Space Missions Away from Earth

Artificial satellites help us in many ways, such as communication, weather forecasting, and collecting information about space. Some special space missions send spacecraft to explore nearby objects in our solar system, like the Moon, Mars, and other planets. These missions help scientists learn more about how the solar system was formed and how it works.

Escaping Earth's Gravity:

To send a spacecraft into space, it must overcome the Earth's gravitational pull. This means it must travel at a very high speed, called escape velocity. The escape velocity is the minimum speed needed for an object to break free from the Earth's gravity and enter outer space.

The formula to calculate escape velocity is:

V_esc = `sqrt((2 GM)/(R))`

V_esc = `sqrt((2 xx 6.67 xx 10^-11 xx 6 xx 10^24)/(6.4 xx 10^6))`

= 11.18 x 10³ m/s = 11.18 km/s

Where:

• G is the gravitational constant = 6.67×10⁻¹¹ Nm²/kg²
• M is the mass of the Earth = 6×10²⁴ kg
• R is the radius of the Earth = 6.4×10⁶ m

Using the formula, we find:

V_esc​=11.2km/s

So, a spacecraft must travel at least 11.2 kilometres per second to leave Earth's gravity and go into space.

Travel to the Moon: The Moon is the closest astronomical object to Earth. Light from the Moon takes only 1 second to reach Earth because light travels very fast. But a spacecraft moves much slower than light. The fastest time a spacecraft has taken to reach the Moon is 8 hours and 36 minutes.

v_esc = \[\sqrt{\frac{2\mathrm{~GM}}{\mathrm{R}}}\]

where

• G = Gravitational constant
• M = mass of the planet
• R = Radius of the planet