The Ceres program began in early 1965 just as the Luna program was commencing. This program was intended to ready astronauts for manned space flights and would work with the Luna program to eventually allow manned flights and landings to the moon. The Ceres spacecraft used were self-propelled, unlike the Jupiter craft. They were carried on Da Vinci rockets.
Ceres 1 and 2
The Ceres 1 mission took place in November 1965; two astronauts did an orbit of earth. Ceres 2 (June 1966) was the first to get Europan astronauts (Guglielmo Conti and E. Pazzini) out of earth’s orbit. 2 days later they re-entered and fell in the Mediterranean Sea.
Ceres 3 and 4
Ceres 3 (launched March 1967) sent astronauts Victor Jankovic and Luis Benitez to orbit the moon. The Ceres craft had no landing gear so they did not land on the moon. Ceres 4 (launched 5 July 1969) was meant to do the same as Ceres 3. The Da Vinci rocket carrying the astronauts exploded during liftoff, killing them (an ominous sign as the Apollo 11 mission was a few days from taking off).
Ceres 5 was the last manned mission planned to orbit the moon, but it was cancelled as the Luna 4 was a few months away from taking place. Conti and Jankovic, who participated in the Ceres 2 and 3 mission, respectively, were chosen for the Luna mission which placed them on the moon.