The Space Shuttle Program - In 1972, NASA embarked on the Space Shuttle Program, which would go on to run until 2011. In the 30-year period between 1981 and 2011, it carried over 300 astronauts into low-Earth orbit.
Apollo 11 - Russia may have been the first to put a human in space, beyond the Karman line, but NASA was the first to put humans on the moon, winning the space race.
Cassini - The Cassini mission, launched jointly by NASA, the ESA, and the ASI to study Saturn in 1997, is coming to an end in 2017.
Juno - The probe arrived in orbit on July 4, 2016, and is scheduled to complete a number of close flybys of the planet, collecting more data on our solar system's biggest planet and its moons than we've ever had before.
New Horizons - The New Horizons probe spent nine years in transit, finally intersecting with the dwarf planet's orbit in July 2015, providing us with a wealth of data that will keep researchers learning more for years.
Hubble Space Telescope - The Hubble Space Telescope has blessed us with spectacular, unprecedented images of the wonders of space since 1990 from its position in low Earth orbit. This image shows Westerlund 2, released in 2015 for Hubble's 25th birthday.
Voyager - It may have taken nine years to reach Pluto, but the Voyager mission is even more ambitious, traveling beyond the solar system carrying information about humanity and tools to collect data as it goes.
The Kepler mission - Kepler is a spacecraft launched in March 2009, orbiting the sun while scanning the skies, searching for exoplanets (planets outside the solar system) that could host life as we know it.
The Mars rovers - Jupiter, Saturn, Mercury, and Pluto got probes. Mars got rovers. We all watched with excitement as Curiosity touched down in August 2012, joining the inactive Sojourner and Spirit rovers and the active Opportunity, which arrived in 2004.
The International Space Station - A station in low-Earth orbit, it has allowed astronauts to spend time and conduct experiments in space since commencing operations in 2000.