The following block diagram describes the key components of the Ground Sphere Test Transmitter.
BA1. There are two reasons for building this test transmitter. First, it helps to have an initial "smoke test" for the Ground Sphere Ground Station. What this means is that when someone assembles a copy of the Ground Sphere hardware, they should be able to easily test it to make sure that nothing major is wrong. Second, there are very few other 915 MHz satellites in orbit that are useful for testing the Ground Sphere Ground Station at the time of this project's inception. Having a test apparatus like this allows us to simulate satellite reception through terrestrial tests and possibly even High Altitude Balloon launches.
BA2. The Ground Sphere Ground Station is for SkyCube backers, students, teachers, scouting troops, space enthusiasts, and anyone who wishes to directly participate in the SkyCube mission. Therefore, this test transmitter is intended for the same audience.
BA3. Ground Sphere Ground Station operators will use the test transmitter to:
BA4. The designs will be open so that anyone, without necessarily a technical education in amateur radio or satellite operations, would be able to build and operate a Ground Sphere Test Transmitter.
TA1a. The test transmitter needs to:
TA1b. In the future, the project (or related projects) may need to:
TA2. To maintain compatibility with other projects, the system should:
PA1. As an open source hardware kit, the long term objective is to promote and sell as many ground station kits to as large of an audience (schools, scouting troops, makerspaces, space enthusiasts, etc) as possible. However, the narrow focus on supporting SkyCube operations with the Ground Sphere may limit the number of kits which will be sold for this specific ground station, especially since the SkyCube is going to be on orbit for a very limited period of time. The sales lifetime of this specific kit (and in turn the number of kits we will want to sell) will depend on how many other satellites there are to observe in the same frequency range as the SkyCube.
PA2. The materials cost should be kept under $75 to limit the retail cost of any kit versions.
PA3. The timeline for this project is dictated by the SkyCube launch and deployment timeline. SkyCube is currently scheduled was launched in January 2014, with deployment from the ISS in Q1 or Q2 of 2014. Southern Stars has stated they would be comfortable with a February 2014 delivery date for the kits.
PA4. TBD
The Bill of Materials outlines the components needed to build a functional unit. For lab testing purposes the TI Launchpad can be connected directly to a laptop and not powered by the battery.
The Quick Start Guide for the Air Boosterpack outlines the instructions to connect a MSP430 based Launchpad evaluation unit and the boosterpack. These instructions will also help the user bring the unit up to a point where it is running the example software used for testing. Please note that the testing procedure in the guide requires two sets of launchpads and boosterpacks, but this procedure uses one set with a Ground Sphere Ground Station.
The quick start guide instructs the user to install the "Install ATC-Booster Stack Lite GUI". Once this is installed and the Launchpad/Boosterpack combo is plugged into a USB port, follow the steps below.
The Ground Sphere Test Transmitter will transmit radio signals on 915 MHz
Be mobile so that the terrestrial tests can be done by adding distance between the transmitter and Ground Sphere receiver
The Ground Sphere Test Transmitter will only require simple tools (screw drivers, pliers, wrenches, etc) for assembly
The Ground Sphere Test Transmitter will take no longer than 60 minutes (threshold)/30 minutes (objective) to assemble by an average maker
The Ground Sphere Test Transmitter kit will cost no more than $15 (threshold)/$7.50 (objective) to ship by ground across the USA.
The Ground Sphere Test Transmitter software must run on Windows 7 or Windows 8 (32bit or 64bit)
The Ground Sphere Test Transmitter software must ship in a Windows installer
The Ground Sphere Test Transmitter radio must connect to the ground station computer through a commonly available port (for example: USB)
The Ground Sphere Test Transmitter hardware should minimize the opportunity for mechanical failures (from things such as broken connectors or a lack of strain relief)
The Ground Sphere Test Transmitter design must enable the production of at least 30 +/- 5 v1.0 kits by volunteers in one or more makerspaces
The materials cost must be under $75 per kit.
The project budget (covering three prototypes) must be no more than $200 (threshold)/$100 (objective)
Version 1.0 of the Ground Sphere Test Transmitter will be ready for kit production no later than Feb 14, 2014.
End user manuals, including how to assemble and operating instructions for performing tests with the Ground Sphere Ground Station.
Full OSHW project documentation - covers component acquisition and assembly, packaging of kits, and other project level documentation needed to replicate the Ground Sphere from source.
Full OSHW project design documentation - covers design from concept through final design.
| v0.1 | Description | Documentation |
Welcome to the Ground Sphere Test Transmitter wiki. This is a Mach 30 project designed to give an initial "smoke test" for Ground Sphere hardware before trying to receive Skycube transmissions from orbit.
Mach 30 believes that Makers and Makerspaces will be a large part of the new spacefaring workforce, partnering with us in our mission "[t]o hasten the advancement of humanity into a spacefaring civilization through sustainable leadership, open design practices, and a bias toward mature technology." If that sounds like something you want to be involved in, we encourage you to jump right in. If you want to start with our design rationale, take a look at the Systems Engineering Process section in the navigation bar at the right. If building, testing, and operating a ground station is more your speed, start with the Documentation section of the navigation bar. Always make sure to read any Safety Procedures first so that you can have the safest experience possible with Ground Sphere and this project. Also, don't forget to register for an Open Design Engine account so you can start posting to the forums.
We intend to have Ground Sphere kits available sometime in the first quarter of 2014. If you're interested in finding out more about Ground Sphere in education, please contact Mach 30 . If you're planning to build and operate a Ground Sphere ground station on your own, please start by reading the Safety Procedures.
If you're a student who's ready to start working with Ground Sphere, be sure to start with the Safety Procedures. Once you're up to speed on those, you'll want to take a look at the Operating Manual to learn how to operate the ground station. Any other documentation that you may need should be in the navigation bar at the right under Documentation. Also, don't forget to register for an Open Design Engine account so you can start posting to the forums.