Chandrayaan-1, launched in 2008, was the first Indian spacecraft to encounter a comet, specifically Comet Tempel 1.

Chandrayaan-1 was primarily designed for lunar exploration, aiming to study the Moon's surface, composition, and mineralogy.

Mangalyaan, also known as the Mars Orbiter Mission, was launched in 2013 to study the Martian atmosphere, surface, and mineralogy.

Mangalyaan's primary objective was to study the Martian atmosphere, surface, and mineralogy, making it India's first interplanetary mission.

Astrosat, also known as the Indian Space Observatory, is designed to study astronomy and astrophysics, focusing on X-ray, optical, and ultraviolet observations.

Astrosat's primary objective is to study astronomy and astrophysics, including X-ray astronomy, optical astronomy, and ultraviolet astronomy.

NISAR, or the NASA-ISRO Synthetic Aperture Radar mission, is a joint mission between ISRO and NASA to study Earth's ecosystems, natural hazards, and climate change.

NISAR's primary objective is to study Earth's ecosystems, natural hazards, and climate change using synthetic aperture radar technology.

Dr. K. Radhakrishnan, former Chairman of ISRO, played a significant role in the development of Chandrayaan-1, India's first lunar mission.

Dr. Mylswamy Annadurai, former Director of the ISRO Satellite Centre, was the Project Director of the Mangalyaan mission.

Dr. Vikram Sarabhai, renowned Indian scientist and engineer, is widely regarded as the 'Father of the Indian Space Program' for his contributions to India's space research.

The Indian Space Research Organization (ISRO) is the Indian space agency responsible for cometary missions and spacecraft encounters, among other space exploration endeavors.

Chandrayaan-1, launched in 2008, was the first Indian spacecraft to encounter a comet, specifically Comet Tempel 1.

Mangalyaan, also known as the Mars Orbiter Mission, was launched in 2013 to study the Martian atmosphere, surface, and mineralogy.

Astrosat, also known as the Indian Space Observatory, is designed to study astronomy and astrophysics, focusing on X-ray, optical, and ultraviolet observations.