CAPE CANAVERAL, Fla. — What may be a first-of-its-kind U.S. spy satellite is set to lift off Thursday atop an Atlas V rocket.
The countdown from from Cape Canaveral Air Force Station is set to begin Thursday morning after a more than two-week delay because of damage to an Air Force tracking radar needed to ensure public safety during the flight.
The 19-story United Launch Alliance rocket and its classified National Reconnaissance Office payload returned to their Launch Complex 41 pad on Wednesday morning, repeating a trip they made March 24, the same day an electrical short disabled the tracking radar located on Kennedy Space Center.
Air Force meteorologists expect near-perfect launch weather, with only a 10 percent chance that thick clouds could pose a problem.
Launch windows are not disclosed for NRO missions, but weather forecasts showed it may extend about 40 minutes. The Air Force’s posted a hazard area that boaters should avoid is active until 3:15 p.m.
The NRO also does not discuss what it is launching.
A ULA poster for the mission shows an electric blue Pegasus striding over Earth’s horizon and the Latin phrase “In Scientia Opportunitas,” or “In knowledge, there is opportunity.”
Amateur astronomers who make a hobby of tracking satellites, including secret missions, suspect the payload is a signals intelligence, or SIGINT, satellite bound for a geosynchronous orbit more than 22,000 miles above the equator.
Signals intelligence satellites are designed to detect transmissions from broadcast communications systems such as radios, as well as radars and other electronic systems, according to an overview from the Federation of American Scientists.
The analysis is based on the type of rocket being used, the satellite’s estimated mass, the flight’s eastward trajectory from Cape Canaveral and public knowledge about previous NRO missions.
Those factors provide “strong evidence” for a next-generation signals intelligence spacecraft headed for geosynchronous orbit, Toronto-based Ted Molczan wrote in a recent post on the SeeSat-L electronic mailing list, updating one he titled “NRO payload guesses.”
The Atlas V is flying in one of its most powerful configurations, with four solid rocket motors strapped to the first-stage booster, and may be equipped with a special package intended to extend the life of the Centaur upper stage.
That would allow the rocket to place the satellite — estimated to weigh roughly 8,000 pounds — directly into its final orbit instead of the satellite maneuvering itself into position, consistent with past NRO practice for these types of missions.
ULA will air a webcast starting 20 minutes before liftoff, but it will go black about four minutes into flight to help preserve the mission’s secrecy.
The launch is proceeding after the Air Force reactivated a backup tracking radar to replace the damaged one, which is still being repaired. The launch is the first of two planned within four days, with SpaceX targeting a Monday afternoon launch of cargo to the International Space Station.