Can a gravity assist slow a spacecraft?

Depending on the relative direction of motion of the planet and the spacecraft, a gravity assist can either speed up, slow down, or merely change the direction of the spacecraft.

How does gravity assist help a spacecraft reach its destination?

Gravity assistance can be used to accelerate a spacecraft, that is, to increase or decrease its speed or redirect its path. The “assist” is provided by the motion of the gravitating body as it pulls on the spacecraft.

How does gravity affect the planets?

The sun’s gravity pulls the planet toward the sun, which changes the straight line of direction into a curve. This keeps the planet moving in an orbit around the sun. Because of the sun’s gravitational pull, all the planets in our solar system orbit around it.

What is the purpose of the gravity assist maneuver?

In orbital mechanics and aerospace engineering, a gravitational slingshot, gravity assist maneuver, or swing-by is the use of the relative movement (e.g. orbit around the Sun) and gravity of a planet or other astronomical object to alter the path and speed of a spacecraft, typically in order to save propellant, time.

How does a gravity assist around a planet affect a spacecraft?

A gravity assist around a planet changes a spacecraft’s velocity (relative to the Sun) by entering and leaving the gravitational field of a planet. The spacecraft’s speed increases as it approaches the planet and decreases while escaping its gravitational pull (which is approximately the same).

What is “gravity assist” flyby?

The “gravity assist” flyby technique can add or subtract momentum to increase or decrease the energy of a spacecraft’s orbit. Generally, it has been used in solar orbit, to increase a spacecraft’s velocity and propel it outward in the solar system, much farther away from the Sun than its launch vehicle would have been capable of doing.

What is a gravity assist with Jupiter?

A gravity assist with Jupiter involves not a stationary planet as considered above, but a planet with enormous angular momentum as it revolves around the Sun. In the diagram at left, Jupiter’s motion along its solar orbit has been illustrated with a vector colored red (simplified, of course: Jupiter revolves along an arc, not a straight line.

How does a Jupiter flyby affect the mass of a spacecraft?

Since a flyby can also decrease a spacecraft’s orbital momentum, the Galileo spacecraft decreased its energy, relative to Jupiter, with a gravity assist flyby in front of the Jovian moon Io. In this way, it was possible to decrease the mass of rocket propellant needed for Jupiter orbit insertion.