Correct: C. 24-Jul-69

Apollo 11 splashed down in the Pacific Ocean on July 24, 1969. The command module Columbia landed about 13 miles from the recovery ship USS Hornet after a mission lasting more than eight days.

Correct: D. 650 million

NASA estimates that approximately 650 million people watched Neil Armstrong's televised first steps on the Moon. The broadcast allowed a vast global audience to witness the Apollo 11 landing in real time.

Correct: A. Frank Borman

Frank Borman commanded Apollo 8, the first crewed mission to orbit the Moon. James Lovell served as command module pilot and William Anders as lunar module pilot.

Correct: B. Borman, Lovell, Anders

Frank Borman, James Lovell, and William Anders formed the crew of Apollo 8. They became the first humans to travel to the vicinity of the Moon and enter lunar orbit.

Correct: C. Gemini VIII

Gemini VIII achieved the first docking of two vehicles in space on March 16, 1966. Neil Armstrong and David Scott docked their Gemini spacecraft with an uncrewed Agena target vehicle.

Correct: A. David Scott

David Scott flew aboard Gemini VIII with Neil Armstrong. Armstrong served as command pilot while Scott served as pilot during the mission's historic first docking in space.

Correct: B. A life-threatening thruster malfunction

A life-threatening thruster malfunction forced Gemini VIII to end its mission early. A stuck thruster caused the spacecraft to tumble rapidly until Armstrong and Scott regained control using the re-entry control system.

Correct: B. Fra Mauro

Apollo 13 was originally intended to land in the Fra Mauro region of the Moon. Geologists considered the lunar highland site valuable because it contained material associated with the enormous Mare Imbrium impact.

Correct: C. 17-Apr-70

Apollo 13 safely splashed down in the Pacific Ocean on April 17, 1970. The return concluded nearly four days of emergency operations after an oxygen-tank explosion crippled the spacecraft on the way to the Moon.

Correct: B. Hadley-Apennine

Apollo 15 explored the Hadley-Apennine region of the Moon. NASA selected the site for its scientifically valuable combination of mountainous terrain and Hadley Rille.

Correct: C. David Scott

David Scott commanded Apollo 15. James Irwin served as lunar module pilot while Alfred Worden remained in lunar orbit as command module pilot.

Correct: C. Harrison Schmitt

Harrison Schmitt was a professional geologist and served as lunar module pilot on Apollo 17. His scientific training was especially valuable during the mission's extensive geological exploration of the Taurus-Littrow Valley.

Correct: C. Taurus-Littrow Valley

Apollo 17 landed in the Taurus-Littrow Valley on the Moon. NASA chose the site because it offered opportunities to study both relatively old and relatively young lunar materials.

Correct: B. Atlantis

Galileo was deployed from Space Shuttle Atlantis during mission STS-34 in October 1989. After deployment, an Inertial Upper Stage sent the spacecraft on its interplanetary journey toward Jupiter.

Correct: C. Almost eight years

Galileo orbited Jupiter for almost eight years. It entered Jovian orbit in December 1995 and continued studying Jupiter and its moons until September 2003.

Correct: B. To prevent possible contamination of Europa

NASA deliberately sent Galileo into Jupiter in 2003 to prevent an accidental future collision with Europa. Galileo had discovered evidence suggesting that Europa may have a subsurface saltwater ocean, making planetary-protection concerns especially important.

Correct: C. 2016

Juno arrived at Jupiter in 2016. The spacecraft successfully entered orbit around the planet on July 4 after an almost five-year interplanetary journey.

Correct: C. More than 30 years

Pioneer 10 continued operating for more than 30 years despite being designed for a 21-month mission. Its final signal was received in January 2003 when the spacecraft was billions of miles from Earth.

Correct: C. Arrokoth

New Horizons flew past the Kuiper Belt object Arrokoth on January 1, 2019. The encounter became the most distant close exploration of an object ever conducted by a spacecraft.

Correct: B. Jupiter

Jupiter provided New Horizons with a gravity assist in February 2007. The flyby increased the spacecraft's speed and shortened its journey to Pluto while also allowing scientific observations of the Jupiter system.

Correct: C. Ares Vallis

Mars Pathfinder landed in Ares Vallis on July 4, 1997. NASA selected the ancient flood plain partly because it offered a wide variety of rocks that may have been transported by past catastrophic floods.

Correct: D. 72

The Ingenuity Mars Helicopter ultimately completed 72 flights. It had originally been designed as a technology demonstration for no more than five test flights over about 30 days.

Correct: C. Gusev Crater

The Spirit rover landed in Gusev Crater on Mars in January 2004. Scientists selected the large basin because geological evidence suggested that it may once have contained a lake.

Correct: A. Dawn

Dawn became the first spacecraft to orbit two different extraterrestrial targets, the giant asteroid Vesta and dwarf planet Ceres. Ion propulsion allowed the spacecraft to leave orbit around Vesta and later enter orbit around Ceres.

Correct: C. It intentionally impacted Mercury

The MESSENGER mission ended when the spacecraft intentionally impacted Mercury on April 30, 2015. Its propellant was exhausted, so controllers allowed the spacecraft's orbit to decay until it struck the planet's surface.

Correct: A. 24-Sep-23

The OSIRIS-REx sample capsule returned to Earth on September 24, 2023. It landed at the Department of Defense's Utah Test and Training Range carrying rocks and dust collected from asteroid Bennu.