Star wars returns
“RONALD REAGAN wanted it many years ago,” declared Donald Trump, “but they didn’t have the technology.” Now, he said, America could finally build a “cutting-edge missile-defence shield”. Mr Trump’s Golden Dome—an allusion to Israel’s more modest Iron Dome—is intended to protect America from attack using, among other things, hundreds or thousands of satellites that can both track and attack enemy missiles as they take off.
Mr Trump had promised such a shield on the campaign trail. On May 20th he said his “big, beautiful” tax bill, which has not yet been approved by Congress, included $25bn in initial funding and that the project would cost $175bn in total. In practice, the Golden Dome will probably cost far more—the Congressional Budget Office reckons the bill could run to more than $500bn over 20 years—and take far longer than Mr Trump’s wildly optimistic timeline of “two and a half to three years”.
Similarly suspect is Mr Trump’s claim that the system will offer “close to 100% protection”. The success rate is likely to depend on the scope of the shield. A recent report by the American Physical Society, a group of physicists, suggested that 16,000 space-based missiles would be needed to be sure of intercepting a salvo of just ten North Korean Hwasong-18 missiles. But if American leaders wanted 30 seconds of decision time before acting, they would need 36,000 interceptors. And “many more interceptors” than that would be required if America was also defending very northerly cities, Alaska or the Midwest.
Golden Dome is in part a response to the Pentagon’s concern that America’s adversaries are building huge numbers of new and more diverse missiles. American radars and defences have historically focused on missiles travelling over the North Pole. But long-range hypersonic missiles, which are more manoeuvrable, and “fractional orbital” systems, which can partly encircle the Earth, can take more unpredictable routes. A recent report by the Defence Intelligence Agency shows arrows plunging into America from all directions. Canada, which already has a joint aerospace defence command with America, is in talks about joining Golden Dome.
The defensive shield also highlights how Earth orbit is becoming a front line in the new struggle between Russia, China and America. It is being waged by the likes of Cosmos 2553, a Russian satellite that America believes is an unarmed prototype of a particularly lurid space weapon: a nuclear weapon capable of wiping out satellites across large swathes of low-Earth orbit—such as those that would be part of Golden Dome. China is also building a range of counter-space weapons. “They’re moving at jaw-dropping speed,” said General Stephen Whiting, the head of America’s Space Command, of China’s expanding anti-satellite arsenal.
Such weapons put far more than just defence infrastructure at risk. They also threaten the spacecraft that provide communications and, perhaps more important, the positioning, navigation and timing data that are essential for modern economies. The vulnerability of satellite navigation systems has been exposed by a huge increase in the jamming and spoofing (counterfeiting) of their signals.
Russia and China have been developing satellites with “advanced manoeuvring capabilities” that would allow them to interfere with or destroy American satellites. In May 2024, for instance, Cosmos 2576, another Russian satellite, entered a “coplanar” orbit with USA 314, an American spy satellite, in a manner that “could signal the positioning of a counterspace weapon”, according to a new report by the Centre for Strategic and International Studies (CSIS), a think-tank in Washington. France has become so alarmed that it has talked about developing “bodyguard” systems for satellites, which could allow satellites to detect threats and then defend themselves using a robot or laser.
There are also other sorts of celestial sparring under way. At one point last year, TJS-4, a Chinese suspected signals intelligence spacecraft, manoeuvred to get between an American surveillance satellite and the sun. That, says CSIS, would have created shadows preventing the Americans from taking good photos of the Chinese craft. General Michael Guetlein, the new head of Golden Dome, earlier this year accused China of practising “dogfighting in space”.
Yet America is hardly a shrinking violet in this area. Last month USA 324, one of General Whiting’s surveillance satellites, sidled up to TJS-16 and TJS-17, a Chinese pair of suspected electronic-intelligence satellites. It passed within 17km of the former and 12km of the latter, according to COMSPOC, a firm that tracks objects in space. This “buzzing” of the Chinese satellites was, notes Jonathan McDowell of the Harvard-Smithsonian Center for Astrophysics, “the sort of thing that causes DoD officials to issue outraged comments when China does it to ours”. ■