Advanced COM Device

The ACOM team is working to create a faster more reliable communication system to be deployed on a sub-orbital balloon, as well as prototyping more efficient enclosures.

Background
In the past NASA AMES has used Iridium Modems to establish communication between flight experiments and ground stations in order to facilitate the transfer of data. However in previous experiments the equipment used was based on the 9602 Iridium Modem which only supports short bursts data communication. In order to make missions more efficient they are seeking a way to increase the amount of data that can be received during a single missions.

Deliverables

 * Complete 9523 Iridium Modem Data Streaming System.
 * 3D printed and Fully Tested Tube Deployed Reentry Vehicle prototypes.
 * Zigbee Mesh Network Prototype.

Specifications
Hardware
 * 9523 Iridium Modem Development Board
 * Breaks out all 9523 functionality
 * Integrate Zigbee Wireless module

Software
 * 9523 Iridium Modem interface Library
 * Interface with 9523 Iridium Modem
 * Data streaming capability
 * Unit Test
 * Zigbee interface library
 * TBD
 * Code Documentation

Mechanical
 * Create CAD designs of components
 * Space efficient design for modem assembly
 * Efficient strut deployment method
 * Fit into a 8”x8”x12” rectangular cavity
 * Reusable
 * 3D print prototypes
 * Deploy from High altitude balloon for testing

Electrical Design
The diagram below shows the high level overview of the interconnected devices found in the system, This is an example of how a single system would be connected within the TDRV.



The below diagram is an example of our altered RS232 connection protocol. While the black-box device we are using to interface with the Iridium Modem has the ability to utilize the normal RS232 standard, we must use a slightly altered version that uses less wires due to the limitations of our system.



Software Design
The software we're writing for this project will be running on top of an Arch Linux distribution. This platform was chosen because it allowed us to write operating-system-agnostic software so that, if the hardware requirements changed in the future, would make it easier for teams to change the type of hardware to something else as long as a Linux system could be loaded onto it.

Below is flow diagram that gives the overview of how our software will interface with the modem through the sending of AT commands.

Mechanical Design
The Mechanical Engineering focus will be to take the above parts and assemblies and redesign them to accomplish several goals.
 * Fit the iridium modem and associated hardware efficiently inside.
 * Find an efficient way to deploy the struts in order to deploy the wing.

A prototype will be created using 3D printing technologies for design validation. It will then be tested in flight on a high altitude balloon.

The final design while folded, has to fit into a 8”x8”x12” rectangular cavity and should be reusable.

Digital File Repository
Xbee Code

Iridium Modem Code

Server Code

Team Information

 * Team_ACOM_picture.png