UPSC CSE Prelims
Question 54
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
View correct answer and explanation
Correct answer: D
Correct Option: D (Evolved LISA)
Explanation: The proposed evolved Laser Interferometer Space Antenna (eLISA) envisaged three laser-linked spacecraft millions of kilometres apart for detecting low-frequency gravitational waves.
Option-wise Analysis:
A. Incorrect - Voyager 2 is an outer-planet exploration probe, not a triangular laser observatory.
B. Incorrect - New Horizons was built for Pluto/Kuiper Belt exploration.
C. Incorrect - LISA Pathfinder tested precursor technology with a single spacecraft and test masses, not the full constellation.
D. Correct - evolved LISA describes the three-spacecraft laser-interferometry mission.
Review note: Mission designs and spacecraft baselines have evolved since the older eLISA proposal.