PRISMA and FFIORD objectives

PRISMA is a "technology in-orbit testbed mission" for demonstrating Formation Flying and Rendez-Vous technologies, as well as flight testing of sensor and actuator technologies.

The primary goals for PRISMA are technology demonstrations and manoeuvre experiments containing Guidance, Navigation and Control (GNC) and sensor technology for a family of future missions where Rendez-Vous and/or Formation Flying must be utilized. The main demonstrations are:

GNC manoeuvring experiments with high level of autonomy containing: Autonomous Formation Flying, Homing and Rendez-Vous, Proximity Operations and Final Approach and Recede Operation. The experiments are run mainly by SSC with important contributions from DLR.
Evaluation of the Vision Based Sensor (VBS) as a multirange range tracking and Rendez-Vous sensor.
A demonstration flight test of the RF metrology subsystem (FFRF) in open- and closed-loop configuration.

In addition, the mission also has some secondary goals mainly oriented toward testing of new technologies appropriate for future small satellite missions. These include: in-flight testing of High Performance Green Propellant (HPGP) and cold gas micro-thruster propulsion systems, onboard software development with Matlab/Simulink and autocode generation, validation of new Ground Support Equipment with multi-satellite support capability.

Prisma three propulsion systems: The hydrazine system (in red), the HPGP system (in green) and the Cold gas micro-thruster system (in purple)		Mango FFRF sub-system (in gold) among the satellite's other equipments (in grey)

CNES participates to PRISMA through the FFIORD experiment (Formation Flying In-Orbit Ranging Demonstration).
The main goal of FFIORD is to perform a first in-orbit demonstration of the FFRF sub-system, with the aim of preparing for future formation flying missions. The main objectives of this demonstration are twofold:

In-orbit validation of the RF metrology sensor (FFRF): functional and performance envelope tests of the metrology sensor system at various relative ranges, range rates and relative orientations of the satellites. The Inter Satellite Link (ISL) performances will be also evaluated during these operations
FFRF based open and closed loop formation flying to validate on-board GNC (Guidance, Navigation and Control) algorithms for future formation flying missions. Moreover, FFIORD is an opportunity for CNES to acquire competencies within the system domain necessary for future formation flying missions, allowing simultaneous validation of Formation Flying Management (FFM) routines and GNC algorithms. Further, FFIORD will help to define commissioning scenarios for specific formation flying hardware and functions. Finally, acquiring experience in rapid Flight Software (FSW) development though autocoding via Matlab/Simulink is a secondary objective.

In order to fulfil these general objectives, the hardware and algorithms developed within the framework of FFIORD should of course be as generic as possible. As a consequence, future formation flying missions will be able to benefit from validated hardware and navigation loop algorithms, of which recurrent procurement will thus be possible.