Mechanical Design
Talus_OP5-01.jpg

Talus

PROJECT TALUS

PROBLEM STATEMENT

Space missions to the micro-gravity environment of a  comet or asteroid are a relatively new desire from private companies and space agencies. The only mission attempting to land a probe on a comet or asteroid so far has been the Rosetta mission with its Philae lander. The mission resulted in a failure of the lander’s anchoring system. In addition, there are few other developed concepts exploring a method of anchoring a spacecraft to an asteroid or comet. Team Talus investigated a solution to the problem of anchoring a spacecraft in a low-g environment and produced a prototype demonstrating the ability to provide an anchoring force between a lander and a simulated asteroid or comet surface.

This project was part of the Purdue senior design course that took place from January to May 2016. The given budget was $400.

MAIN CONTRIBUTIONS

  • Control systems algorithms (LabVIEW with myRIO)
  • Part drawings and manufacturing
  • Machining of structure components
  • Test rig construction
  • Logo design

PROJECT DEVELOPMENT AND PROTOTYPE

This slideshow displays the final prototype developed by Talus. The sections below describe each subsystem in more detail, but the design is much too complicated to describe on here. So if you're really curious, check out the report to the right - or just ask me about it! 

 
 

SUBSYSTEM DESIGN OVERVIEW

1| BARB CASING

  • Perforated root system casing
  • Conical shaped leading edge to minimize penetration resistance
  • Compliant flaps that increase force required to remove the anchor from the surface

2| ROOT SYSTEM

  • Horizontally acting root deployment with DC motor
  • Flexible braided wire roots housed as coils in root casing
  • Increases area of regolith column underground which increases anchoring force

3| VIBRATIONS / PERCUSSIVE DIGGING

  • 45-85 Hz operating frequency
  • Reduces required surface penetration force by 15 times - reduces static friction on anchor casing
  • Slider-crank vibration mechanism consisting of crank, follower arm, and inner structure tube as "slider"

4| DAMPING SYSTEMS AND REGOLITH SIMULANT

  • Dissipates 24 kJ/kg of landing energy
  • Anchor attaches to spacecraft via top plate
  • Nomex crushable honeycomb damping material seated between plates
  • Regolith simulant is phenolic foam (wet floral foam) with realistic compressive strength of 62.5 kPa
  • Material properties of damping material and regolith simulant obtained through manual compressive strength tests

5| STRUCTURES AND CONTROL SYSTEMS

  • Root deployment control with accelerometer
  • MyRIO microcontroller + LABVIEW system design platform
  • Stepped connection joints provide flush outer anchor surface
  • Damping system performance measured using two accelerometers and by comparing the acceleration spikes