The first half of the payload fairing for the Orbital ATK Pegasus XL rocket is inside Building 1555 at Vandenberg Air Force Base in California on Aug. 4, 2018. The Pegasus rocket is being prepared for NASA's Ionospheric Connection Explorer, or ICON, mission. The explorer will launch on June 15, 2018, from Kwajalein Atoll in the Marshall Islands (June 14 in the continental United States) on Orbital ATK's Pegasus XL rocket, which is attached to the company's L-1011 Stargazer aircraft. ICON will study the frontier of space - the dynamic zone high in Earth's atmosphere where terrestrial weather from below meets space weather above. The explorer will help determine the physics of Earth's space environment and pave the way for mitigating its effects on our technology, communications systems and society.

Orbital ATK technicians remove the second half of the payload fairing for the Orbital ATK Pegasus XL rocket from its shipping container Aug. 4, 2017, at Vandenberg Air Force Base in California. The Pegasus rocket is being prepared for NASA's Ionospheric Connection Explorer, or ICON, mission. The explorer will launch on June 15, 2018, from Kwajalein Atoll in the Marshall Islands (June 14 in the continental United States) on Orbital ATK's Pegasus XL rocket, which is attached to the company's L-1011 Stargazer aircraft. ICON will study the frontier of space - the dynamic zone high in Earth's atmosphere where terrestrial weather from below meets space weather above. The explorer will help determine the physics of Earth's space environment and pave the way for mitigating its effects on our technology, communications systems and society.

The payload fairing for Orbital ATK's Pegasus XL rocket arrives by flatbed truck Aug. 4, 2017, at Vandenberg Air Force Base in California. The Pegasus rocket is being prepared for NASA's Ionospheric Connection Explorer, or ICON, mission. The explorer will launch on June 15, 2018, from Kwajalein Atoll in the Marshall Islands (June 14 in the continental United States) on Orbital ATK's Pegasus XL rocket, which is attached to the company's L-1011 Stargazer aircraft. ICON will study the frontier of space - the dynamic zone high in Earth's atmosphere where terrestrial weather from below meets space weather above. The explorer will help determine the physics of Earth's space environment and pave the way for mitigating its effects on our technology, communications systems and society.

Technicians move the first half of the payload fairing for the Orbital ATK Pegasus XL rocket inside Building 1555 at Vandenberg Air Force Base in California on Aug. 4, 2018. The Pegasus rocket is being prepared for NASA's Ionospheric Connection Explorer, or ICON, mission. The explorer will launch on June 15, 2018, from Kwajalein Atoll in the Marshall Islands (June 14 in the continental United States) on Orbital ATK's Pegasus XL rocket, which is attached to the company's L-1011 Stargazer aircraft. ICON will study the frontier of space - the dynamic zone high in Earth's atmosphere where terrestrial weather from below meets space weather above. The explorer will help determine the physics of Earth's space environment and pave the way for mitigating its effects on our technology, communications systems and society.

Orbital ATK technicians remove the first half of the payload fairing for the Orbital ATK Pegasus XL rocket from its shipping container Aug. 4, 2017, at Vandenberg Air Force Base in California. The Pegasus rocket is being prepared for NASA's Ionospheric Connection Explorer, or ICON, mission. The explorer will launch on June 15, 2018, from Kwajalein Atoll in the Marshall Islands (June 14 in the continental United States) on Orbital ATK's Pegasus XL rocket, which is attached to the company's L-1011 Stargazer aircraft. ICON will study the frontier of space - the dynamic zone high in Earth's atmosphere where terrestrial weather from below meets space weather above. The explorer will help determine the physics of Earth's space environment and pave the way for mitigating its effects on our technology, communications systems and society.

Orbital ATK technicians remove the first half of the payload fairing for the Orbital ATK Pegasus XL rocket from its shipping container Aug. 4, 2017, at Vandenberg Air Force Base in California. The Pegasus rocket is being prepared for NASA's Ionospheric Connection Explorer, or ICON, mission. The explorer will launch on June 15, 2018, from Kwajalein Atoll in the Marshall Islands (June 14 in the continental United States) on Orbital ATK's Pegasus XL rocket, which is attached to the company's L-1011 Stargazer aircraft. ICON will study the frontier of space - the dynamic zone high in Earth's atmosphere where terrestrial weather from below meets space weather above. The explorer will help determine the physics of Earth's space environment and pave the way for mitigating its effects on our technology, communications systems and society.