Iain Clark is a teenager now. He was eight years old when his mother, Dr Laurel Clark, and six other astronauts died when the space shuttle Columbia fell apart in the skies over Texas 10 years ago today.
Iain's father, Dr. Jonathon Clark, told ABC News recently that he and Iain will never really recover.
"There will always be a sense of loss and pain and hurt," said Clark. "I've lost a lot, but I've gained a lot, too. I have a perspective and reverence for life. I have my son, and seeing him through this has been very rewarding -- though it has been difficult, as well."
Feb. 1, the anniversary of the Columbia accident, is the day NASA chooses to remember all the astronauts who have died during missions.
Spaceflight is a risky business. Some of the accidents are well known. Others, not really. But they all illustrate just how dangerous it is to leave our planet and venture into orbit.
Three accidents, in particular, are seared in our memories because NASA's missions have been so dramatic, and so public.
First, there was the fire on Jan. 27, 1967, which killed Apollo 1's crew of Command Pilot "Gus" Grissom, Senior Pilot Ed White and Pilot Roger Chaffee. At the time, NASA was racing to beat the Soviet Union to the moon.
Second was the space shuttle Challenger's accident on Jan. 28, 1986, which was seen live by children across the country because its crew included the first teacher in space, Christa McAuliffe.
Finally, Columbia's accident, on a clear, sunny Saturday, Feb. 1, 2003, as it re-entered from space after a seemingly routine science mission, stunned the country. It also meant the end of NASA's space shuttle program.
This morning at 9:16 a.m. ET, the time Columbia would have landed at the Kennedy Space Center in 2003, there will be a minute of silence. A bell will toll seven times at the Johnson Space Center for the seven astronauts who died on Columbia's final mission, STS 107: Commander Rick Husband, Pilot Willie McCool, Mission Specialists Michael Anderson, David Brown, Laurel Clark, Kalpana Chawla and Ilan Ramon.
It took months for the commission investigating the accident to determine the cause: foam. A piece the size of a briefcase broke off one of the shuttle's external fuel tanks, punching a hole in the orbiter's left wing.
The crew of seven knew something was wrong very late during re-entry, but there wasn't anything they or mission control could do to save them or Columbia. It took managers at the Johnson Space Center months to accept that something so simple as a piece of foam could do so much damage.
Wayne Hale, who guided NASA's space shuttle program back from the accident, was the only NASA employee who publicly accepted responsibility for Columbia's accident.
Hale now works in the private sector, but recently wrote in a blog about the internal discussion at mission control while engineers discussed what they thought might be a problem -- but weren't sure.
"After one of the MMTs [mission management teams] when possible damage to the orbiter was discussed," Hale wrote, "[Flight Director Jon Harpold] gave me his opinion: 'You know, there is nothing we can do about damage to the TPS [thermal protection system]. If it has been damaged it's probably better not to know. I think the crew would rather not know. Don't you think it would be better for them to have a happy successful flight and die unexpectedly during entry than to stay on orbit, knowing that there was nothing to be done, until the air ran out?'
"I was hard pressed to disagree. That mindset was widespread. Astronauts agreed. So don't blame an individual; look for the organizational factors that led to that kind of a mindset. Don't let them in your organization.
"After the accident," he added, "when we were reconstituting the mission management team, my words to them were, 'We are never ever going to say that there is nothing we can do.' That is hindsight."
Twelve children lost a parent on Columbia.
Husband's daughter is a seminary student. Before his final mission he recorded Bible verses on videotape to be played back to his children while he was in space.
Israeli astronaut Ramon, a hero in his country, had a son who followed him as a fighter pilot, and who later died in a plane crash.
Iain Clark has become a young man his late mother would be proud to claim. He inherited many of her skills, is a master scuba diver and will soon be going to college.
His father, a former NASA flight surgeon, crusades for research to keep future astronauts safer on missions.
Astronauts now hunger to go to Mars, but a three-year round trip is not just a logistical and engineering challenge, it's life-threatening. There is no quick rescue.