Not all NASA missions are flown in space. In fact, one current Earth-based NASA mission is designed to help predict and track air pollution close to the ground. And that information, in turn, should eventually help those of us on the ground to predict when to open the windows and when to turn up our air purifiers.

Meanwhile, the U.S. space shuttle program comes to an end after the shuttle Atlantis, launched last Friday, returns to Earth late next week.

But NASA is alive and well and actively involved in exploration closer to home with projects such as “DISCOVER-AQ” that involves flying a research plane in spirals over Maryland.

The purpose of DISCOVER-AQ is to collect air pollution information that can help pave to way for future space-based pollution monitoring.

The program name, by the way, stands for “Deriving Information on Surface Conditions from Column and Vertically Resolved Observations Relevant to Air Quality.” Got that?

Ultimately, the goal of the mission is to enable scientists to make better air quality forecasts, more accurately determine the source of air pollutants in the air and get a better understanding of fluctuations in emissions levels.

Flights of a specially equipped P-3B aircraft began in late June and are expected to continue through July. The P-3 is a four-engine turboprop plane that has been extensively modified for the NASA mission.

A second, smaller aircraft is also being used for the mission.

The planes are detecting variations in ozone and particulate pollution levels at various elevations from a low of 1,000 feet (30,480 cm) to a highest elevation of over 15,000 feet (457,200 cm). The results of the data collected in the spiraling flights, combined with data from the ground and from a high-flying plane, will enable air-quality trackers to use satellites more precisely in space to track air pollution close to the ground.

The low-level spiraling flights are easily viewed along Interstate 95 in the greater Washington, D.C., area and have left spectators near the Chesapeake Bay gawking in wonder.

The flights can last up to eight hours. The DICSCOVER-AQ planes were flying yesterday over the northeast Maryland with plenty more soon to come.

Real-time flight tracking and other information is available at theDISCOVER AQ website.