to the mission profile, JAXA defined the following success criteria and corresponding scores for major milestones in the mission prior to the launch of the Hayabusa spacecraft. As it shows, the Hayabusa spacecraft is a platform for testing new technology and the primary objective of the Hayabusa project is the world's first implementation of microwave discharge ion engines. Hence 'operation of ion engines for more than 1000 hours' is an achievement that gives a full score of 100 points, and the rest of the milestones are a series of world's first-time experiments built on it. MINERVA mini-lander Hayabusa carried a tiny mini-lander (weighing only , and approximately tall by in diameter) named "MINERVA" (short for MIcro-Nano Experimental Robot Vehicle for the Asteroid). The MINERVA has an on-board microcomputer. Its main CPU microprocessor is Hitachi's SH-3, clocked at 10MHz, adopted for its low power consumption, performance efficiency and reliability. The computer's memory includes 2MB RAM, 512KB ROM, and 2MB Flash ROM. An error during deployment resulted in the craft's failure. This solar-powered vehicle was designed to take advantage of Itokawa's very low gravity by using an internal flywheel assembly to hop across the surface of the asteroid, relaying images from its cameras to Hayabusa whenever the two spacecraft were in sight of one another. MINERVA was deployed on 12 November 2005. The lander release command was sent from Earth, but before the command could arrive, Hayabusa's altimeter measured its distance from Itokawa to be and thus started an automatic altitude keeping sequence. As a result, when the MINERVA release command arrived, MINERVA was released while the probe was ascending and at a higher altitude than intended, so that it escaped Itokawa's gravitational pull and tumbled into space. Had it been successful, MINERVA would have been the first hopping space rover. The Soviet mission Phobos 2 also encountered a malfunction while attempting to deploy a hopping rover. Scientific and engineering importance of the mission Scientists' current understanding of asteroids depends greatly on meteorite samples, but it is very difficult to match up meteorite samples with the exact asteroids from which they came. Hayabusa will help solve this problem by bringing back pristine samples from a specific, well-characterized asteroid. Hayabusa bridged the gap between ground observation data of asteroids and laboratory analysis of meteorite and cosmic dust collections. Also comparing the data from the onboard instruments of the Hayabusa with the data from the NEAR Shoemaker mission will put the knowledge on a wider level. The Hayabusa mission has a very deep engineering importance for JAXA, too. It allowed JAXA to further test its technologies in the fields of ion engines, autonomous and optical navigation, deep space communication, and close movement on objects with low gravity among others. Second, since it was the first-ever preplanned soft contact with the surface of an asteroid (the NEAR Shoemaker landing on 433 Eros was not preplanned) it has enormous influence on further asteroid missions. Changes in mission plan The Hayabusa mission profile was modified several times, both before and after launch. The spacecraft was originally intended to launch in July 2002 to the asteroid 4660 Nereus (the asteroid (10302) 1989 ML was considered as an alternative target). However, a July 2000 failure of Japan's M-5 rocket forced a delay in the launch, putting both Nereus and 1989 ML out of reach. As a result, the target asteroid was changed to , which was soon thereafter named for Japanese rocket pioneer Hideo Itokawa. Hayabusa was to deploy a small rover supplied by NASA and developed by JPL, called Muses-CN, onto the surface of the asteroid, but the