Item 2. PROPERTIES

Our corporate headquarters are located in Reston, Virginia. We have administrative, sales, marketing, research and development and operations facilities located in the U.S., Europe, Asia, and Australia. As of December 31, 2018, we owned approximately 454,000 square feet of space, which includes facilities in Reston and Dulles, Virginia and New Castle, Delaware. As of December 31, 2018, we leased approximately 17,000 square feet of space in Europe, Australia and Asia. These facilities are under lease agreements that expire at various dates through 2022.

We believe that our existing facilities are well maintained and in good operating condition, and are sufficient for our needs for the foreseeable future. The following table lists our major locations and primary use as of December 31, 2018:

The table above does not include approximately 58,000 square feet of space owned by us and leased to third parties.