PPT Propulsion system with
non-volatile liquid propellant
Serge Barral
QuinteScience, Warsaw, Poland
Jacek Kurzyna, Agnieszka Szelecka, Hubert Rachubiński,
Dariusz Daniłko, Jan Miedzik
Institue of Plasma Physics and Laser Microfusion, Warsaw, Poland
Eduardo Remírez, Ricardo Martín
JMP Ingenieros, Sotés (la Rioja), Spain
Pablo Ortiz, Javier Alonso
NASP, Sotés (la Rioja), Spain
Yann Mabillard, Stefano Bottinelli
Mecartex, Muzzano, Switzerland
Ana Zaldívar, Pelle Rangsten
Nanospace, Uppsala, Sweden
Christophe Koppel
KopooS Consulting Ind., Paris, France
(credit: IPPLM)
The FP7 L-µPPT consortium
electronics
thrust balance
thruster design &
vacuum testing
[coordination]
propellant tank
propellant flow
rate control
[subcontractor]
thruster design & testing
mission analysis
PPT propulsion system with non-volatile liquid propellant — EPIC Workshop, Bruxelles, 25-28 November 2014
L-µPPT project goals
Main objective
Design and feasibility demonstration of a liquid propellant PPT for µSat
Motivations
⊳ shared propellant storage
⊳ propellant management via flow rate control
⊳ constant geometry discharge
⇒ no long term impulse bit variability
⊳ propellant mass not constrained by geometry
⊳ lower exposed propellant area
⇒ better propellant efficiency (?)
Target performance
⊳ Isp: 600 s
⊳ pulse energy: 2 J
⊳ repetition rate: 1 Hz
⊳ Ibit: 34 µNs
⊳ Itotal: 125 Ns per thruster
PPT propulsion system with non-volatile liquid propellant — EPIC Workshop, Bruxelles, 25-28 November 2014
L-µPPT project timeline [1/2]
November 2012
Kick-off meeting
November 2012 — January 2013
Proof-of-concept prototype design & manufacturing:
⊳ propellant: PFPE
⊳ micro-syringe/step motor propellant injection
⊳ 2x25ml piston propellant tank
⊳ ≈1W power supply
⊳ on-board logic & power supply units
Initial testing facility procurement:
⊳ 3000 l/s turbomolecular pump
⊳ 2m3 chamber
⊳ compact, high sensitivity thrust balance (Mecartex)
February 2013 — March 2014
Propulsion system integration and performance characterisation:
⊕ it works!
⊕ no propellant charring
⊕ high thrust-to-power ratio (≈36 µN/W)
⊖ injector unusable: front plate had to be wetted with thin propellant layer
⇒ could not assess mass bit, Isp and efficiency
⊖ capacitor lifetime only ≈6000 discharges
Mission analysis (KopooS):
⊳ best config: 4-thruster system (shared tank)
⊳ slender or asymmetric design preferable for satellite integration
PPT propulsion system with non-volatile liquid propellant — EPIC Workshop, Bruxelles, 25-28 November 2014
L-µPPT project timeline [2/2]
March 2014 — July 2014
Demonstration prototype design & manufacturing:
⊳ propellant feeding in open groove
⊳ time-metered propellant injection
⊳ single 25ml piston propellant tank
⊳ small power spark gap
Testing facility upgrade:
⊳ 30000 l/s closed cycle cryopump
July 2014 — October 2014
Propulsion system integration and performance characterisation:
⊕ very good efficiency ...for a PPT ≈10%
⊕/⊖ high specific impulse (1000–1400 s) but lower thrust-to-power ratio (≈18 µN/W)
⊕ capacitor lifetime as high as ≈50 000 discharges
⊖ capacitor lifetime only ≈50 000 discharges
⊖ injector not sufficiently calibrated and prone to bubbling: ad-hoc capillary injector used instead
Mission analysis:
cf C. Koppel “Active attitude and orbit control with liquid µPPT 4 thrusters system„ (session 6)
December 2014
Final review meeting
Expected TRL: 3/4
PPT propulsion system with non-volatile liquid propellant — EPIC Workshop, Bruxelles, 25-28 November 2014
Principle of operation
pressurised PFPE
(approx. 1 bar)
Why PFPE?
⊳ non-volatile
⊳ non-toxic
⊳ dense (>1.6 g/cm3)
⊳ extreme stability: -50°C to +150°C
⊳ space-qualified as lubricant
⊳ Teflon-like fluoropolymer
⇒ lower development risk
PPT propulsion system with non-volatile liquid propellant — EPIC Workshop, Bruxelles, 25-28 November 2014
In action
PPT propulsion system with non-volatile liquid propellant — EPIC Workshop, Bruxelles, 25-28 November 2014
Impulse bit measurement @750 V
(credit: IPPLM)
PPT propulsion system with non-volatile liquid propellant — EPIC Workshop, Bruxelles, 25-28 November 2014
Impulse bit measurement @1000 V
(credit: IPPLM)
PPT propulsion system with non-volatile liquid propellant — EPIC Workshop, Bruxelles, 25-28 November 2014
Specific impulse & efficiency
(credit: IPPLM)
PPT propulsion system with non-volatile liquid propellant — EPIC Workshop, Bruxelles, 25-28 November 2014
What next?
LµPPT review
TRL 3/4
TRL 5
TRL 6
TRL 7
⊳ propellant FC improvements
⊳ dual/wide groove injector
⊳ PPU efficiency improvements
further improvements:
⊳ lifetime
⊳ reliability
⊳ EMC
testing in view of CubeSat
demonstration flight
Technological development
PPT propulsion system with non-volatile liquid propellant — EPIC Workshop, Bruxelles, 25-28 November 2014
What next?
LµPPT review
TRL 3/4
TRL 5
TRL 6
TRL 7
⊳ propellant FC improvements
⊳ dual/wide groove injector
⊳ PPU efficiency improvements
further improvements:
⊳ lifetime
⊳ reliability
⊳ EMC
testing in view of CubeSat
demonstration flight
Technological development
2014
Main objective
improve our understanding of
the fundamental processes:
⊳ to improve reliability
(long term target: 25-30%)
⊳ to mitigate capacitor load
⊳ to improve repeatability
⊳ ...
The tools
⊳ improved diagnostics:
combined TOF/Thomson
spectrometer
(full ion mass-energy
spectrum in a single pulse!)
⊳ analytical models
⊳ numerical models
⊳ ...
Fundamental research
PPT propulsion system with non-volatile liquid propellant — EPIC Workshop, Bruxelles, 25-28 November 2014
2030
Thank you for your attention!
(credit: IPPLM)
The research leading to these results has received funding from the European Community's
Seventh Framework Programme (FP7/2007-2013) under grant agreement n°283279 for
the L-µPPT project. IPPLM has also received financial support from the Polish fund for
science in years 2012-2014 for the execution of a partially funded international project.
PPT propulsion system with non-volatile liquid propellant — EPIC Workshop, Bruxelles, 25-28 November 2014