First conceived in 1997 as a 350-kg minisatellite to be launched on a Russian Eurokot launcher, this low-cost deep-space mission evolved to a 200-kg microsatellite launched as a secondary payload on the Ariane 5.
The revised design was made possible as a result of a competitive contract won by SpaceDev from the Jet Propulsion Laboratory (JPL) in which SpaceDev designed multiple Mars MicroMissions that could be performed for less than $50 million. After the conclusion of the JPL study, SpaceDev continued working on possible mission designs and found that the same basic spacecraft design could perform almost twenty different inner-planet missions from Mercury out to and including the main Asteroid belt.
SpaceDev examined the case for changing NEAP's target to a near earth object with a later launch date. This would delay the planned NEAP launch date in order to provide time to find full mission financing. NEAP was designed to carry a mix of science, entertainment, engineering and "novelty" payloads as multiple attached and ejectable packages. NEAP could be ready to launch in as little as 3-5 years, choosing from many different potential target objects. When the mission was first conceived in early 1997, only about 300 near earth asteroid targets had been discovered. Five years later that number was over 1,000, providing many more options than previously available.