1. Optical Mass Gauging System for Use in Microgravity Environments
Isaiah Franka
Jordan Rath
Michael Yeager
Abby Wilbourn
Brian Lee
Azer Yalin

2. Project Description
Existing fluid measurement systems require the use of costly, wasteful and typically ineffective methods to approximate fluid volumes in zero gravity environments.
Dissatisfaction with current methods has revealed a need for a more effective and efficient measurement systems.
Laser interferometry is a theoretical method of measuring fluid volumes that offers advantages such as reduced weight and increased durability during launch while still providing functionality in a microgravity environment.

3. Mach-Zehnder Interferometer

4. Interference
Destructive
Intermediate
Constructive

5. Mach-Zehnder Interferometer
Tabletop Setup

6. System Layout

7. Mechanical System Design

8. Mechanical System

9. Linear Actuator Driver
Electrical System
Logic
Arduino Nano
Master Chip
Arduino Duemilanove
Linear Actuator Driver
Data Storage
32Mbit memory

10. Fringe to Mass Conversion

11. Fringe Calculations Change in Optical Path Length ∆𝑚= ∆𝜙 2𝜋 = 𝑙Δ𝑛 𝜆
𝜕𝑛 𝜕𝑚 = 𝜆 𝑙
Lorentz-Lorenz Equation
𝑛 2 −1 𝑛 2 +2 = 4𝜋 3 𝑁𝛼
𝑛= 1+ 3𝐴𝑃 𝑅𝑇 ⟶ 𝑃= 𝑅𝑇 𝑛 2 −1 3𝐴
𝜕𝑃 𝜕𝑛 = 2𝑅𝑇𝑛 3𝐴

12. Fringe Calculations Combining these two Equations
𝜕𝑃 𝜕𝑚 = 𝜕𝑃 𝜕𝑛 𝜕𝑛 𝜕𝑚 = 2𝑅𝑇𝜆 3𝐴𝑙
Assuming Constant Temperature and constant Molar Refractivity
ΔP 1 Δm 1 = ΔP 2 Δm 2
Using Boyle’s Law
Δm 𝑟𝑒𝑓 Δm 𝑡𝑎𝑛𝑘 = ΔP 𝑟𝑒𝑓 ΔP 𝑡𝑎𝑛𝑘 = 𝑉 𝑐𝑒𝑙𝑙 + 𝑉 𝑝𝑖𝑠𝑡𝑜𝑛 + 𝑉 𝑡𝑎𝑛𝑘 𝑢𝑙𝑙𝑎𝑔𝑒 𝑉 𝑐𝑒𝑙𝑙 + 𝑉 𝑝𝑖𝑠𝑡𝑜𝑛
𝑉 𝑡𝑎𝑛𝑘 𝑢𝑙𝑙𝑎𝑔𝑒 = 𝑉 𝑐𝑒𝑙𝑙 + 𝑉 𝑝𝑖𝑠𝑡𝑜𝑛 Δm 𝑟𝑒𝑓 Δm 𝑡𝑎𝑛𝑘 −1
𝑉 𝑙𝑖𝑞𝑢𝑖𝑑 = 𝑉 𝑡𝑎𝑛𝑘 − 𝑉 𝑡𝑎𝑛𝑘 𝑢𝑙𝑙𝑎𝑔𝑒

13. Testing-Vibrational
Environmental Testing Characteristics specified by Wallops:
Wallops Flight Facility’s Environmental Test for the RockSat Program has two components: The Sine Test and the Random Test.
Sine Test:
The Sine Test will vibrate the payload along the thrust axis at no more than 3 in/s. These rates will occur between the frequencies of 10 and 144 Hz. The thrust axis will also see 7G from 144 to 2000 Hz. The sweep rate is 4 octaves per minute.
Random Test:
The random test will be completed in all three axes: thrust, lateral, and 90 degrees from lateral. The test will begin at lower levels and gradually increase to full level. Each axis will see 20 seconds at full level.
Thrust Full Level10 Grms at G2/Hz from Hz
Lateral and Lateral 90 Full Level: Grms at G2/Hz from Hz

14. Testing-Vibrational Random Test Sine Test Thrust Full Level
10 Grms at G2/Hz from Hz
Lateral and Lateral 90 Full Level
7.6 Grms at G2/Hz from Hz

15. Lessons Learned
There will always be unexpected problems that will impede progress
Communication is the key to success
There is a large disconnect between the idea world and real world

16. Questions?