I have an old children’s book about space. Published in 1960, it concluded on a hopeful note: “Perhaps one day mankind shall reach the moon.”

Who thought that the next spring would see Yuri Gagarin and Alan Shepard shooting into space? Or upon Shepard’s return, President Kennedy’s proclamation that it was America’s destiny to land on the moon before the decade’s end? Or, that in 1969 Neil Armstrong would indeed take that giant step for humankind?

Those were heady days. They were, despite war abroad and unrest at home, hopeful days. Millions of children saw the landing and dreamed of becoming astronauts.

This week, we remember seven who achieved that dream.

I grew up in a different time. The Apollo program was over. Skylab had fallen into the ocean. A new model for space flight was born. The first space shuttle was named Enterprise, after a fictional starship that explored uncharted galaxies.

I wanted to be an astronomer then. Which planet was the smallest? Which star was the brightest? Which planet had the most moons? Did other stars have planets, too? How many light-years was it from Earth to Alpha Centauri? How far is a light-year, anyway? Did intelligent life exist elsewhere in the universe?

The search for answers to those questions filled countless hours during my childhood. Could other planets besides Earth support human life? The more I learned, the more the answer seemed to be “No.”

Other solar systems? At 25,000 miles per hour, our fastest spacecraft would reach the nearest star in about 115,000 years. The odds against reaching another solar system are, well, astronomical. But astronomers discovered in early 1980s that many nearby stars were orbited by solid objects.

Then Challenger exploded.

For much of our generation, it was a shared memory like the Kennedy assassination. They were the first Americans lost in space. With Columbia’s tragedy, we wonder if the shuttle is safe at all.

Yet in the darkest days after Challenger, science continued to shed light on our quest for answers. Physicist Richard Feynman, appointed to the committee investigating the explosion, identified the problem on his own. The night before the launch was so cold that ice had built around the rocket boosters, including the rubber O-Rings meant to seal the two massive rockets. Feynman demonstrated how rubber loses all resilience by dropping a piece into a glass of ice water.

NASA said the chance of shuttle failure was one in 100,000. Feynman determined that failure would occur one in every 100 launches. The last Columbia flight was the 113th shuttle launch.

In tragedy’s shadow, we should not forget the successes of the Hubble Space Telescope, Galileo and the Mars Global Surveyor. Unmanned spacecraft have given us incalculable knowledge of our solar system and beyond. They, rather than astronauts, have answered my childhood questions about Mars, moons and stars.

Columbia carried the first scientific payload in two years. Besides tests on human bone, muscle and immune cells in microgravity, the shuttle also housed earthworms, harvester ants and Australian spiders. The creatures carried the experiments of high school students who had won the opportunity to conduct experiments in space.

They are our newest generation of space scientists.

Philip Huang is a student at the University of Oregon.