It has also been developing engines using liquid propellants since 1988, but with mixed results.

The manufacturers then changed the formulation to use permitted propellants.

For these reasons, most orbital launch vehicles use liquid propellants.

A6 was a designation applied to a variant of the A5 test rocket which used different propellants.

Two course correction burns on December 21 used more propellant than planned, leaving the spacecraft short of fuel.

The Shtil' is a 3-stage launch vehicle that uses liquid propellant.

The Volna is a 3 stage launch vehicle that uses liquid propellant.

Cyclers are potentially useful for transporting people or materials using little propellant.

The highest specific impulse chemical rockets use liquid propellants.

Ion thrusters can achieve extremely high speeds and use little propellant however the are power hungry too.