MINERVA (spacecraft)

On 12 November 2005, MINERVA rover was deployed from Hayabusa orbiter with aim to land on asteroid 25143 Itokawa.

[1] The third MINERVA-II rover malfunctioned before deployment from the Hayabusa2 orbiter, but it was released anyway on 2 October 2019 to perform gravitational measurements before impacting the asteroid a few days later.

[2] On 9 May 2003, the MUSES-C spacecraft carrying MINERVA was launched from Kagoshima Space Center, and was named Hayabusa.

After a two-month long observation phase, Hayabusa began descent rehearsals in preparation for its asteroid landings.

[5] While MINERVA was treated as an optional addition in the first Hayabusa, MINERVA-II became part of the nominal payload for Hayabusa2.

[8][9] For shock mitigation during landing and to protect the solar cells, 16 pins are protruding from MINERVA's surface.

After the electric double-layer capacitor ceases function, communication will still be possible but the rover will be unable to make further hops or imaging, so an operation was considered to have a stationary MINERVA continuously measure the asteroid surface temperature of its final resting place.

The three CCD cameras were identical; two of them faced the same direction and were adjacent with each other, enabling closeup stereographic imaging.

Its main CPU microprocessor is Hitachi's SH-3, clocked at 10 MHz, adopted for its low power consumption, performance efficiency and reliability.

MINERVA-II-1 was enlarged from its predecessor as the rover's destination, asteroid Ryugu was more distant from the Sun than Itokawa, necessitating an increase in solar cell area.

[12] Ryugu's greater size compared to Itokawa means rovers will face stronger gravity, thus larger DC motors are used for MINERVA-II-1.

MINERVA-II-2's primary goal is to verify navigation in an environment with extremely small gravitational acceleration.

MINERVA was deployed on 6:24 UTC, but the distance to 25143 Itokawa was 200 m, and Hayabusa was ascending at approximately 15 cm/s away from the asteroid.

The process was conducted fully autonomously, a countermeasure to prevent the recurrence of the error that doomed their predecessor.