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Raumfahrt - Neue chinesische Bedrohung der US-Raumfahrtsysteme

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Last year, China launched a mysterious missile from its southwest region. While Chinese news sources said it was a scientific experiment, there is widespread speculation that the payload was a more advanced anti-satellite test.
Satellites are vulnerable to an array of weapons and disruptive technologies like anti-satellite missiles and sophisticated cyber attacks that can have potentially devastating results from degrading capabilities to complete annihilation, experts said.
There is strong evidence that the anti-satellite weapon China tested in May 2013 went higher than low-Earth orbit, said Charles Miller, president of NextGen Space LLC, a space and public policy consulting group. If China continues to make strides and develops weapons that reach farther, it could one day threaten key satellites in geosynchronous orbit. 
The damage caused by an anti-satellite missile is two-fold: Not only does it destroy its target, but it also causes a massive ripple affect with debris from the collision striking other satellites. China’s 2007 test created a large debris field, which could damage other spacecraft, said Gen. William Shelton, commander of Air Force Space Command.
The Air Force in June took new steps to better track and observe man-made debris in space. The service awarded Lockheed Martin a $915 million contract to develop the Space Fence, which has been in the works for years and is now entering final system development with the delivery of increment 1 and an operations center. The system will track objects in low-Earth orbit and some in higher orbits. The Air Force plans to have the system operational by 2019, and the contract leaves open the possibility for a second radar site.
In February, Director of National Intelligence James R. Clapper said potential adversaries are hard at work developing weapons that could degrade or destroy some of the United States’ key satellites that provide essential communication to the military, the government and U.S. citizens.
“Threats to U.S. space services will increase during 2014 and beyond, as potential adversaries pursue disruptive and destructive counter-space capabilities,” Clapper told the Senate Armed Services Committee. “Chinese and Russian military leaders understand the unique information advantages afforded by space systems and are developing capabilities to disrupt the United States’ use of space in a conflict.”
In the months since his testimony, top U.S. military officials and policy analysts have echoed the same concern. As U.S. dependence on satellites grows, so does the vulnerability of its space assets.
Satellites beam essential information down to Earth. From mapping services to phone calls to Internet access, both the military and civilian world rely on timely and secure connections. The armed services use GPS satellites to guide unmanned aerial vehicles, missiles and other weapons. Reconnaissance satellites track enemy movements.
The military utility of satellite technology cannot be understated, said Shelton. Capabilities provided by satellites help the military conduct humanitarian, disaster relief and combat operations, he said. 
“In space, our sustained mission success integrating these [satellite] capabilities into our military operations has encouraged potential adversaries to further develop counterspace technologies and attempt to exploit our systems and information. Therefore, I believe we are at a strategic crossroad in space,” Shelton said before the SASC in March.
“We are so dependent on space these days. We plug into it like a utility. It is always there. Nobody worries about it,” Shelton said. “You do not even know sometimes that you are touching space. So [to lose our space capabilities] it would be almost a reversion back to … industrial-based warfare.”
Bill Ostrove, a space systems analyst at Forecast International, a Newtown, Connecticut-based marketing and consulting firm, agreed that the military stands to lose much in the event of an attack on satellite systems.
“If satellites are knocked out, even temporarily, it could have serious consequences on the military’s ability to operate effectively,” Ostrove said.
Anti-satellite missiles are one of the most serious threats to space assets, he said.
“There are a few different ways that a satellite could be disabled that the United States is afraid of. The most obvious way is to launch a missile into space that targets a satellite,” Ostrove said. “The United States has a legitimate fear of anti-satellite weapons.”
In 2007, China successfully launched an anti-satellite missile into low-Earth orbit and destroyed one of its aging weather satellites.
The test is concerning because it means China could potentially target a U.S. satellite in low-Earth orbit. The U.S. military is monitoring China’s development of the weapons, Shelton said.
“We are concerned about low-Earth orbit because we saw the 2007 Chinese ASAT test, which was a success,” Shelton said. “We are concerned about work that we have seen since then that includes all the way up to geosynchronous orbit. Some of our most precious assets fly in geosynchronous orbit.”
Low-earth orbit is defined as 160 to 2,000 kilometers above the Earth’s surface. Most spacecraft fly in it, as does the International Space Station. Satellites in geosynchronous orbit fly about 36,000 kilometers above the Earth’s equator. 
As for the 2013 test, it was likely disguised as a research experiment, Miller said, citing a study by the Secure World Foundation, a Broomfield, Colorado-based private foundation that works to keep space sustainable. The rocket reached more than 10,000 kilometers in altitude and then released a canister of barium powder, the report found.
The test is alarming because satellites in geosynchronous orbit are vulnerable, Miller said in May during a panel discussion on space threats at the American Security Project, a Washington, D.C.-based think tank.
“Most of the United States’ assets in space for national security are in geosynchronous orbit. They are completely fragile,” Miller said.
The advanced extremely high frequency system, which provides the U.S. and allied militaries with secure communications, is one example of a key satellite that flies in the orbit and could one day be targeted by adversaries.
Xinhua, China’s state-run news service, said the May 2013 rocket was launched from the Xichang Satellite Launch Center in southwest China and meant to “investigate energetic particles and magnetic fields in the ionized stratum and near-Earth space.”
A U.S.-China Economic and Security Review Commission paper titled, “China Missile Launch May Have Tested Part of a New Anti-Satellite Capability,” said if the launch was indeed an anti-satellite test and not a research experiment, it would show that China is not being transparent about its space objectives. It may also signal that China is attempting to develop weapons that could destroy crucial U.S. satellites, it said.
“Such a test would signal China’s intent to develop an ASAT capability to target satellites in an altitude range that includes U.S. GPS and many U.S. military and intelligence satellites,” the report said. “In a conflict, this could allow China to threaten the U.S. military’s ability to detect foreign missiles and provide secure communications, navigation and precision missile guidance.” 
China’s 2007 test created 3,000 new pieces of debris, according to the National Security Space Strategy of 2011, the Defense Department’s most recent guidance on space issues. Another 1,500 pieces of debris were created when a Russian and U.S. satellite collided in 2009. 
The military tracks about 23,000 objects in orbit, Shelton said. About 1,000 of them are active payloads, and the rest include defunct satellites, pieces of debris and other items, he said.
Military sensors generally can track objects that are larger than 10 centimeters across, Shelton said. However, there could be 500,000 man-made objects in orbit that are smaller than that and can cause significant damage to satellites, he said.
The military is also working to ensure that adversaries do not attack satellites through cyber intrusions, Shelton said.
“We are going system by system looking at our cyber vulnerabilities, and we have a large information assurance program that gets into those vulnerabilities and patches them and tries to prevent access,” he said. “In many cases, these are closed systems. That does not mean there are not vulnerabilities, but they are … not accessible through the Internet. So it would take insider — special access — those kinds of things to get to these closed networks.”
Some countries, such as China, are also developing technologies that use lasers to “dazzle” a satellite, said Micah Walter-Range, director of research and analysis at the Space Foundation, a Colorado Springs-based advocacy group. By shining lasers at the craft, adversaries overload the satellite’s sensors and can temporarily blind or permanently damage it, he said.
While a degradation of the capabilities provided by the nation’s space assets would hurt the military, it would also be detrimental for the general public, said Mariel Borowitz, an assistant professor at the Sam Nunn School of International Affairs at the Georgia Institute of Technology, who studies space issues. Television, Internet access, radio and telephone service could go dark, she said.
“The threat to satellite technology is serious. The United States has more satellites than any other country in the world, and satellite technologies are critical to both our economic system and our military,” Borowitz said.
Economically, the country relies on GPS for logistical, agricultural and safety applications. Boaters and pilots also rely heavily on weather satellites, Borowitz said.
The U.S. government is looking at numerous ways to prevent and mitigate attacks or vulnerabilities. 
Disaggregation, which takes one large satellite and splits it into smaller spacecraft is one way to protect satellite capabilities, Shelton said. If an enemy attacks the system and takes out a few satellites, there will still be some functionality left, he said.
“By separating payloads on different satellites we will complicate a potential adversary’s targeting calculus, decrease size and system complexity and enable use of smaller boosters — with the goal of simultaneously driving down cost,” Shelton said.
Satellites should be built with greater resiliency before they are launched, said Peter Wegner, director of advanced concepts at Utah State University Space Dynamics Laboratory.
Systems must be hardened so in the event of an attack they can return to their original state and continue providing necessary capabilities, he said. 
International treaties are another way the United States could mitigate a future attack, said Douglas Loverro, deputy assistant secretary of defense for space policy, during his testimony before the SASC in March.
The Defense Department is working with the State Department to establish an international code of conduct for responsible space use, he said. It would include standards for “debris limitation, launch notification, on-orbit monitoring and collision avoidance.”
While a set of standards will not necessarily deter all space-faring countries from irresponsible actions, it will help keep space sustainable, he said.
“I am not so naïve as to believe that a simple set of rules will solve all of the major issues we face — they will not; nor would I expect that they will inhibit those who would try to threaten our use of space,” Loverro said. “But common sense rules that can be embraced by a majority of space-faring nations will help stem the rise of uncontrollable debris, add demonstrably to spaceflight safety and clearly differentiate those who use space responsibly from those who do not.”
Quelle: National Defense Industrial Association
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