terminal.
Boost Phase Defense
The boost phase is the part of the missile flight from launch until its rocket engines are exhausted and it stops accelerating under its own power. Typically, the boost phase ends at altitudes of 300 miles or less, and within the first 3 to 5 minutes of flight. During this phase, the rocket is climbing against Earth’s gravity.
Intercepting a missile in its boost phase is the ideal solution. We can defend a large area of the globe and prevent midcourse decoys from being deployed by destroying the missile early in its flight. Of the boost phase defenses, the Airborne Laser (ABL) is the most mature.
Midcourse Phase Defense
The midcourse phase of a ballistic missile trajectory allows the longest window of opportunity to intercept an incoming missile: up to 20 minutes. This is the part of the missile’s flight where its engines have stopped thrusting so it follows a more predictable coasting path. The midcourse interceptor and a variety of radars and other sensors have a longer time to track and engage the target compared to boost and terminal interceptors. Also, more than one interceptor can be launched to ensure a successful hit.
A downside to the longer intercept window is that the attacker has an opportunity to deploy countermeasures against a defensive system. The warhead and decoys are detached from the spent rocket stages during the midcourse phase. However, the interceptor and other sensors have more time to observe and discriminate countermeasures from the warhead. The midcourse defense segment has ground-and sea-based elements, including the Ground-based Midcourse Defense (GMD) and the sea-based Aegis Ballistic Missile Defense (Aegis BMD).
Unlike the Airborne Laser, which fires a beam of light energy to destroy the missile, the midcourse and terminal phase systems employ smaller, high-velocity missiles to strike the incoming warhead; this is known as the “kinetic kill” method.
Terminal Phase Defense
A missile enters the terminal phase when the warhead falls back into the atmosphere. This phase generally lasts from 30 seconds to one minute.
The primary elements in the terminal defense segment are:
The mess hall was big and crowded, but not as noisy as Harry expected from the size of the place. The rest of his laser team was finishing up their breakfast by the time Harry worked his way down the counter and carried his tray to their table. He could spot them from across the cafeteria by their white Anson Aerospace coveralls, like a cluster of ice floes in a sea of Air Force blue.
“She’s hot, I tell you,” Wally Rosenberg was saying as Harry dragged a chair from the next table and sat down between him and Taki Nakamura.
“What do you think, boss?” Angie Reyes asked. He was a chemical technician, in charge of the volatile mix of iodine and oxygen that powered the big laser. Reyes was a wiry bantam cock of a guy, short, slim, dark-haired. He had replaced Pete Quintana; Rosenberg kidded that the company’s management wanted to keep its quota of Hispanics on the project.
“Think about what?” Harry asked, taking his English muffin and mug of coffee off the tray.
“Our new pilot,” Rosenberg answered. A chemical engineer, Rosenberg always had a sly grin on his long, horsey face. “I say she’s hot.”
Taki Nakamura, the only woman in the team, made a mock scowl at Rosenberg. “You say every woman you see is hot.”
“Not you, Tiki-Taki,” Rosenberg shot back.
“You’d better not. Unless you want your nose stuffed up your butt.”
“Kung fu engineer,” Monk Delany cracked. Everybody laughed, even Rosenberg.
“Colonel Christopher?” Harry replied to Rosenberg’s question. “I just met her last night, same as you guys. I guess she’s good-looking, all right.”
“Well, you’re an eligible bachelor, aintcha?” Rosenberg said, his grin turning into a smirk.
“I’m still a married man,” Harry said. “We’re separated; we’re not divorced yet.”
Delany shook his head. “When are you gonna bite the bullet, Harry? Go through with the divorce, pal. Get on with your life.”
Harry said nothing.
Nakamura asked, “Is the colonel married?”
“Nope,” Rosenberg answered. “I Googled her. She’s in hot water with the Air Force, as a matter of fact. They caught her sleeping with a married guy—some general, no less.”
“Your kind of woman,” Delany said.
“Yeah. A slut,” added Reyes.
Harry decided the banter had gone far enough. “We’ve got work to do. Let’s get moving.”
As they carried their trays to the disposal area, Taki asked, “Did any of you see the northern lights out there? They’re spectacular!”
Delany said, “So that’s what it was! I caught a glimpse just before the sun came up. Then they faded out. I was wondering what those lights were.”
“Well, shit, we
Nakamura shook her head. “They were awful bright. Must be some big flare on the sun to work them up like that. Or something.”
Standing in front of the desk in the cubbyhole of an office that the base commander had given her, Lieutenant Colonel Karen Christopher was not in a happy mood. Bad enough to be exiled to this godforsaken dump in Alaska. Even worse to push the regular pilot of this oversized bus out of his job and into the right-hand seat. He’s already pissed off at me. Now they’ve stuck me with a navigator who’s so inexperienced he looks like a skinny high school kid who’s snuck into Air Force blues.
Her navigator, Lieutenant Eustis Sharmon, was tall, quite lean, with skin the color of dark chocolate. He was standing at attention before Colonel Christopher, who stood a full head shorter than him. Sharmon looked
