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NASA aims for Tuesday launch of Pegasus rocket

Orbital ATK carrier aircraft will release rocket at 40,000 feet

The Orbital ATK L-1011 Stargazer aircraft. Attached beneath is the Orbital ATK Pegasus XL rocket with NASA's Cyclone Global Navigation Satellite System (CYGNSS).
The Orbital ATK L-1011 Stargazer aircraft. Attached beneath is the Orbital ATK Pegasus XL rocket with NASA's Cyclone Global Navigation Satellite System (CYGNSS).

CAPE CANAVERAL, Fla. – NASA hopes to try again Tuesday morning to launch eight hurricane-monitoring satellites on a rocket dropped high over the Atlantic Ocean.

A problem with the system that releases Orbital ATK's Pegasus XL rocket from its carrier aircraft scrubbed Monday's attempt to launch the $157 million Cyclone Global Navigation Satellite System mission, or CYGNSS, which will study the intensification of hurricanes.

"Ideally, we’re going to get that resolved today," said Tim Dunn, the NASA launch director. "We’re all leaning forward as if we can go (Tuesday)."

The air-launched Pegasus is flying for the first time since 2013, and the first time from Cape Canaveral Air Force Station since 2003.

Fog delayed its departure from the base's Skid Strip by about a half-hour Monday, but the rocket took off under the belly of the L-1011 Stargazer aircraft at 7:37 a.m.

As the aircraft neared its drop point more than 100 miles east of Daytona Beach, at an altitude of nearly 40,000 feet, engineers reported a problem with a pump in the hydraulic system that releases latches holding the 50,000-pound, 57-foot Pegasus in place.

The first drop opportunity at 8:40 a.m. was skipped, and the plane flew in a racetrack pattern for a second and final opportunity at 9:05 a.m.

"We did a lot of valiant troubleshooting in the air," said Dunn. "We did circle around the racetrack once, resetting breakers onboard the aircraft, doing what we could in flight to try to get that system back and functional again."

Weather also proved tricky. Thunderstorms and thick clouds forced the L-1011 to adjust its flight path several times to steer away from trouble that would have violated launch rules.

The ability to maneuver around weather is part of the advantage rockets launched at altitude, but on Monday, the hydraulic pump problem could not be resolved in flight.

"It’s a beautiful launch system to allow you that type of flexibility," said Dunn. "However, just like any other launch vehicle system that we use, you do have hardware issues that crop up."

Dunn said the goal was to fix the pump quickly enough for launch teams to get the rest they need to be ready to return to their stations early Tuesday morning.

A launch Tuesday would targeted for 8:24 a.m., during an hour-long window opening five minutes earlier.

The weather is expected to be better, with an 80 percent chance of favorable conditions.

"Obviously, you’d love to go on the first attempt," said Dunn. "It’s part of our business. We’re used to it...We’re going to keep everybody leaning forward to preserve every opportunity to go (Tuesday)."

Led by scientists from the University of Michigan, the CYGNSS mission aims to launch eight microsatellites that each weigh about 60 pounds and, with solar wings deployed, are described as about the size of a swan.

For at least two years, the satellites will fly in a band round the globe about 315 miles over the tropics. By picking up signals from Global Positioning System satellites that reflect off the ocean surface, the constellation will calculate wind speeds at the center of storms.

Current satellites and aircraft can't take those measurements as often, and their signals may not be able to penetrate heavy rains.

Launch Tuesday

Rocket: Orbital ATK Pegasus XL

Mission: NASA’s Cyclone Global Navigation Satellite System (CYGNSS)

Launch Time: 8:24 a.m. EST

Launch Window: 8:19 a.m. to 9:19 a.m. EST

Runway: Skid Strip at Cape Canaveral Air Force Station

Launch Site: 100+ miles of coast of Daytona Beach

Weather: 80 percent “go”