The U.S. military, which tracks objects in space, said that it was caused by the reentry into the atmosphere of the empty stage of a Russian SL-4 rocket body, which apparently had been launched a day earlier. Read More]]>
The U.S. military, which tracks objects in space, said that it was caused by the reentry into the atmosphere of the empty stage of a Russian SL-4 rocket body, which apparently had been launched a day earlier.
That launch appears to have been the December 21 launch of a Russian Soyuz rocket, carrying a payload to the international space station. This is pretty standard fare—the list of launches on this web page shows that this was the 1245th launch of the Soyuz family of rockets. Based on the statement from the military, the object seen over Arizona was likely the third stage of this rocket.
When the Soyuz takes off, it consists of three rocket stages filled with fuel. These stages accelerate the payload, which sits on the very top of the rocket, into space. The first two stages burn their fuel and drop off fairly close to the launch pad; this reduces the mass the third stage has to accelerate. The third stage carries the payload into orbit and then releases it. In this case the payload apparently maneuvered to rendezvous with the space station, leaving the third stage—now emptied of its fuel—to orbit in space.
The third stage was orbiting at a fairly low altitude (about 275 km). At that altitude atmospheric drag will slow objects and can cause them to fall out of orbit and reenter the atmosphere fairly quickly. Because they are traveling very fast—about 30 times faster than a jet aircraft—the atmospheric drag as they reenter causes them to get so hot that they burn up. That burning was what people saw in the sky.
This kind of thing happens frequently. The U.S. catalog of space junk currently contains about 17,000 objects orbiting the earth (although there are many additional objects that are not in the catalog for one reason or another). About 10% of those objects are empty rocket stages like this one. Those orbiting at high altitude will stay in space for decades or centuries, while those at lower altitudes will fall to earth sooner.
Several of the objects in the catalog fall out of orbit every day. Typically these objects burn up completely and little or nothing hits the ground, so there is little risk to people on the ground. So this event was neither unusual nor dangerous.
Space junk does, however, pose a much bigger threat to other objects in space.]]>
For Congress seems ready to reanimate one of its favorite hard-to-kill ideas: space-based missile defense.
(Nodding here to Theresa Hitchens, who suggested Thor’s hammer might do the trick.)
Specifically, this week it will pass an annual defense bill that directs the Missile Defense Agency to
“commence the concept definition of a space-based ballistic missile intercept layer to the ballistic missile defense system that provides— (1) a boost-phase layer for missile defense; or (2) additional defensive options against direct ascent anti-satellite weapons, hypersonic glide vehicles, and maneuvering reentry vehicles.”
It has been more than thirty years since the denouement of Ronald Reagan’s fanciful Star Wars concept and more than twenty since Brilliant Pebbles, its more limited but still space-based descendant, was cancelled. It’s been twelve years since the American Physical Society’s (APS) in-depth analysis concluded that a system of space-based interceptors “would require a fleet of a thousand or more orbiting satellites just to intercept a single missile” and that “deploying such a fleet would require a five- to tenfold increase in the United States’ annual space-launch capabilities.” And six years since the Obama administration set aside the George W. Bush era plan to build a Space-based Test Bed.
And it’s been three years since the National Academy of Sciences (NAS) was asked to weigh in authoritatively on boost-phase missile defense and judged that space-based missile defense would be “10 times as expensive as any other alternatives, at least $300 billion for a limited capability.” Besides the fact that a great many interceptors would be necessary and would be enormously costly, space-based missile defenses are vulnerable to being overwhelmed or defeated. (We prepared a fact sheet that details these shortcomings.)
What might have changed in the interim to make space-based missile defense a concept worth revisiting? I can’t think of anything. And the Pentagon seems to have concluded that the idea is not worth pursuing either, as the idea is not even mentioned in the Pentagon-led 2010 Ballistic Missile Defense Review Report.
Unfortunately, members of Congress haven’t seemed to have learned the lesson, and in this new study they will force the Pentagon to go back again to get the same answers that we already know.
The only bright side is that included in the study is the requirement that the Director of the MDA submit:
(2) a plan for developing one or more programs of record for a space-based ballistic missile intercept layer, including estimates of the appropriate identifiable costs of each such potential program of record; and (3) the views of the Director regarding such findings and plan.
The costs are sure to be enormous and to put the potential capabilities of space-based missile defense into perspective. There’s no mystery there, except maybe the mystery of why Congress cannot seem to resist returning again to unfertile ground.
You would be forgiven for not thinking that’s remarkable, since the United States and China are the two biggest space players. Read More]]>
You would be forgiven for not thinking that’s remarkable, since the United States and China are the two biggest space players. Why wouldn’t they be talking at a high level about space debris, how to avoid satellite collisions, and ways to collaborate on space science or coordinate weather observations?
But in fact, it has been extraordinarily difficult to get this to happen and it deserves a bit of applause.
Barriers to U.S.-China talks on space
Part of the problem is that since 2011, the natural U.S. interlocutors on civil space issues, NASA and the Office of Science and Technology Policy (OSTP), have been banned by Congress from using federal money “to develop, design, plan, promulgate, implement or execute a bilateral policy, program, order, or contract of any kind to participate, collaborate, or coordinate bilaterally in any way with China or any Chinese-owned company.” Additionally, NASA may not host official Chinese visitors at its facilities. This ban originated with and was championed by Representative Frank Wolf, who headed the House appropriations subcommittee which oversees the NASA and OSTP budgets.
While Representative Wolf has retired, these restrictions continue, and neither NASA nor OSTP may engage bilaterally with China unless specifically granted permission legislatively or unless they have certified that such discussions “pose no risk of resulting in the transfer of technology, data, or other information with national security or economic security implications to China” nor will they be interacting with any official who the U.S. determines to have been involved in human rights violations.
This has predictably cast a chill on space scientists, accustomed as we are to free information exchange and international collaboration. It was an obstacle to official talks that seemed difficult to overcome even if both sides were ready and willing to proceed.
A way forward
However, earlier this year, the outcomes reported from the 2015 U.S.-China Strategic and Economic Dialogue, the seventh of yearly meetings between high level U.S. State and Treasury officials and their Chinese counterparts, stated that regular space meetings would happen:
The United States and China decided to establish regular bilateral government-to-government consultations on civil space cooperation. The first U.S.-China Civil Space Cooperation Dialogue is to take place in China before the end of October. Separate from the Civil Space Cooperation Dialogue, the two sides also decided to have exchanges on space security matters under the framework of the U.S.-China Security Dialogue before the next meeting of the Security Dialogue.
This made clear that civil space and space security issues would remain separate, and perhaps this has made it easier to get off the ground. According to Xinhua, the US delegation was headed by Jonathan Margolis, Deputy Assistant Secretary of State in the Bureau of Oceans and International Environmental and Scientific Affairs, and not by staff in the State Bureau of Arms Control, Verification, and Compliance, which would presumably handle the space security discussions. The Chinese host was Tian Yulong from the China National Space Administration. I believe that the Security Dialogue framework under which the space security discussions will take place are those Strategic Security Dialogues that are part of the Strategic and Economic Dialogue.
We at UCS have been advocating for substantive discussions on space issues with China for years—both civil and security-related. So I have to say that I am delighted to hear about this week’s meeting, as well as that the second meeting is scheduled to happen in Washington in 2016.
As to where these discussions might go? My colleague Gregory Kulacki commented in this space two years ago about the vision China’s scientific establishment has in mind for its future in space science and technology.]]>
“Of all the places where conflict could erupt, space might seem the least likely, except in movies.”
So says a very good New York Times editorial “Preventing a Space War” this week. Sounds right, if X-Wing fighters come to mind when you think space conflict. Read More]]>
“Of all the places where conflict could erupt, space might seem the least likely, except in movies.”
So says a very good New York Times editorial “Preventing a Space War” this week. Sounds right, if X-Wing fighters come to mind when you think space conflict. But in reality conflict in space is both more likely than one would think and less likely to be so photogenic.
Space as a locus of conflict
The Pentagon has known that space could be a flash point at least since the late 1990s when it began including satellites and space weapons in earnest as part of its wargames.The early games revealed some surprises. For example, attacking an adversary’s ground-based anti-satellite weapons before they were used could be the “trip wire” that starts a war: in the one of the first war games, an attack on an enemy’s ground-based lasers was meant to defuse a potential conflict and protect space assets, but instead was interpreted as an act of war and initiated hostilities. The games also revealed that disrupting space-based communication and information flow or “blinding” could rapidly escalate a war, eventually leading to nuclear weapon exchange.
The war games have continued over the years with increased sophistication, but continue to find that conflicts can rapidly escalate and become global when space weapons are involved, and that even minor opponents can create big problems. The report back from the 2012 game, which included NATO partners, said these insights have become “virtually axiomatic.”
Participants in the most recent Schriever war games found that when space weapons were introduced in a regional crisis, it escalated quickly and was difficult to stop from spreading.
The compressed timelines, the global as well as dual-use nature of space assets, the difficulty of attribution and seeing what is happening, and the inherent vulnerability of satellites all contribute to this problem.
Satellite vulnerability & solutions
Satellites are valuable but, at least on an individual basis, physically vulnerable. Vulnerable in that they are relatively fragile, as launch mass is at a premium and so protective armor is too expensive, and a large number of low-earth-orbiting satellites are no farther from the earth’s surface than the distance from Boston to Washington, DC.
While some satellites might be protected from a dedicated adversary under some circumstances, the truth is that it is much easier to attack them than to defend them. For some insights on why that is, take a look at The Physics of Space Security, which we wrote about a decade ago.
However, all is not lost. Constellations of satellites, and systems that use satellites, can be made much more resilient than the individual satellites themselves.
And in Securing the Skies, we suggested ten actions that the United States should take to improve the security and sustainability in space, and continue to think these are a good set of first steps. (Many of the ideas in the New York Times editorial echo these suggestions.)
For example, the United States depends heavily on services provided by satellites, but also has the best ability to recover from the loss of an important satellite. We should keep working on improving the resiliency of our space systems, which can make satellites a less inviting target.
And while the United States is far ahead of China and Russia when it comes to anti-satellite technology, having working ASAT weapons does little to protect our satellites, and in fact unfettered space weapon development would not benefit the United States—or China or Russia, for that matter.]]>
Canada is a member of a coalition of twelve nations called the Nuclear Proliferation and Disarmament Initiative (NPDI) that includes several countries, such as Japan, Germany, Turkey and the Netherlands, which are sometimes described as “nuclear umbrella” states because of their close consultations with the United States on U.S. nuclear weapons policy. They want to keep the requirement on de-alerting in the 2015 report. The NPDI submitted a working paper calling on all nuclear weapons states, including the United States, to take “concrete agreed measures to further reduce the operational status of nuclear weapons systems.”
U.S. Pressures Allies over De-Alerting
The United States is not happy with the NPDI working paper and is trying to bury it. There was no mention of the paper or de-alerting in Secretary Kerry’s statement to the NPT review conference or the U.S. joint statement with Japan, which founded the NPDI in 2010. Rose Gottemoeller, the U.S. undersecretary of state for arms control and international security, participated in a closed-door session at the United Nations with Greg Weaver, the principal director for nuclear and missile defense policy in the office of the U.S. Undersecretary of Defense for Policy, where the two tried to explain why the United States thinks de-alerting is inadvisable.
Last Thursday, the Canadian delegation hosted a side event at the United Nations for delegates interested in discussing the de-alerting initiative and U.S. opposition. David Wright, the co-director of the Global Security Program at UCS, and Hans Kristensen, the director of the Nuclear Information Project at the Federation of American Scientists, helped NPT delegates understand the U.S. position on de-alerting, why it is unfounded, and how de-alerting can be done quickly, simply and safely in a way that increases the collective security of the United States and its allies.
Refusal to De-Alert Could Make a Bad Situation Worse
I focused on a new and unanticipated cost of the U.S. effort to maintain high alert levels: the possibility that China may adopt the same irresponsible hair-trigger mechanisms used by the United States. China currently keeps its nuclear weapons off alert but there are indications a new generation of Chinese military strategists, heavily influenced by U.S. approaches to nuclear deterrence, may convince the Chinese leadership to raise the alert level of China’s nuclear forces in response to perceived threats from the United States.
In my remarks, included below the photo, I argued that U.S. leaders can take steps, including de-alerting, that would encourage China’s leaders to reject the ill-considered advice of their military strategists and keep China’s nuclear weapons off hair-trigger alert.
Remarks Delivered at the NPT Review Conference
As we urge the United States and Russia to take their nuclear weapons off prompt alert, we also need to consider measures to help all nuclear weapons states keep their weapons off alert, especially states with much smaller nuclear arsenals.
China may provide a guide to the types of measures we should consider.
There are three reasons China deserves our consideration.
- The first is that China currently keeps its nuclear weapons off alert.
- The second is that China has articulated, for decades, concerns about trends in the development of conventional military technology that undermine international efforts to control, reduce and eventually eliminate nuclear weapons.
- The third is that China has sought, for decades, international negotiations in the UN Conference on Disarmament to arrest those trends.
China has a comparatively small nuclear arsenal. China will not say how small because it believes ambiguity on this question helps them keep it small.
But for comparative purposes, under the counting rules of the New Start Agreement between Russia and the United States, the total number of Chinese nuclear weapons would be zero.
This is because the New Start Agreement counts “deployed strategic warheads” rather than total warheads. Deployed is defined as “the number of reentry vehicles emplaced on deployed intercontinental ballistic missiles and on deployed submarine launched ballistic missiles.”
At present, China is believed to keep its intercontinental ballistic missiles in a non-deployed mode with the warheads separated from the missiles. And China does not currently deploy submarine launched ballistic missiles.
So, compared to the other nuclear weapons states that are parties to the NPT, China maintains its nuclear weapons in a comparatively safe state. The risk of an accidental or inadvertent Chinese launch is comparatively low.
But that could change.
China’s military scholars recently published a study stating China needs a more flexible nuclear policy. A look at some of the statements from that study reveal cause for concern.
No first use remains an unshakable first principle. But Chinese military scholars see what they describe as “an increasingly complicated nuclear security environment.” And the primary complication is the United States, which they believe is
• Making China its primary strategic competitor
• Expanding its missile defense system in East Asia
• Developing new types of conventional weapons that can destroy China’s nuclear forces.
Chinese military scholars are especially concerned about what they call “the U.S. rapid global strike plan.” They believe that “once it becomes operational it can be used to attack our nuclear missile force, put us in a passive position, greatly influence our ability for nuclear retaliation and weaken the effectiveness of our deterrent.”
In the minds of China’s military scholars, this U.S. plan is emblematic of “developments in science and technology that blur the line between conventional and nuclear weapons.”
Missile defense, anti-satellite, space, cyber and conventional precision strike weapons are the most important.
And because the United States refuses to adopt a no first use policy Chinese military scholars worry that “a future informationalized (信息化) conventional war could develop into nuclear war.”
Chinese military concerns about the vulnerability of its nuclear forces present Chinese military scholars with the perceived need to suggest a solution.
This is not a new problem for China.
Chinese analysts have been thinking about the impacts of advanced conventional weapons on nuclear arms control for decades.
In the late 1970s Chinese researchers were warning that advances in conventional military technology would eventually undermine nuclear arms control agreements.
In the mid 1980s China responded to the U.S. Strategic Defense Initiative by investing heavily in an effort to narrow an already widening gap between U.S. and Chinese military technology while simultaneously proposing international limitations on all military space technology.
China followed its experience as a victim of U.S. advanced conventional military technology in 1999 – the bombing of the Chinese Embassy in Belgrade – by accelerating investment in military space technology and stepping up efforts to open negotiations on an international arms control agreement to restrict it.
Finally, in 2013, the Chinese military let the world know, in a widely read and highly regarded open source publication, it was considering raising the alert level of its nuclear forces in response to the continued unrestrained development and deployment of advanced conventional weapons.
The publication stated the Chinese military was considering responding to the perceived vulnerability of its nuclear forces by making preparations to be able to launch its nuclear-armed missiles after being warned of an incoming nuclear attack but before the attacking forces could destroy their targets.
That statement, from a committee of 35 military scholars from the Chinese Academy of Military Science, is not a definitive indication that China will, in fact, raise the alert level of its nuclear forces and move to a launch on warning posture.
Equipping its forces to implement launch on warning would not be easy, cheap or quick.
Earlier this week, in response to a question from a reporter for the Congressional Research Service, a former Chinese missile designer noted that China’s missiles were not designed to be kept on alert. Replacing them would be prohibitively expensive.
China is not known to have satellite, radar or other sensing systems that would allow it to detect or confirm an incoming nuclear attack.
And there is no evidence China’s missile forces are training to carry out this type of prompt launch operation.
So the statement by the Chinese Academy of Military Science is best interpreted as an aspirational goal or a suggestion for the Chinese Communist Party leadership to consider.
As they do, it will be interesting to see whether China’s leaders continue to chart their own course on nuclear policy, or whether they choose to follow in the footsteps of the United States.
A knowledgeable Chinese arms control expert recently confided, with amusement and concern, that some Chinese security experts are currently raising the following question during internal debates about Chinese nuclear policy: “The U.S. President carries around a nuclear football, why doesn’t our president? Shouldn’t China have its own nuclear football?”
A U.S. decision to de-alert its forces might change the tenor of that conversation.
A U.S. decision to participate in international negotiations on missile defense, space and conventional precision strike weapons might end it.
Regrettably, the United States decided to brush aside talk of de-alerting during this review conference, and it continues to brush aside Russian and Chinese concerns in the UN Conference on Disarmament.
China’s consideration of moving to launch on warning is a warning that the U.S. decision to ignore global calls to take its weapons off hair-trigger alert is not in the best interests of the United States, its allies, or the credibility of the NPT.
U.S. Air Force Lt. General Jay Raymond told the packed house of space enthusiasts that China was enemy number one. He claimed a July 2014 Chinese missile defense test was actually an anti-satellite test and that it was successful, although he offered no new information in support of either claim. U.S. officials are using the recent Chinese test to justify greater U.S. reliance on space weaponry to protect U.S. satellites.
You say tomato, I say 西红柿
Chinese interest in anti-satellite (ASAT) weapons is not new. A survey of Chinese publications contains analyses of U.S. and Soviet ASAT programs from the late 1970s. Interestingly, even these early Chinese studies view anti-satellite and missile defense as two applications of the same hit-to-kill technology. Researchers from the Air and Missile Defense Institute of China’s Air Force Engineering University expressed the same view in a paper published this March. These views are correct, of course. For example, in February 2008 the United States used a modified missile defense interceptor to shoot down a malfunctioning U.S. satellite.
After decades of research and development, China tested its own hit-to-kill interceptor in an ASAT mode in January 2007. The test obliterated one of China’s own satellites. Widespread international condemnation of the test, which created a large field of hazardous space debris, led China to begin sub-orbital testing of the interceptor, much like U.S. missile defense tests. China conducted what it described as missile defense tests of the interceptor in January 2010, January 2013 and July 2014.
The United States did not object to China’s descriptions of the 2010 and 2013 tests, so its decision to challenge China on the 2014 test is a cause for concern.
U.S. officials refuse to reveal why the 2014 test is different than the earlier two tests. China remains characteristically silent. In the absence of additional information neither description is convincing. But even if there were distinguishing characteristics that justify the ASAT label, it is hard to understand why China’s 2014 test suddenly justifies greater U.S. reliance on space weaponry.
Calling off talk of an international agreement
China has been requesting international negotiations on binding limits on space weapons since 1985. China currently has a proposal, submitted together with Russia, for negotiations in the UNCD on the prevention of an arms race in outer space. The United States rejects the proposal on the grounds that it fails to address important U.S. concerns but it is unwilling to offer an alternative.
The Obama administration was willing to promote the voluntary norms proposed by the European Union in their International Code of Conduct for Outer Space Activities. But the July 2014 Chinese test seems to mark a turn towards a more aggressive U.S. approach to space security emphasizing space deterrence, space control and “active defense”—a euphemism for space weaponry. U.S. space diplomacy is now more focused on rallying allies to contribute to a new U.S. effort to deter U.S. enemies in space, especially China.
Negotiating a space security treaty with China and Russia is no picnic. Both want an agreement that includes limitations on U.S. ballistic missile defense, which may be one reason the United States has consistently refused to engage in negotiations on space security within the UNCD. And since missile defense technology can be used to shoot down satellites, it is hard to conceive of a credible international ban on ASAT weapons that would not include restrictions on missile defenses.
After considerable expenditures and decades of development, the United States still does not have a credible missile defense and recent government and independent studies document its failures. It may be time for the United States to reconsider accepting limits on missile defense and to explore an international agreement that would prohibit attacks on satellites.
Negotiating a verifiable treaty to protect satellites from attack may be extremely difficult but at least it is possible. Defending satellites is not. They are inherently defenseless. Satellites are extremely fragile and cannot be hidden, maneuvered, or hardened against a physical attack to any meaningful degree.
Threatening to destroy enemy satellites in the hope of deterring an enemy attack in space is not the best approach to space deterrence and will lead to deploying space weaponry. Whatever the Chinese did in July 2014, a U.S. decision to favor this military option remains a poor strategic choice.
There are a number of practical steps the United States can take to make satellites less attractive targets and blunt the effect of a space attack, such as building redundancy into satellite systems and developing the ability to rapidly replace them. They can be hardened against electronic attack. If, as some people claim, satellites are an Achilles heel for the U.S., then that is very poor military planning and should be fixed.
Limiting the capabilities that countries have to carry out such attacks can strengthen this approach. A binding international agreement forbidding anti-satellite attacks would raise the strategic costs and lower the strategic benefits for any nation that chose to violate it.
The United States has much more to gain from negotiating a binding international agreement to protect U.S. satellites than it does from deploying the means to destroy Russian and Chinese satellites.
The good news is that both Russia and China are ready to open negotiations in the UNCD. Instead of seeing that as a ploy to somehow dupe the United States and its allies, the United States should take advantage of the offer, especially since it holds the potential to solve a serious U.S. security problem. Just because the United States does not like where the negotiations start does not mean that is where they must end up. That’s why they’re called negotiations.]]>
The space plane program inspires speculation in part because its purpose, its budget and most of its details are kept secret. And in part because while the technology is intriguing, few missions are especially suited to a long-duration, elegantly-returning spacecraft with low on-orbit maneuverability and small payload—most space missions can be done cheaper or better using existing technology. Its history of being kicked between NASA, DARPA and the Air Force, and then getting funded in the classified realm inspires skepticism whether the program would survive if it had to compete for funding in the light of day.
One mission that seems to be frequently suggested is a maneuvering sensor to look at “hot spots” on earth. The space plane may be able to do that. But the problem is that the ability to maneuver and the ability to return to earth work at cross purposes. Returning to earth requires massive landing gear and heat shielding, which is like putting rocks in your backpack when you’re trying to be agile. It’s not well-suited—this mission could be done much better and cheaper using other platforms.
And there is nothing stealthy about this craft. It is easily observed from the ground and because of all the extra mass must be launched on a large rocket (Atlas V). So while the space plane may be carrying advanced sensors to orbit so that they can be tested and returned, roving or stealthy sensors are not good missions for it.
Much is being made of the X37B’s long tenure on-orbit. Is there something magic about combining the ability to stay on orbit for a long time and then come back to earth? For a normal satellite, of course, two years on-orbit is brief (take a look at the UCS Satellite Database to see expected lifetimes and time-on-orbit for active satellites) and I’d venture that few customers would pay for an Atlas V launch for a satellite with only a two-year lifetime.
But is two years a long time for a craft that is meant to come back down from orbit? That’s harder to say since staying up in orbit for years and then coming back down is not a high-demand mission and there’s not much to compare it to. Almost all satellites remain on-orbit after they no longer function, or are de-orbited destructively, mostly burning up as they travel through the earth’s atmosphere. Those that do have returning capsules, such as the Space Shuttle, do not have particularly long missions. The Soyuz TMA-9 capsule reportedly has a 210 day warranty (though it’s been on orbit a few more days than that), but it is designed to carry humans, which requires significantly more mass and higher standards than nonliving cargo does. Russian satellites still send back film from satellite-borne cameras, but these also tend to come back relatively quickly because the photographs are time-sensitive.
And there are the occasional orbiting capsules doing experiments that come back to earth, but those also generally have durations of weeks or months. I don’t know about any other craft whose mission requires that it stay on-orbit for long periods of time before it returns, and would be interested in reader comments.
So the X-37B program does seem to be exploring a bit of parameter space that is uncharted-— long-ish duration orbiting then returning to earth, and is developing cutting edge materials and technologies for return and autonomous landing. These are interesting technologies, but returning to earth using valet parking, as David Wright notes, isn’t a mission, it’s a technology. Why classified, though?
Which is really the interesting point. It’s a well-resourced classified military program, so will generate plenty of raised eyebrows and interest in similar technologies in other countries. Is it worth it?
We have yet to hear anything approaching a convincing argument.]]>
Many U.S. observers believe anti-satellite (ASAT) missile attacks are central to Chinese military strategy. They argue China intends to exploit the U.S. military’s reliance on satellites by launching a surprise assault on these valuable but vulnerable space assets, which the U.S.Read More]]>
Many U.S. observers believe anti-satellite (ASAT) missile attacks are central to Chinese military strategy. They argue China intends to exploit the U.S. military’s reliance on satellites by launching a surprise assault on these valuable but vulnerable space assets, which the U.S. military uses for communication, surveillance, navigation, and other support activities. This attack, sometimes referred to as a “space Pearl Harbor,” is supposedly a key part of an “asymmetric” military strategy a weaker China intends to use to defeat a stronger United States in a high-tech regional war.
This U.S. belief took root in the late 1990s and early 2000s in a U.S. analytical environment shaped by information and assumptions that now appear to be wrong. A new UCS analysis of the space-related sections of a classified Chinese military source published in 2003 demonstrates that China’s missile forces were not anticipating or preparing for operations that involved attacking U.S. satellites at that time.
The source is a military textbook published by the General Command of the Chinese People’s Liberation Army (PLA) titled The Science of Second Artillery Operations. The 406-page book is a product of more than 30 years of research and thinking by the PLA on the strategic value of its missile forces and how those forces should be used in the types of military conflicts the Chinese leadership fears may occur in the future. As a result, it is written both to reflect past experience and to be forward-looking. Unlike most sources cited in U.S. analyses of Chinese military space policy, The Science of Second Artillery Operations is a credible and authoritative source on Chinese military planning. The book was not intended for foreign or even general domestic Chinese audiences. It was classified as jimi (机密)—the third highest classification level among the four types of circulation restrictions placed on Chinese military publications.
The Science of Second Artillery Operations describes China’s view of the military uses of space in some detail. That description makes it very clear that the PLA, like the U.S. military, places a high priority on maintaining the normal functioning of its satellites in a time of conflict. For this reason, it is unlikely that China would risk the loss of its satellites by using destructive anti-satellite weapons against others. This may explain why, counter to U.S. expectations, this lengthy and detailed PLA publication on the operations of China’s missile forces contains no discussion of space warfare or missile attacks against satellites.
The role of China’s emerging space capabilities, as discussed in the book, is to support the use and increase the effectiveness of China’s missile forces, rather than to serve as a means of attack themselves. Like their counterparts in the United States, China’s leaders appear to view their satellites as valuable military assets. They are investing aggressively in expanding and improving China’s fleet of satellites as rapidly as they can. To the extent it is possible, Chinese investments in space technology and its military applications are designed to narrow the gap between China and the United States. China is not attempting to exploit asymmetry in space, but working to end it.
Of course, the space-related commentary in one PLA textbook, no matter how credible or authoritative it may be, cannot be interpreted as a definitive indication China is not contemplating the use of anti-satellite attacks against the United States. China conducted multiple tests of a missile-launched anti-satellite weapon, and used it to destroy one of its own satellites in January 2007. It is possible Chinese views about anti-satellite technologies changed after The Science of Second Artillery Operations was published. But it is also possible that, like the United States and the Soviet Union, which both developed and tested anti-satellite weapons at a similar stage in the progress of their military space programs, China may continue to follow in their footsteps and decide not to deploy them.
The commentary on the military uses of space in The Science of Second Artillery Operations indicates that as of 2003 when the book was published, China’s missile forces were not anticipating or preparing for operations that involved attacking U.S. satellites, contradicting beliefs that were prevalent in the U.S. at that time and that have shaped U.S. thinking since then.
As a result, U.S. analysts should reassess their views on China’s approach to military space operations. While by no means definitive, the textbook provides ample reason to question the conventional U.S. wisdom on Chinese intentions, particularly the “space Pearl Harbor” hypothesis positing an “asymmetric” Chinese attack on U.S. satellites.]]>
Gen. William Shelton, head of Air Force Space Command, testified Wednesday at a Senate Armed Forces Subcommittee on Strategic Forces hearing. He responded affirmatively to questions by Senator Joe Donnelly, agreeing that if China is conducting tests targeting high altitude satellites it could “significantly” affect “our GPS capabilities.”
Unclassified Senate hearings are not ideal for elaborating on the nuances of subjects, so it’s useful to unpack what it means to affect the GPS system in a significant way, as this comes up frequently.
China has demonstrated hit-to kill anti-satellite technology, but hasn’t tried it on high-altitude satellites (no country has), although it has rockets that can reach up to and beyond geosynchronous orbits. However, questions about the nature of a high-altitude suborbital rocket flight last year has generated debate about whether it was related to extending China’s ASAT capabilities to higher altitudes.
Of course, having relevant pieces of technology does not equal a reliable or useable military weapon, but it’s still prudent to ask if China (or another actor) had the capability to destroy or degrade a GPS satellite, how bad is that?
GPS is a thoughtfully designed, robust system, and its service degrades very gradually as satellites are lost. The original system design used 24 satellites, keeping six in view from most places on the earth, but typically there are more in orbit. Currently, there are 32.
A user needs a minimum of four satellites in view if no other source of location or timing are available, but the accuracy increases as more satellites are visible. A large number of satellites need to be incapacitated just to bring the constellation size down to the minimum; to leave a user without sufficient coverage to get useable navigation data would require losing more. Coverage depends on geographic location, time of day, and the current constellation architecture (which can be modified in the face of a loss), but Geoff Forden gives an instructive example. An 18-satellite constellation (with the missing satellites chosen to give the most impact) would drop below the four-satellite visible minimum over Beijing for roughly two hours a day.
Details are important here—different missions will require different precision, etc.—but this illustrates that degrading GPS navigation capacity by incapacitating satellites is not a small task.
Adding to the difficulty of the task is the fact that the GPS satellites move with respect to the Earth, leaving only a few within reach, such as those overhead or nearby. The attacker would have to wait for other satellites to come into range or stage the attack from locations all over the globe. A disabling attack would be difficult and time-consuming—not instantaneous—giving the U.S. ample time to react. We go into a bit more detail on these points in a past blog post.
In fact, while Gen. Shelton’s remarks were the ones that made it into the newspaper, later in the hearing Douglas Loverro, Deputy Assistant Defense Secretary for Space Policy, pointed out these strengths of the GPS system:
GPS is somewhat of a disaggregated system. We call it distributed, many, many satellites, that if you lose one you don’t lose the capability. In fact, you could lose several and not lose it. That isn’t an invitation to lose any but it certainly makes it more resilient…
The bottom line is that anti-satellite weapons are a bad idea for many reasons, and the U.S. should work with other countries to keep them from being used. But a disabling attack on the GPS system is much more difficult than is sometimes assumed—in part because of smart planning of the system. That’s good policy, and that approach goes some way to making anti-satellite weapons not useful.
Some U.S. reports, however, interpreted the launch as the test of a rocket that could carry an anti-satellite (ASAT) weapon to very high altitudes. A Pentagon official said they believed the rocket went “nearly to geosynchronous Earth orbit” (GEO, or 36,000 km altitude) but did not place any objects in orbit.
It does not appear possible to determine the true purpose of the flight without more information. China may, of course, have conducted a space experiment on a booster that could also be used to lift an ASAT weapon into space.
However, by looking at the early trajectory of the rocket and its reentry point, it is possible to learn something about the altitude the launch reached.
The rocket was launched from the Xichang Satellite Launch Center in western China. The direction of the launch early in flight is known from the locations of the launch site and the ground area announced before the launch where debris (a faring or an empty stage) from the launcher was expected to fall to Earth. This zone, called a NOTAM, or Notice to Airmen, is a warning to airplane traffic about falling debris (Figure 1).
The Pentagon report of the launch stated that parts of the rocket reentered the atmosphere over the Indian Ocean, which is southwest of the launch site. Since the rocket was launched to the southeast, the duration of its flight must have been long enough that the rotation of the Earth moved the Earth’s surface far enough east to place the Indian Ocean under the reentry point. That allows an estimate of the duration of the rocket flight, and therefore of the maximum altitude that its payload reached.
The Xichang launch center is at 28 degrees north latitude. The rocket was said to have reentered at a latitude somewhat south of the equator (private communication, August 2013). For the first part of this analysis, I assume it reentered over the equator in the Indian Ocean.
To understand the geometry of the flight, it is useful to first consider where the launch would land if the Earth was not rotating (while still taking into account that part of the initial velocity of the launcher that comes from the Earth’s rotational motion). The ground track on the nonrotating Earth follows the initial direction of the launch shown in Figure 1.
The rocket’s track stretches southeast from the Xichang launch site (Figure 2) and must travel far enough south to reach the equator. If it continues along its initial direction, the rocket would land at the point labeled A in Figure 2, at a ground distance of 7,200 km from the launch site.
The fact that the Earth is rotating means that the impact point will effectively move westward by a distance Ve·t during the rocket’s flight, where Ve is the rotational speed of the Earth’s surface (about 0.46 km/s at these latitudes) and t is the flight time of the rocket from launch until reentry.
In order to be safely away from land, the reentry point must be roughly at the point B in Figure 2, or at a point west of B. The Earth’s rotation must therefore carry the point B to the point A during the flight time of the rocket. The ground distance between points A and B in Figure 2 is 8,500 km, which means that the flight time of the rocket must be longer than 8,500 km/(0.46 km/s), or 5.1 hours.
Now consider two trajectories from Xichang to point A, one with an apogee of 10,000 km and one with an apogee of 30,000 km.
To calculate these trajectories, I used a computer model of a rocket based on the Chinese CZ-3 space launcher. However, since the total flight time is much longer than the time the rocket booster is burning, the results are insensitive to the details of the boost phase.
Computer modeling shows that the trajectory with an apogee of 10,000 km has a flight time of 2.0 hours, and the trajectory with an apogee of 30,000 km has a flight time of 6.7 hours.
This implies that the launch must have gone significantly higher than 10,000 km, since the trajectory to 10,000 km gives too short a flight time for the rocket to reenter over the Indian Ocean. A launch that reentered at point B with a flight time of roughly 5 hours would mean the launch must have reached at least 24,000 km. A trajectory with an apogee at GEO would have a flight time of about 7.9 hours, during which time the Earth would rotate 13,000 km, which would put the reentry point near the coast of Africa.
The conclusion is that if reentry occurred over the equator in the Indian Ocean, and if the launch followed the trajectory shown in Figure 2, the apogee of the rocket must have been in the range of about 24,000 to 35,000 km.
This estimate would change, however, if the upper stage(s) of the rocket maneuvered, so that only the first two stages followed the southeasterly trajectory shown in Figure 1. The NOTAM zone and circles in Figure 1 indicate where debris was reported to have fallen. The circle at the southeastern end of the red line in Figure 1 (which is about 1,000 km from the launch site) appears to be roughly consistent with where the empty second-stage booster may have fallen. This would imply that the rocket did not begin to maneuver away from this path until after the second stage burned out. The second stage would have burned out at a ground range of only about 100 km from the launch site (due to the steep angle of the trajectory), so maneuvering would show up as a bending of the ground track starting at a point close to the launch site.
The upper stage(s) may then have used part of their thrust to rotate the trajectory of the rocket so that it was heading in a more southerly direction. A maneuver of this kind, however, requires a lot of fuel, which means less is available to increase the rocket’s speed. We estimate that even a large maneuver of delta-V = 1 km/s would only rotate the horizontal component of the velocity by about 30 degrees (see technical note). That would result in the trajectory shown in Figure 3 (again assuming a non-rotating Earth), which would land on the equator at point C, a ground distance of 5,300 km from the launch site.
The distance from C to B is roughly 6,000 km, which would require the rocket flight time to be 6000 km/(0.46 km/s), or 3.6 hours, for it to land in the Indian Ocean. A trajectory with that flight time would correspond to an apogee of about 18,000 km. If the rocket had a longer flight time and reached a higher altitude it could reenter at a point west of B in the Indian Ocean. In particular, the Earth could rotate by about 10,000 km during the rocket’s flight and the rocket could still reenter over the Indian Ocean. That corresponds to a flight time of 6.0 hours, or an apogee of about 27,000 km. The U.S. statement that the apogee was near GEO would seem to rule out this case.
Another possibility is that the rocket reentered somewhat south of the equator. If reentry occurred at about 15 degrees south latitude, then reentry could occur some 2,500 km east of the reentry point considered above (see point B in Figure 4), near the coast of Australia.
However, as the rocket’s trajectory travels south of the equator, it moves the (non-rotating Earth) impact point A east by essentially the same distance, so that the distance from A to B is about 8,000 km. The rotational speed of the Earth at this latitude is 0.44 km/s, so the minimum flight time of the rocket must be about 5.1 hours, which is the same as the first case above. In this case the distance from the launch site to impact point is 10,600 km, so that the apogee of the trajectory would have been at least 23,000 km. If the impact point were west of B, the apogee could easily have been as high as GEO.
A similar analysis applies if the rocket reentered at 15 degrees south latitude but maneuvered to bend the trajectory southward, as considered in the second example above. Analysis shows that the minimum flight time for a maneuver using delta-V = 1 km/s would be 3.2 hrs, so that the apogee of the trajectory would be at least 16,000 km. If the reentry point were west of B, the apogee could have approached GEO.
There is unfortunately not much publicly available information about the March 2013 launch. If the information used in this analysis is correct, it suggests that the Chinese launch reached, or could have reached, altitudes much greater than 10,000 km. If the rocket did not maneuver horizontally, its flight time suggests it may have reached altitudes of 23,000 to 36,000 km, depending on where in the Indian Ocean it reentered.
If the rocket maneuvered as considered above, it could lower the apogee of the trajectory. But even if it maneuvered very significantly, it appears difficult to get the apogee as low as 10,000 km. Moreover, if the maneuvering fuel had been used instead to increase the speed of the rocket it would have been able to reach a much higher altitude. Either way, this analysis seems to imply that the rocket was capable of reaching altitudes well above 10,000 km, even if it did not actually do so in this launch.