When NASA’s STS-127 mission launches from Cape Canaveral Saturday on the shuttle Endeavor, one Mainer will be onboard and another will be at Ground Control in Houston.

Old Town High School and University of Maine graduate Bridget Ziegelaar is in charge of spacewalks for the mission.

York native and mission specialist Christopher Cassidy will be on the shuttle. He is scheduled to perform the final three of the five scheduled 6½-hour spacewalks.

This will be Cassidy’s first trip to outer space.

During the first two walks, Cassidy will act as a liaison between Ground Control and the astronauts outside the space station, a job that is just as important as the actual spacewalk, according to Jennifer Therrien of the Challenger Learning Center in Bangor.

“It’s something that I don’t think people give much thought to,” Therrien said. “He’s the go-between for those first two [spacewalks].”

According to Therrien, Cassidy is only the second Maine astronaut to spacewalk.

“The other astronaut that we sort of claim is Charlie Hobaugh,” Therrien said.

Hobaugh, a Bar Harbor native, was recently assigned to his third mission, STS-129, she said.

Bridget’s father, Bob Ziegelaar — president of the Telford Group in Bangor and former manager of Bangor International Airport — said that his daughter has wanted to be an astronaut ever since she was a child.

“She first got interested in the space industry by going to the space camp as a 12- or 13-year-old,” he said.

“The first year that she went to college, she studied economics,” he said. “She decided after her first year to study something a little more hands-on.

“She’s never looked back,” he added.

STS-127’s mission is to carry the final components of the Japan Aerospace Exploration Agency’s Kibo laboratory to the international space station. The mission will last 16 days and include five spacewalks.

This is the final of three missions to build the Kibo laboratory.

The crew will install two platforms outside the Japanese module. One is a permanent addition to the space station, and will serve as a test area for experiments requiring direct exposure to space. The other is a detachable storage pallet that will return with the shuttle.