COCOA BEACH, Fla. —As it so often does in the final days before the debut of a new rocket, it all comes down to weather.

Blue Origin expects the New Glenn to provide a viable alternative to SpaceX's market-dominating Falcon family of rockets.

Partly cloudy. Light winds becoming east to southeasterly 15 to 25 km/h in the middle of the day then becoming light in the late evening. Partly cloudy. The chance of fog in the early morning. Slight ...