Cryogenically compatible rocket propellant

Abstract

Propellants for rockets, space transportation vehicles, launch vehicles and systems, crew escape vehicles and systems, launch escape towers, and space vehicle systems are disclosed. Some embodiments provide a rocket propellant comprising a mixture of a small chain alkane from 1 to 4 carbons and a small chain alkene from 3 to 4 carbons. The mixture of the small chain alkane and small chain alkene is in a proportion that lowers the melting of the mixture below the melting point of both the small chain alkane and small chain alkene.

1 . A liquid propellant consisting essentially of:
 methane; and   ethane,   
       wherein said liquid propellant has a melting point less than a melting point of pure methane and a melting point of pure ethane. 
     
     
         2 . The liquid propellant according to  claim 1 , wherein said methane in a mole fraction of about 46% and said ethane in a mole fraction of about 54%. 
     
     
         3 . The liquid propellant according to  claim 1 , wherein said liquid propellant is a liquid when cooled with liquid nitrogen to a temperature between 75 Kelvin and 88 Kelvin. 
     
     
         4 . The liquid propellant according to  claim 1 , wherein said methane in a mole fraction in a range from 40% to 50% and said ethane in a mole fraction in a range from 60% to 50%. 
     
     
         5 . The liquid propellant according to  claim 1 , wherein said propane in a mole fraction in a range from 25% to 75% and the propene in a mole fraction in a range from 75% to 25%. 
     
     
         6 . The liquid propellant according to  claim 1 , wherein said methane in a mole fraction in a range from 20% to 80% and said ethane in a mole fraction in a range from 80% to 20%. 
     
     
         7 . The liquid propellant according to  claim 1 , wherein the melting point of the liquid propellant is less than 84 Kelvin. 
     
     
         8 . The liquid propellant according to  claim 1 , wherein the melting point of the liquid propellant is less than 80 Kelvin. 
     
     
         9 . The liquid propellant according to  claim 1 , wherein the melting point of the liquid propellant is less than 77 Kelvin. 
     
     
         10 . A rocket engine system comprising: the liquid propellant according to  claim 1 , and a liquid oxidizer. 
     
     
         11 . The rocket engine system according to  claim 12 , wherein the liquid oxidizer is liquid oxygen at a temperature less than 90 Kelvin. 
     
     
         12 . The rocket engine system according to  claim 13 , wherein the liquid propellant and the liquid oxidizer are separated by a common wall. 
     
     
         13 . The rocket engine system according to  claim 14 , wherein the liquid propellant and the liquid oxidizer are cryogenically cooled to a temperature less than 80 Kelvin. 
     
     
         14 . The rocket system according to claim  15 , further comprising liquid nitrogen configured to cryogenically cool the liquid propellant and the liquid oxidizer to the temperature less than 80 Kelvin.