The 117-foot P-3B NASA research aircraft on the tarmac at Baltimore/Washington International Thurgood Marshall Airport, Tuesday, June 28, 2011, in Baltimore, Md.

The aircraft is part of a month-long field campaign designed to improve satellite measurements of air pollution. The name of the experiment - Deriving Information on Surface conditions from Column and Vertically Resolved Observations Relevant to Air Quality (DISCOVER - AQ) - is a mouthful, but its purpose is simple. Come July, the aircraft will be flying spirals over six ground stations in Maryland.

Photo Credit: (NASA/Paul E. Alers)