Question
Q 3. “The experiment will employ a trio of spacecraft flying in formation in the shape of an equilateral triangle that has sides one million kilometers long, with lasers shining between the craft.” The experiment in questions refers to
a. Voyager-2
b. New Horizons
c. LISA Pathfinder
d. Evolved LISA
Answer: D
Detailed Explanation
Evolved LISA (Laser Interferometer Space Antenna):
Evolved LISA, or eLISA, is a laser interferometric gravitational wave observatory in space consisting of three spacecraft positioned in a heliocentric orbit.
The spacecraft are arranged in an equilateral triangle formation with arms that span one million kilometers in length.
Hence, the correct answer is option 4.
Mission Objective:
The eLISA mission aims to explore the Gravitational Universe from space for the first time by detecting gravitational waves.
It will allow scientists to study cosmic events that produce gravitational waves, such as merging black holes, which are not accessible to observatories on Earth.
Structure and Formation:
- eLISA involves a “Mother” spacecraft and two “Daughter” spacecraft.
- The three spacecraft form a precision interferometer connected by laser beams that are one million kilometers long, creating an equilateral triangle configuration.
- The passing gravitational waves alter the relative distances between the spacecraft, which is detected by onboard instruments.
Scientific Capabilities:
eLISA is designed to measure gravitational waves at frequencies ranging from 0.1 MHz to 1 Hz.
The configuration allows the observatory to detect and measure the frequency, phase, and polarization of gravitational waves, enabling scientists to resolve overlapping signals and determine their source in the sky.
International Collaboration:
The mission involves scientists from eight European countries, including Denmark, France, Germany, Italy, the Netherlands, Spain, Switzerland, and the UK, along with support from the United States.
Voyager-2:
A NASA spacecraft that studied the solar system’s giant planets, including Jupiter, Saturn, Uranus, and Neptune. It was not designed for gravitational wave detection.
New Horizons:
The first spacecraft to explore Pluto and the Kuiper Belt. It focuses on planetary exploration rather than gravitational wave detection.
LISA Pathfinder:
A precursor mission that successfully demonstrated the technologies required for a future space-based gravitational wave observatory.
It paved the way for the eLISA mission, which is planned for 2034 by the European Space Agency.
