MEMESat-1

Much like Warren, MEMESat has very little control over its attitude. In the context of spacecraft, attitude is the direction that the satellite is oriented in space. MEMESat utilizes a method of attitude control that was developed for the Naval Academy’s PSAT-II mission. This method utilizes white space-rated tape strips placed vertically at the far edge of each of the XY plane solar panels. The white tape reflects more of the light emitted by the sun than the solar cells on the panel, thus creating a solar radiation pressure differential across the face of the satellite. This induces a torque that keeps the satellite in a controlled spin about its Z-axis. This stable spin is an integral part of properly powering the satellite, distributing heat across the entire satellite, and maintaining proper orientation.

MEMESat utilizes only a single torque rod in the z-axis that is strategically fired as the satellite passes near the Earth’s North Pole in order to keep the satellite approximately nadir pointing.

A suite of sensors will be used to gather data on Earth’s magnetic field, the location of the satellite in orbit, and its orientation relative to the Earth. This data will be processed and utilized by the control system to put the satellite in its proper orientation for nominal operations.

The brain of the satellite is the C&DH system. This system handles all of the commands, data flow, and operations of the satellite. MEMESat-1 will be flying a Raspberry Pi Compute Module 4. While this isn’t the typical rad-hardened satellite computer, it does have flight heritage on other CubeSat missions. While radiation can be an issue, it typically a minor threat in Low Earth Orbit (LEO). The flight software will use NASA JPL’s F’ software framework.

MEMESat-1 is an amateur radio satellite, so it communicates exclusively on amateur bands. The satellite will utilize UHF (70cm) bands for uplinking and downlinking telemetry, memes, and digital repeater messages. Because we have to downlink images in a period of a few minutes, UHF was chosen for its higher data rates. Our bands will be allocated by the International Amateur Radio Union in the next several months.

Our primary radio is the half-duplex Little Free Radio from the Universiy of Buffalo Nanosatellite Laboratory. An in-house deployable dipole antenna is being developed, as to provide omni-directional communication.

Because of their size limitations, CubeSats often encounter a power generation issue. When the only power source is the sun, you need to maximize solar panel efficiency and power distribution. Luckily, this bad boy generates power from six custom Let’s Go to Space solar panels and a state-of-the-art lithium-ion battery stack and power distribution system developed by the University of Georgia Small Satellite Research Laboratory. Sporting 16 Spectrolab XTE-SF Triple Junction 27cm^2 solar cells and an in-house-developed battery stack, MEMESat will operate well within the power margins needed for meme transmission and near constant telemetry beacons.

Getting to space provides a unique structural challenge. A satellite must survive the intense launch environment and a less structurally demanding microgravity environment. CubeSats have a strict weight and size requirement of 1.33 kg and 10 cm x 10 cm x 11.33 cm per 1U; because MEMESat-1 is a 2U satellite, our weight and size constraints will be 2.66 kg and 10 cm x 10 cm x 22.66 cm, respectively. The primary structure is made with Al-6061 T6, precision machined to ensure a snug fit and proper alignment. The structure will be coated with a yellow alodine for corrosion resistance and thermal dissipation. The corners of the satellite will be black anodized as to conform to deployer standards. Within the satellite, the electronics are stacked in a PC-104 form factor, with electrical harnesses tied down and staked into place.

Temperatures can rapidly change in space. MEMESat will be going in and out of sunlight for roughly 45 minutes at a time, and temperatures can swing 80 degrees centigrade. While in the sun, the satellite will be stably rotating, thus equally distributing energy across four solar panels. While the sun is eclipsed by the Earth, MEMESat will be heated by its electronics and emergency heaters. These heaters will generate and radiate heat across temperature sensitive components.

The payload is the most valuable part of the mission. Without a payload, a satellite lacks purpose. MEMESat-1 has the most valuable of all payloads – thousands of memes. A high capacity flash storage board – in development by the University of Georgia Small Satellite Research Lab (UGA SSRL) – will contain all of the user donated images and protect them from radiation effects.

Our amateur radio payload will be a digital Repeater operating on the UHF band. This means that licensed amateur radio users will be able to uplink a voice message or sound file to our satellite for broadcasting around the world. Check out the “Interact with Us” page for more details on our repeater frequencies, satellite orbital characteristics, and helpful guides to building a cheap satellite tracking antenna and getting HAM radio licensed!