The July 1971 Apollo 15 mission was the fourth mission to put human beings on the moon. This mission marked the revolutionary debut of the lunar roving vehicle (also known as a “moon buggy”), a four-wheeled, open-air vehicle designed to function with the moon's gravitational pull, thus enabling astronauts to observe a wider range of the lunar surface in a single visit. One aim of the trip was to take more photographs than prior visits, so the crew of this mission traveled with a huge variety of cameras to capture scenes during every part of the journey.
The Apollo 16 mission lasted just over 11 days, beginning on April 16, 1972, and carrying the three-person crew of John Young, Thomas "Ken" Mattingly, and Charles Duke. Young and Duke were the two who set foot on the moon's surface, and they spent over 20 hours there collecting, in an amazing feat, over 200 pounds of lunar samples. Duke also made history by leaving something a behind: a family photo with the message, "This is the family of astronaut Charlie Duke from planet Earth who landed on the moon on April 20, 1972," written on the back.
Apollo 17—which launched on Dec. 7, 1972—marked the last time humans set foot on the moon. However, the legacy of this mission is still very much alive. NASA recently announced it would open a collection of lunar rocks, which have never been studied in full, from Apollo missions 15, 16, and 17. (The latter mission alone brought back 250 pounds of rocks). These samples were preserved for a time when more advanced technology could delve deeply into the clues they may hold, and it's finally time to dig in.
The journey of Pioneer 10, a space probe that launched from Cape Canaveral on March 2, 1972, was filled with firsts. At the time, NASA was gearing up to take advantage of a rare alignment in the solar system that would allow for a “Planetary Grand Tour”—meaning a group of spacecrafts could visit multiple planets in one trip. To prepare for this journey, Pioneer 10 was sent on a data-gathering mission, and became both the first spacecraft to reach Jupiter, and the first to leave the inner solar system.
Pioneer 11 served as a companion probe to Pioneer 10 and was launched into space in 1973. Pioneer 11's journey marked another important first for NASA: this probe was the first to encounter Saturn, and it was also able to send back amazing images of Jupiter's polar regions. The spacecraft experienced a few technical setbacks and failures on its outbound journey, but overcame them and made such discoveries as an additional ring around Saturn. The last contact with this spacecraft occurred in late 1995.
The central goal of NASA's 1970s Viking missions was to gather images of, and data pertaining to, Mars, as knowledge of the planet was slim. The Viking project proved a huge success, producing some 50,000 images of Mars and disproving the theory that the Martian sky was blue, similar to that of Earth. (In reality, it's pinkish during daytime.) Viking landers could also touch down and analyze Martian soil and atmosphere, a huge stepping stone in scientific understanding of this planet.
The space probe Voyager 2 was sent into space in 1977, and in late 2018 it exited the heliosphere—the region of space that surrounds the sun and is impacted by its magnetic field—and officially went interstellar. In the decades preceding this monumental moment, Voyager 2 encountered and photographed Jupiter, Neptune, Uranus, and Saturn; it is the only probe to face the latter two planets. Voyager 1 went interstellar in 2012, and now both probes are on a mission to send back information about what lies beyond the solar system, though they are still many thousands of years from reaching the stars for which they have set course.
Skylab, NASA's first space station, was made out of a component of a Saturn V rocket during a time of NASA budget constraints. It launched unmanned in May 1973. The goal was to test the viability, for the first time, of a space station a crew could inhabit for extended periods to conduct scientific research; in fact, several crews (one of which included Charles Conrad, a member of Apollo 12) visited and occupied the station during its time in space. Skylab's return to Earth became an international media spectacle, as NASA could not pinpoint the exact moment when or location where the craft would crash back through the atmosphere.
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NASA's Space Shuttle Program—in effect from 1981 to 2011—marked a huge scientific stride in creating the first effectively reusable spacecraft. The program created a fleet of five spacecrafts during its three-decade run, and before Space Shuttle Challenger's tragic end, it carried Sally Ride, the first U.S. woman in space. Space Shuttle Discovery successfully shuttled 184 men and women to space and back and spent 365 days in space before it was retired in 2011.
For much of the Cold War, the United States and the former Soviet Union used space to compete against one another, but the Shuttle-Mir program noted a great shift in this dynamic. The program was a U.S.-Russia collaboration, comprising U.S. shuttles and astronauts visiting the Russian space station, Mir. When the U.S. space shuttle Atlantis docked at Mir in 1995, history was made in more ways than one: The U.S. and Russian spacecrafts together formed the biggest man-made satellite, and the trip itself made up this country's 100th human space mission.2018 All rights reserved.