KENNEDY SPACE CENTER, FLA. -- The mated Pegasus XL rocket - AIM spacecraft is secured onto a transporter at Vandenberg Air Force Base in California. The rocket will be transferred to a waiting Orbital Sciences Stargazer L-1011 aircraft for launch. AIM, which stands for Aeronomy of Ice in the Mesosphere, is being prepared for integrated testing and a flight simulation. The AIM spacecraft will fly three instruments designed to study polar mesospheric clouds located at the edge of space, 50 miles above the Earth's surface in the coldest part of the planet's atmosphere. The mission's primary goal is to explain why these clouds form and what has caused them to become brighter and more numerous and appear at lower latitudes in recent years. AIM's results will provide the basis for the study of long-term variability in the mesospheric climate and its relationship to global climate change. Launch is scheduled for April 25.

KENNEDY SPACE CENTER, FLA. -- The mated Pegasus XL rocket - AIM spacecraft leaves Building 1655 at Vandenberg Air Force Base in California. The rocket will be transferred to a waiting Orbital Sciences Stargazer L-1011 aircraft for launch. AIM, which stands for Aeronomy of Ice in the Mesosphere, is being prepared for integrated testing and a flight simulation. The AIM spacecraft will fly three instruments designed to study polar mesospheric clouds located at the edge of space, 50 miles above the Earth's surface in the coldest part of the planet's atmosphere. The mission's primary goal is to explain why these clouds form and what has caused them to become brighter and more numerous and appear at lower latitudes in recent years. AIM's results will provide the basis for the study of long-term variability in the mesospheric climate and its relationship to global climate change. Launch is scheduled for April 25.

KENNEDY SPACE CENTER, FLA. -- The mated Pegasus XL rocket - AIM spacecraft is moved onto a transporter in Building 1655 at Vandenberg Air Force Base in California. The launch vehicle will be transferred to a waiting Orbital Sciences Stargazer L-1011 aircraft for launch. AIM, which stands for Aeronomy of Ice in the Mesosphere, is being prepared for integrated testing and a flight simulation. The AIM spacecraft will fly three instruments designed to study polar mesospheric clouds located at the edge of space, 50 miles above the Earth's surface in the coldest part of the planet's atmosphere. The mission's primary goal is to explain why these clouds form and what has caused them to become brighter and more numerous and appear at lower latitudes in recent years. AIM's results will provide the basis for the study of long-term variability in the mesospheric climate and its relationship to global climate change. Launch is scheduled for April 25.

The Orbital ATK L-1011 Stargazer aircraft has arrived at the Skid Strip at Cape Canaveral Air Force Station in Florida. Attached beneath the Stargazer is the Orbital ATK Pegasus XL with NASA's Cyclone Global Navigation Satellite System (CYGNSS) on board. CYGNSS was processed and prepared for its mission at Vandenberg Air Force Base in California. CYGNSS is scheduled for its airborne launch aboard the Pegasus XL rocket from the Skid Strip on Dec. 12. CYGNSS will make frequent and accurate measurements of ocean surface winds throughout the life cycle of tropical storms and hurricanes. The data that CYGNSS provides will enable scientists to probe key air-sea interaction processes that take place near the core of storms, which are rapidly changing and play a critical role in the beginning and intensification of hurricanes.

The Orbital ATK L-1011 Stargazer aircraft has arrived at the Skid Strip at Cape Canaveral Air Force Station in Florida. Attached beneath the Stargazer is the Orbital ATK Pegasus XL with NASA's Cyclone Global Navigation Satellite System (CYGNSS) on board. CYGNSS was processed and prepared for its mission at Vandenberg Air Force Base in California. CYGNSS is scheduled for its airborne launch aboard the Pegasus XL rocket from the Skid Strip on Dec. 12. CYGNSS will make frequent and accurate measurements of ocean surface winds throughout the life cycle of tropical storms and hurricanes. The data that CYGNSS provides will enable scientists to probe key air-sea interaction processes that take place near the core of storms, which are rapidly changing and play a critical role in the beginning and intensification of hurricanes.

The Orbital ATK L-1011 Stargazer aircraft begins its descent to the Skid Strip at Cape Canaveral Air Force Station in Florida. Attached beneath the Stargazer is the Orbital ATK Pegasus XL with NASA's Cyclone Global Navigation Satellite System (CYGNSS) on board. CYGNSS was processed and prepared for its mission at Vandenberg Air Force Base in California. CYGNSS is scheduled for its airborne launch aboard the Pegasus XL rocket from the Skid Strip on Dec. 12. CYGNSS will make frequent and accurate measurements of ocean surface winds throughout the life cycle of tropical storms and hurricanes. The data that CYGNSS provides will enable scientists to probe key air-sea interaction processes that take place near the core of storms, which are rapidly changing and play a critical role in the beginning and intensification of hurricanes.

The Orbital ATK L-1011 Stargazer aircraft has arrived at the Skid Strip at Cape Canaveral Air Force Station in Florida. Attached beneath the Stargazer is the Orbital ATK Pegasus XL with NASA's Cyclone Global Navigation Satellite System (CYGNSS) on board. CYGNSS was processed and prepared for its mission at Vandenberg Air Force Base in California. CYGNSS is scheduled for its airborne launch aboard the Pegasus XL rocket from the Skid Strip on Dec. 12. CYGNSS will make frequent and accurate measurements of ocean surface winds throughout the life cycle of tropical storms and hurricanes. The data that CYGNSS provides will enable scientists to probe key air-sea interaction processes that take place near the core of storms, which are rapidly changing and play a critical role in the beginning and intensification of hurricanes.

The Orbital ATK L-1011 Stargazer aircraft has arrived at the Skid Strip at Cape Canaveral Air Force Station in Florida. Attached beneath the Stargazer is the Orbital ATK Pegasus XL with NASA's Cyclone Global Navigation Satellite System (CYGNSS) on board. CYGNSS was processed and prepared for its mission at Vandenberg Air Force Base in California. CYGNSS is scheduled for its airborne launch aboard the Pegasus XL rocket from the Skid Strip on Dec. 12. CYGNSS will make frequent and accurate measurements of ocean surface winds throughout the life cycle of tropical storms and hurricanes. The data that CYGNSS provides will enable scientists to probe key air-sea interaction processes that take place near the core of storms, which are rapidly changing and play a critical role in the beginning and intensification of hurricanes.

The Orbital ATK L-1011 Stargazer aircraft has arrived at the Skid Strip at Cape Canaveral Air Force Station in Florida. Attached beneath the Stargazer is the Orbital ATK Pegasus XL with NASA's Cyclone Global Navigation Satellite System (CYGNSS) on board. CYGNSS was processed and prepared for its mission at Vandenberg Air Force Base in California. CYGNSS is scheduled for its airborne launch aboard the Pegasus XL rocket from the Skid Strip on Dec. 12. CYGNSS will make frequent and accurate measurements of ocean surface winds throughout the life cycle of tropical storms and hurricanes. The data that CYGNSS provides will enable scientists to probe key air-sea interaction processes that take place near the core of storms, which are rapidly changing and play a critical role in the beginning and intensification of hurricanes.

The Orbital ATK L-1011 Stargazer aircraft has arrived at the Skid Strip at Cape Canaveral Air Force Station in Florida. Attached beneath the Stargazer is the Orbital ATK Pegasus XL with NASA's Cyclone Global Navigation Satellite System (CYGNSS) on board. CYGNSS was processed and prepared for its mission at Vandenberg Air Force Base in California. CYGNSS is scheduled for its airborne launch aboard the Pegasus XL rocket from the Skid Strip on Dec. 12. CYGNSS will make frequent and accurate measurements of ocean surface winds throughout the life cycle of tropical storms and hurricanes. The data that CYGNSS provides will enable scientists to probe key air-sea interaction processes that take place near the core of storms, which are rapidly changing and play a critical role in the beginning and intensification of hurricanes.

The Orbital ATK L-1011 Stargazer aircraft touches down at 3:57 p.m. EST at the Skid Strip at Cape Canaveral Air Force Station in Florida. Attached beneath the Stargazer is the Orbital ATK Pegasus XL with NASA's Cyclone Global Navigation Satellite System (CYGNSS) on board. CYGNSS was processed and prepared for its mission at Vandenberg Air Force Base in California. CYGNSS is scheduled for its airborne launch aboard the Pegasus XL rocket from the Skid Strip on Dec. 12. CYGNSS will make frequent and accurate measurements of ocean surface winds throughout the life cycle of tropical storms and hurricanes. The data that CYGNSS provides will enable scientists to probe key air-sea interaction processes that take place near the core of storms, which are rapidly changing and play a critical role in the beginning and intensification of hurricanes.

The Orbital ATK L-1011 Stargazer aircraft has arrived at the Skid Strip at Cape Canaveral Air Force Station in Florida. Attached beneath the Stargazer is the Orbital ATK Pegasus XL with NASA's Cyclone Global Navigation Satellite System (CYGNSS) on board. CYGNSS was processed and prepared for its mission at Vandenberg Air Force Base in California. CYGNSS is scheduled for its airborne launch aboard the Pegasus XL rocket from the Skid Strip on Dec. 12. CYGNSS will make frequent and accurate measurements of ocean surface winds throughout the life cycle of tropical storms and hurricanes. The data that CYGNSS provides will enable scientists to probe key air-sea interaction processes that take place near the core of storms, which are rapidly changing and play a critical role in the beginning and intensification of hurricanes.

The Orbital ATK L-1011 Stargazer aircraft has arrived at the Skid Strip at Cape Canaveral Air Force Station in Florida. Attached beneath the Stargazer is the Orbital ATK Pegasus XL with NASA's Cyclone Global Navigation Satellite System (CYGNSS) on board. CYGNSS was processed and prepared for its mission at Vandenberg Air Force Base in California. CYGNSS is scheduled for its airborne launch aboard the Pegasus XL rocket from the Skid Strip on Dec. 12. CYGNSS will make frequent and accurate measurements of ocean surface winds throughout the life cycle of tropical storms and hurricanes. The data that CYGNSS provides will enable scientists to probe key air-sea interaction processes that take place near the core of storms, which are rapidly changing and play a critical role in the beginning and intensification of hurricanes.

The Orbital ATK L-1011 Stargazer aircraft touches down at 3:57 p.m. EST at the Skid Strip at Cape Canaveral Air Force Station in Florida. Attached beneath the Stargazer is the Orbital ATK Pegasus XL with NASA's Cyclone Global Navigation Satellite System (CYGNSS) on board. CYGNSS was processed and prepared for its mission at Vandenberg Air Force Base in California. CYGNSS is scheduled for its airborne launch aboard the Pegasus XL rocket from the Skid Strip on Dec. 12. CYGNSS will make frequent and accurate measurements of ocean surface winds throughout the life cycle of tropical storms and hurricanes. The data that CYGNSS provides will enable scientists to probe key air-sea interaction processes that take place near the core of storms, which are rapidly changing and play a critical role in the beginning and intensification of hurricanes.

The Orbital ATK L-1011 Stargazer aircraft has arrived at the Skid Strip at Cape Canaveral Air Force Station in Florida. Attached beneath the Stargazer is the Orbital ATK Pegasus XL with NASA's Cyclone Global Navigation Satellite System (CYGNSS) on board. CYGNSS was processed and prepared for its mission at Vandenberg Air Force Base in California. CYGNSS is scheduled for its airborne launch aboard the Pegasus XL rocket from the Skid Strip on Dec. 12. CYGNSS will make frequent and accurate measurements of ocean surface winds throughout the life cycle of tropical storms and hurricanes. The data that CYGNSS provides will enable scientists to probe key air-sea interaction processes that take place near the core of storms, which are rapidly changing and play a critical role in the beginning and intensification of hurricanes.

The Orbital ATK L-1011 Stargazer aircraft has arrived at the Skid Strip at Cape Canaveral Air Force Station in Florida. Attached beneath the Stargazer is the Orbital ATK Pegasus XL with NASA's Cyclone Global Navigation Satellite System (CYGNSS) on board. CYGNSS was processed and prepared for its mission at Vandenberg Air Force Base in California. CYGNSS is scheduled for its airborne launch aboard the Pegasus XL rocket from the Skid Strip on Dec. 12. CYGNSS will make frequent and accurate measurements of ocean surface winds throughout the life cycle of tropical storms and hurricanes. The data that CYGNSS provides will enable scientists to probe key air-sea interaction processes that take place near the core of storms, which are rapidly changing and play a critical role in the beginning and intensification of hurricanes.

An Orbital ATK L-1011 Stargazer aircraft carrying a Pegasus XL Rocket with eight NASA Cyclone Global Navigation Satellite System, or CYGNSS, spacecraft is ready for takeoff from the Skid Strip at Cape Canaveral Air Force Station, Florida. With the aircraft flying off shore, the Pegasus rocket will be released. Five seconds later, the solid propellant engine will ignite and boost the eight hurricane observatories to orbit. The eight CYGNSS satellites will make frequent and accurate measurements of ocean surface winds throughout the life cycle of tropical storms and hurricanes.

An Orbital ATK L-1011 Stargazer aircraft carrying a Pegasus XL Rocket with eight NASA Cyclone Global Navigation Satellite System, or CYGNSS, spacecraft is being readied for takeoff from the Skid Strip at Cape Canaveral Air Force Station, Florida. With the aircraft flying off shore, the Pegasus rocket will be released. Five seconds later, the solid propellant engine will ignite and boost the eight hurricane observatories to orbit. The eight CYGNSS satellites will make frequent and accurate measurements of ocean surface winds throughout the life cycle of tropical storms and hurricanes.

A pathfinder aircraft, at left, prepares for takeoff from the Skid Strip at Cape Canaveral Air Force Station in Florida. The airplane will provide photographic and video imagery of the Orbital ATK L-1011 Stargazer aircraft, in view at right, carrying a Pegasus XL Rocket with eight NASA Cyclone Global Navigation Satellite System, or CYGNSS, spacecraft. With the aircraft flying off shore, the Pegasus rocket will be released. Five seconds later, the solid propellant engine will ignite and boost the eight hurricane observatories to orbit. The eight CYGNSS satellites will make frequent and accurate measurements of ocean surface winds throughout the life cycle of tropical storms and hurricanes.

An Orbital ATK L-1011 Stargazer aircraft carrying a Pegasus XL Rocket with eight NASA Cyclone Global Navigation Satellite System, or CYGNSS, spacecraft is ready for takeoff from the Skid Strip at Cape Canaveral Air Force Station, Florida. With the aircraft flying off shore, the Pegasus rocket will be released. Five seconds later, the solid propellant engine will ignite and boost the eight hurricane observatories to orbit. The eight CYGNSS satellites will make frequent and accurate measurements of ocean surface winds throughout the life cycle of tropical storms and hurricanes.

KENNEDY SPACE CENTER, FLA. -- On a runway at Vandenberg Air Force Base in California, the Orbital Sciences Stargazer L-1011 aircraft takes off at 4:26 p.m. EDT with its underbelly cargo of the Pegasus XL rocket-AIM spacecraft. The aircraft will release the Pegasus XL rocket at a drop point over the Pacific Ocean, 100 miles offshore west-southwest of Point Sur, Calif. AIM, which stands for Aeronomy of Ice in the Mesosphere, is being prepared for integrated testing and a flight simulation. The AIM spacecraft will fly three instruments designed to study polar mesospheric clouds located at the edge of space, 50 miles above the Earth's surface in the coldest part of the planet's atmosphere. The mission's primary goal is to explain why these clouds form and what has caused them to become brighter and more numerous and appear at lower latitudes in recent years. AIM's results will provide the basis for the study of long-term variability in the mesospheric climate and its relationship to global climate change. Launch is scheduled for April 25. Photo credit: NASA/Tim Gordon

KENNEDY SPACE CENTER, FLA. -- On a runway at Vandenberg Air Force Base in California, the Orbital Sciences Stargazer L-1011 aircraft is ready for takeoff with its underbelly cargo of the Pegasus XL rocket-AIM spacecraft. The aircraft will release the Pegasus XL rocket at a drop point over the Pacific Ocean, 100 miles offshore west-southwest of Point Sur, Calif. AIM, which stands for Aeronomy of Ice in the Mesosphere, is being prepared for integrated testing and a flight simulation. The AIM spacecraft will fly three instruments designed to study polar mesospheric clouds located at the edge of space, 50 miles above the Earth's surface in the coldest part of the planet's atmosphere. The mission's primary goal is to explain why these clouds form and what has caused them to become brighter and more numerous and appear at lower latitudes in recent years. AIM's results will provide the basis for the study of long-term variability in the mesospheric climate and its relationship to global climate change. Launch is scheduled for April 25. Photo credit: NASA/Tim Gordon

This photo shows the Orbital Sciences Corporation Pegasus XL rocket with NASA NuSTAR spacecraft after attachment to the L-1011 carrier aircraft known as Stargazer.

The mated Pegasus XL rocket - AIM spacecraft is moved onto a transporter in Building 1655 at Vandenberg Air Force Base in California. The launch vehicle will be transferred to a waiting Orbital Sciences Stargazer L-1011 aircraft for launch. AIM, which stands for Aeronomy of Ice in the Mesosphere, is being prepared for integrated testing and a flight simulation. The AIM spacecraft will fly three instruments designed to study polar mesospheric clouds located at the edge of space, 50 miles above the Earth's surface in the coldest part of the planet's atmosphere. The mission's primary goal is to explain why these clouds form and what has caused them to become brighter and more numerous and appear at lower latitudes in recent years. AIM's results will provide the basis for the study of long-term variability in the mesospheric climate and its relationship to global climate change. Launch is scheduled for April 25.

The mated Pegasus XL rocket - AIM spacecraft is secured onto a transporter at Vandenberg Air Force Base in California. The rocket will be transferred to a waiting Orbital Sciences Stargazer L-1011 aircraft for launch. AIM, which stands for Aeronomy of Ice in the Mesosphere, is being prepared for integrated testing and a flight simulation. The AIM spacecraft will fly three instruments designed to study polar mesospheric clouds located at the edge of space, 50 miles above the Earth's surface in the coldest part of the planet's atmosphere. The mission's primary goal is to explain why these clouds form and what has caused them to become brighter and more numerous and appear at lower latitudes in recent years. AIM's results will provide the basis for the study of long-term variability in the mesospheric climate and its relationship to global climate change. Launch is scheduled for April 25.

The mated Pegasus XL rocket - AIM spacecraft leaves Building 1655 at Vandenberg Air Force Base in California. The rocket will be transferred to a waiting Orbital Sciences Stargazer L-1011 aircraft for launch. AIM, which stands for Aeronomy of Ice in the Mesosphere, is being prepared for integrated testing and a flight simulation. The AIM spacecraft will fly three instruments designed to study polar mesospheric clouds located at the edge of space, 50 miles above the Earth's surface in the coldest part of the planet's atmosphere. The mission's primary goal is to explain why these clouds form and what has caused them to become brighter and more numerous and appear at lower latitudes in recent years. AIM's results will provide the basis for the study of long-term variability in the mesospheric climate and its relationship to global climate change. Launch is scheduled for April 25.

An Orbital ATK L-1011 Stargazer aircraft carrying a Pegasus XL Rocket with eight NASA Cyclone Global Navigation Satellite System, or CYGNSS, soars high after takeoff from the Skid Strip at Cape Canaveral Air Force Station, Florida. With the aircraft flying off shore, the Pegasus rocket will be released. Five seconds later, the solid propellant engine will ignite and boost the eight hurricane observatories to orbit. The eight CYGNSS satellites will make frequent and accurate measurements of ocean surface winds throughout the life cycle of tropical storms and hurricanes. Release of the Pegasus XL rocket is scheduled for 8:40 a.m. EST.

An Orbital ATK L-1011 Stargazer aircraft carrying a Pegasus XL Rocket with eight NASA Cyclone Global Navigation Satellite System, or CYGNSS, spacecraft is ready for takeoff from the Skid Strip at Cape Canaveral Air Force Station, Florida. With the aircraft flying off shore, the Pegasus rocket will be released. Five seconds later, the solid propellant engine will ignite and boost the eight hurricane observatories to orbit. The eight CYGNSS satellites will make frequent and accurate measurements of ocean surface winds throughout the life cycle of tropical storms and hurricanes.

An Orbital ATK L-1011 Stargazer aircraft descends toward the Skid Strip at Cape Canaveral Air Force Station in Florida. The aircraft carried a Pegasus XL Rocket with eight NASA Cyclone Global Navigation Satellite System, or CYGNSS, for launch. With the aircraft flying off shore, the Pegasus rocket was released. Five seconds later, the solid propellant engine ignited and boosted the eight hurricane observatories to orbit. The eight CYGNSS satellites will make frequent and accurate measurements of ocean surface winds throughout the life cycle of tropical storms and hurricanes. Release of the Pegasus XL rocket occurred at 8:37 a.m. EST.

An Orbital ATK L-1011 Stargazer aircraft carrying a Pegasus XL Rocket with eight NASA Cyclone Global Navigation Satellite System, or CYGNSS, soars high after takeoff from the Skid Strip at Cape Canaveral Air Force Station, Florida. With the aircraft flying off shore, the Pegasus rocket will be released. Five seconds later, the solid propellant engine will ignite and boost the eight hurricane observatories to orbit. The eight CYGNSS satellites will make frequent and accurate measurements of ocean surface winds throughout the life cycle of tropical storms and hurricanes. Release of the Pegasus XL rocket is scheduled for 8:40 a.m. EST.

An Orbital ATK L-1011 Stargazer aircraft carrying a Pegasus XL Rocket with eight NASA Cyclone Global Navigation Satellite System, or CYGNSS, spacecraft takes off from the Skid Strip at Cape Canaveral Air Force Station, Florida. With the aircraft flying off shore, the Pegasus rocket will be released. Five seconds later, the solid propellant engine will ignite and boost the eight hurricane observatories to orbit. The eight CYGNSS satellites will make frequent and accurate measurements of ocean surface winds throughout the life cycle of tropical storms and hurricanes.

A pathfinder aircraft descends for touchdown at the Skid Strip at Cape Canaveral Air Force Station in Florida. The airplane provided photographic and video imagery of the Orbital ATK L-1011 Stargazer aircraft carrying a Pegasus XL Rocket with eight NASA Cyclone Global Navigation Satellite System, or CYGNSS, spacecraft. With the aircraft flying off shore, the Pegasus rocket was released at 8:37 a.m. EST. Five seconds later, the solid propellant engine ignited and boosted the eight hurricane observatories to orbit. The eight CYGNSS satellites will make frequent and accurate measurements of ocean surface winds throughout the life cycle of tropical storms and hurricanes.

An Orbital ATK L-1011 Stargazer touches down at the Skid Strip at Cape Canaveral Air Force Station in Florida. The aircraft carried a Pegasus XL Rocket with eight NASA Cyclone Global Navigation Satellite System, or CYGNSS, for launch. With the aircraft flying off shore, the Pegasus rocket was released at 8:37 a.m. EST. Five seconds later, the solid propellant engine ignited and boosted the eight hurricane observatories to orbit. The eight CYGNSS satellites will make frequent and accurate measurements of ocean surface winds throughout the life cycle of tropical storms and hurricanes.

An Orbital ATK L-1011 Stargazer touches down at the Skid Strip at Cape Canaveral Air Force Station in Florida. The aircraft carried a Pegasus XL Rocket with eight NASA Cyclone Global Navigation Satellite System, or CYGNSS, for launch. With the aircraft flying off shore, the Pegasus rocket was released at 8:37 a.m. EST. Five seconds later, the solid propellant engine ignited and boosted the eight hurricane observatories to orbit. The eight CYGNSS satellites will make frequent and accurate measurements of ocean surface winds throughout the life cycle of tropical storms and hurricanes.

An Orbital ATK L-1011 Stargazer aircraft descends toward the Skid Strip at Cape Canaveral Air Force Station in Florida. The aircraft carried a Pegasus XL Rocket with eight NASA Cyclone Global Navigation Satellite System, or CYGNSS, for launch. With the aircraft flying off shore, the Pegasus rocket was released. Five seconds later, the solid propellant engine ignited and boosted the eight hurricane observatories to orbit. The eight CYGNSS satellites will make frequent and accurate measurements of ocean surface winds throughout the life cycle of tropical storms and hurricanes. Release of the Pegasus XL rocket occurred at 8:37 a.m. EST.

A pathfinder aircraft gains altitude after takeoff from the Skid Strip at Cape Canaveral Air Force Station in Florida. The airplane will provide photographic and video imagery of the Orbital ATK L-1011 Stargazer aircraft carrying a Pegasus XL Rocket with eight NASA Cyclone Global Navigation Satellite System, or CYGNSS, spacecraft. With the aircraft flying off shore, the Pegasus rocket will be released. Five seconds later, the solid propellant engine will ignite and boost the eight hurricane observatories to orbit. The eight CYGNSS satellites will make frequent and accurate measurements of ocean surface winds throughout the life cycle of tropical storms and hurricanes.

A pathfinder aircraft takes off from the Skid Strip at Cape Canaveral Air Force Station in Florida. The airplane will provide photographic and video imagery of the Orbital ATK L-1011 Stargazer aircraft carrying a Pegasus XL Rocket with eight NASA Cyclone Global Navigation Satellite System, or CYGNSS, spacecraft. With the aircraft flying off shore, the Pegasus rocket will be released. Five seconds later, the solid propellant engine will ignite and boost the eight hurricane observatories to orbit. The eight CYGNSS satellites will make frequent and accurate measurements of ocean surface winds throughout the life cycle of tropical storms and hurricanes.

An Orbital ATK L-1011 Stargazer aircraft carrying a Pegasus XL Rocket with eight NASA Cyclone Global Navigation Satellite System, or CYGNSS, soars high after takeoff from the Skid Strip at Cape Canaveral Air Force Station, Florida. With the aircraft flying off shore, the Pegasus rocket will be released. Five seconds later, the solid propellant engine will ignite and boost the eight hurricane observatories to orbit. The eight CYGNSS satellites will make frequent and accurate measurements of ocean surface winds throughout the life cycle of tropical storms and hurricanes. Release of the Pegasus XL rocket is scheduled for 8:40 a.m. EST.

A pathfinder aircraft touches down at the Skid Strip at Cape Canaveral Air Force Station in Florida. The airplane provided photographic and video imagery of the Orbital ATK L-1011 Stargazer aircraft carrying a Pegasus XL Rocket with eight NASA Cyclone Global Navigation Satellite System, or CYGNSS, spacecraft. With the aircraft flying off shore, the Pegasus rocket was released at 8:37 a.m. EST. Five seconds later, the solid propellant engine ignited and boosted the eight hurricane observatories to orbit. The eight CYGNSS satellites will make frequent and accurate measurements of ocean surface winds throughout the life cycle of tropical storms and hurricanes.

A pathfinder aircraft soars high after takeoff from the Skid Strip at Cape Canaveral Air Force Station in Florida. The airplane will provide photographic and video imagery of the Orbital ATK L-1011 Stargazer aircraft carrying a Pegasus XL Rocket with eight NASA Cyclone Global Navigation Satellite System, or CYGNSS, spacecraft. With the aircraft flying off shore, the Pegasus rocket will be released. Five seconds later, the solid propellant engine will ignite and boost the eight hurricane observatories to orbit. The eight CYGNSS satellites will make frequent and accurate measurements of ocean surface winds throughout the life cycle of tropical storms and hurricanes.

A pathfinder aircraft begins its takeoff from the Skid Strip at Cape Canaveral Air Force Station in Florida. The airplane will provide photographic and video imagery of the Orbital ATK L-1011 Stargazer aircraft carrying a Pegasus XL Rocket with eight NASA Cyclone Global Navigation Satellite System, or CYGNSS, spacecraft. With the aircraft flying off shore, the Pegasus rocket will be released. Five seconds later, the solid propellant engine will ignite and boost the eight hurricane observatories to orbit. The eight CYGNSS satellites will make frequent and accurate measurements of ocean surface winds throughout the life cycle of tropical storms and hurricanes.

Don Walters, chief pilot of the L-1011 Stargazer aircraft for Northrop Grumman Innovation Systems, speaks to news media during a prelaunch mission briefing for NASA’s Ionospheric Connection Explorer (ICON), on Oct. 8, 2019, in the News Center auditorium at the agency’s Kennedy Space Center in Florida. ICON is targeted to launch from Cape Canaveral Air Force Station in Florida on Oct. 9, 2019, aboard a Northrop Grumman Pegasus XL rocket carried aloft by the company’s Stargazer L-1011 aircraft. The explorer will study the frontier of space - the dynamic zone high in Earth's atmosphere where terrestrial weather from below meets space weather above.

The carrier plane, L-1011 Stargazer, that will give NASA NuSTAR and its rocket a lift to their airborne launch site is seen here at sunrise on Kwajalein Atoll in the Pacific Ocean.

Launch and mission managers for NASA’s Ionospheric Connection Explorer (ICON) participate in a prelaunch mission briefing on Oct. 8, 2019, in the News Center auditorium at the agency’s Kennedy Space Center in Florida. From left to right are Karen Fox, NASA Communications; Will Ulrich, launch weather officer with the U.S. Air Force 45th Space Wing; and Don Walters, chief pilot of the L-1011 Stargazer aircraft. ICON is targeted to launch from Cape Canaveral Air Force Station in Florida on Oct. 9, 2019, aboard a Northrop Grumman Pegasus XL rocket carried aloft by the company’s Stargazer L-1011 aircraft. The explorer will study the frontier of space - the dynamic zone high in Earth's atmosphere where terrestrial weather from below meets space weather above.

Karen Fox of NASA Communications moderates a prelaunch mission briefing for NASA’s Ionospheric Connection Explorer (ICON), on Oct. 8, 2019, in the News Center auditorium at the agency’s Kennedy Space Center in Florida. ICON is targeted to launch from Cape Canaveral Air Force Station in Florida on Oct. 9, 2019, aboard a Northrop Grumman Pegasus XL rocket carried aloft by the company’s Stargazer L-1011 aircraft. The explorer will study the frontier of space - the dynamic zone high in Earth's atmosphere where terrestrial weather from below meets space weather above.

Members of the launch team monitor the launch of NASA’s Ionospheric Connection Explorer (ICON) satellite inside Hangar AE at Cape Canaveral Air Force Station (CCAFS) in Florida. The Northrop Grumman Pegasus XL rocket carrying ICON was released from the company’s L-1011 Stargazer aircraft at 9:59 p.m. EDT on Oct. 10, 2019, over the Atlantic Ocean about 50 miles from Daytona Beach following takeoff from CCAFS. ICON will spend two years studying the Earth’s ionosphere – the dynamic zone in our atmosphere where terrestrial weather from below meets space weather from above. The launch was managed by the agency’s Launch Services Program.

Omar Baez, launch director in NASA’s Launch Services Program, speaks to news media during a prelaunch mission briefing for NASA’s Ionospheric Connection Explorer (ICON), on Oct. 8, 2019, in the News Center auditorium at the agency’s Kennedy Space Center in Florida. At left is Karen Fox of NASA Communications. ICON is targeted to launch from Cape Canaveral Air Force Station in Florida on Oct. 9, 2019, aboard a Northrop Grumman Pegasus XL rocket carried aloft by the company’s Stargazer L-1011 aircraft. The explorer will study the frontier of space - the dynamic zone high in Earth's atmosphere where terrestrial weather from below meets space weather above.

Steve Krein, vice president of civil and commercial space for Northrop Grumman Innovation Systems, speaks to news media during a prelaunch mission briefing for NASA’s Ionospheric Connection Explorer (ICON), on Oct. 8, 2019, in the News Center auditorium at the agency’s Kennedy Space Center in Florida. ICON is targeted to launch from Cape Canaveral Air Force Station in Florida on Oct. 9, 2019, aboard a Northrop Grumman Pegasus XL rocket carried aloft by the company’s Stargazer L-1011 aircraft. The explorer will study the frontier of space - the dynamic zone high in Earth's atmosphere where terrestrial weather from below meets space weather above.

Members of the launch team monitor the launch of NASA’s Ionospheric Connection Explorer (ICON) satellite inside Hangar AE at Cape Canaveral Air Force Station (CCAFS) in Florida. The Northrop Grumman Pegasus XL rocket carrying ICON was released from the company’s L-1011 Stargazer aircraft at 9:59 p.m. EDT on Oct. 10, 2019, over the Atlantic Ocean about 50 miles from Daytona Beach following takeoff from CCAFS. ICON will spend two years studying the Earth’s ionosphere – the dynamic zone in our atmosphere where terrestrial weather from below meets space weather from above. The launch was managed by the agency’s Launch Services Program.

A member of the launch team monitors the launch of NASA’s Ionospheric Connection Explorer (ICON) satellite inside Hangar AE at Cape Canaveral Air Force Station (CCAFS) in Florida. The Northrop Grumman Pegasus XL rocket carrying ICON was released from the company’s L-1011 Stargazer aircraft at 9:59 p.m. EDT on Oct. 10, 2019, over the Atlantic Ocean about 50 miles from Daytona Beach following takeoff from CCAFS. ICON will spend two years studying the Earth’s ionosphere – the dynamic zone in our atmosphere where terrestrial weather from below meets space weather from above. The launch was managed by the agency’s Launch Services Program.

Northrop Grumman’s L-1011 Stargazer aircraft, with the company’s Pegasus XL rocket attached beneath, takes off from the Skid Strip runway at Cape Canaveral Air Force Station in Florida on Oct. 10, 2019. NASA's Ionospheric Connection Explorer (ICON) is secured inside the rocket's payload fairing. The air-launched Pegasus XL was released from the aircraft at 9:59 p.m. EDT to start ICON’s journey to space. The explorer will study the frontier of space - the dynamic zone high in Earth's atmosphere where terrestrial weather from below meets space weather above.

Nicola Fox, Heliophysics division director in NASA’s Science Mission Directorate, speaks to news media during a prelaunch mission briefing for NASA’s Ionospheric Connection Explorer (ICON), on Oct. 8, 2019, in the News Center auditorium at the agency’s Kennedy Space Center in Florida. ICON is targeted to launch from Cape Canaveral Air Force Station in Florida on Oct. 9, 2019, aboard a Northrop Grumman Pegasus XL rocket carried aloft by the company’s Stargazer L-1011 aircraft. The explorer will study the frontier of space - the dynamic zone high in Earth's atmosphere where terrestrial weather from below meets space weather above.

Phil Joyce, vice president of space launch programs for Northrop Grumman Innovation Systems, speaks to news media during a prelaunch mission briefing for NASA’s Ionospheric Connection Explorer (ICON), on Oct. 8, 2019, in the News Center auditorium at the agency’s Kennedy Space Center in Florida. ICON is targeted to launch from Cape Canaveral Air Force Station in Florida on Oct. 9, 2019, aboard a Northrop Grumman Pegasus XL rocket carried aloft by the company’s Stargazer L-1011 aircraft. The explorer will study the frontier of space - the dynamic zone high in Earth's atmosphere where terrestrial weather from below meets space weather above.

Members of the launch team monitor the launch of NASA’s Ionospheric Connection Explorer (ICON) satellite inside Hangar AE at Cape Canaveral Air Force Station (CCAFS) in Florida. The Northrop Grumman Pegasus XL rocket carrying ICON was released from the company’s L-1011 Stargazer aircraft at 9:59 p.m. EDT on Oct. 10, 2019, over the Atlantic Ocean about 50 miles from Daytona Beach following takeoff from CCAFS. ICON will spend two years studying the Earth’s ionosphere – the dynamic zone in our atmosphere where terrestrial weather from below meets space weather from above. The launch was managed by the agency’s Launch Services Program.

Omar Baez, launch director in NASA’s Launch Services Program, speaks to news media during a prelaunch mission briefing for NASA’s Ionospheric Connection Explorer (ICON), on Oct. 8, 2019, in the News Center auditorium at the agency’s Kennedy Space Center in Florida. ICON is targeted to launch from Cape Canaveral Air Force Station in Florida on Oct. 9, 2019, aboard a Northrop Grumman Pegasus XL rocket carried aloft by the company’s Stargazer L-1011 aircraft. The explorer will study the frontier of space - the dynamic zone high in Earth's atmosphere where terrestrial weather from below meets space weather above.

Members of the launch team monitor the launch of NASA’s Ionospheric Connection Explorer (ICON) satellite inside Hangar AE at Cape Canaveral Air Force Station (CCAFS) in Florida. The Northrop Grumman Pegasus XL rocket carrying ICON was released from the company’s L-1011 Stargazer aircraft at 9:59 p.m. EDT on Oct. 10, 2019, over the Atlantic Ocean about 50 miles from Daytona Beach following takeoff from CCAFS. ICON will spend two years studying the Earth’s ionosphere – the dynamic zone in our atmosphere where terrestrial weather from below meets space weather from above. The launch was managed by the agency’s Launch Services Program.

Members of the launch team monitor the launch of NASA’s Ionospheric Connection Explorer (ICON) satellite inside Hangar AE at Cape Canaveral Air Force Station (CCAFS) in Florida. The Northrop Grumman Pegasus XL rocket carrying ICON was released from the company’s L-1011 Stargazer aircraft at 9:59 p.m. EDT on Oct. 10, 2019, over the Atlantic Ocean about 50 miles from Daytona Beach following takeoff from CCAFS. ICON will spend two years studying the Earth’s ionosphere – the dynamic zone in our atmosphere where terrestrial weather from below meets space weather from above. The launch was managed by the agency’s Launch Services Program.

Will Ulrich, launch weather officer with the U.S. Air Force 45th Space Wing, speaks to news media during a prelaunch mission briefing for NASA’s Ionospheric Connection Explorer (ICON), on Oct. 8, 2019, in the News Center auditorium at the agency’s Kennedy Space Center in Florida. ICON is targeted to launch from Cape Canaveral Air Force Station in Florida on Oct. 9, 2019, aboard a Northrop Grumman Pegasus XL rocket carried aloft by the company’s Stargazer L-1011 aircraft. The explorer will study the frontier of space - the dynamic zone high in Earth's atmosphere where terrestrial weather from below meets space weather above.

Members of the launch team monitor the launch of NASA’s Ionospheric Connection Explorer (ICON) satellite inside Hangar AE at Cape Canaveral Air Force Station (CCAFS) in Florida. The Northrop Grumman Pegasus XL rocket carrying ICON was released from the company’s L-1011 Stargazer aircraft at 9:59 p.m. EDT on Oct. 10, 2019, over the Atlantic Ocean about 50 miles from Daytona Beach following takeoff from CCAFS. ICON will spend two years studying the Earth’s ionosphere – the dynamic zone in our atmosphere where terrestrial weather from below meets space weather from above. The launch was managed by the agency’s Launch Services Program.

Members of the launch team monitor the launch of NASA’s Ionospheric Connection Explorer (ICON) satellite inside Hangar AE at Cape Canaveral Air Force Station (CCAFS) in Florida. The Northrop Grumman Pegasus XL rocket carrying ICON was released from the company’s L-1011 Stargazer aircraft at 9:59 p.m. EDT on Oct. 10, 2019, over the Atlantic Ocean about 50 miles from Daytona Beach following takeoff from CCAFS. ICON will spend two years studying the Earth’s ionosphere – the dynamic zone in our atmosphere where terrestrial weather from below meets space weather from above. The launch was managed by the agency’s Launch Services Program.

Members of the launch team monitor the launch of NASA’s Ionospheric Connection Explorer (ICON) satellite inside Hangar AE at Cape Canaveral Air Force Station (CCAFS) in Florida. The Northrop Grumman Pegasus XL rocket carrying ICON was released from the company’s L-1011 Stargazer aircraft at 9:59 p.m. EDT on Oct. 10, 2019, over the Atlantic Ocean about 50 miles from Daytona Beach following takeoff from CCAFS. ICON will spend two years studying the Earth’s ionosphere – the dynamic zone in our atmosphere where terrestrial weather from below meets space weather from above. The launch was managed by the agency’s Launch Services Program.

Northrop Grumman’s L-1011 Stargazer aircraft, with the company’s Pegasus XL rocket attached beneath, takes off from the Skid Strip runway at Cape Canaveral Air Force Station in Florida on Oct. 10, 2019. NASA's Ionospheric Connection Explorer (ICON) is secured inside the rocket's payload fairing. The air-launched Pegasus XL was released from the aircraft at 9:59 p.m. EDT to start ICON’s journey to space. The explorer will study the frontier of space - the dynamic zone high in Earth's atmosphere where terrestrial weather from below meets space weather above.

Members of the launch team monitor the launch of NASA’s Ionospheric Connection Explorer (ICON) satellite inside Hangar AE at Cape Canaveral Air Force Station (CCAFS) in Florida. The Northrop Grumman Pegasus XL rocket carrying ICON was released from the company’s L-1011 Stargazer aircraft at 9:59 p.m. EDT on Oct. 10, 2019, over the Atlantic Ocean about 50 miles from Daytona Beach following takeoff from CCAFS. ICON will spend two years studying the Earth’s ionosphere – the dynamic zone in our atmosphere where terrestrial weather from below meets space weather from above. The launch was managed by the agency’s Launch Services Program.

Inside Hangar AE at Cape Canaveral Air Force Station (CCAFS), members of the launch team applaud the successful launch of NASA’s Ionospheric Connection Explorer (ICON) satellite on Oct. 10, 2019. The Northrop Grumman Pegasus XL rocket carrying ICON was released from the company’s L-1011 Stargazer aircraft at 9:59 p.m. EDT over the Atlantic Ocean about 50 miles from Daytona Beach, Florida, following takeoff from CCAFS. ICON will spend two years studying the Earth’s ionosphere – the dynamic zone in our atmosphere where terrestrial weather from below meets space weather from above. The launch was managed by the agency’s Launch Services Program.

Thomas Immel of the Space Sciences Laboratory at the University of California Berkeley speaks to news media during a prelaunch mission briefing for NASA’s Ionospheric Connection Explorer (ICON), on Oct. 8, 2019, in the News Center auditorium at the agency’s Kennedy Space Center in Florida. Immel is ICON’s principal investigator. ICON is targeted to launch from Cape Canaveral Air Force Station in Florida on Oct. 9, 2019, aboard a Northrop Grumman Pegasus XL rocket carried aloft by the company’s Stargazer L-1011 aircraft. The explorer will study the frontier of space - the dynamic zone high in Earth's atmosphere where terrestrial weather from below meets space weather above.

Members of the launch team monitor the launch of NASA’s Ionospheric Connection Explorer (ICON) satellite inside Hangar AE at Cape Canaveral Air Force Station (CCAFS) in Florida. The Northrop Grumman Pegasus XL rocket carrying ICON was released from the company’s L-1011 Stargazer aircraft at 9:59 p.m. EDT on Oct. 10, 2019, over the Atlantic Ocean about 50 miles from Daytona Beach following takeoff from CCAFS. ICON will spend two years studying the Earth’s ionosphere – the dynamic zone in our atmosphere where terrestrial weather from below meets space weather from above. The launch was managed by the agency’s Launch Services Program.

KENNEDY SPACE CENTER, FLA. -- At Vandenberg Air Force Base in California, under the protective clean tent, technicians move the second half of the fairing into place around the AIM spacecraft. The fairing is a molded structure that fits around the spacecraft and forms an aerodynamically smooth nose cone, protecting the spacecraft during launch. Launch will be from a Pegasus XL rocket, carried and released by Orbital Sciences L-1011 jet aircraft. AIM, which stands for Aeronomy of Ice in the Mesosphere, is being prepared for integrated testing and a flight simulation. The AIM spacecraft will fly three instruments designed to study polar mesospheric clouds located at the edge of space, 50 miles above the Earth's surface in the coldest part of the planet's atmosphere. The mission's primary goal is to explain why these clouds form and what has caused them to become brighter and more numerous and appear at lower latitudes in recent years. AIM's results will provide the basis for the study of long-term variability in the mesospheric climate and its relationship to global climate change. Launch is scheduled for April 25.

KENNEDY SPACE CENTER, FLA. -- At Vandenberg Air Force Base in California, technicians prepare the AIM spacecraft for fairing installation. The fairing is a molded structure that fits around the spacecraft and forms an aerodynamically smooth nose cone, protecting the spacecraft during launch. Launch will be from a Pegasus XL rocket, carried and released by Orbital Sciences L-1011 jet aircraft. AIM, which stands for Aeronomy of Ice in the Mesosphere, is being prepared for integrated testing and a flight simulation. The AIM spacecraft will fly three instruments designed to study polar mesospheric clouds located at the edge of space, 50 miles above the Earth's surface in the coldest part of the planet's atmosphere. The mission's primary goal is to explain why these clouds form and what has caused them to become brighter and more numerous and appear at lower latitudes in recent years. AIM's results will provide the basis for the study of long-term variability in the mesospheric climate and its relationship to global climate change. Launch is scheduled for April 25.

KENNEDY SPACE CENTER, FLA. -- At Vandenberg Air Force Base in California, technicians prepare the AIM spacecraft for fairing installation. The fairing is a molded structure that fits around the spacecraft and forms an aerodynamically smooth nose cone, protecting the spacecraft during launch. Launch will be from a Pegasus XL rocket, carried and released by Orbital Sciences L-1011 jet aircraft. AIM, which stands for Aeronomy of Ice in the Mesosphere, is being prepared for integrated testing and a flight simulation. The AIM spacecraft will fly three instruments designed to study polar mesospheric clouds located at the edge of space, 50 miles above the Earth's surface in the coldest part of the planet's atmosphere. The mission's primary goal is to explain why these clouds form and what has caused them to become brighter and more numerous and appear at lower latitudes in recent years. AIM's results will provide the basis for the study of long-term variability in the mesospheric climate and its relationship to global climate change. Launch is scheduled for April 25.

KENNEDY SPACE CENTER, FLA. -- At Vandenberg Air Force Base in California, under the protective clean tent, technicians begin installing the fairing around the AIM spacecraft. The fairing is a molded structure that fits around the spacecraft and forms an aerodynamically smooth nose cone, protecting the spacecraft during launch. Launch will be from a Pegasus XL rocket, carried and released by Orbital Sciences L-1011 jet aircraft. AIM, which stands for Aeronomy of Ice in the Mesosphere, is being prepared for integrated testing and a flight simulation. The AIM spacecraft will fly three instruments designed to study polar mesospheric clouds located at the edge of space, 50 miles above the Earth's surface in the coldest part of the planet's atmosphere. The mission's primary goal is to explain why these clouds form and what has caused them to become brighter and more numerous and appear at lower latitudes in recent years. AIM's results will provide the basis for the study of long-term variability in the mesospheric climate and its relationship to global climate change. Launch is scheduled for April 25.

KENNEDY SPACE CENTER, FLA. -- At Vandenberg Air Force Base in California, under the protective clean tent, technicians work on the second half of the fairing to be installed around the AIM spacecraft. The fairing is a molded structure that fits around the spacecraft and forms an aerodynamically smooth nose cone, protecting the spacecraft during launch. Launch will be from a Pegasus XL rocket, carried and released by Orbital Sciences L-1011 jet aircraft. AIM, which stands for Aeronomy of Ice in the Mesosphere, is being prepared for integrated testing and a flight simulation. The AIM spacecraft will fly three instruments designed to study polar mesospheric clouds located at the edge of space, 50 miles above the Earth's surface in the coldest part of the planet's atmosphere. The mission's primary goal is to explain why these clouds form and what has caused them to become brighter and more numerous and appear at lower latitudes in recent years. AIM's results will provide the basis for the study of long-term variability in the mesospheric climate and its relationship to global climate change. Launch is scheduled for April 25.

KENNEDY SPACE CENTER, FLA. -- At Vandenberg Air Force Base in California, technicians prepare the AIM spacecraft for fairing installation. The fairing is a molded structure that fits around the spacecraft and forms an aerodynamically smooth nose cone, protecting the spacecraft during launch. Launch will be from a Pegasus XL rocket, carried and released by Orbital Sciences L-1011 jet aircraft. AIM, which stands for Aeronomy of Ice in the Mesosphere, is being prepared for integrated testing and a flight simulation. The AIM spacecraft will fly three instruments designed to study polar mesospheric clouds located at the edge of space, 50 miles above the Earth's surface in the coldest part of the planet's atmosphere. The mission's primary goal is to explain why these clouds form and what has caused them to become brighter and more numerous and appear at lower latitudes in recent years. AIM's results will provide the basis for the study of long-term variability in the mesospheric climate and its relationship to global climate change. Launch is scheduled for April 25.

KENNEDY SPACE CENTER, FLA. -- At Vandenberg Air Force Base in California, under the protective clean tent, technicians examine the installation of the fairing around the AIM spacecraft. The fairing is a molded structure that fits around the spacecraft and forms an aerodynamically smooth nose cone, protecting the spacecraft during launch. Launch will be from a Pegasus XL rocket, carried and released by Orbital Sciences L-1011 jet aircraft. AIM, which stands for Aeronomy of Ice in the Mesosphere, is being prepared for integrated testing and a flight simulation. The AIM spacecraft will fly three instruments designed to study polar mesospheric clouds located at the edge of space, 50 miles above the Earth's surface in the coldest part of the planet's atmosphere. The mission's primary goal is to explain why these clouds form and what has caused them to become brighter and more numerous and appear at lower latitudes in recent years. AIM's results will provide the basis for the study of long-term variability in the mesospheric climate and its relationship to global climate change. Launch is scheduled for April 25.

KENNEDY SPACE CENTER, FLA. -- At Vandenberg Air Force Base in California, under the protective clean tent, technicians maneuver the second half of the fairing into place around the AIM spacecraft. The fairing is a molded structure that fits around the spacecraft and forms an aerodynamically smooth nose cone, protecting the spacecraft during launch. Launch will be from a Pegasus XL rocket, carried and released by Orbital Sciences L-1011 jet aircraft. AIM, which stands for Aeronomy of Ice in the Mesosphere, is being prepared for integrated testing and a flight simulation. The AIM spacecraft will fly three instruments designed to study polar mesospheric clouds located at the edge of space, 50 miles above the Earth's surface in the coldest part of the planet's atmosphere. The mission's primary goal is to explain why these clouds form and what has caused them to become brighter and more numerous and appear at lower latitudes in recent years. AIM's results will provide the basis for the study of long-term variability in the mesospheric climate and its relationship to global climate change. Launch is scheduled for April 25.

Albert Sierra (right), chief of NASA’s Launch Services Program’s (LSP) Flight Projects Office, and Garrett Lee Skrobot (second from right), senior mission manager, monitor the launch of the agency’s Ionospheric Connection Explorer (ICON) inside Hangar AE’s Mission Director’s Center at Cape Canaveral Air Force Station (CCAFS). The Northrop Grumman Pegasus XL rocket carrying ICON was released from the company’s L-1011 Stargazer aircraft at 9:59 p.m. EDT on Oct. 10, 2019, over the Atlantic Ocean about 50 miles from Daytona Beach, Florida, following takeoff from CCAFS. ICON will spend two years studying the Earth’s ionosphere – the dynamic zone in our atmosphere where terrestrial weather from below meets space weather from above. The ICON launch was managed by LSP.

Inside Hangar AE’s Mission Director’s Center at Cape Canaveral Air Force Station (CCAFS), Nicola Fox, left, Heliophysics division director in NASA’s Science Mission Directorate, monitors the launch of the agency’s Ionospheric Connection Explorer (ICON) satellite. The Northrop Grumman Pegasus XL rocket carrying ICON was released from the company’s L-1011 Stargazer aircraft at 9:59 p.m. EDT on Oct. 10, 2019, over the Atlantic Ocean about 50 miles from Daytona Beach, Florida, following takeoff from CCAFS. ICON will spend two years studying the Earth’s ionosphere – the dynamic zone in our atmosphere where terrestrial weather from below meets space weather from above. The launch was managed by the agency’s Launch Services Program.

Launch and mission managers for NASA’s Ionospheric Connection Explorer (ICON) participate in a prelaunch mission briefing on Oct. 8, 2019, in the News Center auditorium at the agency’s Kennedy Space Center in Florida. From left to right are Karen Fox, NASA Communications; Nicola Fox, Heliophysics division director in NASA’s Science Mission Directorate; Thomas Immel, ICON principal investigator at the Space Sciences Laboratory at the University of California Berkeley; and Steve Krein, vice president of civil and commercial space for Northrop Grumman Innovation Systems. ICON is targeted to launch from Cape Canaveral Air Force Station in Florida on Oct. 9, 2019, aboard a Northrop Grumman Pegasus XL rocket carried aloft by the company’s Stargazer L-1011 aircraft. The explorer will study the frontier of space - the dynamic zone high in Earth's atmosphere where terrestrial weather from below meets space weather above.

Inside Hangar AE’s Mission Director’s Center at Cape Canaveral Air Force Station (CCAFS), Kennedy Space Center Director Bob Cabana monitors the launch of NASA’s Ionospheric Connection Explorer (ICON) satellite. The Northrop Grumman Pegasus XL rocket carrying ICON was released from the company’s L-1011 Stargazer aircraft at 9:59 p.m. EDT on Oct. 10, 2019, over the Atlantic Ocean about 50 miles from Daytona Beach, Florida, following takeoff from CCAFS. ICON will spend two years studying the Earth’s ionosphere – the dynamic zone in our atmosphere where terrestrial weather from below meets space weather from above. The launch was managed by the agency’s Launch Services Program.

Inside Hangar AE’s Mission Director’s Center at Cape Canaveral Air Force Station (CCAFS), Amanda Mitskevich, right, program manager in NASA’s Launch Services Program (LSP), and Chuck Dovale, second from right, LSP deputy program manager, monitor the launch of the agency’s Ionospheric Connection Explorer (ICON). The Northrop Grumman Pegasus XL rocket carrying ICON was released from the company’s L-1011 Stargazer aircraft at 9:59 p.m. EDT on Oct. 10, 2019, over the Atlantic Ocean about 50 miles from Daytona Beach, Florida, following takeoff from CCAFS. ICON will spend two years studying the Earth’s ionosphere – the dynamic zone in our atmosphere where terrestrial weather from below meets space weather from above. The ICON launch was managed by LSP.

Omar Baez, right, launch director in NASA’s Launch Services Program (LSP), monitors the launch of the agency’s Ionospheric Connection Explorer (ICON) satellite inside Hangar AE’s Mission Director’s Center at Cape Canaveral Air Force Station (CCAFS). The Northrop Grumman Pegasus XL rocket carrying ICON was released from the company’s L-1011 Stargazer aircraft at 9:59 p.m. EDT on Oct. 10, 2019, over the Atlantic Ocean about 50 miles from Daytona Beach, Florida, following takeoff from CCAFS. ICON will spend two years studying the Earth’s ionosphere – the dynamic zone in our atmosphere where terrestrial weather from below meets space weather from above. The ICON launch was managed by LSP.

From left, Kennedy Space Center Director Bob Cabana, NASA’s Launch Services Program (LSP) Deputy Program Manager Chuck Dovale and LSP Program Manager Amanda Mitskevich monitor the launch of the agency’s Ionospheric Connection Explorer (ICON) satellite inside Hangar AE’s Mission Director’s Center at Cape Canaveral Air Force Station (CCAFS). The Northrop Grumman Pegasus XL rocket carrying ICON was released from the company’s L-1011 Stargazer aircraft at 9:59 p.m. EDT on Oct. 10, 2019, over the Atlantic Ocean about 50 miles from Daytona Beach, Florida, following takeoff from CCAFS. ICON will spend two years studying the Earth’s ionosphere – the dynamic zone in our atmosphere where terrestrial weather from below meets space weather from above. The ICON launch was managed by LSP.

From left, Kennedy Space Center Director Bob Cabana, NASA’s Launch Services Program (LSP) Deputy Program Manager Chuck Dovale and LSP Program Manager Amanda Mitskevich monitor the launch of the agency’s Ionospheric Connection Explorer (ICON) satellite inside Hangar AE’s Mission Director’s Center at Cape Canaveral Air Force Station (CCAFS). The Northrop Grumman Pegasus XL rocket carrying ICON was released from the company’s L-1011 Stargazer aircraft at 9:59 p.m. EDT on Oct. 10, 2019, over the Atlantic Ocean about 50 miles from Daytona Beach, Florida, following takeoff from CCAFS. ICON will spend two years studying the Earth’s ionosphere – the dynamic zone in our atmosphere where terrestrial weather from below meets space weather from above. The ICON launch was managed by LSP.

Inside Hangar AE’s Mission Director’s Center at Cape Canaveral Air Force Station (CCAFS), members of the launch team monitor the launch of NASA’s Ionospheric Connection Explorer (ICON) satellite. The Northrop Grumman Pegasus XL rocket carrying ICON was released from the company’s L-1011 Stargazer aircraft at 9:59 p.m. EDT on Oct. 10, 2019, over the Atlantic Ocean about 50 miles from Daytona Beach, Florida, following takeoff from CCAFS. ICON will spend two years studying the Earth’s ionosphere – the dynamic zone in our atmosphere where terrestrial weather from below meets space weather from above. The launch was managed by the agency’s Launch Services Program.

Launch and mission managers for NASA’s Ionospheric Connection Explorer (ICON) participate in a prelaunch mission briefing on Oct. 8, 2019, in the News Center auditorium at the agency’s Kennedy Space Center in Florida. From left to right are Karen Fox, NASA Communications; Nicola Fox, Heliophysics division director in NASA’s Science Mission Directorate; Thomas Immel, ICON principal investigator at the Space Sciences Laboratory at the University of California Berkeley; and Steve Krein, vice president of civil and commercial space for Northrop Grumman Innovation Systems. ICON is targeted to launch from Cape Canaveral Air Force Station in Florida on Oct. 9, 2019, aboard a Northrop Grumman Pegasus XL rocket carried aloft by the company’s Stargazer L-1011 aircraft. The explorer will study the frontier of space - the dynamic zone high in Earth's atmosphere where terrestrial weather from below meets space weather above.

Launch and mission managers for NASA’s Ionospheric Connection Explorer (ICON) participate in a prelaunch mission briefing on Oct. 8, 2019, in the News Center auditorium at the agency’s Kennedy Space Center in Florida. From left to right are Karen Fox, NASA Communications; Omar Baez, launch director in NASA’s Launch Services Program; and Phil Joyce, vice president of space launch programs for Northrop Grumman Innovation Systems. ICON is targeted to launch from Cape Canaveral Air Force Station in Florida on Oct. 9, 2019, aboard a Northrop Grumman Pegasus XL rocket carried aloft by the company’s Stargazer L-1011 aircraft. The explorer will study the frontier of space - the dynamic zone high in Earth's atmosphere where terrestrial weather from below meets space weather above.

KWAJALEIN ATOLL, Marshall Islands - Orbital Science Corp.'s L-1011 aircraft "Stargazer" stands near the runway on Kwajalein Atoll with the company's Pegasus rocket slung underneath in the background near this World War II-era bunker built by the Japanese forces who occupied the island. Photo credit: NASA

KWAJALEIN ATOLL, Marshall Islands - Orbital Science Corp.'s L-1011 aircraft "Stargazer" stands near the runway on Kwajalein Atoll with the company's Pegasus rocket slung underneath. The Pegasus was used to launch NASA's NuSTAR spacecraft mission on June 13, 2012, from the Pacific island chain. Photo credit: NASA

An Orbital ATK Pegasus XL rocket is mated to the underside of the company's L-1011 Stargazer aircraft. The Stargazer is being prepared for takeoff from Vandenberg Air Force Base in California. On board Pegasus XL are eight NASA Cyclone Global Navigation Satellite System, or CYGNSS, spacecraft. When preparations are competed at Vandenberg, the /Pegasus XL combination will be flown to NASA’s Kennedy Space Center in Florida. On Dec. 12, 2016, the carrier aircraft is scheduled to take off from the Skid Strip at Cape Canaveral Air Force Station and CYGNSS will launch on the Pegasus XL rocket with the L-1011 flying off shore. CYGNSS satellites will make frequent and accurate measurements of ocean surface winds throughout the life cycle of tropical storms and hurricanes. The data that CYGNSS provides will help scientists to probe key air-sea interaction processes that take place near the core of storms, which are rapidly changing and play a crucial role in the beginning and intensification of hurricanes.

VANDENBERG AFB, CALIF. - The Orbital Stargazer L-1011 aircraft takes off from Vandenberg AFB, Calif., with the HESSI spacecraft tucked inside a Pegasus XL rocket that is attached to the under belly of the L-1011. Launch of HESSI in mid-air over the Atlantic Ocean is scheduled for 3:26 p.m. EST Feb. 5, 2002.The HESSI spacecraft will be carried approximately 113 nautical miles east-southeast of Cape Canaveral to an altitude of about 39,000 feet for release. During its planned two-year mission HESSI will study the secrets of how solar flares are produced in the Sun's atmosphere

The Northrop Grumman L-1011 Stargazer aircraft, with the Pegasus XL rocket attached beneath, starts down the runway at the Skid Strip at Cape Canaveral Air Force Station in Florida on Nov. 7, 2018. NASA's Ionospheric Connection Explorer (ICON) is secured inside the rocket's payload fairing. The Pegasus XL rocket will be carried aloft by the Stargazer. 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 Northrop Grumman L-1011 Stargazer aircraft, with the Pegasus XL rocket attached beneath, starts down the runway at the Skid Strip at Cape Canaveral Air Force Station in Florida on Nov. 7, 2018. NASA's Ionospheric Connection Explorer (ICON) is secured inside the rocket's payload fairing. The Pegasus XL rocket will be carried aloft by the Stargazer. 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 Northrop Grumman L-1011 Stargazer aircraft, with the Pegasus XL rocket attached beneath, is being prepared for takeoff from the runway at the Skid Strip at Cape Canaveral Air Force Station in Florida on Nov. 7, 2018. NASA's Ionospheric Connection Explorer (ICON) satellite is secured inside the rocket's payload fairing. The Pegasus XL rocket will be carried aloft by the Stargazer. 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 Northrop Grumman L-1011 Stargazer aircraft, with the Pegasus XL rocket attached beneath, starts down the runway at the Skid Strip at Cape Canaveral Air Force Station in Florida on Nov. 7, 2018. NASA's Ionospheric Connection Explorer (ICON) is secured inside the rocket's payload fairing. The Pegasus XL rocket will be carried aloft by the Stargazer. 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 Northrop Grumman L-1011 Stargazer aircraft, with the Pegasus XL rocket attached beneath, starts down the runway at the Skid Strip at Cape Canaveral Air Force Station in Florida on Nov. 7, 2018. NASA's Ionospheric Connection Explorer (ICON) is secured inside the rocket's payload fairing. The Pegasus XL rocket will be carried aloft by the Stargazer. 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 Northrop Grumman L-1011 Stargazer aircraft, with the Pegasus XL rocket attached beneath, starts down the runway at the Skid Strip at Cape Canaveral Air Force Station in Florida on Nov. 7, 2018. NASA's Ionospheric Connection Explorer (ICON) is secured inside the rocket's payload fairing. The Pegasus XL rocket will be carried aloft by the Stargazer. 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.

Northrop Grumman's L-1011 Stargazer aircraft has arrived at the Skid Strip at Cape Canaveral Air Force Station in Florida on Oct. 1, 2019. The company's Pegasus XL rocket, containing NASA's Ionospheric Connection Explorer (ICON), is attached beneath the 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.

Northrop Grumman's L-1011 Stargazer takes off from Vandenberg Air Force Base in California on Oct. 1, 2019. The company's Pegasus XL rocket, containing NASA's Ionospheric Connection Explorer (ICON), is attached beneath the aircraft. The explorer is targeted to launch on Oct. 9, 2019, from Cape Canaveral Air Force Station in Florida. ICON will study the frontier of space - the dynamic zone high in Earth's atmosphere where terrestrial weather from below meets space weather above.

KENNEDY SPACE CENTER, Fla. -- An L-1011 aircraft called the Stargazer gets ready to land at the Skid Strip, Cape Canaveral Air Force Station. Underneath its belly it carries the Orbital Sciences Corp. Pegasus XL launch vehicle with the High Energy Solar Spectroscopic Imager (HESSI) attached. The Pegasus XL will launch the HESSI no earlier than June 12 from CCAFS. The primary mission of HESSI is to explore the basic physics of particle acceleration and energy release in solar flares

VANDENBERG AFB, Calif. – Technicians prepare to roll the Orbital Sciences Pegasus XL rocket with its NuSTAR spacecraft to the waiting L-1011 carrier aircraft known as "Stargazer." The Pegasus will launch NuSTAR into space where the high-energy x-ray telescope will conduct a census for black holes, map radioactive material in young supernovae remnants, and study the origins of cosmic rays and the extreme physics around collapsed stars. Photo credit: NASA/Randy Beaudoin, VAFB

The Northrop Grumman Pegasus XL rocket, carrying NASA’s Ionospheric Connection Explorer (ICON), has arrived at the Skid Strip at Cape Canaveral Air Force Station in Florida on Oct. 1, 2019. The rocket is attached beneath 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.