1. The question asks to identify which option is a spacecraft.
2. Apophis is a near-Earth asteroid.
3. Cassini (Cassini-Huygens) was a highly successful collaborative spacecraft mission sent to the Saturn system.
4. Spitzer refers to the Spitzer Space Telescope, an infrared space telescope (observatory).
5. TechSar (also known as Ofek-8) is an Israeli reconnaissance satellite.
6. Therefore, Cassini is the spacecraft mission among the options.