QB50 System Requirements Document

2. Environmental Requirements for LaunchThe following launch vehicles (LVs) are being considered for QB50: VEGA, Cyclone-4, Dnepr,PSLV, Rokot and Soyuz. Included in this chapter are the environmental requirements forlaunch. The CubeSats shall consider the given values in the requirements for design of theirCubeSats but these numbers are TBC before CDR.It will most likely be a sun-synchronous circular orbit with an altitude of 350 – 400km (TBCbefore CDR) ± 7km, an inclination of 98.6±0.08°, eccentricity of ±0.04, and a local time ofdescending node of 11:00AM (TBC) ± 60 sec.Note:**Section 2.1 (Gas Dynamic Environment and section 2.2 (Thermal Environment) refers to theenvironment outside the deployment system. As such, they are not necessarily applicable toCubeSats, but to the dispenser. These sections are included in this chapter for completeness.2.1 Gas Dynamic EnvironmentQB50-SYS-2.1.1. The payload shall withstand a maximum pressure drop rate of3.92kPa/sec (TBC before CDR).QB50-SYS-2.1.2.The payload shall withstand an airstream velocity of 2m/sec at apressure 0.8...1.1bar (TBC before CDR).2.2 Thermal EnvironmentQB50-SYS-2.2.1. The payload shall withstand a maximum radiant heat flux from thepayload fairing of 400W/m 2 (TBC before CDR) at prelaunchprocessing and in flight.QB50-SYS-2.2.2.The payload shall withstand a maximum free molecular heating of1135W/m 2 (TBC before CDR) following payload fairing jettison.QB50-SYS-2.2.3. The payload shall withstand a maximum thermal effect of 3.0kW·sec/m 2 (TBC before CDR) from the retrorockets.Issue 3 17 5 February 2013