Signs on doors announce the NASA sanctums, from "Ascent/Descent Dynamics" to "Rendezvous Guidance and Procedure." On the one leading to "Trajectory Operations and Planning" is the name of Jarmaine Ollivierre.

The talk inside is of vector propagation - predicting with pinpoint accuracy where the International Space Station will be in the next minute, the next day, the next week as it rounds Earth at five miles per second in a meteor speedway 210 miles up.

Anticipating the precise course so it can be tweaked to avert a big bang isn't easy, Ollivierre said. "You could be chasing that all day."

Every few months, and occasionally as often as three times a month, he pulls a seven-day shift in the room that kept him riveted to the TV when he was a kid, Mission Control. In front of him are the iconic computer superscreens. A few seats away is Kwatsi Alibaruho, the first African American to lead Mission Control as flight director of the space station.

For a young aerospace engineer, it's heaven.

Ollivierre, 31, is one of Say Yes to Education's stellar successes: a former special education student at Belmont Elementary with a payload of degrees. A bachelor's in aeronautical engineering and another in physics from Tuskegee University. A master's in technical management from Embry-Riddle Aeronautical University. What's missing is a doctorate, although he could well need one if he hopes to go into space. And he does.

Without George Weiss, who saw him through five years at Tuskegee, "the road would have been a lot harder and the probability of me sitting here a lot less," he said. "And not just from a financial standpoint. What he really gave us was hope."

Soft-spoken, self-effacing, Ollivierre dismisses the suggestion that he is at the head of the Belmont class, protesting that "I'm not the measuring stick of success in any way, form or fashion. . . . I think success depends on what you want to do."

A single mother raising three children to be good citizens, he asserts, is a success. Like his own mother.

Ollivierre grew up fatherless, but with something that few of his Say Yes peers had - a stable home in which education was paramount. That was the doing of the indomitable Patricia Ollivierre.

Jarmaine's older brother, Michael, had been born with water on the brain, but despite his disability, she fought to get him the services he needed in public school. (He graduated from high school at age 21.) She became so familiar with the Philadelphia district's special-education system that when her younger son showed the restless signs of hyperactivity, she sought a placement for him as well.

Pat never doubted that Jarmaine was bright. What he needed, she said, was help "to get all that intellect out."

At her insistence, he was evaluated, and grouped among children with social or emotional issues. The district transferred him from Rhoads Elementary to a school that took in many special-ed students from throughout West Philadelphia - Belmont Elementary. There turned out to be 44 of them in the class of 112 sixth graders that Weiss adopted.

By deciding not to cut them from his offer of free college tuition, he launched Jarmaine toward a dream already fueled by Star Trek and shuttle launches.

Whether on the flight deck of the Enterprise or the Challenger, "they were heroes and contributed to making the world better," Ollivierre said. "That's what I wanted to do."

While Pat Ollivierre worked for an insurance company, some of the constant care Michael required fell to Jarmaine, his sister, Marian, and his grandmother, also an indefatigable woman who raised six children of her own.

Those duties cut into Jarmaine's study time, yet he squeezed out high grades at Bartram Human Services High School.

Say Yes connected him with a mentor from Boeing and lined up summer jobs at the aerospace company's Delaware County plant. He was sent to a prestigious science program at Penn for high school students and to Community College of Philadelphia for calculus courses. When it became clear he was among the Belmont college-bound, he got SAT tutoring.

At Tuskegee, he decided to take on a second major, which would mean an extra year of not only his time but also Weiss' money. Ollivierre went to his benefactor with a list of pros and cons. Without looking at it, Weiss told him, "Go for it."

Fittingly, Ollivierre graduated on Mother's Day 1998.

After two years with the missile manufacturer Morton Thiokol in Utah, he went to work for United Space Alliance, a NASA contractor supplying mission support staff to the Johnson Space Center.

Suddenly, Ollivierre was where he had always wanted to be. Or, almost.

His bosses have suggested a potential career path that would keep him earthbound, as a flight director for the shuttle or space station. But when he sits in Mission Control watching cosmonauts and astronauts freed from gravity's shackles, he longs to be there, too. Ideally, he says, he would go as a technician, even if on a quick trip to make fixes.

"I just want to make a contribution to space exploration," Ollivierre said.

Yet he risked it all last year without a second thought. When his sister Marian's kidneys failed, he donated one of his, on Valentine's Day 2006.

"She sacrificed for us when we were growing up," he explained. "I figured I would do the same."

Ollivierre already has a stake in the next starry-eyed generation: a 10-year-old daughter, Gina, in North Carolina with her mother, and a 6-year-old, Nadirah, who lives in the Houston suburbs with her mother, from whom he is divorced.

On the day a reporter visited, his BlackBerry delivered the news that the little one had just won five awards at her school.

Asked what he wanted for his girls, he didn't hesitate:

"Perfection."