4:20pm ET Monday Update: Per SpaceX founder Elon Musk, the company is working toward a "hop" test at 6pm ET (22:00 UTC) Monday.
Original post: As soon as Monday afternoon, SpaceX may attempt a second flight for its Starship prototype named "Starhopper." The stubby vehicle, which resembles a water tower, will seek to make a controlled flight to 150 meters above the ground before returning to land safely at SpaceX's test site in South Texas.
One month ago, Starhopper made its first untethered flight, rising about 20 meters. Although smoke from the vehicle's single Raptor engine shrouded most of that test flight from view, it came off successfully and validated the company's ability to control the Raptor engine in flight.