In Palo Alto's Peers Park stand redwood trees that as infants traveled farther than many people do in their lifetimes.

On July 29, 1985, space shuttle Challenger astronaut Loren Acton carried a package of redwood seeds from Palo Alto's eponymous tree, El Palo Alto, into space as a goodwill gesture for his hometown. Circling the earth for seven days, 22 hours, 45 minutes and 26 seconds at speeds up to 17,500 miles per hour, the seeds made 126 orbits, traveling 2,868,514 miles.

Not bad for the oldest living species on the planet. At the time, El Palo Alto itself was already more than 1,000 years old.

Little did Acton know at the time, but his gesture would take on added significance just six months later when the Challenger crew perished in a disastrous explosion after launch. In 1987, 20 of the space-shuttle saplings were planted in a grove at Peers Park on Park Boulevard in remembrance of the Challenger astronauts. Now, 30 years later, the grove of the surviving 10 trees towers above a slate commemorative plaque.

The rest of the 125 saplings were given away, planted in home yards throughout Palo Alto. No one has tracked how many still live, City Arborist Dave Dockter said.

Some have assumed places of stature in their neighborhoods. One tree in the 600 block of Matadero Avenue has reached a majestic height -- 60 to 80 feet -- dwarfing nearby 40-foot utility poles.

Homeowner Christine Stafford said she acquired the sapling after her sister, who was visiting from Boston, read about Palo Alto's giveaway of the special plants on Arbor Day 1987. Her sister and Stafford's then-12-year-old son, Jeremy, went to pick up the sapling, which was grown by the Saratoga Horticultural Society.

Space flight doesn't seem to have altered the tree's genetics in any way, Stafford said, adding that "it grew really fast." She did not attribute its vigor to space travel, however.

Admiring the dark green, luxuriant fronds and deep russet bark, she said the tree thrived on its own because it received healthy doses of an earthly element: water. The tree showed signs of stress in the fourth year of the Bay Area's drought, so she chose to keep watering it rather than to have it decline.

Stafford has her own history with redwoods. When she was 13, her mother sent her father to purchase eucalyptus trees for their home, which is located around the corner from where she now lives. He came home with several redwoods after a nurseryman talked him into buying the trees. Those specimens are now robust 56-year-olds. She's always had an appreciation for redwoods and for trees in general.

"We were a camping family," she said, and they always stayed in forests and other places that cultivated her appreciation for redwood groves.

Stafford's tree's journey from space to her backyard happened because of Acton, who lived in Palo Alto for 29 years while working at Lockheed Palo Alto Research Lab. Acton was a payload specialist and solar astronomer who was in charge of optical scientific instruments and telescopes used for observing the sun.

"One of the telescopes on board was made right there in Lockheed Palo Alto Research Lab," Acton, an affable man, said by phone from his Montana home.

The flight's primary payload was Spacelab-2, according to NASA.

Acton was originally selected for space flight in 1978 but didn't go up in orbit until 1985. He said crew members were typically permitted to take small items on board to give away after the orbits. He thought it would be nice to take something up from Palo Alto. A city official came up with the idea of taking the El Palo Alto seeds.

"They were returned to the city in a ceremony, and the Parks Department gave away the seedlings," he recalled.

Reflecting on his journey into space, Acton said, "The most amazing thing was being part of this human effort, to be a player of this biggest adventure of our time."

But glimpsing the earth through the space shuttle's windows also opened his eyes to the planet's vulnerability.

"To be able to see the earth as a whole and see how very, very thin our layer of breathable atmosphere is has caused me to appreciate the fragility of our atmosphere. It shows up as a lovely blue layer that is paper thin. When you're down on the earth you look up and you think that it goes on forever," he said.