The Ask An Expert lecture series at the National Mall building is presented every Wednesday at noon. A Museum staff member talks to the public about the history, collection, or personalities related to a specific artifact or exhibition in the Museum.

Corrective Optics Space Telescope Axial Replacement (COSTAR), "Contact Lenses for the Telescope," on display at the new "Moving Beyond Earth" gallery in the National Air and Space Museum's Mall building.

Soon after its launch in 1990, scientists realized that the Hubble Space Telescope’s large primary mirror was flawed. It distorted images and data, making everything blurry. Shuttle crews installed this corrective optics package, called COSTAR, in 1993 and returned it to Earth in 2009.

 How to attend

National Air and Space Museum in Washington, DC

6th St. and Independence Ave SW. Washington, DC 20560