LMP-103S and hydrazine differ in more ways than that hydrazine unlike LMP-103S is highly toxic and carcinogenic and that LMP-103S has higher performance.
LMP-103S requires more catalyst heating to burn and the burning temperature (about 1600 C) is considerably higher than for hydrazine (about 800 C).
The propulsion system and thus also the on-board software must take into account and ensure that the thruster-catalyst used is really hot (about 350 C), i.e. if the preheating due to a technical failure has failed and thrusting has been started, the whole mission could be lost.
A hydrazine thruster start burning without preheating of the catalyst, i.e. there is no absolute need to be properly functioning and the power required for normal heating is significantly less than that of LMP-103S.
In addition, hydrazine and LMP-103S have different properties as liquids and all valves that previously was qualified for hydrazine must first be space-qualified for LMP-103S to be safely used in space, i.e. in weightlessness & vacuum.
Se also two new US patent applications:
http://www.faqs.org/patents/app/20150121843
http://www.faqs.org/patents/app/20150128563
The space qualification of LMP-103S is finished. I give here a short update of passed milestones. (updated 2015-09-17)
September 2011 (after about 15 months in space) http://www.lsespace.com/latest-news.aspx
Finally, all planned firings with the HPGP propulsion system on Prisma have been successfully been completed.
On Friday night, September 9th, a 75 sec continuous firing was performed; the longest yet with a HPGP thruster in space, and the accumulated number of pulses exceeded 50,000.
363 sequences have been fired and 63% of the propellant has been consumed.
2 kg of the HPGP propellant remains which will be used for providing ΔV for new mission objectives during the remainder of the mission before decommissioning.
After 15 months in space, with no indications of degradation the flight demonstration is evolving into a space flight qualification.
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From: http://www.sffmt2013.org/PPAbstract/4088p.pdf
Dated 21:th of May 2013
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Table 2-1: The PRISMA mission phases
Mission phase........Start Date......Duration.......Operator
Nominal mission....2010-06-15.....273 days......OHB-SE (SSC)
Extended mission..2011-03-15.....160 days......DLR/GSOC
External parties.....2011-08-22......588 days......OHB-SE
mission
Final mission.........2013-04-01......Ongoing…...OHB-SE
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Table 2-2: External parties participants
Organization....Experiment.............Start Date.......Duration
Space-SI........Interferometry,.........2011-09-19......7 days
......................Space debris,
......................Distributed instrument,
......................Formation flying
GMV...............HARVD.................2011-10-03.......5 days
CNES.............FFRF cont. ............2011-10-10......23 days
DLR............... ARGON..................2012-04-16...... 5 days
CNES.............µNEAT....................2012-09-19.......3 days
ECAPS...........HPGP6...................2013-02-15.......1 day
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From: http://www.dlr.de/ra/Portaldata/55/Resources/dokumente/rheform/replacement-of-hydrazine.pdf
From EU Horizon 2020 Project Rheform - A most important document
Dated 15.th of June 2015
More than 344 sequences comprising over 50,525 pulses have been performed in continuous, pulse or off-modulation mode.
Performance mapping has been performed by executing firing sequences with pulse durations from 50 ms up to 100 s and pulse mode firings have been performed with duty cycles ranging from 0.1 % to 99 %.
Pulse trains lasting up to 90 min have been executed.
Pulse mode and single impulse bit predictability has been demonstrated to be very accurate for the HPGP
system.
The accumulated burn time is more than 3.5 h to date and 76 % of the propellant being consumed.
Theremaining propellant will be used to provide ?V for extended mission objectives before eventual decommissioning.
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From https://directory.eoportal.org/web/eoportal/satellite-missions/p/prisma-prototype#mission-status
During the rendezvous phase in August 2014, there was a problem with one of the propulsion system on PRISMA and the PRISMA project could not catch the opportunity to execute the inspection before the fly-by of Picard.
SNSB (Swedish National Space Board) January 27:th 2015
We're just discussing how to best use the fuel remaining in the HPGP system and if de-orbit can be combined with something else.
SNSB February 23:th 2015
It is, as said hydrazine which is at the end, not the LMP-103S. The HPGP system works just fine and will be used for the maneuvers remaining. Both systems have been used in parallel until the hydrazine ended.
From a comment to:
http://www.popularmechanics.com/space/rockets/a17162/nasa-green-rocket-fuel/
Mike Lara · Works at Orbital ATK
The ECAPS LMP-103S based HPGP systems has performed extremely well on-orbit for five years in support of the PRISMA satellite.
SNSB September 8:th 2015
Mango has in 2015 been given the task to circularize / lowering its orbit to reduce the risk of collision. In connection with this, the HPGP system is used and has thus been able to demonstrate 5 years of operational capability in space.
