Context:

On June 10, Axiom Space announced the indefinite postponement of its Axiom-4 (Ax-4) mission to the International Space Station (ISS). The crew included India’s astronaut-designate Shubhanshu Shukla, who would have become the first Indian in Earth orbit in 40 years and the first to visit the ISS.

About Axiom-4 Mission:

The Ax-4 mission is the fourth planned crewed mission to the ISS by Axiom Space, a private U.S.-based aerospace company. It is a commercial mission, distinct from NASA’s regular ISS operations. The four-member crew includes:

·        Peggy Whitson (Commander) – Former NASA astronaut

·        Shubhanshu Shukla (Pilot) – Indian Air Force officer, selected for India’s Gaganyaan mission

·        Sławosz Uznański-Wiśniewski – Representing Poland

·        Tobir Kapu – Representing Hungary

Axiom Space contracted SpaceX for launch services using the Falcon 9 rocket and Dragon crew capsule.

What Will the Mission Do?

The crew will spend approximately 14 days on the ISS conducting scientific, educational, and commercial experiments. Highlights include:

·        Diabetes Research – Studying how diabetic individuals can safely participate in space missions.

·        Cyanobacteria Study – Investigating microgravity’s effects on photosynthetic bacteria for use in life-support systems

·        Zero-G Indicator – A swan plushie named Joy, representing resilience and shared wisdom across India, Hungary, and Poland.

Significance for India:

The mission reflects ISRO-NASA collaboration. ISRO contributed about 10 experiments, including:

·        Microgravity’s impact on muscle performance

·        Cognitive changes linked to screen exposure in space

·        Growth behavior of six crop seed varieties in space

·        Tardigrade experiments to study survival in extreme space conditions

These studies were initially planned for India’s Gaganyaan mission, now expected in 2027. Ax-4 provides critical data to refine India’s human spaceflight capabilities.

Why Was the Launch Delayed?

• A technical issue was detected during pre-launch checks: a liquid oxygen (LOX) leak in one of the Falcon 9 engines. LOX, a cryogenic oxidizer essential for combustion, poses serious risks if it leaks, as it can affect thrust generation.
• Originally scheduled for May 29, the mission had faced several delays due to technical problems and weather. June 12 was the final backup date before the indefinite hold.

Understanding the LOX Leak Issue:

LOX is stored at ~90 K (-183°C) and vaporizes quickly at room temperature, making detection difficult. Compounding the issue, engine components are insulated or enclosed.
Repairing such leaks involves:

·        Thermal Contraction – Joints may seal at ambient temperatures but leak when cold

·         Complex Testing – Involves proxies like liquid nitrogen, ultrasonic detection, thermal imaging, and helium leak tests

·        Safety Protocols – Direct LOX testing is risky and minimized when possible