HOUSTON – Bridget Ziegelaar Johnson’s mission is on hold.

The 28-year-old graduate of Old Town High School and the University of Maine works for NASA as a project manager for extravehicular activities – also known as spacewalks. Johnson is in charge of spacewalks for the Atlantis, the next scheduled space shuttle mission.

Atlantis originally was set for launch on March 1. NASA delayed the mission indefinitely Saturday after the space shuttle Columbia broke up into flames on its way to landing, killing all seven astronauts.

Reached at her Houston home Saturday afternoon, Johnson said she’d been told to refer all questions from the media to the press office at the Johnson Space Center. A spokesman there said Sunday afternoon that all space shuttle launches had been suspended.

Planned spacewalk activities Johnson was to oversee for the Atlantis mission include the installation of a storage platform for spare parts, replacement of equipment for two science experiments that gauge space’s impact on various materials, replacement of one of the gyros that controls the station’s “attitude,” and the installation of a camera and a scientific instrument.

Johnson, the daughter of Bob Ziegelaar, the former manager of Bangor International Airport, and Barbara Hampel of Old Town, was honored in November by the University of Maine’s Alumni Association with the group’s second Spirit of Maine Achievement Award. The honor is given to an accomplished UM graduate from the past 15 years.

While in Maine to receive that honor, Johnson talked about how space shuttle flights had become a routine occurrence for the American public.

“Missions have become more routine, and people forget that spaceflight is still risky,” she said. “People seem surprised by problems. We know there are going to be problems. That’s why we have teams of people in place to work on them when they happen.”

She also talked about the need for continued funding of space exploration.

“It’s really an investment in the future,” Johnson said. “NASA gets less than 1 percent of the national budget. The potential rewards far outweigh the actual cash invested. You never know what scientific discoveries might occur. There are benefits in terms of research and technology, as well as inspiring kids like myself to go on and study engineering.”

An Old Town native, Johnson graduated from UM in 1996 with a bachelor’s degree in mechanical engineering and a 3.9 GPA. She earned a master’s degree in science, technology and public policy with a concentration in economics from The George Washington University. As part of a fellowship with that school’s Space Policy Institute, she interned at the National Aeronautics and Space Administration headquarters in Washington as a research associate.