Weather OK for SpaceX launch from KSC as system brews in Caribbean

Weather conditions are trending toward favorable for the Saturday launch of a previously flown SpaceX Falcon 9 rocket from Kennedy Space Center, according to Air Force forecasters.

The 6:53 p.m. launch is expected to face 60 percent "go" conditions during a two-hour window at pad 39A, but a tropical system brewing in the Gulf of Mexico could quickly alter plans if projections shift east.

Forecasters said the system "will likely develop into a tropical cyclone threatening the northern Gulf Coast," noting that a mission delay to Sunday could make it more vulnerable to the storm's path.

"Meteorological models are spread and impact the coast anywhere from Louisiana to the Florida Panhandle," the latest forecast reads.

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Sunday's forecast also stands at 60 percent "go" and the presence of cumulus and thick clouds are the primary concerns through the weekend.

Pad 39A saw a successful 7-second firing of the rocket's nine Merlin main engines at 4:30 p.m. Monday. The operations, known as "static test fires," are routine checkouts of vehicle operations prior to every SpaceX launch.

Atop the previously flown Falcon 9 rocket will be EchoStar 105 / SES-11, a dual-mission spacecraft being launched for Colorado-based EchoStar and Luxembourg-based SES. The 11,000-pound commercial communications satellite will cover a swath of North America, including all 50 U.S. states and parts of Mexico and the Caribbean.

Saturday's mission marks SpaceX's third attempt at flying a previously launched booster. SES was the first customer to fly on a recycled rocket in March, followed by BulgariaSat in June – both from KSC's pad 39A.

If the landing goes smoothly, the first stage should arrive at Port Canaveral by early-to-mid next week. The Hawthorne, California-based company has so far successfully landed 16 of its boosters on both coasts.

SpaceX CEO Elon Musk sees rocket reusability as the key to reducing launch costs, increasing access to space and achieving his long-term objective of colonizing Mars.

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