Over 15 years ago, Usain Bolt became the world’s fastest man , completing a 100-meter race in just 9.58 seconds . During that momentous achievement, the sprinter reached a maximum speed of 44 km/h using nothing but his own body. However, when it comes to human speed in a transportation medium , the record is much older and far more extraordinary. We’re not just talking about pilots zipping through the skies in a Bugatti Veyron or the Lockheed SR-71, but rather the astronauts of the Apollo 10 mission.
A record etched in stone. On May 26, 1969 , as they were returning to Earth from lunar orbit, astronauts Thomas Stafford , John Young , and Eugene Cernan achieved a record that still stands today. The spacecraft they traveled in, known as Charlie Brown Command Module , re-entered Earth’s atmosphere at a staggering speed of 39,937.7 km/h, equivalent to traveling from Madrid to Barcelona in less than a minute. For 56 years , no one has traveled that fast.
The rehearsal for the first lunar landing. To appreciate the feat of Apollo 10 , it’s essential to consider its context. The flight served as a dress rehearsal for the historic Apollo 11 mission. The crew approached within just 15 kilometers of the lunar surface, testing all systems of the lunar module and importantly, ensuring a safe return journey.
The incredible speed was not due to a more powerful engine but rather a carefully plotted trajectory . The path back to Earth was intentionally short, taking about 42 hours , as opposed to the usual 56 hours . This more direct descent, amplified by Earth’s gravitational force, sent the capsule and its crew hurtling toward Earth at unprecedented speeds during re-entry, described by Eugene Cernan as being in “a ball of white and violet flames .”
It has never been surpassed. Since that historic mission, no crewed mission has had the need—or the capability—to achieve such remarkable speed. The era of space shuttles and missions to the International Space Station (ISS) has unfolded at low Earth orbit velocities, around 28,000 km/h . Thus, the record set by Apollo 10 has remained unbroken, primarily because we haven’t returned to the Moon. However, this relic from the golden age of space exploration is poised for change.
The heirs to the record. The Artemis program , named after Apollo’s twin sister in Greek mythology, is NASA’s response to this prolonged absence. The first crewed mission, Artemis II , is scheduled for early 2026 , and the Orion spacecraft will set a new speed record as it travels around the Moon.
If all goes according to plan, astronauts Jeremy Hansen (from the Canadian Space Agency), Victor Glover , Reid Wiseman , and Christina Hammock Koch (from NASA) are expected to re-enter Earth’s atmosphere at 40,234 kilometers per hour , a figure that will marginally surpass Apollo 10’s record.
All eyes on the heat shield. To achieve such a record-speed re-entry and withstand the plasma and temperatures exceeding 2,760 ºC created by atmospheric friction, NASA has designed the Orion spacecraft with a specially thick and resilient thermal shield . However, during the unmanned Artemis I mission, this heat shield developed cracks during re-entry, causing several pieces to break off. To prevent this from happening again in Artemis II, the Orion will modify its re-entry profile, avoiding a rebound phase that can trap gases within the thermal shield material. Nonetheless, speed will be maintained, establishing a new record.
Image | Liam Yanulis (NASA)
As we continue to explore the cosmos and push the boundaries of our capabilities, the story of Apollo 10 serves not only as a testament to human ingenuity but also as a reminder of the exciting future that lies ahead. The Artemis program represents the next monumental leap in lunar exploration, equipped with the lessons learned from past experiences.