THIS DAY IN SPACE

Apollo 17 Moon Landing
On December 11, 1972, NASA's Apollo 17 mission successfully landed on the Moon, marking the sixth and final time humans have walked on its surface. Astronauts Eugene Cernan and Harrison Schmitt descended in the lunar module Challenger to the Taurus–Littrow valley, while Ronald Evans remained in orbit aboard the command module America. This mission was historically significant for several reasons: it was the only Apollo mission to include a professional geologist—Schmitt—on the lunar surface, enabling detailed geological exploration and sample collection. The astronauts spent over 22 hours conducting extravehicular activities (EVAs), collecting 110.5 kg of lunar samples and deploying scientific instruments, including a gravimeter and seismic explosives to measure subsurface structures. The Lunar Roving Vehicle was used to cover greater distances, and the mission captured some of the most iconic images of the Moon. Apollo 17 also brought back important data on the Moon’s composition and helped refine theories about its volcanic history. Cernan famously left the last human bootprint on the Moon, stating, 'We leave as we came, and, God willing, as we shall return, with peace and hope for all mankind.'

STS-88: First ISS Assembly Mission
On December 11, 1998, the Space Shuttle Endeavour’s STS-88 mission played a historic role in human space exploration by completing the first major assembly step of the International Space Station (ISS). The crew successfully connected the U.S.-built Unity module to Russia’s Zarya module, forming the ISS's initial backbone. Astronauts performed three spacewalks to make the physical and electrical connections, marking a major milestone in international space cooperation. Unity, the first U.S.-built module of the ISS, provided docking ports and internal access that would later support future modules and visiting spacecraft. STS-88 was crucial in demonstrating the feasibility of orbital construction, a key component for building a large, permanently inhabited platform in space. The mission also tested new tools and procedures for on-orbit assembly. Over time, the ISS would grow into the largest and most ambitious space laboratory ever constructed, but this mission marked the first successful physical union of its components. It also highlighted the increasing collaboration between former Cold War rivals, the United States and Russia, in space. The mission’s legacy lies in how it helped lay the foundation for over two decades of continuous human presence aboard the ISS, advancing science, diplomacy, and engineering in space.