SPARTAN (for Shuttle Pointed Autonomous Research Tool for Astronomy) was a series of satellites deployed and retrieved during Space Shuttle missions during the 1980s and 1990s. The practice took the place of sounding rocket missions, having the Shuttle deploy the probes as satellites for the duration of the Shuttle flight, retrieving them to return. The satellites operated independently, recording data for later analysis. SPARTAN missions were in the 1980s and 1990s using a series of probe designs. Some, such as SPARTAN-201, were used for Solar research. One was intended to view Comet Halley, but was lost in the Challenger launch disaster.