MINERVA by themindseye

Last crawled date: 3 years ago

MINERVA
Micro/Nano Experimental Robot Vehicle for Asteroid
Before the European Space Agency (ESA) Rosetta mission's failed attempt to land Philae on Comet 67P/Churyumov-Gerasimenko captured our hearts and minds on 12 November 2014, another "lander" had been lost on a similar mission to an asteroid. This earlier mission was a joint Institute of Space and Astronautical Science (ISAS) of Japan and Japan Aerospace Exploration Agency (JAXA) MUSES-C technology verification mission ("HAYABUSA") which was launched on 9 May 2003. The goal of Hayabusa was to evaluate the ability to "collect samples from a small celestial body and to bring them back to the Earth." And this portion of the mission was successful, with the reentry of Hayabusa into the Australian desert on 13 June 2010.
NOTE: The final resting spot for the "lost" ESA Philae lander was discovered on 5 September 2016.
The asteroid that Hayabusa landed on was Itokawa (25143)--a small 535m x 294m x 209m hunk of stony S-type space rock. Prior to its initial touchdown on the asteroid, Hayabusa was scheduled to deploy a small rover/lander that was programmed to explore the surface of Itokawa. Known as MINERVA (Micro/Nano Experimental Robot Vehicle for Asteroid), this rover was incredibly small (120 mm x 100 mm; about the size of a lunchbox) and contained a unique propulsion system. Operating within the asteroid's micro-gravity environment, MINERVA was supposed to "hop" for mobility. This unusual movement was governed via a spinning turntable and two large flywheels. Although the pre-deployment telemetry from MINERVA was correct, the little rover was launched from Hayabusa on 12 November 2005 and was immediately "lost in space." The rover operated for over 18 hours following separation, but never reached the surface of Itokawa. Only a single image was transmitted from MINERVA along with a couple of 18+ hour data streams (e.g., voltage, photo-diode light intensity, and outside temperature). By studying these data ISAS and JAXA scientists determined that MINERVA was tumbling through space. In the words of one of the researchers, "MINERVA...became a small artificial satellite."
The Model
Due to the small size of MINERVA, this model is a life-size 1:1 scale model. Most of the internal scientific components have been reproduced except for the photo-diode sensors and orientation sensors. You can either glue these components together or "press fit" them together for maximum flexibility in disassembly and reassembly of your MINERVA model. Furthermore, the support structure inside MINERVA is made from several beams and clips that can be held together with #4-40 fasteners (NOTE: M3 fasteners should also work).
Parts
For building a complete life-size MINERVA, you will need to print the following parts:
Beam-Long (x10)
Beam-Short (x8)
Clips (x4)
Base (this part has built-in, disposable supports)
Upper Body
Top
Lip
Turntable
Comm
Flywheel (x2)
PC (x2)
Spindle (x4)
Torquer
Axle
Motor
Camera
Aperture
Condenser (x2)
Additionally, you will need:
Plastic Cement (recommended Testors Cement for Plastic Models # 3512 or Tamiya Extra Thin Cement #87038)
4-40 x 1/2 inch + nuts (x16)
4-40 x 3/4 inch + nuts (x12)
[M3 hardware may be substituted.]
Assembly Overview

Glue the Lip to the inside of the Top. Use the Upper Body as a guide for aligning the Lip.


Assemble the internal support structure using the photographs and drawing as a guide. Attach the Beams and Clips with either metal fasteners or plastic cement.


Carefully insert the internal support structure inside the Base and mark the center point of the Base floor. Remove the support structure and glue the Axle to this center point.


Glue the connector sides of the two PC parts together.


Carefully cut three (x3) Spindles to 60mm in length.


Insert these Spindles into the first three openings of the two cross support Beams. You can optionally glue these Spindles into place.


Glue the two Condensers together lengthwise with the electrodes topsy-turvy (end-to-end) from each other.


Attach the joined Condensers, Torquer, Flywheels, long Spindle, and Camera to the support structure and lower this assembly into the Base. Slip the Comm (Communications) component down alongside the structure end that is furthest away from the Aperture opening in the Upper Body.


Lay the Turntable on the Axle and insert the Motor beside the Turntable and inside the two lower support Beams.

Slide the Upper Body onto the Base and insert Aperture through the Upper Body (the Aperture should "plug" into the Camera body). Lay the joined PCs upside down on the internal support structure. Place the Top on your completed MINERVA model.
Enjoy.
References
You can download a FREE 3D-printable model of the asteroid Itokawa from NASA at:
https://nasa3d.arc.nasa.gov/detail/itokawa

Yoshimitsu, T., Kubota, T., Nakatani, I., Adachi, T., Saito, H., "Hopping Rover "MINERVA" for Asteroid Exploration," Pro. Fifth International Symposium on Artificial Intelligence, Robotics, and Automation in Space, June 1999, ESA SP-440; pgs. 83-88.


Yoshimitsu, T., Sasaki, S., Yanagisawa, M., Kubota, T., "Scientific Capability of MINERVA Rover in Hayabusa Asteroid Mission," Lunar and Planetary Science XXXV, 2004; 1517.pdf.


Yoshimitsu, T., Kubota, T., Nakatani, I., "MINERVA Rover Which Became a Small Artificial Solar Satellite," 20th Annual AIAA/USU Conference on Small Satellites, SSC06-IV-4

Hayabusa: A Technology Demonstrator for Sample and Return, Pamphlet; http://global.jaxa.jp/projects/sat/muses_c/