AIV (Assembly, Integration and Verification)

After the development and design stage BayernSat's individual components and subsystems will be assembled. They will be integrated on the premises of the Institute of Astronautics.
As soon as the first items of hardware will be available, they will be examined very thoroughly to make sure they satisfy the strict requirements of a space mission. The verification includes tests with real hardware as well as analyses of designs supported by computations and simulations such as finite element analysis for BayernSat's structure.
Figure 1 shows the development of the satellite structure as an example for the verification process.

Figure 1: Verification process for the structure

BayernSat will be built with a 2 model philosophy. This means that there will be a structural / thermal model, which will culminate in an engineering model, as well as a definite flying model. All the qualification tests will be carried out with the engineering model. The flying model will just have to go through acceptance tests at the end in order to detect possible structural defects, and to prove that the satellite will survive the launch. These final tests will probably be carried out at the Company IABG, as they dispose of the required installations.
The most tedious test will be the integrated system test. First of all, a complete simulation of the satellite including its environment in the Earth orbit will be modelled with software. Individual software modules, which simulate subsystems of the satellite, will then be replaced step by step by real hardware, and their functional efficiency will be tested in a hardware-in-the-loop test. The verification of the on-board software, which will take over the control of the satellite later on, plays a very important part. Gradually all the individual components of the satellite will be linked, and their interaction will be tested. The structure formed by this process is also called a flat satellite (see figure 2), as the components are not yet integrated into the flying model.

Figure 2: Flat satellite

The sensible components of the satellite need to be handled in a very clean and air-conditioned environment. To be able to do this, the Institute of Astronautics will set up a corresponding clean room.
Currently the clean room has to fulfil the following requirements:

clean room class 100,000 (US Federal Standard 209e)
flexible design, which can be adapted to future projects
the clean room has to fit into an existing room of the Institute
the clean room must not be too expensive.

Three concepts are currently being evaluated in a study.
The first concept is to include the use of the existing air-conditioning system in the building in order to achieve the required clean room class. This involves smaller alterations of the existing room.
In the second concept the requirements will be achieved by means of a cabin or a tent, which will be set up within the existing room. On the upper side of the cabin / tent will be filter units (Filter Fan Unit, FFU), which will fill the cabin / tent with filtered air (see figure 3 and 4).

Figure 3: Integration room with clean room cabin and two FFUs (green)

Figure 4: Clean room tent with aluminium structure, plastic walls and two FFUs

The third concept is similar to the first one. The difference here is an additional flow tower in order to avoid larger alterations of the air-conditioning system of the building. The flow tower draws in the air from below within the clean room and blows the filtered air out again (see figure 5 and 6). This gradually cleans the air within the room and thus the desired clean room class will be achieved. Smaller alterations of the existing room are also necessary.

Figure 5: Flow tower with inlet on the lower and outlet on the upper end	Figure 6: Flow tower within the clean room with air circuit (clean air blue, polluted air red)

	Additional Information AIV
	Project: Cleanroom for BayernSat