Overview:
Overview A brief review of key technologies for formation flying missions
EP and micro thrusters
FF GNC communications
Ranging and Metrology
Electric Propulsion:
Electric Propulsion Investigation into several options
Miniature gridded ion engine systems
Conventional scaled thruster (5cm diameter grids)
Total impulse capability > 0.5x106 Ns
Specific impulse > 3000s @ 5mN
5N – 5mN thrust range (5cm diameter)
Wide and controllable trust range provides significant mission design options
TRL = 3
Supporting sub-systems also at TRL=3, require optimisation and development. Breadboard model of 5cm GIE (front & rear views)
FF GNC Communications :
FF GNC Communications Requirements
Provide an extremely high QoS physical layer to facilitate data exchange between distributed architectures for processing and control.
Minimise spacecraft resource demands (mass power etc)
Candidate Solutions
Proximity-1
A reliable, interoperable, low-power, sub-network protocol for space links which can implement the physical layer of constellation GNC architecture.
As implemented on MELACOM
CCSDS File Deliver Protocol – CFDP
A protocol for robust file delivery between spacecraft and/or spacecraft and ground segment.
Development
TRL = 5 for existing systems
TRL = 3 for development technologies
Development required to improve latency and QoS.
Ranging and Metrology:
Ranging and Metrology Requirements
Mission dependant, nanometres – meters - kilometres
Current baselined techniques rely upon multi-wavelength interferometric techniques
QinetiQ is offering optical methods, which when combined with technologies such as hollow waveguides and photonic crystal fibres, offers alternative space-capable precision ranging systems.
Time correlated single photon counting
Low Coherence Optical Reflectometry (Femtosecond laser pulse) range finding
Other technologies to enable ‘loose’ formation flying
DALOMIS RF relative location monitoring (75m and 0.5). Uses code autocorrelation combined with radio direction finding to determine range and position. TRL = 4.
Time-correlated single photon ranging:
Time-correlated single photon ranging Capable of micron level range measurement accuracy
Low laser power
It is possible to detect a single photon reflected from a corner cube at range 10m<R<17km. In principle R
Accuracy is proportional to the number of photons received for N=106 counts, range resolution is ~ 45mm achievable in 1s @ 1MHz
TRL = 3, development required to build space-capable demonstrators.
Low Coherence Optical Reflectometry:
Low Coherence Optical Reflectometry A femtosecond laser pulse range-finding technique offering potential 1mm range precision
Exploits interferometry and optical vernier principle
Broadband pulse generated with non-linear photonic crystal fibres
Exploits integrated optics – hollow waveguides
TRL = 3 development required for space qualification and application