Scattered quietly across the Purdue campus stand a handful of trees that look no different from any of their neighbors. Yet each one carries an extraordinary secret in its rings: it began life not in an Indiana greenhouse, but in orbit around the Earth. Known affectionately as the \u201cspace trees\u201d or \u201cshuttle gums,\u201d these sweet gums and a lone sycamore grew from seeds that traveled aboard NASA\u2019s Space Shuttle, germinated in the weightlessness of low-Earth orbit, and were carried back home by two Purdue alumni who became astronauts. They are among the most remarkable\u2014and most overlooked\u2014specimens in the Arboretum\u2019s living collection.<\/p>\n<\/div>\n\n\n\n
The Space Trees at a Glance<\/strong><\/p>\n\n\n\n Most of Purdue\u2019s space trees are sweet gums, and they trace back to 1984 and to Purdue alumnus Charles Walker<\/strong>, a 1971 graduate. In August of that year, Walker flew aboard STS-41-D<\/strong>\u2014the very first mission for both Walker himself and for the brand-new Space Shuttle Discovery<\/em>. During the flight, the crew germinated 200 sweet gum tree seeds<\/strong> in orbit.<\/p>\n\n\n\n The young trees spent five years at an arboretum in St. Louis before Walker donated several of them to Purdue in 1992. Purdue\u2019s Grounds staff, who nurtured the seedlings in the University nursery, dubbed them \u201cthe shuttlegums\u201d\u2014and once the trees were large enough to survive outdoors, they transplanted them into generally inconspicuous spots around campus. To the everyday passerby they look like ordinary sweet gums, which is precisely what makes them such a delightful discovery. As Purdue arborist Tim Detzner put it, Walker \u201cthought it would be an interesting contribution for Purdue to have.\u201d<\/p>\n\n\n\n The last of the donated shuttlegums to find a home on campus was transplanted into Pickett Park on October 12, 1999<\/strong>, as part of a park renovation given by the Purdue Class of 1999. A plaque at its base dedicates it as a living memorial to Purdue\u2019s aerospace tradition.<\/p>\n<\/div>\n<\/div>\n<\/div>\n\n\n\n The Shuttle Gum Plaque at Pickett Park<\/strong> Four years after Walker\u2019s flight, a second Purdue astronaut added a single, special tree to the collection. Jerry Ross<\/strong>\u2014who earned his bachelor\u2019s degree in mechanical engineering from Purdue in 1970 and his master\u2019s in 1972\u2014flew as Mission Specialist 2 aboard the Space Shuttle Atlantis<\/em> on STS-27<\/strong>, a four-day mission that ran from December 2\u20136, 1988<\/strong>. On that flight Ross carried seed packets of sycamores, sweet gums, and tulip poplars to be germinated in space, as part of a project to give back to Indiana\u2019s 4-H community. From those seeds grew the tree now celebrated as Purdue\u2019s \u201cSpace Sycamore.\u201d<\/p>\n\n\n\n When Ross returned to Earth, Purdue forestry professor Walter Beineke grew the sycamore seed into a seedling in the university\u2019s greenhouses. After about a year and a half, the young tree was ready, and in the spring of 1990 it was planted on the south side of the Lilly Hall of Life Sciences<\/strong> to mark an anniversary of Purdue Extension. Ross went on to a legendary career: he shares the record for the most launches into orbit with seven Space Shuttle missions, performed nine spacewalks, retired in 2012, earned 15 NASA medals, and was inducted into the Astronaut Hall of Fame in 2014.<\/p>\n<\/div>\n<\/div>\n<\/div>\n\n\n\n The Space Sycamore Planted at Lilly Hall<\/strong> This tree was grown in the Department of Forestry from a seed which orbited the Earth on the United States Space Shuttle Atlantis STS 27 from December 2\u20136, 1988, as part of a 4-H project.<\/em><\/p>\n\n\n\n It is planted in honor of the 1989 Diamond Anniversary of Extension Service to the people of Indiana by the Purdue University School of Agriculture and the Department of Botany & Plant Pathology.<\/em><\/p>\n\n\n\n Planted April 19, 1990<\/em><\/strong><\/p>\n<\/div> Charles Walker<\/a><\/strong> \u2014 Purdue Class of 1971. Flew on STS-41-D (August 1984), the maiden voyage of Shuttle Discovery<\/em>; his crew germinated 200 sweet gum seeds, several of which became Purdue\u2019s shuttlegums. The space trees are spread across campus in unassuming locations. Most have a small plaque at their base explaining their history and significance, but otherwise look no different from the surrounding trees. <\/p>\n\n\n\r\n
The Shuttlegums: Charles Walker and Shuttle Discovery<\/em><\/h2>\n\n\n
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\u201cThis Sweetgum tree is dedicated as a living memorial to Purdue University\u2019s aerospace tradition. It is one of several Sweetgum trees that originated as seeds shuttled into space by 1971 Purdue graduate Astronaut Charles Walker in August, 1984. Located at the St. Louis arboretum for five years, it was donated to the university in 1992 along with several others. The Sweetgums were dubbed \u2018The Shuttlegums\u2019 by Purdue Grounds staff who nurtured the trees in the University nursery before transplanting them. Transplanted here on October 12, 1999 as part of the renovation of Pickett Park, a gift from the class of 1999. It is the last of the donated \u2018Shuttlegums\u2019 to be planted on campus.\u201d<\/em><\/p>\n<\/div><\/div>\n<\/div>\n<\/div>\n<\/div>\n\n\n\nThe Sycamore: Jerry Ross and Shuttle Atlantis<\/em><\/h2>\n\n\n
– Sycamore tree –<\/em><\/strong><\/p>\n\n\n\n![\"\"](\"https:\/\/www.arboretum.purdue.edu\/wp-content\/uploads\/2026\/07\/space_sycamore-1024x805.jpg\")
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Jerry Ross<\/a><\/strong> \u2014 Purdue Class of 1970 (B.S.) and 1972 (M.S.), mechanical engineering. Seven shuttle flights, nine spacewalks, Astronaut Hall of Fame (2014). Carried sycamore, sweet gum, and tulip poplar seeds on STS-27 (1988).<\/p>\n<\/div>\n<\/div>\n<\/div>\n\n\n\nFinding the Space Trees on Campus<\/h2>\n\n\n\n