Context:
Aditya-L1 is headed to one of the Lagrange points.
About Lagrange Points:
- Positions where the gravitational pull of two large masses precisely equals the centripetal force required for a small object to move with them.
- These points in space can be used by spacecraft to reduce fuel consumption needed to remain in position.
- Named in honor of the 18th century Italian-French mathematician Josephy-Louis Lagrange
- This mathematical problem is known as the “General Three-Body Problem“.
- 5 Lagrange points – There are 5 special points where a small mass can orbit in a constant pattern with two larger masses.
- 3 are unstable (L1, L2 and L3) – lie along the line connecting the two large masses.
- 2 stable Lagrange points (L4 and L5) – form the apex of two equilateral triangles that have the large masses at their vertices.
- L4 leads the orbit of earth and L5 follows.
L3
- L3 lies behind the Sun, opposite Earth, just beyond our planet’s orbit.
- Objects in L3 cannot be seen from Earth.
- It is unlikely to find any use for the L3 point since it remains hidden behind the Sun at all times.
L4 and L5
- L4 and L5 tend to accumulate a lot of interstellar dust and asteroids called Trojans.
- Space scientists are also exploring the potential of the L4 and the L5 points to host space colonies in the future.
- These points are relatively close to the Earth.
- Spacecraft will need very little fuel to remain in orbit or to launch to another planet.
L1 is already home to 4 other robotic explorers:
- NASA’s Solar and Heliospheric Observatory Satellite
- Deep Space Climate Observatory
- Advanced Composition Explorer
- Global Geospace Science Wind satellite
A halo orbit is a recurring, three-dimensional orbital path located in close proximity to one of the Lagrange points, specifically L1, L2, or L3, within the context of the three-body problem in orbital mechanics.
Source: The Hindu
Previous year question
“The experiment will employ a trio of spacecraft flying in formation in the shape of an equilateral triangle that has sides one million kilometres long, with lasers shining between the craft.” The experiment in question refers to
[UPSC Civil Services Exam – 2020 Prelims]
(a) Voyager-2
(b) New horizons
(c) Lisa Pathfinder
(d) Evolved LISA
Answer: (d)
