A NASA statement says the event Saturday will help celebrate the agency's 60th anniversary and the 20th anniversary of the International Space Station.
Officials say the public will be offered a free behind-the-scenes look at NASA accomplishments. Visitors can check out moon rocks, Apollo-theme items and a Destination Station mobile exhibit.
Johnson Space Center is home to U.S. astronauts and Mission Control.
Saturday's open house will be held from 10 a.m. to 2 p.m., with last entry for guests at 1:30 p.m.