Weather looks good for Friday launch of 'flight proven' SpaceX Falcon 9

Weather conditions are expected to be favorable for the launch of a SpaceX Falcon 9 rocket from Kennedy Space Center on Friday despite the presence of Tropical Storm Cindy in the Gulf of Mexico.

Forecasters with the Air Force's 45th Weather Squadron on Wednesday said conditions for the 2:10 p.m. launch from pad 39A with the BulgariaSat-1 communications satellite are 90 percent "go" with cumulus clouds being the only concern. Conditions drop slightly to 80 percent "go" if the launch is delayed to Saturday.

The mission was delayed from Monday due to a technical issue with a fairing valve, according to SpaceX CEO Elon Musk. Fairings, affixed to the top of rockets, are protective structures that encapsulate spacecraft and separate after launch.

"Postponing launch to replace fairing pneumatic valve," Musk said via Twitter. "It is dual redundant, but not worth taking a chance."

[SpaceX bets the house to become satellite internet provider]

[SpaceX booster may be displayed near Port Canaveral, Air Force Station]

In the Gulf, the National Hurricane Center is monitoring Tropical Storm Cindy, a system that has initiated storm watches and warnings for portions of the Texas coast and the entirety of the Louisiana coast. Air Force weather officials do not expect the system to significantly impact launch probabilities.

"For Friday, as the aforementioned tropical disturbance tracks farther northward and inland along the Gulf States, an upper-level high and associated dry air will build over the Florida peninsula producing favorable conditions for about 48 hours," the 45th Weather Squadron said.

Hurricane center forecasters Wednesday morning said the system had maximum sustained winds of 50 mph and its strength was expected to remain about the same through Thursday.

SpaceX has a two-hour window to launch the nine-engine rocket, the first stage of which was previously flown in January on a mission with 10 Iridium NEXT satellites from Vandenberg Air Force Base in California. This will be the company's second attempt to launch a "flight proven" first stage.

[SpaceX launches ISS cargo from KSC, lands Falcon at Cape Canaveral]

[SpaceX launches secret U.S. mission, sticks Cape landing]

Due to fuel constraints, however, the first stage will not return to land at Cape Canaveral Air Force Station's Landing Zone 1 – instead, it will target a soft landing on the "Of Course I Still Love You" drone ship stationed off the east coast of Florida. The booster and ship should return to Port Canaveral a few days after landing.

This Falcon 9 has been enlisted to launch Bulgaria's first geostationary communications satellite, meaning it will match the speed of Earth's rotation and stay in a fixed position over the globe. The 8,000-pound spacecraft will deliver television programming to the Balkans and southeastern Europe.

It could be a historic weekend for the California-based company – if all goes according to plan, SpaceX will also launch a Falcon 9 rocket from Vandenberg on Sunday, this time with more Iridium satellites. That would mark the shortest time between Falcon 9 launches and is ultimately crucial to Musk's vision to increase launch capacity while simultaneously lowering costs through reusability.

Contact Emre Kelly at aekelly@floridatoday.com or 321-242-3715. Follow him on Twitter and Facebook at @EmreKelly.

Launch Friday

Rocket: SpaceX Falcon 9

Mission: Delivery of BulgariaSat-1 to geostationary orbit

Launch Time: 2:10 p.m.

Launch Window: Two hours

Launch Pad: 39A at Kennedy Space Center

Weather: 90 percent "go"

Backup launch date: Saturday