NASA’s latest exploration spacecraft launched over the weekend, beginning a 12-year journey to visit Jupiter’s Trojan asteroids.

A tool familiar to Wall Street was used to craft the mission’s intricate path: Microsoft Excel.

The Lucy spacecraft, which Lockheed Martin built and United Launch Alliance’s Atlas V rocket launched for NASA on Saturday, is expected to travel 4 billion miles through space to fly by and study eight asteroids.

Years before Lucy took off, Lockheed Martin mission architect Brian Sutter used Excel to chart the mission’s path and choose which of the about 5,000 Trojan asteroids the spacecraft should visit.

“Part of the science of this mission was to try to look at as many of these Trojans as we can in a single mission,” Sutter told CNBC.

While Lockheed Martin has a “high fidelity” tool to run individual trajectories, Sutter said that would have taken “forever.” He instead turned to an Excel macro, which is “perfectly suited for sorting through large quantities of data.”

“I had already found a trajectory that connected two of the asteroids to a trajectory that also connected to Earth,” Sutter said.

Orbit propagation – or modeling the future location of objects in space – “is what I do,” Sutter explained. While his macro consists of “different equations than you’d normally put into Excel,” he emphasized that “at the end of the day it’s all math.”

Sutter took a broad list of 750,000 asteroids and entered them into Excel to “see if they ever accidentally kind of come close to each other.”

“I think this thing took about 12 hours to cycle through all 750,000 of them,” Sutter said. After he ran the macro, he had “a little list of 10 to 20 asteroids that the spacecraft was going to be flying close to.”

His use of Excel to help chart Lucy’s trajectory became famous within Lockheed Martin. He recalled that a colleague once described to others that Sutter “built the most ridiculously complicated Excel spreadsheet I’ve ever seen in my life.”

The Lucy mission, which has a total cost of $981 million, is expected to visit its first asteroid in 2024. Further flybys are set to take place until 2033.

While the launch was successful and the spacecraft is stable, NASA said on Sunday that one of the spacecraft’s two solar arrays “may not be fully latched.”

“Lucy can continue to operate with no threat to its health and safety,” NASA said. “The team is analyzing spacecraft data to understand the situation and determine next steps to achieve full deployment of the solar array.”