Gravity assist
Asistencia gravitatoria
- Date
- 1918-1959 · confidence medium
- Place
- Moscow, Russia
- Credited to
- Friedrich Zander (theoretical formulation, 1925); first practical use by the Soviet probe Luna 3, 1959
- Field
- Movement
⚠️ Disputed: the sources disagree.
What was discovered
Baltic-born engineer Friedrich Zander described in 1925 the physical principle of using a planet's or moon's gravitational field to accelerate or redirect a spacecraft without expending fuel; earlier sketched by Yuri Kondratyuk (1918-1919), the maneuver was first used in practice in 1959, when the Soviet probe Luna 3 used lunar gravity to photograph the far side of the Moon.
Theoretical priority is disputed between Kondratyuk (1918-1919, unpublished until the 1960s) and Zander (1925); in practice, the Soviet Luna 3 (1959) used it before the more commonly cited Mariner 10 (1974), the first probe to visit another planet using it.
What it led to
- a drastic reduction in fuel needed for interplanetary missions
- the design of the Voyager probes' 'Grand Tour' trajectories in the 1970s
- a standard technique in outer solar system exploration
Made possible
- Pioneer 10: first visit to Jupiter and crossing of the asteroid belt3 de diciembre de 1973
- Mariner 10: first visit to Mercury and interplanetary gravity assist29 de marzo de 1974
- ISEE-3: first halo orbit at a Lagrange point and first comet visited1978
- Ulysses: first probe over the Sun's poles1994-1995
- Galileo: first atmospheric probe and first orbiter of Jupiter7 de diciembre de 1995
- NEAR Shoemaker: first orbit and landing at an asteroid (Eros)12 de febrero de 2001
- Rosetta and Philae: first orbit of and landing on a comet12 de noviembre de 2014
- New Horizons: first flyby of Pluto14 de julio de 2015