"Houston, we've had a problem."
Today is the 50th anniversary of the launch of the Apollo 13 mission. Two days after NASA astronauts Jim Lovell, Fred Haise, and Jack Swigert launched for the moon, their spacecraft was rattled by an explosion in one of the oxygen tanks, nearly disabling the spacecraft entirely. While Mission control worked on a solution, the astronauts piled into the lunar module, which was designed to support a crew of two for two days. Together with Mission Control, the team worked to ensure that the lunar module would safely carry them back down to Earth. Despite the difficulties, they splashed down in the Pacific Ocean on April 17, 1970.
Space is a dangerous place. There's harmful radiation to contend with, dangerous debris zipping through orbit and, of course, the possibility that a vital piece of equipment will malfunction. The ultimate success of the Apollo 13 mission is one of the greatest demonstrations of ingenuity, teamwork, and determination—the stuff NASA is known for.
Here are ten other cosmic close calls that you may not have heard about.
Update: We've updated the article to reflect that Jack Swigert flew on the Apollo 13 mission. He replaced Ken Mattingly, who was exposed to German measles shortly before launch.
On June 1, 1966, NASA launched a satellite called the Augmented Target Docking Adapter (ATDA). While it successfully reached orbit, telemetry indicated that something was wrong with the satellite.
When Gemini 9A launched two days later, the astronauts soared above ATDA and immediately discovered the source of the telemetry error: the rocket's nose cone fairing hadn't ejected. "It looks like an angry alligator out there rotating around," command pilot Thomas Stafford said at the time.
Neil Armstrong nearly perished in an accident involving a Lunar Landing Research Vehicle on May 6, 1968. The training vehicles, meant to simulate the lunar environment, were incredibly unreliable.
A propellant leak caused Armstrong's LLRV to malfunction, sending it spiraling toward the ground. Seconds before it smashed into the ground, Armstrong ejected himself from the lander and safely floated back on the ground.
Armstrong brushed himself off and went inside to file paperwork.
When Apollo 12 launched in 1969, the spacecraft was struck by two separate bolts of lightning. NASA astronauts Pete Conrad, Alan Bean, and Dick Gordon reported seeing a bright flash out the window.
They weren't the only ones who saw. The launch and the lightning strikes were broadcast on live TV to the horror of everyone on Earth. Fortunately, the strikes didn't have a significant impact on the mission.
The United States and the Soviet Union set political differences aside in 1975 for the Apollo-Soyuz mission. They hoped to dock two spacecraft in outer space for the first time. Three Apollo astronauts and two Soviet cosmonauts docked and conducted experiments together for a total of 44 hours before parting ways and heading back to Earth.
Unfortunately, upon reentry, the Apollo astronauts were exposed a noxious chemical, nitrogen tetroxide. Luckily, once they landed, the cabin was ventilated. They were diagnosed with a form of chemically induced pneumonia but healed soon after.
When the Hubble Space Telescope launched in 1990, the world was excited to see the universe with the clarity the telescope promised.
Unfortunately, when the first image came back to Earth, it was blurry. Really blurry. Operators soon discovered that an aberration in the primary mirror had impacted the telescope's ability to take clear pictures.
NASA sent up a team of astronauts to fix the telescope three years later, and since then, it has revealed (with incredible clarity) the mysteries of the cosmos.
In 1995, Norman Thagard became the first NASA astronaut to launch aboard Roscosmos' Soyuz rocket. He was aboard the Russia's Mir space station when a mishap with exercise equipment nearly blinded him.
An elastic piece of exercise equipment snapped from Thagard's foot and straight into his eye. Fortunately, despite the pain of the initial accident, there was no permanent damage to his vision. He was prescribed some eye drops and recovered completely.
NASA's Mars Climate Orbiter launched for the Red Planet on December 11, 1998. Unfortunately, the uncrewed probe would never make it to the lunar surface.
Almost a year later, as the orbiter approached Mars' orbit, it came too close to the planet and burned up. So what caused the loss of the mission?
Units of measurement. NASA had used the metric system to calculate the amount of thrust the orbiter would need to attain the proper trajectory. Lockheed Martin, one of the contractors, had used English units instead, causing a conversion error of cosmic proportions.
In 2009, a team of astronauts were sent to repair the Hubble Space Telescope. They were tasked with replacing a critical component, the Space Telescope Imaging Spectrograph.
When astronaut Mike Massimino went to remove the spectrograph, he accidentally stripped one of the screws. (It happens in space, too, you know.) The astronauts worked with the crew on the ground to find a solution. All it took was a little brute force. After an hours-long delay, Massimino was able to yank the panel off and the crew finished their repairs.
On August 20, 2018, sensors aboard the International Space Station detected a loss in cabin pressure. The crew searched for the source of the leak and found a small hole in one of the walls. At first, it was suspected to be the result of a micrometeoroid impact, but then astronauts noted the drill marks.
The discovery of the hole, which was obviously man made caused a stir aboard the space station and back on Earth. Both NASA and Roscosmos immediately started investigations. Roscosmos, at one point, accused American astronauts of sabotage. NASA has suggested it was created during the manufacturing process.
How the hole got there remains a mystery today.
Fifty years after Apollo 12's famed brush with lightning, a Soyuz rocket carrying delivering a satellite to orbit was also struck by an errant bolt of lightning shortly after lift off. Fortunately, there was not damage to the mission and the satellite made it to orbit safely.