>You are some wrong because ex-USSR build space rockets with liquid fuel >boosters. >And as i know USA made rockets with solid one . Dmitry, I was only pointing out the _basis_ for the programs. The US uses solid propellants in most combat missiles, and as supplemental boosters to liquid fuels. Historically, (that is, because of which Germans were taken captive by which sides) the programs have been as they are. Thanks for making me be more clear. Andy ================================================================== Andy Kunz - Montana Design - 409 S 6th St - Phillipsburg, NJ 08865 Hardware & Software for Industry & R/C Hobbies "Go fast, turn right, and keep the wet side down!" ==================================================================