Celestial mechanics experienced a new boom in the Sputnik age and he published an introduction to the subject, which also considered the orbits of artificial satellites.
[1][12] With František Link (1906–1984), he estimated the diameter, flattening, and optical properties of Neptune's upper atmosphere.
[13] At the Paris Observatory, Kovalevsky's group developed advanced computer algorithms for celestial mechanics that were also used in the Gaia mission (the INPOP software).
In astrometry, he was involved in the Hipparcos mission to accurately measure the proper motion and parallax of 118,000 stars.
He was also involved in Gaia (the successor to Hipparcos) as a member of the working group Reference Frame and Relativity.
[18] In 1999 he received the ESA Director of Science Medal for the Hipparcos mission (along with Lennart Lindegren, Erik Høg and Catherine Turon).
He was appointed Knight of the Legion of Honour, Commander of the Ordre national du mérite, and Officer of the Palmes Académiques.