Viewed from that height, the hotel was still clearly visible to the naked eye, nestled among acres of forest rising gently to the west. Furrowed snow glistened on the nearby mountain ridges. Ludwig II could only have dreamed of such a place.
Higher up in the atmosphere, the sounds from below petered out altogether.
Now only jet planes taking to the skies or coming into land could still be heard. Seen from an altitude often kilometres, the Chateau blurred into the landscape. Charter planes left white trails in the air, and the horizon curved. Low-lying banks of cloud stood out against the bright blue sky like snow plains and icebergs, the vapour conjuring an illusion of firm ground. Another five or ten kilometres further up, the noise of supersonic jets cut through the thinning atmosphere. The troposphere was governed by the whims of the weather, but further up, the stratosphere was home to the ozone layer, which screened out ultraviolet light. The temperature increased. At that altitude, the clouds were just ethereal wisps, shimmering like mother-of-pearl. Silvery weather balloons shone in the sunlight, sparking reports of UFO sightings below. In 1962 an American recon plane had stolen through the silent skies twenty kilometres above ground to photograph Soviet warheads in Cuba. Because of the extreme altitude, the pilot of the legendary U-2 had been forced to wear a spacesuit. It had been one of the most daring flights of all time, and had taken place in a deep-blue sky that opened into the vastness of space.
At an altitude of eighty kilometres, the interwoven streaks of individual noctilucent clouds glistened in the light. It was minus 113°C. Up here the only sign of human presence was the rare sight of a passing spaceship as it took off or landed. The deep-blue gave way to blue-black. This was the realm of the heathen gods, unmasked by modern science as polar aurorae and glowing meteorites. The thermosphere had given rise to more myths and legends than any other feature of the physical environment. In reality it was an unsuitable home for divinities or for any form of life at all. Gamma and X-rays poured in from above. The thermosphere extended for hundreds of kilometres, but gas molecules were few and far between.
There were other things to see, though.
Travelling at 28,000 kilometres per hour, the nearest satellites orbited the Earth at an altitude of 150 kilometres. By their very nature they were mainly recon satellites, positioned at the minimum possible distance from the ground. Eighty kilometres above them the Shuttle Radar Topography Mission gathered land-elevation data from the Earth's surface to create a twenty-first-century planetary map. At relatively low altitudes such as these, the atmosphere was dense enough to slow the satellites, making them reliant on the occasional injection of fuel to keep them in orbit. Three hundred kilometres above the Earth there was no need for fuel. The centrifugal force and the force of gravity balanced each other out, and the satellite's orbit was stable. The skies began to fill.
The satellites circled the Earth like cars on a network of highways, passing over and under each other. The higher the altitude, the denser the traffic. At 500 kilometres, two elegant little satellites called Champ and Grace monitored the Earth's gravitational and magnetic fields. Six hundred kilometres above the polar regions, ICESat measured lightwave reflections from the Earth's surface, allowing scientists to track changes in the icecaps. Seventy kilometres above that, three state-of-the-art US Army Lacrosse satellites orbited the Earth, scanning its surface with high-resolution radar. At an altitude of 700 kilometres, NASA's Landsat satellites observed the land and coastal regions, acquiring data on advancing and retreating glaciers, mapping the growth of forests and the formation of pack ice, and providing accurate charts of the Earth's surface temperature. SeaWiFS, on the other hand, used optical scanning and infrared to keep tabs on the build-up of algae in the oceans. At 850 kilometres above ground, NOAA's satellites had made themselves at home in a sun-synchronous orbit, with numerous meterological satellites circling the planet, passing close to both poles. The bustle of satellites encroached high into the magnetosphere, where cosmic and solar particles were bundled into two radiation belts, known as the Van Allen Belt – a phenomenon that had developed a life of its own in the media. For many Americans the Van Allen Belt was proof positive that the moon landings had never happened. In fact, even respected scientists had cast doubt on whether the astronauts in the spaceship would have been sufficiently protected to pass through the band of lethal radiation and survive. In satellite terminology, though, space was simply divided into LEO, Low Earth Orbit, then Middle Earth Orbit, used by numerous satellites, including the GPS constellation at 20,000 kilometres above ground; and then finally Geostationary Orbit, where the satellites – primarily Intelsats, used for international communication – kept pace with the Earth at an altitude of 35,888 kilometres.
Mozart was nowhere to be heard.
Though the notes from the piano had been lost in the spring air, Li's conversation with the President had made the long voyage up to the satellites and back. At the peak of the phone call, the two had chatted in outer space, exchanging information that came courtesy of the skies. Without its army of satellites, America would never have been able to fight the Gulf War or the wars in Kosovo and Afghanistan. The air force's campaigns of precision bombing had relied on help from outer space, and if it hadn't been for the high-resolution images from Crystal, also known as KH-12, the US high command would have been blind to enemy movements in the mountains.
KH stood for Keyhole. America's most sensitive spy satellites were the optical counterpart to the radar system of Lacrosse. They could detect objects of just four to five centimetres across and could operate in infrared light, which allowed them to work through the night. Unlike satellites orbiting above the Earth's atmosphere, they were equipped with a rocket engine, permitting them to travel in a very low orbit. They usually circled the planet at an altitude of 340 kilometres from pole to pole, which meant they could photograph the whole Earth within twenty-four hours. When the attacks had begun off the coast of Vancouver Island, some of the Keyhole satellites had been brought down to an altitude of 200 kilometres. In response to the 9/11 terrorist attacks, America had launched twenty-four new high-resolution optical spy satellites that orbited the Earth at a very low altitude, and with Keyhole and Lacrosse, they formed a formidable recon network whose capabilities exceeded even Germany's famous SAR-Lupe system.
At eight p.m. a call came through to two men in an underground bunker in Buckley Field, not far from Denver. The intelligence base was one of several secret ground stations belonging to America's National Reconnaissance Office, the NRO, whose mission was to co-ordinate satellite espionage for the American air force. It had close ties with the NSA, an agency responsible for national security and cryptology. Its brief was to bug and intercept. The alliance of the two intelligence agencies gave the American administration an unprecedented power of surveillance. In addition to that, the entire planet was continually monitored by an almost fully automated reconnaissance network known as ECHELON, which used various technological systems to listen in to international communication, including satellite, radio and fibreoptic traffic.
The two men were sitting below ground, beneath an enormous satellite dish. Working in a room full of monitors, they spent their time receiving real-time data from Keyhole, Lacrosse and other recon systems, analysing and evaluating the information, then forwarding it to the relevant authorities. According to their job titles, they were intelligence agents, though their outward appearance gave nothing away. Dressed in jeans and sneakers, they looked more like grunge rockers.