Objective of Launch
The T-LogoQube Satellite mission provides attitude determination and control in a low-cost small platform for performing experiments in space. This platform design is ideal for pointing or scanning the sky.
This allows for controlled observations of the earth and space via a camera or detector system. Future missions will incorporate x-ray/gamma ray detectors for use in studying specific sources of gamma ray bursts in addition to studying the cosmic x-ray background. The ability to point to cosmic gamma ray sources is required in order to study the spectral composition within the short lifetime of low-earth orbiting femto-satellites.
Torque-Coils
Magnetic coils to induce a orthogonal magnetic field vectors used to control the satellite's coordinate plane. The control system for the coils drives a field normal to the earth's magnetic field.
Sensors: The satellite has a magnetic sensor for attitude determination and two torque coils for attitude control. Additional attitude determination sensing data is provided by the voltage output of the four solar panels on each of the sides of the satellite.
Magnetometer
One 3-axis magnetometer used to provide magnetic field information. It sampled every four seconds throughout the orbit. Onboard flash stores an entire orbits magnetometer data. An uplink command triggers the satellite to downlink the entire orbits magnetometer data. The magnetic field information also allowed us to do a Fourier transform on orbit to give us the spin and precession rate of the satellite.
MicroLogo (uLogo)
T-LogoQube flight software is written in the language microLogo, allowing commands to be created, up-linked and executed in real time, making this satellite the ideal platform for experimental space science. Logo is a member of a class of languages that have extensible dictionaries of words, similar to Forth. Developing a flight environment entails the creation of new “words” that define how to control the functions of the system. The entire Logo development system is a few tens of Megabytes. The compiled flight environment for T-LogoQube is less than ten kilobytes, allowing the satellite to be completely reprogrammed over the radio. The flexibility and compactness of Logo is well suited for a CubeSat or PocketQube environment.
SSU students working on T-LogoQube
Results
The T-LogoQube Satellite launched into low earth orbit on 21 November, 2013. The ground stations at Morehead State University and Sonoma State University received telemetry packets from the satellite. First data packets were received on November 23, a command was sent the following day, with a prompt response from the satellite orbiting 700 km above the ground station. We used an RFM22B radio operating in the 70 cm ham-band operated at 437.465 MHZ using FSK with a 12 khz deviation at 500 baud. With the radio output of 100mW, ~4 times less power than a typical cell phone, packets from the satellite at distances ranging up to 2700 km were received and decoded.
First T-LogoQube Packets being recieved every ~20 seconds
Stream of many T-LogoQube Packets every ~2 seconds