Terra complex is a set of simulators for teaching the basics of spacecraft operation in space conditions and also for conducting semi-natural simulation of missions with OrbiCraft and OrbiCraft 3D functional kit (figure 1).

With this complex you can:

• Simulate the flight of a spacecraft in an equatorial orbit;
• Simulate spacecraft communication with ground mission control center (MCC) via ultrahigh frequency and high-frequency channel;
• Simulate Earth remote sensing;
• Simulate orientation of spacecraft in space environment.

Fig. 1. Terra complex

Magnetic field frame imitator is a current frame made for creating a magnetic lines of manipulating measure going through its vertically installed plane (working plane). Magnetic's flow controls by user with a special software, where you can change the current in the coil.

Sun imitator is a light source that provides a beam of light, similar in a number of characteristics to the solar one, in order to influence the orientation system of the layout, as well as the conditions for shooting areas of the globe with a camera installed in the spacecraft layout. The radiation spectrum of the simulator is as close as possible to the solar one, and the mounting system (tripod) allows you to adjust the light source in height and angle of inclination to the horizon.

Earth simulator is a globe with base providing:

• Geometrically - the appearance of the Earth, visible from the satellite, is either real or reasonably scaled, with a diameter of 130 cm;
• Kinematics of the spacecraft layout movement along the equatorial orbit in real time;
• The conditions for shooting certain areas of the surface are similar and in the same terms as shooting the real Earth's surface by satellites;
• Simulation of communication with the “Ground” (ground–based MCC) by radio link: when the ground station is in the radio visibility zone of the spacecraft layout, the LEDs of the corresponding “ground station” turn on;
• Conditions for data transmission over a high-speed communication channel when the ground station is in the radio visibility zone of the spacecraft layout.

The software installed on the PC is compatible with Windows OS, and provides synchronous operation of the magnetic field simulator, rotation of the globe, day-night simulation relative to the location of the sun simulator, and also displays the location of the spacecraft layout in orbit and the operation of the “ground-based MCC”.

Terra Ground Control software is used to control the current frame and the globe. Figure 2 shows the main window of the program.

Figure 2. The main window

The Home tab shows a map. The cities that are highlighted on the globe are marked in blue. When Terra rotates on the sunny side of the city, the LEDs light up on the dark side, and the satellite image moves along the equator. Also on the equator of the globe there are four IR receivers (yellow circles on the map) for communication with OrbiCraft 1.0 and OrbiCraft 3D, simulating receiving stations. To activate them, click on the circles in the program and they will change color to red (Figure 3):

Figure 3. Activating ground stations for recieving on the globe (IR-recievers)

On the Settings tab the following settings are available (Figure 4):

1. Rotation speed - adjusts the speed at which the globe rotates.
2. Zero setting - setting the location of the solar radiation simulator relative to the globe.
3. Frame current - regulates the current in a frame with an alternating magnetic field.
4. Telemetry interval - sets the time interval for receiving images from the satellite constructor.
5. Connection - When connected to the Terra 2.0 wireless network, connection information will appear.

Figure 4. Settings tab

To set zero, follow these steps:

1. Start the rotation of the globe and stop at the moment when the satellite image is at the zero point of the meridian.
2. Look at which meridian your satellite constructor is located above.
3. Go to the Settings tab and in the menu Zero setting Enter a value. If the point in front of which the satellite is suspended is west of the zero meridian, then the value is set to negative. If to the east-positive.

1. Download and unarchive file with Terra Ground Control software sx-terra-ground_v1.7.zip
2. Connect to ORBICRAFT 3D and open Houston Server and Houston Application. Connect to functional kit via UHF;
3. Open address F(Paspberry_Pi) and in command execute_script put: id=100, arg=0 to change OrbiCraft 3D from the hotpoint to the client;
4. Connect to Wi-Fi Terra 2.0;
5. Enter the router's IP address in the browser's address bar 192.168.0.1;
6. Open the tab Settings and wait for the constructor to appear on the network;
7. To connect to the Web interface of the constructor, enter the IP address of OrbiCraft 3D, which is specified in your Settings tab