Q. What is the purpose of ‘evolved Laser Interferometer Space Antenna’ (eLISA) project?

• To detect neutrinos
• To detect gravitational waves
• To detect the effectiveness of missile defence system
• To study the effect of solar flares on our communication systems

Answer: (b) To detect gravitational waves

evolved Laser Interferometer Space Antenna (eLISA)

• The evolved Laser Interfermoter Space Antenna (eLISA) is a mission aiming at exploring the Gravitational Universe from space for the first time.
• It involves scientists from eight European countries ‒ Denmark, France, Germany, Italy, The Netherlands, Spain, Switzerland, and the UK ‒ as well as the support of several US-based ones. 
• The eLISA mission consists of a “Mother” and two “Daughter” spacecrafts. These will orbit the Sun in a triangular configuration. The three satellites will form a precision interferometer, with the two Daughter spacecrafts connected to the Mother one by 1 million km long laser beams. This interferometer will be capable of detecting gravitational waves at frequencies in the range of 0.1 mHz to 1 Hz.
• Such a frequency interval is not accessible on Earth due to arm length limitations and to noise caused by the terrestrial gravity gradient noise: in this sense, eLISA will complement the efforts of ground-based gravitational-wave detectors.