Bathynellacea is an order of crustaceans which live interstitially in groundwater. They are less than long, and live interstitially. Species of Palpigradi live interstitially in wet tropical and subtropical soils. They are less than long, and live interstitially in the intertidal zones of sandy beaches. Segments of "HypaSpace" aired interstitially between Space programs. Debuting in 2005, it airs interstitially on the Space television schedule.