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Taurus rocket nose shroud dooms another NASA satellite

Posted: March 4, 2011

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For the second flight in a row, a solid-fueled Taurus rocket failed to orbit a NASA climate research satellite Friday because the launcher's nose shroud clung to the booster after it was supposed to jettison.

The Taurus rocket blasted off at 2:09 a.m. local time from Vandenberg Air Force Base, Calif. Credit: Orbital Sciences
The extra burden of the payload fairing kept the Taurus rocket from attaining the required velocity and altitude to achieve orbit, causing the Taurus upper stage and NASA's $424 million Glory climate satellite to fall back to Earth.

"We're expecting to shed weight as the fairing comes off," said Omar Baez, NASA's launch director for the mission. "Obviously we didn't shed that weight, and the rocket just can't carry on into orbit with that extra amount of weight."

The rocket and the Glory satellite likely plummeted into the southern Pacific Ocean, Baez said.

The failure dealt a major blow to Orbital Science Corp., which built the Glory satellite and is the Taurus rocket's prime contractor.

"I think it's not an understatement to say that tonight we're all pretty devastated, but we will recover," said Ron Grabe, general manager of the Orbital Sciences launch systems group. "The team will bounce back because they're all professionals. And Orbital Sciences will bounce back with the Taurus vehicle."

The clamshell-like fairing was supposed to jettison nearly three minutes after the Taurus rocket blasted off at 2:09:43 a.m. PST (5:09:43 a.m. EST; 1009:43 GMT) Friday from Vandenberg Air Force Base, Calif.

The rocket's flight was normal up until the scheduled time of fairing separation, according to NASA officials.

"We have lost the Glory mission," said Mike Luther, deputy associate administrator for programs in NASA's science division. "It would have made important measurements for the understanding of Earth as a system and the impacts of climate change."

The 63-inch-diameter fairing, built by Vermont Composites, shields sensitive satellites and sensors from atmospheric contaminants on the launch pad and in the first few minutes of flight. The shroud separates once the rocket reaches the thin outer layers of the atmosphere.

But something prevented the nose cone from peeling away during Friday's mission.

NASA and Orbital Sciences are convening investigation teams to probe what went wrong.

Another nose cone mishap doomed a $273 million satellite mission in February 2009, when an identical Taurus rocket fell short of orbit with NASA's Orbiting Carbon Observatory.

Since that failure, NASA and Orbital Sciences meticulously redesigned the Taurus fairing separation apparatus, turning to a flight-proven system with a successful track record on three launches of the company's Minotaur 4 rocket.

An inquiry into the 2009 failure could not pin down a smoking gun for the loss of OCO, but engineers uncovered four potential reasons for the anomaly and identified a most probable cause. Officials addressed the board's findings when they redesigned the Taurus shroud jettisoning system.

Investigators determined the most probable cause of the OCO launch failure was in the fairing separation initiation system, according to Grabe.

Rich Straka, Orbital's deputy general manager of launch operations, said the Taurus fairing uses explosive charges to separate the two halves of the nose shroud. Pneumatic pistons then push the fairing halves apart in a hinge-like motion.

The Glory satellite was placed inside the Taurus payload fairing in early February. Credit: NASA/Don Kososka/VAFB
Taurus rockets previously used a hot gas generator to push the fairing separation pistons. Orbital Sciences switched to the Minotaur 4 rocket's cold gas system for the Glory launch, relying on a high-pressure nitrogen bottle instead of hot gas to force the shroud apart.

"We really went into this flight feeling confident that we had nailed the fairing issue," Grabe said in a press conference Friday morning.

Before Friday's launch, officials said they did all they could to make sure Glory's Taurus rocket was good to go. The Glory mission was the first Taurus flight since the loss of OCO.

"It's kind of like there's that cold pool and you've got to dip your toe in it. We've done everything we can," Baez said before the launch. "We're as comfortable as we're going to get. I think the the whole team has done some soul-searching and looked deep at everything we've done. I don't think we can uncover anything else."

John Brunschwyler, Orbital's Taurus program manager, said last month that engineers not only revamped the fairing, but also made upgrades in the rocket's structures, electrical and guidance systems, and ordnance charges.

But all of that work wasn't enough to prevent Friday's launch failure.

It was the 9th flight of a Taurus rocket since 1994. Six of those launches were successful.

The 1,164-pound Glory satellite was heading for a 438-mile-high orbit to join a fleet of NASA climate research spacecraft in a formation called the A-Train.

Glory's two scientific sensors were designed to monitor the sun's impact on Earth's climate and track tiny atmospheric particles called aerosols, according to researchers.

The mission was expected to help policymakers decide how to deal with climate change, according to Joy Bretthauer, the Glory program executive at NASA Headquarters.

A Total Irradiance Monitor was designed to measure solar brightness, continuing a 32-year data record that serves as a log of the sun's natural influence on Earth's climate. The sun is the largest contributor to the planet's energy budget.

"As we try to decide what policies are going to be needed to mitigate or control climate change, we need to be able to distinguish how much of it we have control over versus how much we don't," said Greg Kopp, the Total Irradiance Monitor's instrument scientist from the University of Colorado's Laboratory for Atmospheric and Space Physics.

Glory's Aerosol Polarimetry Sensor was supposed to identify natural and manmade aerosols, tiny particles that introduce uncertainties into existing climate models. Aerosols include soot, smog and dust.

Aerosols can be transported by winds around the world, and Glory was designed to collect millions of measurements across the globe.

Scientists say aerosols are a key method of redistributing solar energy in the atmosphere.

The Taurus rocket was also carrying three small CubeSat satellites built by university students in Montana, Colorado and Kentucky.

Officials said it was too early to discuss how the back-to-back Taurus launch failures could impact NASA's plans to fly more satellites on the rocket. The Taurus currently has just one more mission on the manifest in early 2013, a reflight of the OCO carbon-mapping satellite lost in 2009.

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