their ~~ats azid chcc&zg ~~ “FOREST GREEN shows three units with amphtu~e pu’Ise threshold readings. System reports confirmation of readouts, repeat, system reports readout confirmation, event confidence is high.” Technicians at Cheyenne Mountain seldom used words like “nuclear detonation” or “explosion”-these were collectively called “events” and “readouts.” emotional detachment prevalent inside the Mountain, as if they could somehow block the horrors they saw by naming them something harmless. It was a relatively low-tech device that issued a warning on that Wednesday afternoon, a device that had gone all but unused for years. In an effort to increase the number of nuclear detection devices in orbit without increasing the actual number of satellites, in the late 1 970s and early 1 980s a secret program code-named FOREST GREEN was implemented. NAVSTAR Global Positioning System navigation satellites were fitted with electromagnetic pulse sensors and devices called (quite appropriately for nuclear detonation detection) Bhangmeters, which were sensitive optical flash detectors that could determine the explosive yield of a nuclear explosion by the brightness of the flash. Unlike AMWS, which were used only on specific (albeit very wide) areas of the Earth, FOREST GREEN had global coverage because the eighteen- satellite NAVSTAR constellation had at least three satellites looking at every piece of the Earth at every moment. A nuclear explosion has a definite pattern of two pulses-the first less intense than the second-caused first by the detonation of the triggering device, followed exactly one-third of a second later by the main explosion; this was the reason Bhangmeters were mounted in pairs, with one more sensitive than the other. The EMP detectors on the three FOREST GREEN satellites also registered the disruption of the ionosphere before communication between the satellites and their receivers on Earth were abruptly cut off. The senior controller in the Operations Center, an Air Force colonel named Randolph, immediately put the staff sergeant’s console display up on the “big board, ” a rectangle of six 2-by-3foot screens in the front of the Operations Center. The display was relatively uninformative at this point-three lines out of eighteen on the display were flashing, with a string of numbers showing the system readings and the threshold levels preprogrammed into the system. “All stations, this is Randolph. I confirm a FOREST GREEN event detection and classification, I need a status check and report in thirty seconds, all stations stand by.” The problem with the FOREST GREEN sensors was that they were not highly directional-the sensors could accurately record a nuclear detonation but not precisely pinpoint the explosion’s location; when the Bhangmeters were installed on older Vela nuclear-detection satellites, the device’s telescopic eye could pinpoint the location of the detonation, but on NAVSTAR satellites the sensors were relegated to area reports only. In a few moments Amy Hector had replaced the cryptic lines of data with a graphic pictorial of the information: a chart of the Earth that was within line-of-sight reach of the three NAVSTAR satellites that had suddenly gone off the air. Somewhere within the three overlapping shaded spheres, the first aboveground nuclear device in thirty years had detonated. Unfortunately, the display showed the explosion could have occurred anywhere from Hawaii to Thailand and from Japan to Australia. “I need better information than that, ” Colonel Randolph said. “Find out why no DSP systems issued an alert.” DSP was a constellation of satellites so sensitive that they could detect brush fires, structure fires, or even high-performance aircraft using afterburners-all from twenty-two thousand miles in space. “Sir, this is Staff Sergeant Hector on FOREST GREEN, ” Hector interjected. “I think I can come up with a rough triangulation.”
“Let’s have it, Sergeant.” “I’ve got the exact time when all three of the NAVSTAR satellites shut down, ” Hector explained, “and I’ve got the time down to one-one-hundredth of a second. I can Randolph looked at her. “I get the picture, Sergeant Hector. Speed of gamma particle versus time. Are the off-air times that different?”
“Stand by, sir.” There was a slight pause, then Hector replied: “Two times are the same; the other is different. I can poll the sensor threshold-release circuits and get a more exact time; I can also try a laser orbital velocity measurement to see if the event changed the orbits-“
“Just do it, Amy.” This was the first time he had ever recalled calling Hector by her first name, but it seemed oddly appropriate now. “But first, I need an acknowledgment of a suspected FOREST GREEN event from CINCSPACECOM right awayalso get SAC and JCS on the line.”
“Yes, sir. “NORAD hasn’t issued an alert yet, ” Randolph muttered half-aloud. “Why the hell haven’t they said anything? Something big enough to knock out three satellites is not good news. ABOARD SKY MASTERS DC-10, OVER CALIFORNIA SAME TIME Jon Masters had his feet up on the bulkhead, was on his third plastic squeeze bottle of Pepsi and halfway through a bologna and cheese sandwich when the toneless, emotionless voice of the Air Force mission control tracking officer on the radio said, “Masters One, College, contact lost with Jackson One.” Masters sat upright, put down the Pepsi, and quickly checked his readouts. “College, this is Masters One, I-” He did a double-take. Seconds ago he’d been getting a stream of position and velocity readouts from the NIRTSat in its orbit. Now the readouts were zero. Masters sighed. “Confirmed on this end. Stand by. I’ll try to re-establish communications.” On the interphone to his crew, he said, “Give me a turn westbound and a climb to best altitude. We’ve got a problem with the satellite.” Helen Kaddiri entered the flight deck. “What is it, Jon?”
“We lost contact with the satellite.” She looked at him as if to say, I’m not surprised. Instead, she said, “Same problem we had before?”
“That was a loose plug, Helen, this”-he scratched his head in an uncharacteristic moment of confusion-“has got to be something else. But what, I don’t know.” ABOARD WHISPER ONE-SEVEN, OVER POWDER RIVER MOA, MONTANA SAME TIME McLanahan began programming the final launch instructions on his Super Multi Function Display so they could take out the last few sortie targets in General Jarrel’s setup and then head home. The display shimmered and abruptly changed. “What the-” McLanahan muttered. Instead of the gently rolling hills and dry gullies of southeastern Montana, the SMFD showed a confusing pattern of light spots in a blank, featureless background. It did have one very prominent terrain feature-a mountain nearly twenty thousand feet high and sixty miles wide. It was as if Mount Everest had just been transplanted into the middle of the Great Plains. “I don’t believe this . . .” McLanahan said, staring at the SMFD. “What is it?” Ormack asked. “That doesn’t look like the target area.”
“The computer must be decoding the signal wrong, McLanahan guessed. Amazingly, the computer began plotting a recommended course on the erroneous computer display, with sharp changes in heading away from the larger moving spots but fairly close to the smaller, non-moving ones. The computer even made weapon selections, although with only two weapons on board the choice was relatively simple-the longer-range SLAM missile for the large moving spots that were to be circumnavigated, and the STRIKER glide-bomb for the smaller, stationary ones. The strike computer began the arming and countdown procedures to attack these “targets, ” and that’s when McLanahan got tired of this. “There’s some glitch in the system and it’s not 1 clearing. I’ll reset the system and go manually until I get a usable display back.” But he did not simply reset the computers-he used the on-board computer memory to save the last few seconds of images first before clearing the bogus display. “What do you think is the problem?” Ormack asked. “I don’t know, ” McLanahan replied. “I’ll check switchesthe system will report on any switches out of position in the post-mission computer dump. Maybe there was a glitch in the satellite. Who knows?” He bent toward the screen and began identifying radar aimpoints, getting ready for the “bomb” releases. “Probably something minor. . But that new satellite image did not look like something minor, McLanahan thought uneasily. It was more than a glitch. The computer was processing the data it received from NIRTSat as if it were real, uncorrupted data, and he knew enough about the NIRTSat system to know that the computer would reject false data. No, whatever that twentythousandfoot~high “mountain” was, McLanahan thought, it was real. Something very serious had just happened somewhere in the world. HIGH TECHNOLOGY AEROSPACE WEAPONS CENTER “What the hell happened?” Colonel Wyatt exclaimed. They were looking in stunned amazement at the high-definition TV monitor, and at the monstrosity that the computer was showing them: a mountain thousands and thousands of feet high and dozens of miles wide, engulfing ships in its path with devastating power. “Must be a sensor glitch. .. a solar flare or a power spike, ” Major Kelvin Carter tried. He spoke with the technicians, but none of those present could understand the display. “Whatever it is, it killed the satellite, ” Carter said. “This is the last image received; the satellite is off the air.”
“Too bad, ” Wyatt said. “McLanahan’s run was looking real good, too.” Captain Ken James’ attention was riveted on the display frozen on the screen. “It’s a weird picture, but the computer is displaying valid data on it, ” he said. “Look: height, width, speed, density, course-the thing is moving and growing all at once. “But it’s showing it as terrain, Ken, ” Carter said. “That can’t be right. We were looking at the Philippines first, then at Montana. There’s no mountain in either place.” Wyatt shrugged, then began packing up his notebook. “It was still a spectacular display, gents, ” he said, “but I-“
“Sir, phone call for you, ” one of the technicians said. “Urgent from NMCC.” As Wyatt trotted to the phone, James turned to Carter and asked, “Nimic? What’s that?”
“National Military Command Center, ” Carter replied. “The War Room at the Pentagon.” James nodded,
