Best Movie -- Maybe, Scientifically Realistic -- No Way in Hell

Mark declared Gravity to be 2013's best movie, and I liked it. But I couldn't just let the idea that it was scientifically accurate stand unchallenged. But Gravity is not the only Hollywood movie to fall into that trap.

Warning: spoilers ahead.

While Gravity was visually impressive, it was not scientifically realistic. There are a zillion things wrong with it that others have pointed out (like, why the hell is a medical doctor swapping circuit boards out of a space telescope?), but I'll just mention the ones that struck me.

First, all the shuttles have been decommissioned, which means that the whole movie takes place in an alternate reality. There are no plans for future shuttles and Hubble will deorbit by 2021.

Second, the Hubble Space Telescope, which Bullock and Clooney were working on, is not in the same orbit as the International Space Station. Hubble's orbit is nearly circular at 559 km (inclination 28 degrees), while the ISS's perigee and apogee are 413km x 420km (inclination 51 degrees). (Even in an alternate reality the Hubble and the ISS would be in separate orbits because you don't want them to collide or the ISS to interfere with the Hubble's sight lines.)

That means it would take many hours if not days to travel from Hubble to ISS, even with the space shuttle. It would be impossible for Clooney's backpack to move two people from Hubble's orbit to the ISS's orbit in the time allotted, because the delta-V (change in velocity) required would use far more reaction mass than could be stored in the small backpack (assuming typical gas jets and not some super-powered plasma rocket pack).

Exactly how far apart are we talking about?

The circumference of the Hubble orbit is about 25,000 miles, while the circumference of the ISS's orbit is a few hundred miles less. Hubble and the ISS are basically randomly located along those orbits, as far as 12,000 miles away. They're not orbiting at the same speed (ISS is going about 17,100 mph, while Hubble is going maybe 50 mph slower). Also, they're not orbiting in the same plane: the ISS's orbit takes it as far north as London and almost as far south as Tierra del Fuego, Argentina. The Hubble's orbit takes it as far north as Orlando, Florida, and as far south as Johannesburg, South Africa.

That means Hubble and ISS will almost never be anywhere near each other. On extremely rare occasions they might pass within a few hundred miles, whizzing by at a relative speed of hundreds of miles an hour. But even if Clooney and Bullock lucked out, they still wouldn't have enough fuel to change orbits in time, since they had only minutes of oxygen.

Clooney's jetting from Hubble to the ISS is equivalent to jumping out of an airplane flying from London to Tierra del Fuego and parachuting over to a plane flying from Orlando to Johannesburg. Their paths might intersect, but the odds they'd be anywhere near each other at any random moment is nil.

The same thing is true for a future Chinese space station: it cannot be in the same orbit as the ISS because they would eventually collide. They would be nowhere near each other by design. For all the same reasons of orbital mechanics it's impossible for Bullock to go from the damaged ISS to a Chinese station in the time allotted.

It's reasonable that Bullock would be trained to read Russian and land a Soyuz spacecraft, but she simply wouldn't know enough to deorbit a Chinese lander -- it's a completely different design, and she obviously didn't read Chinese, and you can't just make wild guesses when landing spacecraft.

When Clooney and Bullock get to the ISS she gets hung up in the parachute cords from the Soyuz lander. Clooney is still hanging on to her. At this point Clooney detaches himself to "save" her and sacrifices his own life.

This is the absolutely stupidest thing about this movie. This sacrifice is totally unnecessary. They tried to make it seem that Clooney was somehow weighing Bullock down, and letting go would allow her to get back "up."

But this is space. When the chute cords became taut the two of them would stop. They might even be jerked back towards the station from the elasticity, and they would at least have been able to get themselves back to the station by yanking on the chute cords to get themselves moving back towards the station (they're weightless -- it would take almost no force to get going). Even if they were rotating around the station like a lasso around a cowboy's head (which they weren't -- they were just "dangling" from the station looking down at earth) they'd be able to climb up the cords.

The people who wrote this script either have no understanding of the conditions in space, or they thought they had to dumb reality down for the audience. But there's no reason for this: what matters in the movie are the visuals and the human emotions. All the picky details are irrelevant to the human drama -- you can simply arrange those details to stay true to the realities of space travel, without damaging the story line.

For example: there's no need for Hubble or the shuttle. Clooney and Bullock could be on a spacewalk on the ISS to deploy a medical experiment, like, say, one she developed to help kids who suffer from whatever killed her daughter. While she's wrapping things up, Clooney is farting around with his jet pack. Quoting one of Newton's laws (for every action there is an equal and opposite reaction), he shows all the kids on earth how throwing a wrench (on a long tether) propels him in the opposite direction.

Then catastrophe hits: space junk from a blown-up satellite hits the station, it starts rotating like crazy, casting Bullock away. The American Orion spacecraft is clobbered by debris, and the old Russian Soyuz breaks free, spinning away from the station. Debris hits Bullock's O2 tank, leaving her with a small emergency supply of only a few minutes. Clooney goes after her. He catches up to her and slows her down, stopping her nauseating spinning. The rocket pack is exhausted. Now they're just hanging there, a mile away from the dying station, with no way to get back.

They're both dead, right?

But no, Clooney is a brilliant astronaut: for every action there's an equal and opposite reaction, remember? He lines her up perfectly between him and the station, plants his feet squarely on her back and gives her a big kick toward the station -- sending himself out into the void. This is a sacrifice based on a basic principle of physics that everyone has heard of, which he just demonstrated.

Bullock barely makes it back to the station, gets in, sees weightless doodads spinning around, explosions, deadly perils and fancy special effects. She makes it to the Orion and finds out that debris has cracked the window: the lander is no longer airtight, and it can't possibly reenter the earth's atmosphere.

She's dead, right?

But no. Looking out the cracked window she sees a glinting -- the old Russian Soyuz lander is slowly spinning as it gets further and further from the station. Now she's got to figure out how jury-rig the damaged Orion to reach the Soyuz that she desperately hopes is still functional, before the ISS passes through the debris field on the next orbit, less than 60 minutes from now. She can even use the fire extinguisher gimmick to get from the damaged Orion to the (hopefully) undamaged Soyuz because it's too risky to let the two spacecraft get too close to each other. When she finally makes it to the Soyuz she can barely remember enough Russian to let her press the right buttons (does "старт" mean what she thinks it means?).

Pretty much all the same things can happen, credulity need not be strained, characters are developed, and to top it all off it's a cheaper movie to produce because you only have to generate effects for trashing one space station instead of two.

A real space accident happened with Apollo 13, and Hollywood even made a pretty good movie out of it. That movie hewed closely to the facts and didn't lose any emotional punch because of it.

So, why does any of this matter? Fiction is about character. Details matter because pointless sacrifice is simple suicide. It's out of character for a brilliant and tough astronaut like the one Clooney portrays to give his life up for nothing, not the least because after he's dead he can do nothing to protect Bullock: dead heroes help no one.

Hollywood so often falls into the trap of taking a harrowing situation and turning the excitement level up to 11, when 10 will do just fine. There's no need for movies to force-feed us stupid stuff, when the right stuff is just as easy to make.