Description
The objective of the activity is to design, manufacture and test an accelerometer for drag compensation in Very Low Earth Orbit (VLEO). Targeted Improvements: - Enabling real time compensation of drag by the propulsion system. - Miniaturisation of instrument by a factor 10 compared to existing payload grade accelerometers. - Increase accuracy by factor 10 compared to existing accelerometers used for orbital control.Description: While interest on Very Low Earth Orbit (VLEO) spacecraft is increasing, a number of sensors will become necessary to effectively utilise these new orbits. This is the particularly the case for accelerometers, for which the performance could either support the attitude and orbit control (drag determination for compensation) as well as possibly providevery high revisit scientific data on the atmospheric drag. The accelerations to be measured are extremely small and, in case of circular orbit, close to continuous, which represents the key challenge. On traditional spacecraft, very precise accelerometer bias estimation and compensation can be performed before a burn as no external non gravitational force is exerted on the spacecraft. As accelerometers are rarely used for both Attitude Orbit Control System and Failure Detection Identification Recovery (FDIR) on LEO spacecrafts, it is important to analyse first the number of accelerometers required and their accommodation. Benefits in terms of optimal attitude and early FDIR detection can be assessed and traded against accelerometers technologies performances. The reduction of the risk to reach survival mode and a quicker return from survival mode (mission continuity and survivability) are key aspects to be improved with the addition of accelerometers. The heritage of the ESA Mission GOCE will need to be revisited to become miniaturised andproducible on large scales for telecommunication constellations, ensuring the measurement of micro-g accelerations using affordablesensors (i.e. not a payload-grade gravitometers). Among the different possibilities, one example could be to reach the performance required at system level via the use of the hybridisation with GNSS measurements. A breadboard of an accelerometer for drag compensation on VLEO will be designed, manufactured and tested to validate the performances and enhanced functionality.Footnote: On Delegation Request activities will only be initiated on the explicit request of at least one National Delegation. Procurement Policy: C(1) = Activity restricted to non-prime contractors (incl. SMEs). For additional information please go to: http://www.esa.int/About_Us/Business_with_ESA/Small_and_Medium_Sized_En…