With a doctorate in combustion engineering, Saraswat started his career in DRDO in 1972 at the Defence Research and Development Laboratory (DRDL), Hyderabad, and was responsible for the development of the country's first liquid propulsion engine.

As project director of Prithvi, he steered the design, development, production and induction of the first indigenous surface-to-surface missile system into the armed forces. The successful testing of the Dhanush missile on board a moving ship with high terminal accuracy brought a new dimension to the national defence capability.