Context: US space agency NASA will train an Indian astronaut for a mission to the International Space Station (ISS) by the end of 2024.

Indian Space Station Program

• About: The Indian Space Station is anticipated to have a considerably smaller scale, weighing around 20 tonnes, in contrast to the International Space Station's 450 tonnes and the Chinese Tiangong Space Station's 100 tonnes.
• Orbital Structure: Envisaged as a modular structure constructed in orbit, the planned space station aims to function as a central hub for scientific research, Earth observation, and astronaut training.
• Research Platform: Serving as a testament to India's expanding prowess in space technology, it is poised to drive progress in diverse areas such as microgravity research, climate monitoring, and human spaceflight.

NISAR

• Joint Development: NISAR, the Low Earth Orbit (LEO) observatory, is a collaborative effort between NASA and ISRO.
• Size and Weight: This SUV-sized satellite boasts a weight of 2,800 kilograms.
• Dual-Frequency Radar: NISAR features both L-band and S-band synthetic aperture radar (SAR) instruments, making it a unique dual-frequency imaging radar satellite.
• Capabilities: To utilize two different radar frequencies (L-band and S-band) for monitoring and measuring changes in the Earth's surface.

International Space Station (ISS):

• It is the largest modular space station in low Earth orbit. The project involves five space agencies:

oThe US' NASA, Russia's Roscosmos, Japan's JAXA, Europe's ESA, and Canada's CSA. It orbits Earth approximately every 90 minutes, at an altitude of around 400 kilometers.