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
26 Aug 2026 · 12 Aug 2026 · Prelims and Mains
The lunar south pole
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.
26 Aug 2026 · Prelims and Mains
Lunar launch windows
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.
The Hindu, 26 Aug 2026: Why lunar missions have launch windows (opens in a new tab)
31 Aug 2026 · Prelims and Mains
Space weather forecasting from Aditya-L1
A solar flare gives no useful warning once it has erupted, because its radiation crosses to Earth in about eight minutes. Space weather forecasting is the attempt to read the Sun's atmosphere for a sign hours before that, and India's first solar mission has now found one.
Solar Ultraviolet Imaging Telescope (SUIT)
- Images the Sun in near-ultraviolet light
- Gave the pictures of the lower atmosphere where the brightenings appear
Solar Low Energy X-ray Spectrometer (SoLEXS)
- Gave the low energy X-ray data
High Energy L1 Orbiting X-ray Spectrometer (HEL1OS)
- Gave the high energy X-ray data
- Aditya-L1 watches the Sun from a halo orbit around L1, the first Sun-Earth Lagrange point, about 1.5 million kilometres from Earth.
- From L1 the Sun can be watched without the Earth ever coming in the way.
- A study using Aditya-L1 found that a major solar flare is preceded, hours ahead, by small short-lived brightenings clustered where it later erupts.
- Repeated small releases of magnetic energy appear to destabilise an active region until a large flare breaks out.
- The brightenings show in the Sun's lower atmosphere, in SUIT images read together with both X-ray payloads.
- Hours of notice would let operators safeguard satellites, astronauts and communication systems.
Also filed elsewhere
- Moon Base · on Space policy, private sector and governance
The National Aeronautics and Space Administration (NASA) invited ISRO to join Moon Base, at the ninth India-United States Civil Space Joint Working Group meeting.