Prototyping session

Pizza, modeling clay and satellite mock-up building!

On Friday 18.3.2011 the Aalto-1 team got together in Aalto University’s space technology laboratory to build a live-sized mock-up of the Aalto-1 satellite. The goal of the session was to assemble a mock-up of the Aalto-1 satellite, to have fun and to engage and motivate the team. During a long afternoon the team enjoyed some pizza and snacks while assembling the satellite’s aluminum frame and various subsystems, from the antennas to the ADACS-module and spectrometer. The end result was a happy team and a fine looking satellite mock-up!

Mock up and team
Part of the satellite team with the finished mock-up and two other prototypes.

The mock-up satellite consists of an aluminum frame that is close to the actual size of the future flight model (10x10x30 cm). The different subsystems and components inside and on the satellite were modeled using circuit boards, different plastic and rubber bits, and even modeling clay, pieces of measuring tape and a toilet paper roll. The locations of the subsystems are roughly comparable to those of the future flight model.

In the assembly process the team got a chance to make a proof of concept of the deployment of the UHF/VHF antennas (see photos further down). The antennas on the real satellite (4 antennas, 2 for each frequency band) are most likely going to be made up of springy metallic strands, not unlike a tape measure strand. The antennas were therefore simulated by using 50 cm long pieces of metallic measuring tape. The mock-up antennas were curled up in a tight roll and were held in that position by cotton string to simulate the launch arrangement. In a real satellite the string is usually made up of nylon that is cut by melting it with a heat resistor when the antennas are deployed. The team simulated the deployment by burning the cotton string with a cigarette lighter. Crude but effective! The cotton strings were cut as expected and the antennas deployed, proving the concept’s validity.

Overall, the session succeeded very well. The team now has a platform with which different mechanical solutions can be prototyped and tested. A proper physical manifestation of the satellite also makes the goal of designing and building a real satellite much more concrete.

Here are some photos of the session:

We started off with a short team meeting and recap of each member’s current work status.

After this the prototyping itself was started. There were pieces of aluminum profile to be used as the satellite’s frame…

…and miscellaneous screws, plastic parts, modeling clay and other thingamajigs for the subsystems.

FMI (Finnish Meteorological Institute) had provided some solar cell mock-ups to be used as models for the ones put on the satellite mock-up.

The team started off by getting familiar with the available building materials …and the snacks.

“We can use this measuring tape as an antenna…” “Oh yeah… *omnom*... definitely!”

The circuit boards for the satellite’s subsystems were modeled using generic circuit boards that were cut into a shape fitting inside the 10×10 cm cross section of a cubesat.

The frame starting to take shape…

The ever vigilant project manager observes the progress of on board computer testing.

Pizza time!

Back to work! Drilling a hole to a part of the aluminum frame.

Deploying one of the antennas as proof of concept. The cotton string holding the tape curled up is cut by burning it with a lighter.

Success!

Three competed subsystem mock-ups awaiting integration into the satellite.

Left to right: radiation monitor, ADACS module and the plasma sail tether deployment module.

Putting the subsystems’ modules togeter.

Applying finishing touches.

Finished!

Visible here are many of the subsystems: yellow VHF/UHF antennas on the top, the optics of the spectrometer in the middle, the ADACS module in the middle with its star tracker camera, the S-band antenna (metallic/copper colored cocentric circles) on the left side, solar panels on the bottom left, the red batteries on the lower section and the plasma sail deployer module on the bottom.
The finished mock-up on the left along with a 3D printed plastic model of the satellite's frame and a cardboard mock-up.