It's just one of a slew of superstitious NASA traditions, according to Wired Science.
The peanut tradition started in the 1960s during JPL's Ranger missions, which were spacecraft designed to fly into the moon and take pictures of it. The first six Ranger spacecraft failed during launch or while leaving orbit, but on the 7th launch, someone brought peanuts into mission control, and the mission succeeded. It's been a tradition at JPL launches and landings ever since.
These are some of the other timeless traditions of the world's space-exploring elite.
On the day of their launch, many NASA astronauts eat scrambled eggs and steak, as a tribute to astronaut Alan Shepard, who ate this breakfast before his Mercury Freedom 7 flight in 1961.
Before a launch, the commander must play cards (supposedly either Blackjack or 5-card poker) with the tech crew until he loses a hand. The tradition's origins are a mystery, but it may have begun during the two-man Gemini missions.
The suit-up room, where astronauts must wait an hour while purging their bodies of nitrogen, contains the same recliner chairs as it did during the Apollo era.
After the shuttle orbiter was successfully transported from the Orbital Processing Facility to the Vehicle Assembly Building, the managers would provide the team with round donuts and bagels. It may have to do with the fact that these foods are round like the wheels of the shuttle transporter.
After a successful launch at Kennedy Space Center, the launch controllers enjoy a hearty meal of beans and cornbread. The tradition started when Former NASA Test Director Chief Norm Carlson brought in a small crock-pot of beans after the first space shuttle launch, STS-1.
Dating back at least to the Apollo missions, astronauts have awoken in space to music chosen by mission control, such as Dean Martin's "Going Back to Houston."
After a launch at Kennedy Space Center, it is customary for rookie launch directors, test directors and engineers to have their neckties cut (an aviation tradition following a pilot's first solo flight).
The Russian space program has its own strange space mission tradition.
Before leaving the Star City training complex near Moscow, Soyuz flight crews leave red carnations at the Memorial Wall in memory of first man in space, Yuri Gagarin, and four other cosmonauts. They visit Gagarin's office, sign his guestbook, and supposedly ask his ghost for permission to fly.
As the train that carries the Soyuz rocket booster approaches the Baikonur Cosmodrome, people place coins on the tracks to be flattened into good-luck charms.
The crew are forbidden to attend the rollout of the Soyuz rocket to the launchpad because it is said to be bad luck; instead, they must have a haircut on this day.
The night before launch, cosmonauts attend a mandatory screening of the 1969 cult movie "White Sun of the Desert."
On launch day, the cosmonauts have a champagne breakfast and autograph their hotel room door.
At the hotel, a Russian Orthodox priest blesses the Soyuz crew and sprinkles them with holy water. This is a post-Soviet tradition, started by cosmonaut Aleksandr Viktorenko, who requested a blessing before the Soyuz TM-20 crew's launch to Mir.
As the crew leaves the hotel, the Soviet-era rock song "The Grass Near My Home" is played by the band Zemlyane ("The Earthlings").he cosmonauts travel to the launchpad in buses outfitted with horseshoes for good luck.
On their way to the launch, Russian cosmonauts are known to urinate on the right rear wheel of their transfer bus, an act supposedly performed by Yuri Gagarin.
The Soyuz capsule carries a small talisman hung from a string, chosen by the crew commander, which signifies when weightlessness is achieved.