Pegasus rocket returns for "liftoff" from aircraft
NOTE: The Monday (Dec. 12) scheduled launch attempt was scrubbed. We are awaiting word on new launch day, time.
TUNE IN NOW: Live video and launch commentary from FLORIDA TODAY's spaceteam.
Previous update:
This morning’s planned rocket launch of NASA weather satellites isn’t one you’ll hear or see, except on TV.
Orbital ATK’s winged Pegasus XL rocket, flying from the Cape for the first time in 13 years, will launch far out over the Atlantic Ocean, after being dropped from a carrier aircraft at nearly 40,000 feet.
How to watch the Pegasus XL rocket 'liftoff'
“Maybe on a perfect weather morning you might see a glimpse of something, but we are going to be about 100 miles offshore, almost due east of the Daytona area,” said Tim Dunn, the mission’s NASA launch director. “So low likelihood to see anything (from the coast).”
An F-18 chase plane will provide views of the rare air-launch, which is targeted for 8:24 a.m., to NASA TV.
The 57-foot, 50,000-pound Pegasus is charged with delivering NASA’s $157 million Cyclone Global Navigation Satellite System mission, or CYGNSS, to low Earth orbit.
Pegasus, CYGNSS arrive for Cape Canaveral launch
The experimental mission, led by University of Michigan scientists, will try out a new technique for measuring sustained winds in the middle of tropical storms.
That's important information to help forecasters determine if storms are gaining strength or weakening.
But it’s difficult to get from current satellite instruments, which can’t penetrate heavy rain, and “hurricane hunter” aircraft that can only fly over parts of storms every so often.
As a result, forecasts over time have gotten better at predicting where storms are headed, but not how strong they’ll be when they make landfall.
How to watch the Pegasus XL rocket 'liftoff'
“Our ability to forecast how strong the hurricane is going to be when it makes landfall will get much better,” said Chris Ruf, the mission’s lead scientist from the University of Michigan.
The weather forecast has improved for Monday’s launch attempt.
Saturday, a forecast of potential rain and clouds had combined for a 40 percent chance of acceptable weather during a one-hour launch window opening at 8:19 a.m., but on Sunday, the weather forecast has improved to a "60 percent go."
The flight plan calls for Orbital ATK’s L-1011 Stargazer carrier aircraft to take off from the Skid Strip at Cape Canaveral Air Force Station about 7 a.m., with the roughly 50,000-pound, 57-foot-long Pegasus fastened to its belly.
A launch conductor on the ground will give the pilot the go-ahead to release the rocket inside a designated “drop box” measuring about 45 miles by 10 miles.
If conditions aren’t right, the aircraft can circle around for one more try later in the window.
Once dropped, the three-stage, solid-fueled Pegasus will fall for about five seconds before igniting its first-stage engine and rocketing upward.
The first pair of CYGNSS micro-satellites should be deployed about 13 minutes later, followed by three more pairs in 30-second intervals.
Each spacecraft weighs about 64 pounds and is described as the size of a grown swan, once solar panels are deployed.
The constellation will form a line around the planet 315 miles up, flying within a band above and below the equator where most tropical storms form.
“All these satellites in combination give us great coverage over the tropics, where we expect most of the tropical cyclones to be,” said Mary Morris, a University of Michigan doctoral student involved in the mission.
The spacecraft are equipped with receivers to catch Global Positioning System signals — the same signals smart phones and other devices use to give your location — that are reflected off the surface of the oceans.
The strength of the reflected signals will enable calculations of wind speeds at the center of storms, with measurements of the same location possible every seven hours on average.
If the technique works well, it could be folded into official hurricane tracking models.
The mission is funded for two years, but could be extended. The micro-satellites are designed to last five years or more.
If the Pegasus can’t take flight on Monday, another opportunity is available Tuesday morning.
Contact Dean at 321-242-3668 or jdean@floridatoday.com.And follow on Twitter at @flatoday_jdeanand on Facebook at facebook.com/jamesdeanspace.
Schedule of upcoming Florida rocket launches
TUNE IN NOW: Live video and launch commentary from FLORIDA TODAY's spaceteam.
Launch Monday
Rocket: Orbital ATK's air-launched Pegasus XL
Mission: NASA’s Cyclone Global Navigation Satellite System (CYGNSS)
Launch time: 8:24 a.m.
Launch window: 8:19 a.m. to 9:19 a.m. EST
Runway: Skid Strip at Cape Canaveral Air Force Station
Launch zone: 100+ miles off coast of Daytona Beach
Weather: 60 percent “go”
Join floridatoday.com for launch updates, including streaming of NASA TV coverage, starting at 6:45 a.m. Monday.