On Saturday April 22, 2017, Expedition 51 Flight Engineer Thomas Pesquet of the European Space Agency photographed Orbital ATK's Cygnus spacecraft as it approached the International Space Station. Using the station's robotic Canadarm2, Cygnus was successfully captured by Pesquet and Commander Peggy Whitson at 6:05 a.m. EDT Saturday morning.

Once launched into space, the Webb telescope’s 18-segmented gold mirror is specially designed to capture infrared light from the first galaxies that formed in the early universe.

The Soyuz MS-04 rocket launches from the Baikonur Cosmodrome in Kazakhstan on Thursday, April 20, 2017 at 1:13 p.m. Baikonur time carrying NASA astronaut Jack Fischer and cosmonaut Fyodor Yurchikhin of the Russian space agency Roscosmos into orbit to begin their four and a half month mission on the International Space Station.

UGC 12591's classification straddles somewhere between a lenticular and a spiral galaxy. It lies just under 400 million light-years from us in the Pisces–Perseus Supercluster.

Dione's lit hemisphere faces away from Cassini's camera, yet the moon's darkened surface features are dimly illuminated in this image, due to Saturnshine.

Here is a view of Earth and its moon, as seen from Mars. It combines two images acquired on Nov. 20, 2016, by the HiRISE camera on NASA's Mars Reconnaissance Orbiter, with brightness adjusted separately for Earth and the moon to show details on both bodies.

This image from NASA's Cassini spacecraft is one of the highest-resolution views ever taken of Saturn's moon Pandora. Pandora (84 kilometers, or 52 miles across) orbits Saturn just outside the narrow F ring.

Apollo 8, the first crewed Saturn V launched from NASA's Kennedy Space Center on Dec. 21, 1968. Here, the S-IC stage is being erected for final assembly of the Saturn V launch vehicle in Kennedy's Vehicle Assembly Building.

A constellation of eight microsatellites, called NASA’s Cyclone Global Navigation Satellite System mission, or CYGNSS, got a boost into Earth orbit aboard an Orbital ATK Pegasus XL rocket, deployed from an L-1011 aircraft.

Expedition 50 Commander Shane Kimbrough of NASA shared this photograph of the Japan Aerospace Exploration Agency’s Kounotori H-II Transfer Vehicle (HTV-6) as it approached the International Space Station.

Welders inside a large liquid hydrogen tank for NASA's Space Launch System at the Michoud Assembly Facility in New Orleans are plugging holes left after the tank was assembled.

On July 20, 1976, at 8:12 a.m. EDT, NASA received the signal that the Viking Lander 1 successfully reached the Martian surface. This major milestone represented the first time the United States successfully landed a vehicle on the surface of Mars, collecting an overwhelming amount of data that would soon be used in future NASA missions.

The second and final qualification motor (QM-2) test for the Space Launch System’s booster is seen, Tuesday, June 28, 2016, at Orbital ATK Propulsion Systems test facilities in Promontory, Utah. During the Space Launch System flight the boosters will provide more than 75 percent of the thrust needed to escape the gravitational pull of the Earth.

NASA's Juno spacecraft obtained this color view on June 21, 2016, at a distance of 6.8 million miles (10.9 million kilometers) from Jupiter. Juno will arrive at Jupiter on July 4. As Juno makes its initial approach, the giant planet's four largest moons -- Io, Europa, Ganymede and Callisto -- are visible.

The drizzle of stars scattered across this image forms a galaxy known as UGC 4879. UGC 4879 is an irregular dwarf galaxy — as the name suggests, galaxies of this type are a little smaller and messier than their cosmic cousins, lacking the majestic swirl of a spiral or the coherence of an elliptical.