Description

Source: ESA

Disclaimer: Copyright infringement not intended.

Context

The Indian Space Research Organisation (ISRO) will launch the European Space Agency’s Proba-3 mission on its PSLV rocket to study the solar corona, the outermost and hottest part of the Sun’s atmosphere, from Sriharikota on December 4.

About sun: https://www.iasgyan.in/blogs/structure-of-the-sun

Details

Aspect	Details
Mission Type	Advanced solar mission focusing on the Sun's corona and space weather
Orbit Details	Highly elliptical orbit: 600 x 60,530 km, orbital period: 19.7 hours
Mission Duration	Two years
Estimated Cost	200 million euros

Objectives

Objective	Details
Studying Solar Corona	Explore the Sun's outermost atmosphere, which reaches temperatures of up to 2 million °F.
Understanding Space Weather	Investigate phenomena like solar storms and solar winds that impact Earth’s satellite systems.
Precision Formation Flying	First-ever demonstration of two satellites flying in a precise configuration in space.

Features

Feature	Details
Dual Satellite System	Two satellites, Occulter Spacecraft (200 kg) and Coronagraph Spacecraft (340 kg), operate in tandem.
Artificial Solar Eclipse Creation	Satellites positioned 150 meters apart mimic an eclipse by casting a shadow for sustained observations.
Increased Observation Time	Enables 6 hours of continuous observation of the solar corona equivalent to 50 natural eclipses annually.
Autonomous Flight	Satellites maintain their position and alignment autonomously to facilitate precise operations.

Instruments Onboard

Instrument	Purpose
ASPIICS (Coronagraph)	Observes the Sun’s inner and outer corona by blocking its bright light using a 1.4-meter diameter occulting disk.
DARA (Digital Absolute Radiometer)	Measures the Sun’s total energy output (total solar irradiance).
3DEES (3D Energetic Electron Spectrometer)	Monitors electron fluxes passing through Earth's radiation belts aiding space weather studies.

Significance of Proba-3

Aspect	Details
Technological Demonstration	First mission showcasing precision formation flying in space.
Scientific Breakthrough	Allows detailed study of the solar corona and its influence on space weather.
Improved Data Availability	Extends observation time for corona studies contributing to better solar weather models.
International Collaboration	Involvement of scientists from Spain, Belgium, Poland, Italy and Switzerland.

India’s Role and Benefits

Aspect	Details
Launch Partner	Highlights ISRO’s reliability and cost-effectiveness in global satellite launches.
Scientific Access	Indian scientists involved in conceptualizing scientific goals; potential access to Proba-3 data.
Collaborative Opportunities	Plans for joint research using data from Aditya L1 (India's solar mission) and Proba-3.

Comparison: Proba-3 vs Aditya L1

Aspect	Proba-3	Aditya L1
Focus Area	Solar corona and space weather	Solar corona, photosphere and chromosphere.
Satellite Count	Two satellites operating in tandem	Single satellite mission.
Launch Vehicle	ISRO's PSLV rocket	ISRO's PSLV rocket.
Orbit	Highly elliptical orbit	Halo orbit around L1 (Lagrange point 1).
Observation Time	Up to 6 hours/day	Continuous solar observation at L1.

Sources:

ESA

PRACTICE QUESTION

Q:With reference to the Proba-3 mission, consider the following statements:

Proba-3 will be launched by the European Space Agency’s Ariane-5 rocket.
The mission aims to study the solar corona using precision formation flying of two satellites.
The mission will observe the Sun’s corona continuously for six hours mimicking an artificial eclipse.

Which of the above statements is/are correct?

(a) 1 only

(b) 2 and 3 only

(d) 1, 2, and 3

Answer: (b)

Explanation:

Statement 1 is Incorrect

Proba-3 will not be launched by the European Space Agency’s Ariane-5 rocket. Instead, the mission will be launched by ISRO using its Polar Satellite Launch Vehicle (PSLV) in the extended XL configuration. This demonstrates ISRO’s capability to launch international scientific payloads.

Proba-3 is a European Space Agency (ESA) mission but ESA has partnered with ISRO for the launch.

Statement 2 is Correct

Proba-3 is a unique mission that employs two satellites flying in precise formation to create an artificial eclipse.

The lead satellite acts as an occulter blocking sunlight while the second satellite observes the solar corona — the outermost part of the Sun’s atmosphere. This formation-flying technique has been hailed as a technological milestone in satellite coordination.

Statement 3 is Correct

Proba-3 will observe the solar corona continuously for six hours at a time by creating an artificial eclipse in space. This is critical for studying the corona’s role in solar wind and space weather phenomena such as coronal mass ejections which can disrupt satellite operations and power grids on Earth.