Proposed Approach Research available commercial satellite communications services Explore viable battery technologies Investigate GPS receiver functionality at high altitudes Study current HABET program

Technologies Considered Satellite Communications Network

ORBCOMMIridium Satellite

GPS ReceiverGarmin OEM ReceiversThales Navigation OEM Receivers

Testing Considerations Battery capacity as function of temperature System functionality under flight conditions

Abstract

Problem Statement HABET currently requires Federal Aviation Administration (FAA) approval prior to flight due FAA weight restrictions. Furthermore, HABET’s communication system requires a complicated array of equipment. It requires the presence of a Federal Communications Commission (FCC) licensed amateur radio operator during flights for its communication system. This restricts HABET’s use to a select audience and facility.

Solution: Produce a version of HABET using lightweight components and a satellite-based technology for communications

Operating Environment Spacecraft will fly to altitudes of 100,000 ft. Craft will experience temperatures below -50°C Landing impact may be in excess of 1G

Intended Users and UsesUsers: University or high school studentsUses: Provide an initial exposure to spacecraft flight systems and procedures

Assumptions Satellite communication network latency low enough to allow tracking Similar operating environment to HABET Users will have internet access Users will have transportation to recover payload

Limitations Must fit within previously designed payload Spacecraft must weight less than 4 pounds Must be operable without FCC license Equipment must operate with external temperatures below -50°C

The team members thank the SSOL for its assistance and financial support. Further thanks go to the facility advisor, Prof. Mani Mina, for his expertise and counsel in this endeavor. Finally, thanks to Profs. Lamont and Patterson for their advice in the management of the project.

The project team will deliver the following: Functional StratoLink Spacecraft Bus (power, navigation, and communications systems) Charging system for StratoLink’s power bus Documentation for operating StratoLink Spacecraft Bus

Design Objectives Must be easy to use Users must receive accurate position data quickly Operation requires minimal assistance from SSOL staff

Functional Requirements Rechargeable power system Equipment must function at peak altitude

Design Constraints Batteries must sustain operation for 4 hours Payload must weigh less than 4 pounds Must communicate without requirement for FCC license

Measurable Milestones Communication between transceiver and ORBCOMM satellite network Successful flight of StratoLink Spacecraft Bus aboard HABET mission Successful flight of StratoLink payload

Project Requirements

The StratoLink Spacecraft Bus provides the power, communications, and navigation systems for the StratoLink project. It’s lightweight components and satellite-based communication system allow for flight without federal regulatory approval. This allows students from a variety of educational institutions to fly with minimal SSOL assistance.

Spring 2006

StratoLink Spacecraft Bus (May 06-17)StratoLink Spacecraft Bus (May 06-17)

Introduction

End Product Deliverables

Basic Operation of StratoLink

StratoLink is launched by a helium-filled latex balloon, ascending to its peak altitude when the balloon pops. The spacecraft descends slowed by an onboard parachute.

Prior to launch, the spacecraft connects to the ORBCOMM satellite network, sending a state of health message. The network accepts the message, relays it to the ORBCOMM ground station, and sends the message via email to the ground team’s predetermined email account.

During the flight, StratoLink acquires its position from the built-in GPS receiver. It sends its location data periodically over the ORBCOMM network and is received in the ground team’s email.

Technical Approach

Battery Chemistry Lithium IonLithium Polymer

Resources and Schedule

Acknowledgment

The Spacecraft Systems and Operations Laboratory (SSOL) created the StratoLink program to provide a compact platform for high altitude scientific balloon flights. Using a helium-filled latex balloon, its payload ascends to a near space environment of around 100,000 ft.

The StratoLink program shares a similar purpose with the highly successful HABET (High Altitude Balloon Experiments in Technology) program. However, the StratoLink Spacecraft Bus (SSB) will utilize lightweight and efficient technology, bringing space to a greater audience. Use of the current HABET system is limited by federal regulations to select SSOL personnel.

The SSB contains the spacecraft’s power, navigation, and communication systems. Its differs from HABET’s systems, consisting of lightweight, power-efficient hardware and integrating a satellite-based communications system, allowing data relay without the use of amateur radio equipment. These modifications yield a system that requires no preflight regulatory clearances or licenses, allowing a broader, less technical audience to reach the edge of the sky.

It serves as a platform for high altitude research as well as a way to demonstrate and test different space-related technologies.

Summary

Team MembersAdam Allison (EE) Bob Bond (EE)Hai Duong (EE) Alan Johnson (CprE)David Johnson (EE)

Faculty AdvisorProf. Mani Mina

ClientSpacecraft Systems and Operations Lab (SSOL)

Dr. Mani Mina, Director

A recovery team is dispatched by the ground team to the transmitted location for spacecraft recovery.

Resource UsageFinancial resources largely went toward the purchase of the satellite transceiver..

Schedule and Time DistributionProject time focused on component research and system integration.