OPS-SAT was a recent study in the CDF to create an In-Orbit Demonstrator to test innovative mission control and operations concepts by using a "3U" cubesat. The latter is approximately 10 x 10 x 30 cm, which is 3 times the volume of a single cubesat, (or "3U" in cubesat parlance). Near the end of the study the customer asked if it were possible to create a full-scale mockup of the spacecraft.
The CDF has experience creating scale models (typically 1:10 to 1:40) of spacecraft using a rapid prototype machine (see link), but this was the first time that a 1:1 model was requested and it was clear from the outset that this was an opportunity to create a high fidelity model by means of combining different techniques. By close collaboration with the CDF team and the ESTEC workshop, which has extensive experience in model building the best way to make the model was determined.
It was decided to make the model out of a combination of plastics and metal. The circuit boards were printed in the rapid prototyping machine using ABS plastic, based on the actual CAD data generated in the study. The frame was made of aluminium, and several larger boxes on the spacecraft were modelled using blocks of PE1000 plastic. Overall this model was generated in about 1 week.
The model was then shown at the final presentation of the OPS-SAT study and was very poular with the study participants who got to see their design realised in a physical 1:1 form. It was also shown at the VEGA launch event at ESTEC, since the VEGA maiden fight was carrying a number of cubesats similar to the OPS-SAT designed in the CDF.