Pathfinder Solar Array Spring 2019
Form Factor
Author: Henry Martinez (Design and Manufacturing Engineer)
Table of Contents
Introduction
As a requirement of the customer, the design of the Pathfinder solar array had to follow a specific form factor. The purpose of the form factor is to ensure the project resemble JPL’s Spirit and Opportunity Rovers.
Analysis
I used Adobe Illustrator to measure the panel lengths shown in figure 1. In order to achieve the correct form factor and get the appropriate dimensions, 9 measurements were taken from the image and were used to define length and height ratios of each panel. This ensured that the final length and height of the panels were scaled proportionally.
Figure 1: Opportunity’s panoramic camera captured this self-portrait on Mars in 2014. Credit: NASA/JPL-Caltech/Cornell Univ./Arizona State Univ.
For example, the height and length of the main panel in the figure 1, 96.13mm and 107.18mm respectively, were used to get a ratio of 107.18/96.13 = 1.11. The panel dimensions in solidworks were found by taking hand measurements of the generation 1 panels and comparing those ratios to the ratios found on the rover image.
| JPL Image Measurements | JPL Calculated Ratios | Solidworks Measurements | Solidworks Calculated Ratios | % Error | |
| Main Panel | Height: 96.13mm
Length: 107.18mm |
107.18/96.13= 1.11 | Height: 444.5mm
Length: 403.35mm |
444.5/403.35 = 1.10 | .9% |
| Tail Panel | Height: 47.93mm
Length of Base: 103.75mm Length of the top:54.13mm |
103.75/47.93 = 2.16
103.75/54.13= 1.91 |
Height: 209.55mm
Length of Base: 436.79 mm Length of the top:228.69 mm |
436.79/209.55 = 2.08
436.79/228.69 = 1.91 |
3.7%
0% |
| Wing Panels | Top Right Height:
46.44 mm Bottom Right Height: 44.4mm Length: 77.96mm |
77.96/46.437 = 1.68
77.96/44.44 = 1.75 |
Top Right Height: 209.55 mm
Bottom Right Height: 201.93mm Length: 361.95mm |
361.95/209.55 = 1.72
361.95/201.93 = 1.79 |
2.3%
2.3% |
|---|
Conclusion
In summary, I used a solidworks model to create and match the dimensions of the JPL Opportunity and Spirit rovers. Possible measurement errors could have come from the measurements taken from the image considering the end to end points of the lines may not completely line up with the panels. Aside from this, the panels created in solidworks have a max error of 3.7% which proves for a successful model.