Launch today! Atlas V with secretive space plane
Editor's note: The Atlas V launched today (May 20) with Air Force mini-shuttle space plane.
9 a.m. update
United Launch Alliance is fueling an 206-foot Atlas V rocket with supercold liquid hydrogen and liquid oxygen in preparation for a planned 11:05 a.m. liftoff from Launch Complex 41 at Cape Canaveral Air Force Station with the Air Force's fourth X-37B space plane mission.
The Atlas V booster's Russian-made RD-180 engine burns Rocket Propellant-1, a highly refined kerosene, which was loaded Tuesday after the rocket rolled to the pad. The Centaur upper stage's Aerojet Rocketdyne RL10C-1 engine burns liquid hydrogen.
Weather is currently "go" for an on-time 11:05 a.m. launch at the opening of the first of two 10-minute launch windows available today.
8 a.m. update
The latest forecast from the Air Force's 45th Weather Squadron continues to show a 60 percent chance of acceptable weather for a launch today of an Atlas V rocket and unmanned military space plane.
Conditions are expected to be better for the first 10-minute window running from 11:05 a.m. to 11:15 a.m.
Then cumulus clouds are expected to build and potentially produce showers and thunderstorms by the second window of 12:42 p.m. to 12:52 p.m., continuing through the afternoon.
If the mission is unable to launch today, the forecast is slightly worse Thursday, with a 30 percent chance of good weather.
7 a.m. update
A 206-foot United Launch Alliance Atlas V rocket is counting down toward an 11:05 a.m. launch today from Cape Canaveral Air Force Station.
The targeted launch time is at the opening of the first of two 10-minute windows just disclosed this morning because of secrecy surrounding the fourth mission by the Air Force's unmanned X-37B space plane program.
The first window runs from 11:05 a.m. to 11:15 a.m., and the second from 12:42 p.m. To 12:52 p.m.
There's a 60 percent chance of favorable weather, and conditions are expected to be better earlier in the day.
Earlier report
One mission will fly under a cloak of darkness, another will test flying by light.
The Air Force's secretive X-37B space plane and a citizen-funded solar sailing experiment headline an eclectic group of spacecraft targeting an 11:05 a.m. launch Wednesday from Cape Canaveral atop a United Launch Alliance Atlas V rocket.
The entire launch window won't be made public until Wednesday because of the the unpiloted mini-shuttle's mostly classified mission — the fourth by a military program moving its operations from California to Kennedy Space Center.
But in a somewhat strange pairing, the same launch brought Bill Nye the Science Guy, who is CEO of The Planetary Society, to Cape Canaveral on Tuesday to discuss the organization's first LightSail mission.
"You can go to very distant destinations in the solar system without any fuel," the bow tie-clad Nye explained of the solar sailing technology, speaking to reporters at the Air Force's Space and Missile History Center. "You can do it much more cheaply."
Through donations from more than 40,000 of its members, including some large gifts by undisclosed donors, the nonprofit Planetary Society raised $4.3 million to develop the LightSail mission.
No bigger than a loaf of bread, the spacecraft is the first of two designed to deploy a square sheet of Mylar measuring 322 square feet.
The sail will catch the sun's steady stream of radiation to maneuver the spacecraft, a bit more slowly than traditional chemical propulsion. A small satellite could reach the moon in a month rather than days, said Nye, or head for Mars or an asteroid.
"You get a continuous very small push, indefinitely," he said. "You can tack, just like a sailboat, this really elegant, wonderful thing."
The spacecraft launching today is one of 10 small satellites known as CubeSats that are hitching rides with the X-37B. The National Reconnaissance Office sponsored nine of them, while NASA facilitated the launch of the first LightSail mission.
Only in orbit for about a month, "LightSail A" won't actually sail but will serve as a shakedown cruise ahead of next year's planned launch by a SpaceX Falcon Heavy rocket of "Lightsail B" on a months-long sailing demonstration.
This test mission hopes to confirm that booms will properly deploy the sail's four triangular sections about two weeks after launch, that software can control the spacecraft and that engineers can communicate with it. Cameras are expected to provide some images from space.
Carl Sagan, one of The Planetary Society's founders, embraced the concept of solar sailing as far back as 1976, when he discussed the idea on "The Tonight Show" with Johnny Carson. The organization attempted to launch a sail in 2005, but a submarine-launched Russian rocket failed.
A Japanese mission successfully demonstrated solar sailing in 2010, but LightSail will be the first to try it with low-cost CubeSats used widely for university-led missions and increasingly for commercial applications.
A recently announced Kickstarter crowdfunding campaign quickly raised more than $500,000 supporting next year's LightSail flight.
Said Nye of LightSail's thousands of donors: "Mostly it was people who just think it's cool. They want to participate in space exploration."
Contact Dean at 321-242-3668 or jdean@floridatoday.com. And follow on Twitter at @flatoday_jdean and on Facebook at facebook.com/jamesdeanspace.
Launch details:
Rocket: United Launch Alliance Atlas V ("501" configuration)
Mission: U.S. Air Force's fourth X-37B Orbital Test Vehicle mission
Launch time: 11:05 a.m.
Launch window: To be disclosed Wednesday; no more than four hours
Launch complex: 41 at Cape Canaveral Air Force Station
Weather: 60 percent "go"
Visit floridatoday.com at 10 a.m. for countdown updates, chat and streaming of ULA's launch Webcast beginning at 10:45 a.m.