Conventional ballistic missiles operate on the same principle as employed for firing a gun or throwing a stone. You impart a high velocity to a bullet, shell or a missile. Depending on its initial velocity, the projectile can travel anywhere from a few yards to a few thousand miles following equations of ballistic trajectory that students routinely solve in high school.
One such futuristic system was envisioned by a genius called Eugen Sanger. An Austrian-born aeronautical engineer, Sanger was a member of the Nazi party as well as the notorious SS Gestapo!
Sanger was obsessed with bombing the American mainland from across the Atlantic. A grandiose idea – in an era when flying a missile across the English Channel was regarded a great achievement. Sanger realized that ballistic missiles had inherent limitations of range. Making them bigger and bigger, increased both cost and complexity prohibitively.
Sanger proposed a novel idea — as out-of-the-box as it could be. In principle, his idea was somewhat like the game of Ducks and Drakes. Kids throw a flat piece of stone at a shallow angle, on a huge expanse of water. Instead of sinking in the water, the stone skips on it several times. Travelling much farther than it would, if thrown in the air.
In Sanger’s mind, the flat piece of stone in Ducks and Drakes, was replaced by his pet ‘Amerika Bomber’ project. The expanse of water became Earth’s dense atmosphere. And the air in Ducks and Drakes was replaced by the rarefied air or near vacuum of outer space. Since regular air-breathing engines cannot operate in vacuum, Sanger’s bomber would require rocket engines or specialized jet engines. How would it reach outer space? Well, a rocket would lift vertically from the ground and take it to about 150 km up. From there, it would launch the bomber.
The bomber, named Silbervogel (Silverbird) would have a fuselage, so shaped that when it would strike the denser layers of the atmosphere at a shallow angle, like the piece of stone in Ducks and Drakes, it would also start skipping over it. Since there is practically no friction or air drag up there, the skipping or hopping bomber would cover 19-24,000 km across the globe with very little fuel spent and developing speeds of Mach 17 (that is, 17 times the speed of sound)!
Today, we call them as boost-glide, skip-glide or a variant of FOBS (Fractional Orbital Bombardment System).
What is a fractional orbital bombardment system?
FOBS is the highest-velocity missile deployment system that currently exists.
Broadly speaking, the slowest missiles are cruise missiles, which are essentially drone planes. Though they may initially ride a rocket booster launched from the ground or a submarine, they go on to cruise through the atmosphere like a jet-powered plane.
Ballistic missiles, meanwhile, are essentially suborbital rockets, operating on the principle that what goes up must come down. When launched, they can climb to altitudes up to 1,200 miles (2,000 kilometers) — much higher than satellites or space stations in low Earth orbit. They can also reach speeds of up to several miles per second before reentering the atmosphere. However, their ballistic nature also makes their trajectories predictable, and therefore vulnerable to missile defense systems.
In contrast, in a fractional orbital bombardment system, the rocket achieves low Earth orbit, which requires more energy than a ballistic missile has. But before completing one full orbit, a FOBS rocket deorbits by turning around and performing a retrograde engine burn. This allows it to slow down so that its trajectory intersects with its target on the ground.
The FOBS concept was originally developed by the Soviet Union, in part to bypass international agreements that prevent weapons of mass destruction from being stationed in Earth orbit. A fractional orbital bombardment system, Moscow asserted, was not prohibited by those agreements.
Being able to strike from low Earth orbit carries several advantages. By staying relatively low, never climbing above 150 miles (240 km) or so, they remain below the line-of-sight of radar designed to pick up arcing ballistic missiles. Orbital trajectories also allow militaries to strike from unexpected directions. For example, the Soviet Union's FOBS gave missiles the ability to evade potential U.S. anti-ballistic missile systems in Alaska. How? By launching to an orbit that flies over the South Pole, blindsiding the U.S from below.
In essence, HGVs are spacecraft. They are incredibly similar to rocket-launched spaceplanes like the Air Force’s X-37B, which launches to orbit, reenters the atmosphere, and glides to make a precise landing on a runway. China also tested a similar orbital spaceplane for the first time in September 2020. “[This] is the same concept, except you put a nuclear weapon on the glider and don’t bother with a landing gear,” tweeted arms control expert Jeffrey Lewis.
An HGV’s ability to maneuver as it descends into thicker and thicker air allows it to be both more accurate and unpredictable. When the vehicle’s wings begin generating lift as it reaches the upper wisps of the atmosphere, it gains the ability to roll and maneuver. This means it can alter its trajectory to take aim at a different target than its orbit suggested, or to evade an anti-ballistic missile.
And it's so fast that the air pressure in front of the weapon forms a plasma cloud as it moves, absorbing radio waves and making it practically invisible to active radar systems.
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astronomy.com
U r ambushing me from both sides as if i am DoD spokesperson. I feel like members like u r police interogatting me. U guys seldom make suggestions or share sources.
Just have fun
