SpaceX entered the world of classified space flights today as it launched the Orbital Test Vehicle 5 (OTV-5) mission atop a Falcon 9 booster from Launch Complex 39A at NASA's Kennedy Space Center in Florida. The dramatic launch carrying the secret US Air Force X-37B spaceplane came at 10:00 am EDT, as mission control raced against the threat of the advancing hurricane Irma.

Today's launch was unusual for SpaceX. It's the first military launch for the company and the first OTV flight of the X-37B by a company besides United Launch Alliance. The countdown took place under partly cloudy skies and went without any major delays.

Liftoff and first stage separation occurred on time, but in keeping with the classified nature of the mission, SpaceX's usual live-stream coverage of the launch terminated at the point of first stage shutdown and separation. No videos, time, tracking, or orbital information was given for the second stage burn or the spaceplane's separation.

Instead, the web broadcast focused exclusively on the reentry and successful landing of the first stage at SpaceX's Landing Zone 1 (LZ-1) at Cape Canaveral Air Force Station, Florida. The status of the X-37B has not been confirmed beyond it being a successful launch.

One note of suspense in today's proceedings is the approach of hurricane Irma, which is currently approaching Florida. The category 5 tropical storm isn't expected to reach Cape Canaveral until about Sunday, but had today's launch been scrubbed, the next launch window would not have been until Friday, before which the weather around the launch complex could have deteriorated below an acceptable level as the hurricane approached.

The X-37B is an unmanned resuable spacecraft build along the lines of a mini-Space Shuttle. Part of its purpose is to act as a long-duration technology demonstrator. During its mission, it will carry out small satellite deployments, and will operate the Air Force Research Laboratory Advanced Structurally Embedded Thermal Spreader payload for long-term space testing of experimental electronics, as well as testing oscillating heat pipe technologies. However, the mission's primary purpose, its duration, and current orbit remain a mystery.

The video below recaps today's launch.

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