Mission Design for the CubeSat OUFTI-1

CHAPTER 1111.1 Test philosophy and facilitiesAll the elements need to be tested before being placed on board and someintegrated system test are then performed after the assembly. In the case ofOUFTI-1, the D-STAR system will undergo many functional and radiationstests before being placed on the platform for the integrated tests.The qualification and acceptance test document of a launcher, in our case Vega[AD2], gives the test intensity and duration based on the typical mission envelop.Two levels and durations are specified: the acceptance test and the qualificationtest. The acceptance spectrum envelops the expected environment and is higherthan the conducted level specified by the launch vehicle contractor to accountfor structural resonance and acoustic inputs. Respect to the qualification level,it is 3 dB lower for random vibrations and 80% of sinusoidal acceleration.Concerning the assembled satellite, the number of tests to be performed as wellas their level and duration depend on the so called test philosophy. In fact,many satellite models can be produced and tested, depending on schedule andbudget:• structural (SM), thermal (TM) and structural and thermal (STM) models:they need to be representative of the satellite mechanical (mass, eigenfrequencies,stiffness) and/or thermal behavior. They are tested at qualificationlevel to verify if the design satisfy the testing requirements.• engineering model (EM): it is composed by all the electromagnetic componentsand it undergoes to electromagnetic compatibility and functionalitytests.• qualification model (QM): it is the assembled satellite and it is tested atqualification level.• flight model (FM): it is the final model and undergoes to acceptance test.The same kind of classification can be done for all the satellite components.In the OUFTI-1 case some models of the D-STAR board will also be tested.The spacecraft verification strategy is specified in Vega acceptance and qualificationtest document [AD2]. Three main types of tests are envisioned, namelymechanical, thermal and electromagnetic compatibility tests. Because of scheduleand budget reasons, only one complete model of the CubeSat will be built:our test philosophy is therefore based on an EM/PFM protoflight model philosophy.On the PFM, the tests will be performed at qualification levels withdurations for acceptance tests.As explained in the next paragraph, severity Level 2 defined in [AD2] shouldbe assumed. As in the area of random vibration the required level could bechallenging for the compliance of CubeSats, we do not exclude the possibilityGalli Stefania 106 University of Liège