there were all those computer banks full of blinking lights surrounding the crew at all times.
"Practically, visually, it's a terrible choice," Ferdowsi says. "Look at the way cockpits of modern aircraft go dark" — which means that if a blinking light needs your attention, you see it instantly. The Next Generation's LCD panels and smoother, more neutral colors seem less likely to make a crew crazy.
Stay cool, Captain Kirk
As for the outside of the ship, that classic design seems very much a product of the 1960s to Ferdowsi — the flying saucer married to a Coke bottle with tail fins straight out of Detroit. Still, it does a few very smart things, spacecraft design-wise.
First of all, it's all one color — meaning you don't have potentially disastrous thermal problems where one part of the ship takes on more heat than another. Secondly, it's white, but not so white that it reflects every photon, which would put too much pressure on the vessel. "If you're in the black of space, it's good to be a light color," Ferdowsi says — which is why you see probes, landers and the sun-facing side of the Shuttle decked out in gold or white.
Not only does that help you avoid taking on too much heat from a nearby star, but you can also use a reflective surface as free propulsion. All those bouncing photons can help you move all those extra grams of carpeting.
(The ideal situation is a ship that could turn from white to black when it's far from a star and needs to take on heat, which is why Ferdowsi recently proposed building a "Kindle craft" covered in e-ink, which can switch easily from one to the other.)
The other smart thing the Enterprise design does? It puts the warp nacelles — those propulsion fins — on stalks, far away from the areas the crew lives within. That's a useful safety feature in case your futuristic energy resource should start to backfire. "We don't want the humans near the dilithium crystal chambers," Ferdowsi insists.
As he points out, there are plenty of ships in the Trek universe with a one-piece design, sticking their warp nacelles way too close to the main bulk of the vessel. Whoever designed the Enterprise clearly had safety in mind.
The Death Star vs. the Borg Cube
For the most part, Ferdowsi is more of a Star Trek than a Star Wars fan. Star Wars is a fantasy that flagrantly ignores physics, which was kind of the idea. George Lucas wanted "spaceships you could get into and drive around as easily as cars."
The kind of turns the Millennium Falcon makes in space are impossible without an atmosphere.
The Last Jedi's bombing run is impossible without gravity ("maybe the bombs were spring-loaded," suggests Ferdowsi). There's no reason for X-Wings to change their wing alignment like that, other than the fact that it looks cool. And TIE fighters don't even have a visible system of propulsion.
But that's not to say Ferdowsi rejects Star Wars completely. Like many of us he was awed by that silent moment in The Last Jedi where a vast Star Destroyer is ripped in two by a rebel ship performing a suicidal lightspeed maneuver.
And then there's the Death Star.
"The Death Star would be a very efficient design because it's a perfect sphere," Ferdowsi points out. Of any spacecraft shape, a sphere has the lowest possible ratio of surface area to volume, requiring the least possible amount of energy and material to build and maintain. "Ideally, you'd also curve the interior," he says.
The same is not true for the Borg Cube of Star Trek fame. For all the villainous Borg's supposed efficiency, their vast six-sided planet-threatening vessel is a massive waste of space. The Death Star may cost an estimated $852 quadrillion in steel alone, but that figure would be far higher if it employed any other shape.
That's no moon — it's a highly efficient use of surface area.
For a sitcom, Red Dwarf paid a surprising amount of attention to science.
The 1990s show explores what happens when the mining vessel Red Dwarf accelerates for millions of years; it doesn't break the laws of physics by going faster than the speed of light, unlike most sci-fi ships. But it gets close, creating appropriately weird time dilation effects.
Not only that, the Dwarf was on the cutting edge of future spacecraft design. That radio mast-like scaffolding on the front of the ship, to the right of the picture?
That's a Bussard ramjet, a theoretical means of powering a ship using nothing but the stuff of space itself. Free-floating hydrogen atoms are compressed in an electromagnetic field until they create a fusion reaction.
Bussard ramjets have fallen out of favor these days, since we don't think there's enough hydrogen out there to compress. Still, points for the attempt!
Then there's the body of the ship itself, partially constructed from an asteroid the crew mined. Companies are looking at mining asteroids in the near future.
"They have a ton of resources, you can hollow them out, it's really practical and it's already in space," with no energy required to get it there, Ferdowsi said.
The Arboghast (from The Expanse)
It may not be the best-known ship in the history of science fiction.
But the science vessel Arboghast, which probes the mysteries of Venus in season 2 of Syfy's The Expanse, does something novel and highly useful in spacecraft design: It expands with a large inflatable ring when coming in for landing.
"That's exactly what you want," Ferdowsi said enthusiastically.
"Leaving the atmosphere, you want to be as small as possible, to save on fuel. On the way in, you want to be big and wide as possible" — to increase drag and slow the ship down, Ferdowsi added.
Serenity (from Firefly)
That bare-bones submarine aesthetic Ferdowsi favors is also present in the Serenity, the janky trading ship from cult favorite sci-fi series Firefly.
The ship's aerodynamic bird-like design is appropriate given that it has to enter atmospheres on multiple planets. "Very utilitarian" is Ferdowsi's verdict.
Furthermore, Ferdowsi applauds the use of retro rockets on the side of the wings — particularly as they flip upwards during landing. This is reminiscent of the design of SpaceShipOne, a private, suborbital spacecraft, which won the X-Prize in 2004, a year after Firefly went off the air.
SpaceShipOne (and its successor SpaceShipTwo, now being developed for space tourism by Virgin Galactic) flips its wings upwards to increase drag and slow itself down in the upper atmosphere, like a shuttlecock.
Serenity's controlled rocket landing also looks a lot like the most amazing real-life spacecraft images of recent years: the SpaceX and Blue Origin boosters that can land themselves after delivering their payloads to orbit, saving millions of dollars in the process. That's a level of thriftiness the Firefly crew would certainly appreciate.
Like Firefly, Battlestar Galactica (the 2004 miniseries, that is) had one big realistic thing going for it out of the gate: Both shows represented space as utterly silent.
Galactica also takes the submarine aesthetic and upgrades it to that of a battleship or aircraft carrier.
"It's practical," says Ferdowsi. "There's a logic to it. You don't have a lot of big open spaces, other than the hangars. Nothing in space is going to be ornate or over-the-top."
Galactica boasts ribs along the length of the frame that act as shock absorbers, helping to explain why it could take such a beating over four seasons of war. It also has a rusted, broken-down feel — appropriate for a ship that was about to be decommissioned and turned into a museum when the Cylons attack at the beginning of the show.
Galactica's need to repair and replenish — a constant background plot point — makes it unique among on-screen spaceships. Ferdowsi compares it to an old Volkswagen, known for being relatively easy to fix. Less software, more mechanics.
The ship was saved from a Cylon computer virus because it was old and non-networked, largely driven by analog technology and wired phone lines. Which brings up the interesting question of whether future spacecraft will need to be similarly "air-gapped" to prevent any kind of malicious infection.
Currently the International Space Station does have an internet connection, but Ferdowsi points out that the station mostly relies on older, more reliable telemetry systems.
Sometimes, even in the future, old school is the way to go.