Michael Minovic.
Michael Andrew Minovic (about 1936) is an American mathematician. He changed people's general understanding of how rocket-propelled aircraft sail in the sun and interstellar space. 196 1 year, Minovic was a graduate student at UCLA, and Minovic used IBM 7090, the fastest computer at that time, to solve trisomy.
IBM-7090 is huge, but its operation speed is very slow. Although it was the fastest computer at that time, it was far worse than the worst laptop today. It's just slow, and it's especially expensive to use. Once opened, it will cost 1000 dollars an hour. Minovic made many simulations with this computer and explained his answer in 1962. Gravity slingshot (also known as gravity boost) technology was first discovered.
What is gravitational slingshot effect?
Gravitational slingshot effect uses the relative motion and gravity of planets or other celestial bodies to change the orbit and speed of aircraft, thus saving fuel, time and planning cost. Gravity slingshot can be used not only to accelerate the aircraft, but also to reduce the speed of the aircraft. In the solar system, the acceleration can be obtained because the orbital direction of the aircraft flying to the inner planet is towards the sun; However, the speed of the aircraft flying to the outer planets will gradually decrease because it flies with its back to the sun.
Usually, rocket propulsion is one of the important methods to accelerate and decelerate an aircraft. But rocket propulsion needs fuel, and fuel has weight. Even if a small amount of load is added, we should consider launching the aircraft out of the earth with a larger rocket engine. An airplane using the law of gravity boosting can accelerate and decelerate without carrying extra fuel.
In addition, under suitable conditions, atmospheric brakes can also be used to slow down the aircraft. If possible, the two methods can be combined to save fuel to the greatest extent.
What is gravitational slingshot effect?
More generally, when a spacecraft approaches a planet, it will be attracted by its gravity. Because the planet itself revolves around the sun at high speed, it will drag the spacecraft to run together, thus transmitting its speed to the spacecraft. In this way, as long as the spacecraft is not captured by the planet, it can get the extra speed provided by the planet, so it can be thrown out at a much higher speed than before.
In other words, the planet has become a space gas station to accelerate the spacecraft, and you can understand this physical process as hitchhiking. If a person runs on the road, his speed is always limited. But if he runs on an open-top train, his speed will be superimposed with the speed of the train and greatly increased.
Application of Gravitational slingshot effect
Gravitational slingshot effect is a landmark discovery in the history of human spaceflight. Before the gravitational slingshot was discovered, the spacecraft launched by human beings could not even reach Mars, and after that, human beings had the ability to explore the whole solar system. The task of using gravity slingshot effect for the first time is Pioneer 10. It passes Jupiter at 1973 and 12, and uses gravity slingshots to increase its speed.
1 Voyager1,launched in 1977, became the farthest man-made aircraft from the earth and the first man-made aircraft to leave the solar system through gravitational slingshot effect. At present, Voyager 1 is still flying along the hyperbolic orbit, entering the interstellar medium and becoming an interstellar spacecraft. Voyager 2, also launched at 1977, also accelerated its flight to Uranus and Neptune through the gravitational slingshot of Mars, becoming the first spacecraft to visit Uranus and Neptune.
The picture shows the route map of Voyager 2, which was first thrown to Saturn by Jupiter's gravity slingshot, then to Uranus by Venus' gravity slingshot, then to Neptune by Uranus' gravity slingshot, and finally to outer space by Neptune's gravity slingshot. With the help of gravity slingshots, Voyager 2 went to these four planets at the same time.