海角大神

海角大神 / Text

Glitch delays launch of hurricane-watching microsatellites

NASA scrubbed the launch of a fleet of eight hurricane-monitoring satellites on Monday after discovering problems with the hydraulic system used to release the satellite-carrying rocket from its plane.

By Lonnie Shekhtman, Staff

It will be at least another day until NASA can get its set of eight microsatellites into Earth鈥檚 orbit to observe how tropical storms form, helping scientists better predict the intensity of life- and property-threatening hurricanes.

The space agency scrubbed Monday鈥檚 satellite drop-off midflight after engineers realized that the hydraulic pump on the plane carrying the Pegasus XL rocket, with the satellites on board, failed to release the latches that would have freed Pegasus to take off for low-Earth orbit, where it would have dropped the satellites.

鈥淭he aircraft is on its way back with the Pegasus XL rocket still safely attached,鈥 NASA reported online Monday morning after canceling the mission. 鈥淭he next possible launch opportunity is Tuesday, pending resolution of the pump issue,鈥 said the agency.

If the pump is fixed and the mission resumes Tuesday, the piloted L-1011 Stargazer aircraft will take off from Cape Canaveral Air Force Station again in the morning, with Pegasus XL attached to its underbelly. Both aircraft and rocket were built by Dulles, Va.-based aerospace and defense company Orbital ATK. When the Stargazer reaches about 40,000 feet over the Atlantic Ocean 鈥 a few thousand feet higher than commercial airlines reach 鈥 it will release Pegasus.

Then Pegasus will free-fall for five seconds before igniting its first-stage rocket motor to help launch itself to low-Earth orbit, a strip of near-Earth space that stretches between 100 miles and 1,200 miles聽above sea level. Once there, Pegasus will deliver the constellation of eight microsatellite observatories, known collectively as the Cyclone Global Navigation Satellite System, or CYGNSS, in about 10 minutes, according to Orbital ATK鈥檚 web site. The eight instruments, built by the Southwest Research Institute in San Antonio, Tex.聽will orbit the tropics, where most cyclones and hurricanes form.

鈥淔or the most part, we can predict track very easily,鈥 says Derek Posselt, a University of Michigan professor who is a deputy principal investigator for CYGNSS, in a video. 鈥淲e still have a very hard time knowing how intense the storms will be when they get where they鈥檙e going. The intensity of hurricanes is really what causes all the damage.鈥

CYGNSS will use radio signals from four GPS satellites, the same ones that beam directions to the mapping apps on our phones, to measure the wind speed near the oceans. As Space.com explains:

Using eight satellites helps scientists increase the area of Earth that can be measured, according to NASA. The satellites will be deployed separately around the planet, with successive satellites passing over the same region every 12 minutes. As the CYGNSS and GPS satellites move around the earth, their collaboration will could more quickly provide information about wind speed over the entire tropics: every few hours聽compared to every few days for a single satellite.

"This sampling strategy will overcome the limitations of a previous single, wide-swath approach," said Chris Ruf, a University of Michigan scientist and聽the mission's principal investigator, in a statement online.