Colombo studied the planet Mercury, and it was his calculations which showed how to get a spacecraft into a solar orbit which would encounter Mercury multiple times, using a gravity assist maneuver with Venus. Due to this idea, NASA was able to have the Mariner 10 accomplish three fly-bys of Mercury instead of one. Mariner 10 was the first  spacecraft to use gravity assist. Since then, the technique has become common.
Colombo also made significant contributions to the study of Saturn's rings, mostly using ground-based observations in the era before space exploration reached the outer solar system.
- Colombo invented the concept of tethers for tying satellites together.
- Colombo participated in the planning of Giotto, the European Space Agency's mission to Halley's Comet, but died before the spacecraft was launched.
- The Giuseppe Colombo Centre for Space Geodesy in Matera, Italy.
- ESA awards a 'Colombo fellowship' each year to a European scientist working in the field of astronautics
Several astronomical objects and spaceships are named after to honor him:
- The ESA mission to Mercury, which launched at 1:45:28 UTC on 20 October 2018, is named BepiColombo.
- The Colombo Gap in Saturn's rings.
- The asteroid 10387 Bepicolombo
- "Giuseppe Bepi Colombo Grandfather of the fly-by". Welcome to ESA. Retrieved 6 January 2019.
- "Mariner 10". 30 November 2010. Archived from the original on 19 February 2014. Retrieved 6 January 2019.
- ESA Press Release: ESA's Mercury mission named BepiColombo in honour of a space pioneer