Patzer

In the opening scene, when Roy first steps out of the craft and onto a ladder to fix a robotic arm, he tethers himself to the craft. One presumes all personnel tether themselves in this way, yet when the electrical system malfunctions and the craft begins to explode, very many astronauts including Roy fall from the structure, before the structure itself is damaged enough that one could assume the attachment points themselves broke away.

Upon arriving at Mars, Roy states he's been away from Earth for seven weeks. The planned trip was only about three weeks. They did detour to answer a mayday call, but that doesn't account for an extra four weeks for a ship that can rocket to Mars in 20 days.

When Roy is watching the Lima Mutiny Classified Briefing the timer on the screen starts counting up from zero, implying that it is timing the recording. After the introduction, the timer again starts at zero as Roy's father gives an apparently uninterrupted and unedited speech. However, subsequent times shown on screen do not match up with the actual time passed, in fact, jump back and forth significantly.

While in the Mars lake, Roy listens to the radio broadcast from Cepheus Launch control giving "T-11min7seconds and counting" and "planned lift-off time at 7:51UTC." Roy then looks at his wrist-display showing "7:44:53 UTC," thus indicating a five-minute differential between the planned take-off times (7:44:53+0:11:07 = 7:56 rather than 7:51).

The mutiny message was video with audio, so it would only make sense for a reply 29 years later to use at least the same technology, if not advance.

Antimatter, when it comes into contact with normal matter, does not cause a "chain reaction," as is stated when Roy is being briefed about the Lima Project. When antimatter and matter come into contact, they mutually annihilate each other into pure energy, using Albert Einstein's E=mc2 equation (100% matter-to-energy conversion). There would be no possibility of an antimatter incident at Neptune affecting Earth, except for the one-time burst of energy that such an explosion would create.

The distance from Mars to Neptune and back again is about eight light-hours, and yet the team waits only a short while for Roy to receive a reply from his father.

As with scare stories about the Large Hadron Collider, any antimatter explosion near Neptune having lethal consequences for humanity would be dwarfed by the galaxy's ultra-high energy cosmic rays which are continuously bombarding the Earth.

The speeds at which the spacecraft Pitt pilots to Neptune requires a constant acceleration to make the trip in 79 days. Every external shot of the ship shows its thrusters firing creating this acceleration. This would also facilitate perceived gravity on the ship; however, it is pointed out that the ship has zero gravity.

While landing on Mars after the system failure, manual mode is switched and Roy tries to set the angle of fall to zero, but he doesn't turn off the engines at any time; he succeeds in setting the angle in the very last second and yet the rocket lands right in the place where it should, instead of miles away from it.

During the lunar rover journey, dust is seen "hanging in the air." One might think this would not occur on the Moon, as there is virtually no atmosphere. In such an environment, all dust thrown up from the ground should immediately fall back to the ground and stay there. However, lunar surface dust builds up an electric charge from being constantly bombarded by ions in the solar wind. The result is a thin layer of lunar dust suspended about one meter above the lunar surface. The charge suspending these dust particles is so great, in fact, that it has actually been suggested as a potential source of electrical power for future lunar missions.

When Roy McBride sneaks aboard the Cepheus and is confronted by the crew, all persons are floating in zero-G. At that time, the Cepheus has just launched a few minutes earlier and is still accelerating away from Mars. Due to this, everyone on board should be pushed towards the back end of the rocket.

This is a false assumption. The sequence is obviously time-compressed. The zero G part would be after the first stage cut off and before the second stage firing, which we do see take place.

Errors in Roy's free fall at the beginning of the film: Roy should have gone "full tilt delta" (arms and legs fully extended) to increase his horizontal distance from the International Space Antenna in order to avoid the falling debris. Once his canopy was damaged by debris, he should release it and deploy his spare.

There is no indication that the workers would have a backup parachute. They are workers, not skydivers.

Roy would not have needed to check his patch on the Cepheus as the suit he used to cross the lunar surface would (probably) been too dirty to reuse. Lunar dust is very abrasive. The ground crew taking him the the rocket were wearing clean suits to prevent unwanted contamination.

However, Roy also needs privacy to read his message and going to check his patch is a convenient reason to leave the cockpit.

Moon gravity is one-sixth of Earth's gravity, rendering any attempt to walk into a series of bounces. Yet, everyone walks the same way they do on Earth.

During the descent to Mars, the vertical speed shown in the conning display is 7235 m/s and increasing. Right after, Roy says "2000 meters," giving the ship 0.28 seconds to land.

At the end of his first transmission from Mars, Roy McBride signs off with "Over and out." Although it has been used in movies for decades, it's incorrect procedure. "Over" means "Awaiting your response." "Out" means "I'm hanging up." So saying "Over and out" equates to "Awaiting your response but not listening."

The Moon is much closer to re-supply from Earth than Mars is yet, despite the threat from "pirate" attacks, the SpaceCom base on the Moon is not equipped with any vehicles for surface travel except the open (and thus extremely vulnerable) rovers. Even for a VIP as high-priority as Roy McBride, no armored vehicle is available to transport him securely. Mars is much further from the Earth (the prime logistic base for all space operations) than the Moon yet the Mars Space.Com base does have enclosed vehicles. This makes zero military or logistic sense.

Roy says the Lima project dates to about 29 years ago, that his father disappeared 16 years into the mission, and that he himself was 16 when his father left and 29 when he disappeared. This doesn't add up, as either Roy would need to have been 13 when his father left, or 32 when he disappeared.

Secondly, Roy then is somewhere between 42 and 45 in the present day, while Brad Pitt would have been around 56 when the movie filmed, and he looks pretty close to his age, not very believable as being in his early 40s.

Thirdly, Tommy Lee Jones would have been in his early 70s at the time of filming, and some photos of him, as well as the video his character Clifford sent Roy around 2 years into the mission (27 years, 3 months and 2 days prior to present day), look that age. Even if--like Pitt--Jones's character is younger than the actor, he is still old enough at the time of departure that it is odd such an old man was sent out on such a long mission. It is also odd that commanders would have an easy time believing he was alive 29 years later.

The distance from Tycho crater (where Roy lands on the Moon) to the center of Farside (where the "Cepheus" is located) is roughly 1,700 miles. Traveling at the speed shown and assuming no stops, Roy's lunar rover would take a couple of days to get there.

Early in the film, while still on Earth, the camera pans up to show the last-quarter moon, but what is actually shown is the first-quarter moon reversed.

The film never identifies what year it is taking place in, but it does show a trip from Mars to Neptune that passes close to Jupiter and Saturn. There is no depiction or discussion of slingshot maneuvers around these giant planets; so, it is fair to assume the roughly 80-day flight was more-or-less in a straight line (especially because SPACECOM urgently wanted to destroy the source of the Surges). The first year in which the four planets involved will be anywhere close to a straight line is 2237. However, it is also stated that the moon's phase is almost full at the end of May. The moon will be full in mid-May 2237, not the end of that month.

Even if there were a ban on sending human crews, robotic probes orbiting Neptune are already possible and NASA have had one fly-by. It is just a matter of money, and much cheaper than sending humans.