Mission Design for the CubeSat OUFTI-1

CHAPTER 8Figure 8.8: Total power and integrated power for the circular orbit with Ω = 0and ω = 0is different. In fact, being at lower altitude, the communication system needsless power to communicate as the path losses at smaller: even if the availablepower is less than in the elliptic case, we could in theory guarantee all the samea good communication. However, as above mentioned, this orbit present themain drawback of en extremely brief lifetime.8.3.3 Parametric studyThe availability of power is the main parameter in the development of a Cube-Sat. In fact, due to the limited solar arrays surface and to to the missionrequirements, the power is often less than what needed. If the design is carriedout in the hypothesis of a certain amount of power and then the power effectivelyavailable on board is less than expected, the mission would definitely becompromised. That’s the reason why we used an efficiency of 25% instead of25,5% and why we also performed a parametricl study on the orbit parmetersthat haven’t been fixed yet: the right ascension of ascending node Ω and theargument of perigee ω.We studied many possibles combinations of those two parameters and we foundout that the most different situations are those with them set to 90 ◦ . In figures8.9, 8.10 and 8.11, the total power produced and the integrated power for thesecases are represented. The important remark that comes out, is that the mostcritical situation, the one with the minimum power available, always happens,even if shifted in time. This means that the two missing parameter haven’t apredominant role in this phase of mission design as we have all the same toguarantee a correct functionality of the payload with 1.3 W.Galli Stefania 82 University of Liège