What is Orbicraft for?
How to work with it
What is Orbicraft for?
How to work with it
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The Orbicraft Construction Set integrates with the Terra Space Environment Simulator Complex for semi-natural simulation and is intended for teaching the basics of spacecraft design, development, assembly, testing and operation to school and university students. Most importantly, rather than design individual systems and drill down into their intricate details, the integrated complex and the construction set in particular place emphasis on the systemic design of spacecraft as a whole, providing a shortcut to a working prototype.
Scope of Supply
The complex includes:
A functional model of a satellite (an object assembled using the Orbicraft Construction Set) may consist of:
Earth is represented by a globe that simulates:
The satellite “orbits Earth” by being hung in the simulated “geomagnetic” field (within the current loop) and spins horizontally on its suspension thread – either freely or commanded by its user-programmed control system – as the globe simulating Earth rotates evenly in front of it, as if the orbiter were to fly along an equatorial orbit. The surface area of the globe of interest for photographing will sooner or later face the suspended orbiter. By this time the orbiter’s control system will have to orient and stabilize the satellite on its suspension rope while positioning the camera’s field of vision on area of interest with required precision. After the area is photographed, the data will have to be sent to users “on the ground” – this is accompanied by pointing a laser beam to the required “ground receiving station”.
The globe is controlled from a PC via a USB port. The required functionality on the PC side must include controlling the rotation of the globe and managing a network of “ground telemetry stations” (GTSs, situated on the surface of the globe) along with “surface” centers receiving high-speed data traffic. These centers are located on the surface of the simulated “Earth” in known predetermined geographic points that are invariable in time.
Conditions for communicating with “Earth” over telemetry and telecommand radio links are simulated computationally when a particular GTS on the surface of the globe occurs in the geometrical radio visibility zone of the string-suspended orbiter and by issuing the respective command to turn on/off the particular ground station. Once turned on, the ground station enters the telemetry reception mode by default.
The conditions of data transfer from the orbiter toward “Earth” (to a photoreceiver on the surface of the globe) over a high-speed link are simulated by pointing a laser beam from the orbiter to a predefined market on the surface of the rotating globe. After normal orientation of the orbiter toward “Earth” is confirmed by a light beam falling on the light-sensing diode on the surface of the globe, data is transferred over a regular Wi-Fi link as long as the LED of the HF transmitter lights the required marker.
Key properties of the globe:
Globe control system properties:
All geometrical parameters of the globe and kinematic parameters of its rotation are aligned with capabilities of the simulated orbiter’s dynamic control system (response time, accuracy, number of degrees of freedom, continuous uptime) as well as capabilities of the orbiter payload (field of vision, exposure time, lighting conditions, data transmission rate) used in model settings for obtaining special information.
The Sun is simulated by a light source with light output properties approximating those of solar light. This light influences the positioning system of the model as well as the conditions for photographing globe areas by the camera integrated in the orbiter model. Key features of the simulator:
The Sun Simulator must be turned on by the user before holding the experiment and turned off manually using a simple switch when the experiment is completed.
Earth Magnetic Field Simulator
The Earth’s magnetic field is simulated using a closed solenoid (Helmholtz coil) producing controlled magnetic flux directed through its vertical setting plane (the working plane). Such a loop acts as a simplified single-axis simulator of the Earth’s magnetic field.
The current loop is set on the floor and enables the Orbicraft construction set to be suspended on a thread so that the mass center of the construction set would end up in the working plane – the equatorial plane of the globe, about 80 cm above the floor, while letting the set rotate freely.
Key properties of the solenoid:
Principle of Operation
A functional model of the “satellite” assembled using the kit and programmed by the user is suspended on a thread, then slightly twisted around and released, leaving it to spin back and forth in a single plane. Depending on the satellite mission, the choice of positioning sensors, the composition and integration of major systems and payload as well as software downloaded into it, the “satellite” will have to stabilize itself on the suspension string (to stop rotation), then turn one of its sides toward the “Earth” and take a picture of a particular area of the running Earth surface underneath. The variety of problems is determined by a multitude of criteria for success e.g. shortest response time, different guidance algorithms, guidance precision, implementation simplicity and speed, maximum amount of data delivered from the orbiter etc. The Setup Shown below is the overall appearance of the assembled Complex with the classic layout of Terra space environment simulator and the Orbicraft construction set as its component.