Astronomy & Space Technology

Context: The Axiom-4 Mission to the International Space Station (ISS) was launched on June 25, 2025 to conduct scientific research, outreach and commercial activities in space. Shubhanshu Shukla, an Indian Air Force (IAF) officer and ISRO astronaut piloted the Mission.

Relevance of the Topic: Prelims: Key facts about Axiom-4 Mission; ISRO’s Experiments in Axiom-4 Mission.

Axiom-4 Mission is a private spaceflight organised by Axiom Space. The crew will spend about 14 days aboard the International Space Station (ISS) and conduct various experiments in the microgravity environment. 

Key ISRO’s Experiments in Axiom-4 Mission

1. Myogenesis Study:

• Shukla performed operations in Life Sciences Glovebox (LSG) for the Myogenesis study.
• Aim: To uncover the molecular mechanisms driving muscle loss in space.
• Significance: These findings could also pave the way for:
  • Targeted treatments to prevent muscle atrophy during prolonged space missions. 
  • New therapies to address muscle-wasting conditions on Earth such as those related to ageing or immobility.

2. Growing Sprouts and Moong Beans: 

• The Sprouts-ISRO experiment focuses on the growth of green gram (moong) and fenugreek (methi) seeds in space. These are staple, nutrient-rich foods in India. 
• Aim: To study how microgravity affects their germination, genetics, and nutritional content. 
• Significance: Understanding these changes can help in:
  • Developing reliable plant-based food systems for future space missions. 
  • Supporting agricultural advancements on Earth, particularly in resource-constrained or extreme environments where conventional farming is difficult. 

3. Microalgae Experiment:  

• Aim: To study how Microalgae grow and evolve in the absence of gravity. 
• Microalgae are highly efficient organisms known for producing oxygen, absorbing carbon dioxide, and providing dense nutrition. 
• Significance:
  • If successful, microalgae could become a sustainable food source for long-duration space missions. 
  • Open up possibilities for using them in Earth-based environmental and food solutions, especially in areas with limited access to resources. 

4. Survival of Tardigrades in Space:

• The Voyager Tardigrade-ISRO experiment aims to observe how tardigrades survive and reproduce in extreme space conditions and compare their gene expression with Earth-based samples. 
• Tardigrades are tiny aquatic creatures that can survive radiation, vacuum, and freezing temperatures.
• Significance: The research will decode the biology behind their resilience, which could lead to innovations in radiation protection for astronauts, and even new materials or therapies for use in harsh environments on Earth.

5. Human interaction with Technology in Microgravity: 

• Voyager Displays-ISRO explores how spaceflight alters human interaction with electronic interfaces like touchscreens. Tasks involving gaze, touch, and eye movement will be analysed to understand cognitive and motor changes caused by microgravity. 
• Significance: 
  • To improve the design of control systems for spacecraft and future space habitats.
  • The results may also benefit high-stress environments on Earth, such as aviation or emergency response, where quick, intuitive interaction with digital systems is crucial for safety and performance.

6. Cerebral Hemodynamics Study:

• Using Ultrasound technology, ISRO and NASA will explore how blood circulates in the brain under microgravity conditions. 
• Significance: The findings could improve our understanding of cardiovascular adaptation in space and inform medical diagnostics and treatments for conditions like stroke and hypertension on Earth.

The experience gained through the experiments is expected to nurture a microgravity research ecosystem in India resulting in the induction of advanced microgravity experiments in various disciplines in the Indian space programme.

Also Read: Indian Astronaut to pilot Axiom Mission 4 

Context: The Vera C. Rubin Observatory is set to become fully operational by the end of 2025.

Relevance of the Topic: Prelims: Key facts about Vera C. Rubin Observatory. 

About Vera C. Rubin Observatory: 

• Formerly known as the Large Synoptic Survey Telescope (LSST), it is a large astronomical observatory designed to conduct a ten-year survey of the entire visible southern sky. 
• Location: 8,684 feet above sea level on Cerro Pachón mountain in Chile. 
• It is named after Vera C. Rubin who provided the first evidence of dark matter in the 1970s.
• It is a joint project of the US National Science Foundation (NSF) and the US Department of Energy's Office of Science.

Key Features: 

The centerpiece of the Rubin Observatory is the Simonyi Survey Telescope. This device is unique for three main reasons: 

• Wide Field of View: 
  • Most telescopes observe only tiny portions of the sky (E.g., Hubble sees just 1% of the full Moon’s disc).
  • The Simonyi Survey telescope can observe an area equivalent to 40 full moons at once, due to its distinct design comprising three differently curved mirrors.

• Largest Digital Camera: 
  • The telescope has the world's largest digital camera, which is the size of a small car, weighs 2,800 kg, and boasts a staggering resolution of 3,200 megapixels. 
  • It can detect objects 100 million times dimmer than visible to the naked eye.
  • The camera has six filters designed to capture light from different parts of the electromagnetic spectrum. This will help astronomers gather information about various celestial objects based on the type of light they emit. 

• Fastest-Slewing Telescope:
  • The Simonyi Survey Telescope is the fastest-slewing telescope in the world, and takes just five seconds to move and settle from one target to another.
  • This speed is due to the telescope’s compact structure (owing to the three-mirror design), and its mount which floats on a film of oil.
  • Such speed will allow the telescope to snap up to 1,000 images a night, meaning it can capture the whole sky in just three days. 

Why is Rubin Observatory Revolutionary?

• The Vera Rubin Observatory will constantly scan the sky of the southern hemisphere for 10 years, this continuous scanning helps detect even small or sudden changes in the universe.
• It captures 20 terabytes of data each night. This massive data pool will help solve some of the biggest mysteries of the universe, and discover numerous celestial objects such as comets and asteroids.
• It took 225 years of astronomical observations to detect the first 1.5 million asteroids, Rubin will double that number in less than a year.
• On June 23, when the first test images of the observatory were released, astronomers at the Rubin Observatory said that its software had identified 2,104 brand-new asteroids- including seven near-Earth objects with merely 10 hours of engineering data.

The observatory will expand our knowledge about the nature of dark matter and dark energy. While galaxies, stars, and planets make up 5% of the universe, dark energy makes up about 68%, and dark matter about 27%. 

Context: China is about to launch a space mission called Tianwen-2 to explore a small asteroid named Kamo‘oalewa. 

Relevance of the Topic: Prelims: Key facts related to Tianwen-2 Mission.

Tianwen-2 Mission: 

• Tianwen-2 aims to explore a near Earth asteroid named Kamo‘oalewa. 
• The mission will use touch-and-go technique, which has been successfully implemented by the United States’ OSIRIS-Rex and Japan’s Hayabusa2 missions. In touch-and-go technique, the spacecraft hovers close to the surface of the asteroid, while a robotic arm fires an object or burst of gas to knock fragments into a collection chamber. 
• Depending on the surface conditions, the Tianwen-2 probe might also use anchor and attach technique. In this technique, four robotic arms extend and drill into the surface to retrieve material.  
• After collecting the samples, the mission will drop them on Earth. The probe will then head towards the main asteroid belt for another mission (towards comet 311P/PANSTARRS). The fragments collected by Tianwen-2 will return to Earth about 2.5 years after the launch.
• If successful, China will join the US and Japan as the third country to bring back asteroid samples to Earth. 

Kamo‘oalewa Asteroid:

• It is a near-Earth asteroid discovered in 2016 by the Pan-STARRS 1 telescope in Hawaii. It is quite small, measuring just 40 to 100 metres in diameter. 
• It belongs to a rare class called quasi-satellites- celestial bodies that orbit the Sun but remain gravitationally close to Earth.  
• It appears to follow Earth’s orbit in a "leading and trailing" motion due to its highly elliptical path. This gives the impression the asteroid orbits Earth.

Significance of the Mission

• Kamo‘oalewa has garnered attention due to its unusual orbit and unknown origin. Scientists believe exploring this asteroid would help them find clues about quasi-satellites, and how their orbits evolved over time. 
• Some researchers suggest that Kamo‘oalewa could be the first known asteroid composed of lunar material. The exploration of the asteroid could settle the hypothesis that the Moon was formed as a result of a collision between the Earth and another small planet (Kamo‘oalewa could be a small remnant of that collision).

Context: The Indian Space Research Organisation (ISRO) could not complete its 101st satellite launch mission, PSLV-C61/EOS-09, due to a technical glitch.

Relevance of the Topic: Prelims: Key facts about PSLV-C61 Mission; PSLV. 

ISRO’s 101st satellite launch mission

• PSLV-C61 rocket was carrying the Earth Observation Satellite (EOS-09). However, a few minutes after the liftoff, the rocket suffered an issue in its third stage and the PSLV-C61 mission ended in a failure. (The chamber pressure in the casing that contained the third-stage motor fell during the flight)
• The 1,700-kg Earth observation satellite was intended to be placed at an altitude of about 597 km in a sun-synchronous polar orbit (the satellite was to pass over a given place at the same time every day).
• The EOS-09 satellite carried a Synthetic Aperture Radar (SAR) payload, capable of providing images of the Earth in all weather conditions. It was designed to produce high-quality radar images for civilian applications (such as land-use mapping and hydrology studies) and also for defence surveillance. 

ISRO will assess the reasons for the loss of pressure and subsequently reattempt the mission EOS-09.

Polar Satellite Launch Vehicle (PSLV)

• PSLV is an expendable launch vehicle developed and operated by ISRO since its first successful launch in 1994. 
• ​​Workhorse of ISRO known for its reliability, versatility, and cost-effectiveness since 1994.
• Stages: Four-stages launch vehicle
  • First stage is powered by a solid rocket motor (burns hydroxyl-terminated polybutadiene-bound (HTPB) propellant)
  • Second stage uses a liquid propulsion system (Vikas Engine which uses unsymmetrical dimethylhydrazine as fuel and nitrogen tetroxide as oxidiser)
  • Third stage is a solid rocket motor that provides the upper stages high thrust after the atmospheric phase of the launch (burns HTPB propellant)
  • Fourth stage is a liquid-fueled engine (burns a combination of monomethylhydrazine and mixed oxides of nitrogen in two engines.
• PSLV can deliver payloads of up to: 
  • 3250 kg to Low Earth Orbit 
  • 1600 kg to Sun Synchronous Orbit 
  • 1400 kg to Geosynchronous Transfer Orbit 
• Successful launches: Chandrayaan-1 Mission (2008), Mars Orbiter Mission/Mangalyaan (2013), 104 satellites at one go (2017). 
• It has been used for launching a wide range of payloads, including Earth Observation satellites, Navigation satellites, Communication satellites, and scientific payloads for various domestic and international customers. 
• Success rate: Since their introduction in the 1990s, the PSLV rockets have only failed thrice- the first during the inaugural flight in 1993, once in 2017 and the latest in 2025.  

Also Read: ISRO’s Satellite Launch Vehicles