Science and Technology › Space

Moon, Sun and planetary missions

Missions to the Moon, the Sun, the planets and the asteroids, India's and other countries': what each is sent to find, and what it finds. Prelims has asked about Mangalyaan, the Mars Orbiter Mission.

UPSC has asked

Prelims 2016: Mangalyaan, the Mars Orbiter Mission

Showing 1 of 3 subjects, those that changed from 1 to 15 August 2026.Show all

The lunar south pole

Prelims and Mains

Every serious lunar plan now points at the same few hundred kilometres of the Moon's south, China's as much as America's. Sunlight and water ice do not usually sit near one another, and there they almost do.

Sunlight lasts longer near the lunar poles, which a solar powered outpost needs.
A permanently shadowed region is a crater floor beside them that the Sun never reaches, and the water ice held there is the resource that makes a base worth building.

Why launches wait

China called off Chang'e 7 and postponed its lunar south pole mission to next year, which is less a failure than a fact of orbital mechanics. A launch window missed is a month lost, and for a polar landing often more.

A launch window is when Earth, the Moon and the spacecraft align so the target orbit costs least fuel.
For the Moon a window opens roughly once a month.
A south pole mission needs a near polar orbit, which the 5.1 degree tilt of the Moon's orbit complicates.
A solar powered lander must also land in sunlight.

What changed

Also filed elsewhere

The Artemis Accords · on Space policy, private sector and governance
The Artemis Accords are the terms on which the American lunar programme admits a partner, and India accepted them in 2023.