The Winged Pegasus: An Unusual Launch Experience

Technicians and engineers perform final wing installations on the Orbital ATK Pegasus XL rocket which will launch eight NASA Cyclone Global Navigation Satellite System, or CYGNSS, spacecraft.

Pegasus_launch_fullOrbital ATK’s Pegasus rocket gets its payloads into space just like a conventional rocket, but instead of lifting off from the ground, the Pegasus starts its trip already in the air. That’s because a modified L-1011 airliner carries the Pegasus and its payload – CYGNSS in this case – to about 39,000 feet. Pegasus begins its solo flight by being released from the belly of the airliner.

Five seconds of free-fall ends when the solid-fueled first stage ignites. With its main, delta-shaped wing providing lift and a rudder and elevators on the back steering, the Pegasus noses up quickly and heads into orbit, discarding its first stage after leaving the thick portion of the atmosphere. The second and third stages, also burning solid propellants, take over to place the satellites in their prescribed orbit. Here’s a look at what makes the Pegasus flights different:

Forecast Worsens to 40 Percent ‘Go’

A revised forecast from the U.S. Air Force 45th Weather Squadron predicts deteriorating conditions and a 40 percent chance of favorable weather for the launch of NASA’s CYGNSS spacecraft. Launch is scheduled for 8:24 a.m. EST Monday, Dec. 12 aboard an Orbital Sciences ATK air-launched Pegasus XL launch vhicle, seen on the right beneath the L-1011 aircraft called “Stargazer” that will carry the rocket to a deployment altitude about 39,000 feet above the Atlantic Ocean.

The primary concerns are for precipitation, lightning and Cumulus clouds. The rocket is scheduled for deployment over the Atlantic Ocean from Orbital’s L-1011 carrier aircraft, seen above with the Pegasus underneath.

NASA’s Kennedy Space Center will host a Facebook Live event at noon on Saturday from the Skid Strip runway at nearby Cape Canaveral Air Force Station. Briefers will highlight the science involved in the CYGNSS mission, the L-1011 aircraft and the Pegasus rocket, and participants will get a view inside the airplane. The event will stream live on Kennedy’s Facebook page at http://www.facebook.com/NASAKennedy

Managers from NASA and Orbital ATK will hold a final Launch Readiness Review Saturday morning, followed by two news conferences. The Prelaunch News Conference will be at 1 p.m., followed by the CYGNSS Mission Science Briefing at 1:45 p.m. Both will be carried live on NASA Television and the agency’s website.

CYGNSS will make frequent and accurate measurements of ocean surface winds throughout the lifecycle of tropical storms and hurricanes. The CYGNSS constellation consists of eight microsatellite observatories that will measure surface winds in and near a hurricane’s inner core, including regions beneath the eyewall and intense inner rainbands that previously could not be measured from space. For more information about NASA’s CYGNSS mission, visit https://www.nasa.gov/cygnss

Forecast 70 Percent ‘Go’ For CYGNSS Launch on Monday

The first weather forecast for NASA’s CYGNSS mission shows meteorologists from the U.S. Air Force 45th Weather Squadron predict a 70 percent chance of favorable weather for the launch window. Launch is scheduled for 8:24 a.m. EST on Monday, Dec. 12. During the one-hour window, which opens at 8:19 a.m., CYGNSS will take off aboard an Orbital Sciences ATK air-launched Pegasus XL launch vehicle. The rocket is scheduled for deployment over the Atlantic Ocean from Orbital’s L-1011 carrier aircraft, seen in these photos with the Pegasus rocket beneath it. Photos by NASA/Kim Shiflett (top) and NASA/Randy Beaudoin.

NASA’s Kennedy Space Center will host a Facebook Live event at noon on Saturday from the Skid Strip runway at nearby Cape Canaveral Air Force Station. Briefers will highlight the science involved in the CYGNSS mission, the L-1011 aircraft and the Pegasus rocket, and participants will get a view inside the airplane. The event will stream live on Kennedy’s Facebook page at: http://www.facebook.com/NASAKennedy

Managers from NASA and Orbital ATK will hold a final Launch Readiness Review Saturday morning, followed by two news conferences. The Prelaunch News Conference will be at 1 p.m., followed by the CYGNSS Mission Science Briefing at 1:45 p.m. Both will be carried live on NASA Television and the agency’s website.

CYGNSS will make frequent and accurate measurements of ocean surface winds throughout the lifecycle of tropical storms and hurricanes. The CYGNSS constellation consists of eight microsatellite observatories that will measure surface winds in and near a hurricane’s inner core, including regions beneath the eyewall and intense inner rainbands that previously could not be measured from space.

To learn more about the CYGNSS mission, visit: https://www.nasa.gov/cygnss

Orbital ATK Stargazer Arrives with Pegasus XL and CYGNSS

Orbital ATK Stargazer aircraft arrives at the Skid Strip at Cape Canaveral Air Force Station in Florida.The Orbital ATK L-1011 Stargazer aircraft touched down at 3:57 p.m. EST at the Skid Strip at Cape Canaveral Air Force Station in Florida. Attached beneath the Stargazer is the Orbital ATK Pegasus XL with NASA’s Cyclone Global Navigation Satellite System (CYGNSS) on board. CYGNSS was processed and prepared for its mission at Vandenberg Air Force Base in California.

CYGNSS is scheduled for its airborne launch aboard the Pegasus XL rocket from the Skid Strip on Dec. 12. CYGNSS will make frequent and accurate measurements of ocean surface winds throughout the life cycle of tropical storms and hurricanes. The data that CYGNSS provides will enable scientists to probe key air-sea interaction processes that take place near the core of storms, which are rapidly changing and play a critical role in the beginning and intensification of hurricanes.

Photo credit: NASA/Kim Shiflett

CYGNSS Mission ‘Go’ to Continue Processing After Flight Readiness Review

Technicians and engineers perform final wing installations on the Orbital ATK Pegasus XL rocket which will launch eight NASA Cyclone Global Navigation Satellite System, or CYGNSS, spacecraft.At the conclusion of Flight Readiness Review at Kennedy Space Center in Florida on Monday, senior NASA and contractor managers voted unanimously to proceed with processing toward the targeted launch of the CYGNSS mission on an Orbital ATK Pegasus XL rocket on Monday, Dec. 12.

The eight NASA Cyclone Global Navigation Satellite System (CYGNSS) spacecraft installed on their deployment module undergo inspectionsThe team is progressing towards mating the Pegasus rocket to Orbital ATK’s L-1011 aircraft, nicknamed “Stargazer,” next week at Vandenberg Air Force Base in California for the ferry flight to Kennedy. A final “go” decision will be made at the CYGNSS Launch Readiness Review on Saturday, Dec. 10.

On launch day, the Stargazer aircraft will take off from the Skid Strip at Cape Canaveral Air Force Station in Florida, carry the Pegasus XL rocket to a precise drop point for its release and launch. The two-year CYGNSS mission will make frequent and accurate measurements of ocean surface winds throughout the life cycle of tropical storms and hurricanes. The data that CYGNSS provides will enable scientists to probe key air-sea interaction processes that take place near the core of storms, which are rapidly changing and play a critical role in the beginning and intensification of hurricanes.

Photo above: NASA/Alex Valdez
Photo at right: NASA/Randy Beaudoin