PACE-PAX uses the unique vantage point of the ER-2 aircraft to gather data on small particles in the atmosphere and ultimately help verify the data gathered by the satellite in orbit.

NASA's ER-2 aircraft flies high in the sky—approximately 70,000 feet in altitude, where the pilot can see the curvature of Earth. At that high an altitude, pilots must be equipped with a uniform closer to that of an astronaut rather than a flight suit. In fact, while flying the ER-2, the pilot sports a pressurized suit that is essentially a spacesuit.

"The spacesuit is the last line of defense against the elements at altitude," said Kirt Stallings, an ER-2 research pilot. "If the aircraft cabin lost pressurization the spacesuit would automatically inflate protecting the pilot from the elements and allowing them to safely recover the aircraft.