Consider the following space missions:

How many of the space missions given above encourage and support microgravity research?

(a) Only one

(b) Only two

(c) All the three

(d) None

Answer: (c) All the three

Explanation:

Microgravity research explores how physical, chemical, and biological systems behave when gravity is extremely weak, as in space. This knowledge is vital for human health in space, materials science, agriculture beyond Earth, and planning future exploration missions.

Option I Axiom‑4 Mission (Ax‑4)

The Axiom‑4 (Ax‑4) mission is a major international human spaceflight initiative involving Axiom Space, NASA, ESA, and ISRO. It launched a crew to the International Space Station (ISS) in June 2025 and included Indian Air Force test pilot Group Captain Shubhanshu Shukla as part of the crew.

• Ax‑4 conducts extensive microgravity research aboard the ISS, with around 60 scientific studies from 31 countries, covering biology, human physiology, materials, and life sciences in low‑gravity conditions.

• Indian‑led experiments onboard include studies on:

  • Muscle regeneration to understand muscle atrophy in space.

  • Growth of microalgae and crop seeds, including moong and methi, for future space agriculture and crew nutrition.

  • Tardigrade survival and biological resilience in space.

  • Human interaction with electronic displays in microgravity.

  • These experiments support deeper understanding of human health, biology, and life‑support concepts for longer missions.

These make Ax‑4 a significant contributor to microgravity research infrastructure and data.

Option II Space Docking Experiment (SpaDeX) with POEM‑4

The Space Docking Experiment (SpaDeX) mission by ISRO primarily aims to demonstrate in‑orbit rendezvous, docking, and undocking technologies between two spacecraft — crucial for future station building, satellite servicing, and deep‑space missions.

• SpaDeX itself is not a dedicated microgravity science mission, but it carries the PSLV Orbital Experimental Module‑4 (POEM‑4) — the repurposed spent fourth stage of a PSLV launch.

• POEM‑4 serves as a microgravity research platform, hosting 24 payloads from ISRO and academic institutions. These include:

  • Plant growth studies, such as seed germination and early plant growth in microgravity.

  • Radiation environment monitoring and biological responses due to space conditions.

  • Robotics and sensor experiments, which contribute additional science data under microgravity conditions.

Thus, while SpaDeX’s core objective is docking technology demonstration, the POEM‑4 payloads meaningfully support microgravity research by providing a platform for scientific experiments in orbit.

Option III Gaganyaan Mission

Gaganyaan is India’s ambitious indigenous human spaceflight programme aimed at sending a crew into low‑Earth orbit aboard an Indian spacecraft.

• The mission plans include scientific experiments related to microgravity, with biological and physical science studies designed to explore how living organisms and materials behave in space. ﹘ For example, earlier planning documents listed biological experiments like kidney stone and genetic marker studies in Drosophila, fluid physics experiments, and other investigations relevant to human health and microgravity science.

• Even uncrewed precursor missions like G1 with the humanoid robot Vyommitra are designed to test life‑support and microgravity systems, providing insights that can feed into microgravity research on future crewed flights.

While space microgravity science on Gaganyaan may be less extensive than on Ax‑4, microgravity experiments are part of the mission’s science objectives and preparatory studies to support future long‑duration human missions.

Answer: (c) All the three