Rare NASA WB-57 Formation Flight Over Houston

The three WB-57s took off from NASA's Ellington Airport facility on Thursday for a formation flight around the greater Houston area. The event was to showcase the unique aircraft and how its crews prepare for their usual high altitude flights that are conducted above 55,000 feet. But crowds were treated to a much lower pass and were encouraged to take videos and photos to share on social media.

Here's a look at the WB-57s taking off into formation.

The WB-57 was developed from the English Electric Canberra and first entered service with the United States Air Force as a tactical bomber. But the aircraft has been flying research missions since the early 1960s and continue to do so, including recent missions that assisted during this year's hurricane season.

See photos from the historic flight here.