Goals

Collect information about space, Receive exclusive images of the earth/moon, Store files 'over the cloud'. Every day the satellite would generate a series of random numbers with information coming from its sensors, including a geiger counter... will we receive the megasena numbers?!!?!

AND MAINLY: show everyone that nothing is impossible

The Format

Let's consider the CubeSat format, 100x100x100mm and a limit of 1kg. There are around 13,000 satellites in orbit, but only around 300 are CubeSats.

Communication

I believe the best way would be 2 frequencies, one uplink and one downlink. Frequencies must be between 130 and 450 MHz [calculated?], and must be registered with the Amateur Radio Association.

Because the satellite is not geostationary, it will only pass over Brazil a few times a day [a 120-minute window perhaps]. Because it is in an elliptical orbit, it would be necessary to calculate the distortions of the Doppler Effect [where the frequency is higher when approaching and lower when moving away]

Energy

Four sides with high-efficiency solar panels would be enough to power the interior and charge the batteries. I believe that 4 common lithium batteries [the same as cell phones] would be enough.

Care must be taken with radiation. At 600km, the Earth's magnetic field will not protect much against solar radiation. A current limiter, some capacitors, switches and maybe even a Leiden Bottle can help.

It would also be interesting to try using coils to generate energy.

In projects I studied, I saw that the antennas consumed 300mW.

Control

Of course, we would not have the power to control the direction and rotation of the satellite, in this topic we will talk about computational control.

I thought of separate systems in order and hierarchy. BIOS, power control, logging system, arduino, payload.

-BIOS: it will be a microcontroller connected directly to the antenna, it will interpret and decode the signal, it will control the power system, based on the commands received by the antenna, and it will forward the packets to the Arduino.

-Energy control: responsible for managing the batteries and solar panels, it will also have the function of shutting down if the current exceeds pre-stipulated limits.

-Logging system: will record everything, all systems report to it, but are not controlled by it. It will be read by the BIOS in case of a report.

-Arduino: it will be the real 'brain' of the CubeSat, it will control all the 'payload' sensors.

Payload

This will be 'the payload' of the satellite. It will be controlled and will communicate through Arduino. Bearing in mind the weight and size limitations, and considering that there will only be around 300g available, I was thinking about putting:

-Mini 4 mega pixel camera. -GPS of at least 5Hz [5 updates per second] and at least 15 channels [ability to locate using at least 15 satellites simultaneously] -Accelerometer, would be necessary to know when it will be pointing towards the earth, and necessary to calibrate other sensors. -Barometer -Magnetic field meter -Geiger counter?! -Series of light sensors such as LDR and infrared phototransistor. They would possibly also be used to measure the temperature of the Earth's surface. -Thermistor, temperature sensor.

Antenna

In space, the fewer moving parts the better, remembering that we will only have one chance that will separate whether we have a satellite or 1kg of space debris. But, with the limitations of the launch, it is essential that the antenna 'emerges' from inside the satellite. I saw a very clever solution in a project:

The group used a metallic measuring tape [which tends to stay straight] folded around the satellite, and held in place by a thin nylon thread. When activated, the satellite heats a 'nichrome' wire or something similar to red-hot, cutting the nylon wire, thus opening the antenna.

So, let's take this project forward...?! Guys, this is what I managed to research, I ask for everyone's help, this project is possible