Comparison of SOLID Propellant Vs LIQUID Propellant 
PROPELLANT 
 |    
HTPB 
(SOLID) 
 |    
UDMH-N2O4 
(Liquid) 
 |    
LOX- P1 
( Semi   Cryogenic) 
 |    
LOX- LH2 
(Cryogenic) 
 |   
Density 
 |    
1.80 
 |    
1.15 
 |    
1.05 
 |    
0.35 
 |   
Theoretical ISP Vacuum 
 |    
310 s 
 |    
340 s 
 |    
360 s 
 |    
460 s 
 |   
Density x ISP 
 |    
558s 
 |    
391 s 
 |    
378 s 
 |    
161 s 
 |   
VOLUME RATIO 
 |    
REF. 
 |    
X 1.5 
 |    
X 1.5 
 |    
X 3 
 |