The US Federal Aviation Administration said on Thursday that it has approved the next three launches of the SpaceX "starship" prototype and confirmed that the head of the FAA made talks with ElonMusk on safety issues last month.
The FAA said it would investigate to verify that SpaceX had implemented corrective measures before launching SN15. The investigation is ongoing and is expected to continue until the December launch.
The FAA also said SpaceX "may need to take additional corrective actions" for subsequent SN16 and SN17 launches "if a new accident investigation is initiated."
SpaceX is testing a series of prototypes for its heavy-lift rocket. SpaceX plans to use the rocket to send people and 100-ton cargo to the moon and Mars. Starship's first orbital flight is scheduled for the end of the year.
This month, NASA awarded SpaceX a $2.9bn contract to build spacecraft that could send astronauts to the moon as early as 2024.
As a condition of granting SpaceX the license, the FAA required that FAA safety officers be on site in Boca Chica, Texas, before launching the Starship spacecraft. Safety officers from the FAA were expected to arrive on Thursday "to provide support for a possible launch this week."
The FAA said SpaceX violated launch authorization requirements by failing to demonstrate that the public risk of "far-field explosive overpressure" met regulatory standards during the launch of Starship SN8 in December.
If the launch vehicle explodes on impact, the far-field explosion overpressure may pose a hazard to the public. The shockwave from the explosion may even damage Windows in distant areas.
The FAA said the analysis used by SpaceX to calculate the risk had not been approved by the agency.
After the December launch, the FAA began requiring SpaceX to be on-site supervised by safety officers, effective March 12.
On Thursday, the F.A.A. also confirmed that its administrator, SteveDickson, had a 30-minute conversation with Mr. Musk on March 12 as "part of the F.A.A. 's ongoing engagement with the company."
SpaceX did not respond to a request for comment.
The FAA said Mr Dixon "highlighted the FAA's role in protecting public safety by ensuring regulatory compliance. He made it clear that the FAA expects SpaceX to build and develop a strong safety culture and adhere to FAA compliance."
In February, the FAA said it had asked SpaceX to investigate the accident and conduct a full self-examination of its safety culture. SpaceX's corrective measures were previously included in a launch in February.
In January, Musk said on Twitter that the FAA's "space division has fundamentally broken the regulatory structure" and that "humans will never land on Mars" under its rules.
But this week Musk took to Twitter to say that the FAA and other regulators "are fair 99.9 percent of the time. I agree with the regulators! On rare occasions, we may disagree. This is almost always due to new technologies that previous regulations could not have predicted.