The teacher spoke with PEOPLE 40 years ago, where she shared her excitement about the space voyage.

Forty years ago today, on August 5, 1985, Christa McAuliffe, 36, was exhausted from making the publicity rounds.

The New Hampshire-based high school teacher had become an overnight sensation after being chosen as the first “average citizen” to go to space — a contest held by NASA to encourage people to get excited about the space program again.

She’d been picked out of 11,000 applicants, 114 finalists, and 10 semifinalists, all of whom were teachers, and was being whisked from event to event, including a White House meeting with then-President George Bush, alongside the other semifinalists. PEOPLE was along for the ride.

“When I go on the shuttle, there will be one body, but I’ll be taking 10 souls with me,” she told her fellow finalists, almost apologetic that she’d won the coveted spot.

“I don’t know [why they chose me],” she said. “I thought they’d have to put everyone’s name in a hat to pick a winner. I’m still floating. I don’t know when I’ll come down to Earth.”

At the time, she wasn’t at all worried about the upcoming flight, which would take place on January 28, aboard the Challenger space shuttle.

“I really see the shuttle as a safe program,” she told reporters during her press day, also noting that she was eager to wrap up her promotional duties and get back home to her high school sweetheart husband Steven, and their kids Scott, 9, and Caroline, 6.

Her plans for the voyage were mostly educational, unsurprising considering she’d studied history and taught a popular law and economics class at her Concord High School.

“I want to give an ordinary person’s view of space, the idea that there’s a new way of living out there,” McAuliffe said of her plans. “I mean, there’s going to be space law, there’s going to be business in space, and students have to prepare for that future.”

She also planned to teach a class from space about what it was really like up there.

“When I talk to my students, I liken what I’m going to do to the women who pioneered the West in Conestoga wagons,” she said. “They didn’t have a camera; they described things in vivid detail, in word pictures. They were concerned with daily tasks and the interaction between people, with hopes and fears. Those diaries and journals are the richest part of the history of our westward expansion — without them, it would just be how many Indians were killed and the number of settlements started.”

She continued, “I’ll be able to take the time to report on feelings and emotions; how it is to live in a close environment with people you don’t really know; housekeeping; weightlessness. A lot of things you kind of wondered how they did them up there. Eating! Kids may not relate to satellites, but they can relate to breakfast, lunch and dinner,” she said.

The night before the shuttle was to blast off from Cape Canaveral, Fla., McAuliffe’s mother, Grace Corrigna, then 75, later told PEOPLE that her daughter was so excited about the excursion. “She was on a high,” Corrigan said. “She didn’t talk about the risks.”

The following morning, the shuttle lifted off at 11:39 a.m. 73 seconds into the flight, it broke apart midair, killing all seven onboard — a disaster that was aired live on TV and shook the nation to its core.

Along with McAuliffe, the explosion also claimed shuttle commander Francis Scobee, 46, pilot Michael Smith, 40, and astronauts Judith Resnik, 36, Ronald McNair, 35, Ellison Onizuka, 39, and Gregory Jarvis, 41.

The family McAuliffe left behind each grieved in their own way. Her mother, Grace, refused to succumb to depression, instead traveling the country telling people about her brave daughter. “People like to be able to know about her,” she said. “She touched so many lives.”

McAuliffe’s father, Ed, who died in 1990, was “very angry at NASA,” Grace said. (NASA and manufacturer Morton Thiokol eventually settled with four affected families for $7.7 million.)

Her husband, Steve, later remarried and became a federal judge. Her children, Caroline and Scott, followed in her footsteps and became teachers. Next January will mark the 40th year since the disaster, but on the 30th anniversary, Steven McAuliffe released a statement saying the disaster felt as fresh as though it were yesterday.

Still, according to McAuliffe herself, there was no way she wasn’t going to embrace the opportunity:

“You know,” she said. “people come up to me and say, ‘I really admire you, but I wouldn’t want to do it.’ I can’t understand that. If you had a chance, wouldn’t you want to do it?”