After days of uncertainty, the Federal Aviation Administration announced Sunday that SpaceX had been cleared to press ahead with the planned Monday launch of the European Space Agency's $398 million Hera asteroid probe, stormy weather permitting.
With forecasters calling for an 85% chance of thick clouds and showers that would trigger a delay, Hera's launch atop a Falcon 9 rocket from pad 40 at the Cape Canaveral Space Force Station is targeted for 10:52 a.m. EDT Monday. The forecast is 75% "no-go" if launch is delayed to Tuesday.
"The last hurdle is the weather. So, please, please, I need you to do something about it!" Hera project manager Ian Carnelli joked with reporters Sunday. "It's the only thing I really cannot control. ... It looks like we have some opening around the time of launch, but it's really impossible to say at the moment."
Hurricane Milton, meanwhile, poses threats throughout the week as the cyclone is expected to cross the Florida peninsula Wednesday and move out over the Atlantic Ocean near Florida's Space Coast.
Launch of NASA's $5.2 billion Europa Clipper mission, which had been planned for Thursday from the Kennedy Space Center, has been put on hold pending passage of the storm.
"The safety of launch team personnel is our highest priority, and all precautions will be taken to protect the Europa Clipper spacecraft," said Tim Dunn, a senior launch director with NASA's Launch Services Program.
"Once we have the 'all-clear' followed by facility assessment and any recovery actions, we will determine the next launch opportunity."
Likewise, the return to Earth of three astronauts and a Russian cosmonaut aboard a SpaceX Crew Dragon ferry ship has been delayed by predicted bad weather.
Crew 8 commander Matthew Dominick, Mike Barratt, Jeanette Epps and cosmonaut Alexander Grebenkin, launched to the International Space Station last March. They had planned to undock Monday, returning to Earth to close out a 217-day mission.
But NASA announced Sunday their departure would be delayed to at least Thursday because of expected bad weather. Crew Dragon ferry ships require calm winds and seas in the Gulf of Mexico or the Atlantic Ocean to permit a safe splashdown.
As for the Falcon 9, the FAA clearance only applied to the Hera launch while the agency continues overseeing an investigation into what caused a Falcon 9 second stage to malfunction Sept. 28 and miss its targeted re-entry point into Earth's atmosphere over the Pacific Ocean.
SpaceX routinely sends spent second stages into the atmosphere for destructive breakups at the end of their missions to prevent possible collisions or other problems that might add to the space debris already in low-Earth orbit.
The FAA wants to make sure the problem is understood and corrected so future re-entries are carried out as planned, ensuring any debris that survives re-entry heating will splash down harmlessly in targeted ocean impact "footprints," well away from shipping lanes and populated areas.
The second stage being used for the Hera mission will boost the space probe into deep space, using all of its propellant in the process. It will not return to Earth, so a malfunction, should one occur, would pose no safety threat.
"The FAA has determined that the absence of a second stage reentry for this mission adequately mitigates the primary risk to the public in the event of a reoccurrance of the mishap experienced with the Crew-9 mission," the agency said in a statement, referring to the most recent Falcon 9 flight.
"Safety will drive the timeline for the FAA to complete its review of SpaceX's Crew-9 mishap investigation report and when the agency will authorize Falcon 9 to return to regular operations," the statement concluded.
The FAA did not address plans to launch the Europa Clipper atop a Falcon Heavy rocket Thursday for its long-awaited mission to Jupiter and its ice-covered moon Europa.
Like the Hera mission, the Clipper's upper stage, the same one used for all Falcon-family rockets, will not return to Earth. Instead, it will burn all of its propellants to accelerate the probe to an Earth-escape velocity of 25,000 mph.
But FAA clearance to proceed, assuming it comes in time, likely will be a moot point, at least in the near term. It is unlikely the Clipper and its Falcon Heavy rocket will be moved to the Kennedy Space Center launch pad until after Milton has passed through the area.
Bill Harwood has been covering the U.S. space program full-time since 1984, first as Cape Canaveral bureau chief for United Press International and now as a consultant for CBS News.