Board to report on Galileo launch mishap in two weeks
BY STEPHEN CLARK
Posted: August 25, 2014
An eight-member independent board of inquiry will look into the causes and implications of a launcher failure that left a pair of European Galileo navigation satellites in the wrong orbit Friday, while engineers scramble to determine whether the twin spacecraft can be salvaged.
The two 1,615-pound satellites launched aboard a Soyuz ST-B rocket Friday from the Guiana Space Center, a spaceport on the northern coast of South America. The initial phase of the launch appeared to go as planned, with the Soyuz rocket's three main stages falling back to Earth as a Fregat-MT upper stage ignited for two engine firings to place the Galileo satellites in a circular orbit 23,522 kilometers (14,615 miles) above Earth.
But the Russian-made Fregat upper stage released the Galileo spacecraft in the wrong orbit. Tracking data from the U.S. Air Force's space surveillance network showed the satellites in an orbit with a low point of about 13,700 kilometers (8,500 miles) and a high point of approximately 25,900 kilometers (16,100 miles).
The orbit's angle to the equator was also off target. Instead of an inclination of 55 degrees programmed into the Fregat upper stage, the rocket delivered the satellites to an orbit inclined 49.8 degrees.
Arianespace and ESA initially declared the launch successful, but a closer look at data indicated the satellites were deployed off the mark.
Johann-Dietrich Woerner, chairman of the German Aerospace Center (DLR), described the course of events in a blog post Monday.
"Initially, all of the measurements suggested a perfect mission; the launcher took off at the scheduled time, followed the prescribed trajectory, and the stage separation was carried out correctly," Woerner wrote. "However, the first problem became apparent when the two satellites proved unable to deploy their solar arrays as intended. A more detailed analysis then revealed that the eccentricity, the altitude and the inclination of the satellites' orbits with respect to Earth's equator did not meet the specifications."
Woerner wrote that the Fregat upper stage "also evidently failed to induce the planned rotation around the longitudinal axis of the spacecraft." Known as the "barbecue roll," the maneuver is designed to ensure the satellites receive even exposure to the heat of the sun and the cold of deep space.
Engineers are still studying whether the satellites can complete their mission after the orbit shortfall. The satellites are under the control of the European Space Operations Center in Darmstadt, Germany, officials said.
The European Commission is working with ESA "to maximize the possibilities to use the two satellites as part of the Galileo network," the commission said in a statement.
Woerner used a quote from Elon Musk, founder and chief executive of SpaceX, to illustrate the complexities of space launches.
After a SpaceX test rocket detected an on-board failure and self-destructed in an explosive fireball, littering the company's Central Texas test site with debris, Musk tweeted: "Rockets are tricky."
"Going back to the quote from Elon Musk, I am concerned that we should fall into the trap of mutual recriminations," Woerner wrote. "Instead, we need to focus on identifying the causes and on taking the necessary steps to ensure the success of future launches."
The spacecraft launched Friday were the first two of 22 satellites built by OHB System AG of Bremen, Germany, to build out the fully operational Galileo navigation system, a civilian-run counterpart to the U.S. Air Force's Global Positioning System.
Europe launched four Galileo satellites in 2011 and 2012 to validate the network's technologies, but one of the demonstration spacecraft suffers from a "permanent degradation" of two of its three navigation signal bands, according to Javier Benedicto, ESA's Galileo project manager.
Managers cleared the first two Galileo Full Operational Capability, or FOC, satellites for launch after determining they were not at risk from the fault that struck the validation craft.
The operational Galileo satellites carry navigation payloads supplied by Surrey Satellite Technology Ltd. of the United Kingdom.
Chaired by Peter Dubock, former inspector general of the European Space Agency, the board was appointed by Arianespace in conjunction with ESA and the European Commission, the executive body of the 28-nation European Union which owns the Galileo satellites. ESA acts as a technical agent for the European Commission's $7.2 billion Galileo program.
The hydrazine-fueled Fregat rocket stage, designed to fire up to 20 times in a single flight, has launched 45 times with payloads atop Soyuz and Zenit rockets. Friday's mishap marked the second failure of a Fregat stage during a launch.
Officials also blamed a modified Fregat upper stage for the loss of Russia's Phobos-Grunt Mars mission in 2011.
NPO Lavochkin is the builder of the Fregat upper stage.
The board's liaison with Russia is Alexander Daniliuk, deputy director general of TsNIIMash, the Russian space agency's Central Research Institute of Machine Building.
The European Commission said Monday it invited ESA and Arianespace to present the initial findings of the investigation in Brussels the first week of September.
"The problem with the launch of the two Galileo satellites is very unfortunate," said Ferdinando Nelli Feroci, European commissioner for industry and entrepreneurship. "The European Commission will participate in an inquiry with ESA to understand the causes of the incident and to verify the extent to which the two satellites could be used for the Galileo program. I remain convinced of the strategic importance of Galileo and I am confident that the deployment of the constellation of satellites will continue as planned."
Officials said before Friday's launch the satellites were "self-insured" because 20 more Galileo spacecraft were in production. The satellite constellation will include 30 satellites when complete, including six spares spread among three orbital pathways to ensure global coverage.
"We are, in a way, self-insured due to our procurement process," said Didier Faivre, director of ESA's navigation program, in a conference call with reporters last week. "We prefer to invest in hardware or launch services than to go into the insurance market. If something goes wrong, we use spares."
"I would like to thank Peter Dubock for having accepted the chairmanship of this commission, which was appointed in conjunction with ESA and the European Commission and with the support of the space agencies from France (CNES), Germany (DLR) and Italy (ASI), along with a team of high-level European experts," said Stephane Israel, chairman and CEO of Arianespace, in a written statement. "The commission will now be able to carry out its work independently, operating under a very tight schedule. We sincerely hope that the commission's recommendations will lead to a rapid resumption of missions, while ensuring the high reliability expected of our Soyuz launches from CSG."
Before Friday's launch anomaly, the next Soyuz launch from the Guiana Space Center was set for December with another pair of Galileo navigation satellites.
The failed injection of the satellites marked the first major anomaly on an Arianespace mission since December 2002, ending the longest unblemished launch record in the space industry.
The investigation panel's members are:
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