Small Satellite Technology

JPL Small Satellite Technology Weather Balloon Design Project
Project Goal: To demonstrate a proof of concept for a radio science technique to measure the dynamics of a planetary atmosphere using a capsule in flight. [pantheondesignproject.wordpress.com]

Introduction


Project Background

An important measurement in the study of planetary atmospheres is the profile of wind speeds from the upper atmosphere to the surface. Entry and descent probe measurements of the winds of Venus, Jupiter, and Saturn’s largest moon Titan have been made by Doppler tracking of Pioneer and Venera probes, the Galileo probe, and the Huygens probe, respectively. The winds in the upper atmosphere of Venus were also measured by tracking the Soviet VEGA balloons. The most significant shortcoming to these measurements is that they provide one profile of winds at a single location. The dynamics of planetary atmospheres can be better characterized if the winds are measured simultaneously at multiple locations. One concept for doing this is to have a single ground station such as a planetary lander that would release multiple balloon-borne transceivers that continuously transmit to the ground station. By making precise frequency measurements at the ground station of the signal from each balloon capsule in flight, the Doppler shift of the signal can be used to provide an accurate measurement of the balloon dynamics and from this the wind dynamics can be inferred.

Pantheon Team
Members:

Mentor: Instructor:
 * David Eld
 * Touraj Assefi

Sponsors:


 * NASA Jet Propulsion Labratory
 * Kamal Oudrhiri
 * NASA Idaho Space Grant Consortium
 * David Atkinson

Project Deliverables
Electrical Requirements


 * Design, build, test communications system for measuring frequency at sampling rate TBD
 * Select three transmission antennas to consider
 * Must be (1) linearly polarized and (2) low gain (omni-directional)
 * Select three receiver antennas to consider
 * Must be directional
 * Provide end to end test of communications system
 * Develop two independent methods of measuring wind speeds

Mechanical Requirements


 * Mass (FAA)
 * Less than 2.72 kg
 * Dimensions (CubeSat standard as defined by Cal Poly)
 * Cube 10 x 10 x 10 cm, known as 1U
 * Temperature (VAST data collection)
 * Internal requirements
 * No less than 0 °C and no greater than 40 °C
 * External minimum reaches -50 °C

Mechanical Engineering

 * Cube Material Research


 * SolidWorks Cube Model:


 * Heat Transfer:


 * Preliminary EES Solution


 * Required Specifications:


 * Minimum Inside Cube Temperature of -15°F
 * Altitude Dependent Values
 * Assumptions:
 * Carbon Fiber Structure Negligible
 * DOW Utilityfit Insulation
 * Generated Heat is removed by convection to the surroundings and radiation by the box
 * Altitude of 80,000ft
 * Solution:
 * Insulation Thickness
 * Total Power Loss

Electrical Engineering

 * Transmitter Selection


 * Board Selection


 * Crystal Oscillator

Specifications:
 * SG-8002JF-PCC (Digikey)
 * 1 MHz-125 MHz
 * Can be used with Spartan 3E TQ144 and CP132
 * 3.3 V (max)
 * 28 mA (max)
 * -20C ~ +70C
 * 7.1mm X 4.6mm X 1.5mm

Project Timeline
November December January February March April May
 * Finalize communications hardware
 * Order most components
 * Verify communication link
 * Finalize structure
 * December 6 Snapshot 2
 * December 20 complete prototype
 * January 23 Begin structure testing
 * February 10 Complete all testing
 * Start compiling paper
 * Mid-March 2014 flight date
 * Evaluate for areas of improvement
 * April 25 Finalize paper
 * May 2, 2014 Engineering Expo

Meeting Minutes
MeetingMinutes.pdf