The application relates to a Ramjet solid fuel having an ignition temperature of less than 400 C., the fuel comprising a bis-(ethylene oxy) methane polysulfide polymer (BMPP) and hydroxyl-terminated polybutadiene (HTPB), the copolymer having a BMPP/HTPB weight ratio of from 1/3 to 3/1; and the fuel comprising at least 85 weight % copolymer. The BMPP comprises from 5 to 8 weight percent mercaptan. Furthermore, the BMPP is selected from
HS(RSS).sub.aCH.sub.2CH((SSR).sub.cCSH)CH.sub.2(SSR).sub.bSHa) where R(CH.sub.2).sub.2OCH.sub.2O(CH.sub.2).sub.2 and a+b+c<7; and
H(SC.sub.2H.sub.4OCH.sub.2OC.sub.2H4S).sub.nH where n=7.b)

The application relates to a Ramjet solid fuel having an ignition temperature of less than 400 C., the fuel comprising a bis-(ethylene oxy) methane polysulfide polymer (BMPP) and hydroxyl-terminated polybutadiene (HTPB), the copolymer having a BMPP/HTPB weight ratio of from 1/3 to 3/1; and the fuel comprising at least 85 weight % copolymer. The BMPP comprises from 5 to 8 weight percent mercaptan. Furthermore, the BMPP is selected from
HS(RSS).sub.aCH.sub.2CH((SSR).sub.cCSH)CH.sub.2(SSR).sub.bSHa) where R(CH.sub.2).sub.2OCH.sub.2O(CH.sub.2).sub.2 and a+b+c<7; and
H(SC.sub.2H.sub.4OCH.sub.2OC.sub.2H4S).sub.nH where n=7.b)

The application relates to a Ramjet solid fuel having an ignition temperature of less than 400 C., the fuel comprising a bis-(ethylene oxy) methane polysulfide polymer (BMPP) and hydroxyl-terminated polybutadiene (HTPB), the copolymer having a BMPP/HTPB weight ratio of from 1/3 to 3/1; and the fuel comprising at least 85 weight % copolymer. The BMPP comprises from 5 to 8 weight percent mercaptan. Furthermore, the BMPP is selected from

HS(RSS).sub.aCH.sub.2CH((SSR).sub.cCSH)CH.sub.2(SSR).sub.bSHa) where R=(CH.sub.2).sub.2OCH.sub.2O(CH.sub.2).sub.2 and a+b+c<7; and

H(SC.sub.2H.sub.4OCH.sub.2OC.sub.2H4S).sub.nH where n=7.b)

A power controller includes an input power terminal, an output power terminal, a power switching circuit connected between the input power terminal and the output power terminal, a detection circuit connected to the power switching circuit, one or more data interfaces, and a control device connected to the detection circuit and the one or more data interfaces. The detection circuit measures a load current and a current squared time (I.sup.2t) value between the input power terminal and the output power terminal. The control device automatically turns the power switching circuit OFF whenever the load current exceeds a first value or the current squared time value exceeds a second value or an OFF signal is received from the one or more data interfaces, and automatically turns the power switching circuit ON whenever an ON signal is received from the one or more data interfaces.