Rocket Propulsion: escape velocity of various planets.

Monday, September 10, 2012

Escape Velocity

It is the velocity required for a body to escape the attractive force of the planet or star.

Escape velocity of
Mercury - 4.300 km/s
Venus - 10.300 km/s
Earth - 11.190 Km/s
mars - 5.027 km/s
Jupiter - 59.500 km/s
Saturn - 35.600 km/s
Uranus - 21.200 km/s
Neptune - 23.600 km/s
Pluto - 1.200 km/s

sun - 617.700 km/s

Escape velocity of the planet or star can be calculated by the following formula

$v_e = \sqrt{\frac{2GM}{r}} = \sqrt{\frac{2\mu}{r}} = \sqrt{2gr\,}$

Ve - escape velocity
G - Gravitational constant -

$G = 6.67384(80) \times 10^{-11} \ \mbox{m}^3 \ \mbox{kg}^{-1} \ \mbox{s}^{-2} = 6.67384(80) \times 10^{-11} \ {\rm N}\, {\rm (m/kg)^2}$

M- Mass of the escaping body
r - is the distance between the center of the body and center of the escaping body

for example :
Escape velocity of object on earth when it is in ground is about 11.19 km/s , but it will gets reduced to 3.76 km/s once the body reaches the height of 50,000 km from earth's surface