Thruster propellants

1 . A thruster propellant comprising a plurality of cations and an anions and having an overall net zero charge, said cation comprising one or more heads, and one or more hydrophobic fluorinated tails that comprise one or more sulfur atoms, said sulfur atoms being separated from said fluorination and said head group by at least one carbon, said one or more tails being covalently bound to said one or more heads, each of said one or more heads being independently selected from the group consisting of an imidazolium, an imidazolinium, a phosphonium, an ammonium, a sulfonium, a pyridinium, a pyrrolidinium.

2 . The thruster propellant of claim 1 wherein each of said one or more tails is independently an aliphatic moiety connected to one or more sulfur atoms which are each then connected to a partially hydrogenated fluorinated carbon chain.

3 . The thruster propellant of claim 2 wherein each of said one or more tails is independently selected from the group consisting of tails having Formula 1 or Formula 2 below wherein:

a) S is sulfur;

b) F is fluorine;

c) X is hydrogen or fluorine;

d) the indice a is an integer from 0 to 20;

e) the indice b is an integer from 1 to 10;

f) the indice c is an integer from 1 to 18;

g) the indice d is an integer from 1 to 14; and

h) represents an attachment point for Formulas 1 and 2 below to the thruster propellant

4 . The thruster propellant of claim 3 wherein for Formula 1 and Formula 2 the indice a is an integer from 2 to 12; the indice b is an integer from 1 to 8; the indice c is an integer from 1 to 8; and the indice d is an integer from 1 to 10.

5 . The thruster propellant of claim 4 wherein for Formula 1 and Formula 2 the indice a is an integer from 2 to 4; the indice b is an integer from 1 to 3; the indice c is an integer from 6 to 8; and the indice d is an integer from 1 to 4.

6 . The thruster propellant of claim 1 comprising one or more organic linking groups that link one or more of said one or more heads.

7 . The thruster propellant of claim 6 , wherein each of said one or more linkers is independently selected from the group consisting of aliphatic, aromatic, poly(ether), (poly)thio(ether), and isocyanurate.

8 . The thruster propellant of claim 3 , said thruster propellant comprising a material selected from Formulas 3 through 14 below and mixtures thereof:

wherein for each of Formulas 3 through 14:

a) each anion A is independently selected from the group consisting of tetrafluoroborate, hexafluorophosphate, and bis(trifluoromethylsulfonyl)azanide;

b) each R 1 is independently selected from the group consisting of: hydrogen; Formula 1 wherein the indice a is an integer from 1 to 20; Formula 2; a C 1 -C 12 branched alkane; a C 1 -C 12 linear alkane; a substituted aromatic moiety; or an unsubstituted aromatic moiety;

c) each R 2 , R 3 and R 4 is independently selected from the group consisting of, hydrogen; Formula 1; Formula 2; a C 1 -C 12 branched alkane; a C 1 -C 12 linear alkane; a substituted aromatic moiety; or an unsubstituted aromatic moiety;

d) each R 5 is independently selected from the group consisting of: hydrogen; Formula 1 wherein the indice a is an integer from 1 to 20; a C 1 -C 12 branched alkane; a C 1 -C 12 linear alkane; a substituted aromatic moiety; and an unsubstituted aromatic moiety;

9 . The thruster propellant of claim 8 wherein:

a) for R 1 said substituted aromatic moiety is a substituted benzene moiety and said unsubstituted aromatic moiety is a benzene moiety;

b) for R 2 , R 3 and R 4 , said substituted aromatic moiety is a substituted benzene moiety and said unsubstituted aromatic moiety is a benzene moiety, with the proviso that for Formula 3, Formula 5 and Formula 6, adjacent R 3 and R 4 moieties can be one or more benzo moieties rather than single independent moieties; and

c) for R 5 said substituted aromatic moiety is a substituted benzene moiety and said unsubstituted aromatic moiety is a benzene moiety.

10 . The thruster propellant of claim 8 wherein Formula 3's R 1 through R 4 groups are selected from the following sets:

a) moiety Set 1 wherein:

(i) the R 1 adjacent to R 4 is methyl;

(ii) the R 1 adjacent to R 3 is a tail having Formula 1 wherein the indice a is 3, the indice b is 2 and the indice c is 8, X is fluorine; and

(iii) R 2 , R 3 and R 4 are hydrogen;

b) moiety Set 2 wherein:

(i) each R 1 is a tail having Formula 1 wherein the indice d is 1, the indice b is 2 and the indice c is 8, X is fluorine; and

(ii) R 2 , R 3 and R 4 are hydrogen;

c) moiety Set 3 wherein:

(i) the R 1 adjacent to R 4 is methyl;

(ii) the R 1 adjacent to R 3 is a tail having Formula 2 wherein the indice d is 1, the indice b is 2 and the indice c is 8, X is fluorine; and

(iii) R 2 , R 3 and R 4 are hydrogen;

d) moiety Set 4 wherein:

(i) the R 1 adjacent to R 3 is formula has Formula 15 below wherein the indice f is 10 and R 6 is a tail having Formula 1 wherein for Formula 1, the indice a is 3, the indice b is 2 and the indice c is 8, X is fluorine

(ii) the R 1 adjacent to R 4 is a tail having Formula 1 wherein the indice a is 3, the indice b is 2 and the indice c is 8, X is fluorine; and

(iii) R 2 , R 3 and R 4 are hydrogen;

e) R 1 through R 4 moiety Set 5 wherein:

(i) the R 1 adjacent to R 3 has Formula 15 below wherein the indice f is 2 and R 6 is a tail having Formula 1 wherein for Formula 1, the indice a is 3, the indice b is 2 and the indice c is 8, X is fluorine

(ii) the R 1 adjacent to R 4 is a tail having Formula 1 wherein the indice a is 3, the indice b is 2 and the indice c is 8, X is fluorine; and

(iii) R 2 , R 3 and R 4 are hydrogen.

11 . A space craft comprising a thruster and a thruster propellant according to claim 1 .

12 . A space craft according to claim 11 , said space craft being selected from a satellite or a space station.