The Ionospheric Connection Explorer - or ICON - will investigate Earth’s ionosphere to study the boundary where ground-based weather meets space-weather.

The mission will look at the interaction between Earth’s weather systems and how they are influenced by space weather that causes disturbances in the upper atmosphere.

The goal of the mission is to better understand this interaction so disruptions to communications, GPS tracking, and our every-day technology can be minimized.

ICON is part of NASA’s Explorers Program.The small satellite has a launch mass of just 287 kg (633 lb) and is 1.93 m x 1.06 m (6.3 x 3.4 ft) in size.

Its single solar array is 2.54 m x 0.84 m (8.3 x 2.7 ft) in size and can produce 780 watts of power.

ICON will operate in a 575 km orbit inclined 27 degrees to the equator (meaning it will pass as far north and south as the 27th parallel of Earth).

It will operate for 2 years (planned) at least.ICON was selected by NASA as a mission on April 12th, 2013, with a planned launch for December 2017.

The launch has been repeatedly delayed due to persistent problems with its Pegasus XL rocket.

Pegasus

Meet Pegasus, a small satellite rocket capable of taking up to 443 kg to a low Earth orbit.

Now owned by Northrop Grumman but originally developed by the Orbital Sciences Corporation, Pegasus flew for the first time on April 5th, 1990 and has since performed more than 40 missions.

Unlike most rockets, Pegasus is not launched from the ground but is flown to 12 km altitude by an aircraft named Stargazer and then dropped from underneath the plane’s wing.

Five seconds after it’s dropped, Pegasus ignites its first stage, an Orion 50S solid rocket motor. The first stage contains a wing and tail for aerodynamic control, steering, and lift.

The first stage brings Pegasus up to 61 km before the second stage, an Orion 50 solid rocket booster, fires to bring the rocket’s apogee to the right altitude for the mission.

Pegasus then coasts up to that point so its third stage solid rocket motor can burn to bring the orbits perigee up to the correct mission-needed altitude.

Stargazer

Pegasus’s sibling: Stargazer. This plane is a heavily modified Lockheed, triple engine L-1011 that was built in 1974.

It was in service to Air Canada from March 1974 to May 1992 when it was bought by Orbital Science for conversion into a rocket launch plane for Pegasus.

During launches, Stargazer carries a small team of pilots, engineers, and technicians who look over the rocket and systems before launch.

After dropping Pegasus from underneath its wing, Stargazer’s pilots perform an evasive maneuver to ensure good spacing between the plane and the rocket before Pegasus ignites its first stage.

With Stargazer, Pegasus can be launched from any location in the world that has a long enough runway for the plane and adequate security. It has been used to launch missions from California, Florida, and Virginia in the United States as well as Gando Air Base, Spain and Kwajalein Atoll in the Republic of the Marshall Islands.

Photo: Pegasus under Stargazer’s wing. Credit: Northrop Grumman