The Federal Aviation Administration approved a license on Saturday for the launch of SpaceX's Starship 5 set for Sunday after earlier saying it did not expect to make a decision until late November.
Reuters first reported this week the faster than expected timetable after the FAA in September had suggested a much longer review.
SpaceX is targeting Sunday for the launch and said a 30-minute launch window opens at 7 a.m. CDT.
The FAA said on Saturday SpaceX had "met all safety, environmental, and other licensing requirements for the suborbital test flight" for the fifth test of the Starship and has also approved the Starship 6 mission profile.
The Starship spacecraft and Super Heavy rocket are a fully reusable system designed to carry crew and cargo to Earth orbit, the moon, and beyond.
The fifth test flight of the Starship/Super Heavy from Boca Chica, Texas, includes a return to the launch site of the Super Heavy booster rocket for a catch attempt by the launch tower, and a water landing of the Starship vehicle in the Indian Ocean west of Australia.
The FAA said if SpaceX chooses an uncontrolled entry, "it must communicate that decision to the FAA prior to launch, the loss of the Starship vehicle will be considered a planned event, and a mishap investigation will not be required."
On Friday, the FAA approved the return to flight of the SpaceX Falcon 9 vehicle after it reviewed and accepted the SpaceX-led investigation findings and corrective actions for the mishap that occurred Sept. 28.
SpaceX CEO Elon Musk has harshly criticized the FAA, including for proposing a $633,000 fine against SpaceX over launch issues and for the delay in approving the license for Starship 5, which the company says has been ready to launch since August. Musk has called for the resignation of FAA Administrator Mike Whitaker and threatened to sue the agency.