By Air Marshal Anil Chopra (Retd)
Bangalore. Group Captain Shubhanshu Shukla ‘Shux’, the second Indian in space, is back after record-setting space mission. The four astronauts, Shukla and his crewmates, Commander Peggy Whitson (USA), Slawosz Uznanski (Poland), and Tibor Kapu (Hungary) splashed down in the Pacific Ocean off the coast of California, concluding the his trailblazing 18-day Axiom-4 (Ax-4) space mission.
At re-entry, capsule “Dragon” hurtled down into Earth’s atmosphere at around 27,000 km/h, the final splashdown marked the end of a nearly 22-hour return journey after the spacecraft undocked from the International Space Station (ISS). The mission, a collaboration between NASA, SpaceX, and Indian Space Research Organisation (ISRO), was intended to strengthen international spaceflight cooperation.
SpaceX served as the launch provider that successfully launched the mission from Launch Complex 39A at NASA’s Kennedy Space Centre in Florida. The mission successfully lifted off from on 25 June 2025 at 06:31 UTC. It docked with the ISS on 26 June 2025 at 10:31 UTC. Shukla entered ISS at 12:14 UTC. A few minutes past 14:00 UTC, a formal welcome ceremony for the Ax-4 visiting crew took place, during which Whitson gave Shukla an astronaut pin, as the 634th person to reach space.
Shukla’s multi-nation collaborative mission is a significant leap forward in India’s human spaceflight journey and would help better visualisation of country’s upcoming Gaganyaan mission. Shux is the first Indian to live aboard the ISS and only the second Indian to travel into space after Rakesh Sharma’s 1984 mission aboard the erstwhile Soviet Union’s Soyuz T-11 spacecraft.
The Soviet-led mission was more of a diplomatic gesture with limited immediate technological impact for India. But it was a good beginning and a big morale booster for Indians.
This time, ISRO invested nearly Rs 550 crore (US$65 million) for Shukla’s Ax-4 flight. Shukla’s professionalism and dignified representation of India in space drew widespread attention and national pride. Commander Peggy Whitson praised his professionalism and adaptability on the maiden spaceflight. Shukla and the crew are going through detailed medical evaluations and a week-long rehabilitation program to readjust to Earth’s gravity.
Indian President Droupadi Murmu, Prime Minister Narendra Modi and the Indian Air Force congratulated Shukla on his return through messages on “X”. While onboard the ISS, Shukla participated in public outreach, including a live videoconference with PM Modi on 28 June and ham radio conversations with school students on 4 July and 8 July. On 6 July, Shukla participated in a conversation with Dr. V Narayanan, the Chairman of ISRO and other senior officials, who emphasized the importance of his experiments and activities in advancing India’s Gaganyaan human spaceflight programme.
ISRO Designated Space Experiments
During his time in orbit, Shukla took part in multiple global science experiments across fields like biology, materials science, and artificial intelligence. There were around 60 experiments, with at least seven designated by ISRO. Shukla was involved in the “Sprouts Project” studying plant growth in microgravity that shows hope for sustainable space farming. He also worked on experiments related to cellular health, in-space muscle degeneration, and autonomous robotics research, all of which could inspire learning and lessons for both future space missions and Earth-based sciences.
Great Inputs for Gaganyaan Mission
Shubhanshu’s safe return lays the foundation for India’s human spaceflight.
The Ax-4 mission allowed Indian flight surgeons, engineers, and mission planners to monitor and support an Indian astronaut in space for the first time since 1984, offering critical insight into astronaut selection, in-orbit workflows, emergency procedures, and psychological support. Hands-on ISS experience differs significantly from satellite launches or remote ground-based simulations, making Shukla’s mission an essential stepping stone. Shukla’s successful 18-day stay in orbit, his performance during critical mission phases, and his participation in advanced scientific experiments have helped Indian Gaganyaan teams gain practical understanding of microgravity, spacecraft operations, crew health monitoring, and post-mission rehabilitation.
The rehabilitation programme supervised by flight surgeons after splashdown, for example, will shape medical protocols for India’s own missions. The scientific experiments conducted by him, especially with Indian principal investigators and Indian-developed technologies, will not only benefit global research but also strengthen India’s capabilities for future space stations and lunar ambitions.
Fellow ISRO astronaut Gp Capt Prasanth Balakrishnan Nair, who was designated as the backup crew member, too underwent training at NASA’s Johnson Space Center in Houston.
Global Human Spaceflights
Human spaceflight programs prioritize the safety and well-being of astronauts and continuously advance technologies for life support, spacecraft design, and mission operations. Beyond the technological advancements, human spaceflight contributes to scientific research, expands our understanding of the universe, and inspires future generations.
The first satellites were launched in 1957 and 1958 by the Soviet Union.
Human spaceflight is the act of sending humans into space, typically involving a spacecraft operated by a human crew or remotely controlled from Earth. It encompasses various missions, from orbiting the Earth to exploring other celestial bodies. The Soviet Union’s Vostok 1 with Yuri Gagarin on 12 April 1961 marked the first human spaceflight.
On 5 May 1961, Alan Shepard became the first American in space, as part of Project Mercury, demonstrating humans’ ability to function in space for extended periods. The USSR launched the first woman in space, Valentina Tereshkova, aboard Vostok 6 on 16 June 1963.
Humans travelled to the Moon nine times between 1968 and 1972 as part of the United States’ Apollo program. In 1969, Apollo 11 landed Neil Armstrong and Buzz Aldrin on the Moon on 21 July and returning them safely on 24 July, along with Command Module pilot Michael Collins. Through 1972, a total of six Apollo missions landed 12 men to walk on the Moon, half of which drove electric powered vehicles on the surface.
The Space Shuttle started flying in 1981. A fleet of four shuttles was built: Columbia, Challenger, Discovery, and Atlantis. A fifth shuttle, Endeavour, was built to replace Challenger, which was destroyed in an unfortunate accident during launch that killed 7 astronauts on 28 January 1986.
From 1983 to 1998, twenty-two Shuttle flights carried components for a European Space Agency sortie space station called Spacelab in the Shuttle payload bay. The construction of Soviet/Russian Mir, the first modular, semi-permanent space station, took place from 1986 to 1996. Mir orbited at an altitude of 354 kilometres. It was occupied for 4,592 days and made a controlled re-entry in 2001.
End of Cold War, and US-Russia Space Cooperation
The dissolution of the Soviet Union in 1991 brought an end to the Cold War and opened the door to true cooperation between the US and Russia. The Shuttle-Mir Program included American Space Shuttles visiting the Mir space station, Russian cosmonauts flying on the Shuttle, and an American astronaut flying aboard a Soyuz spacecraft for long-duration expeditions aboard Mir. In 1993, the planned Space Station Freedom was converted into the ISS.
Construction of the station began in 1998. It orbits at an altitude of 409 kilometres. Several of the Space Shuttle’s 135 orbital flights were to help assemble, supply, and crew the ISS.
Russia has built half of the ISS and has continued its cooperation with the US. Humans have had a continuous presence in space for 24 years and 255 days on the ISS from November 2000 to the current date, July 16, 2025. As of now, humans have not travelled beyond low Earth orbit since the Apollo 17 lunar mission in December 1972.
While initially dominated by government-funded agencies like NASA and Roscosmos, human spaceflight is increasingly involving international collaboration and private companies like SpaceX.
SpaceX’s Crew Dragon, Blue Origin, and Virgin Galactic are examples of companies venturing into commercial spaceflight, offering opportunities for tourism and research. The first private human spaceflight launch was a suborbital flight on SpaceShipOne on June 21, 2004. The first commercial orbital crew launch was by SpaceX in May 2020, transporting NASA astronauts to the ISS under United States government contract. Currently, the United States, Russia, and China are the only countries with public or commercial human spaceflight-capable programs. ISRO is developing the Gaganyaan program to launch Indian astronauts into space, aiming for a 2027 launch.
Future human spaceflight endeavours include returning to the Moon under the Artemis program, establishing a lunar base, and eventually venturing towards Mars.
China’s Human Space Program
On 15 October 2003 Shenzhou 5, China’s first crewed spaceflight mission, put Chinese taikonaut Yang Liwei in orbit for 21 hours and returned safely back to Inner Mongolia, making China the third nation to launch a human into orbit independently. In 2011, China launched the Tiangong 1 target spacecraft and Shenzhou 8 uncrewed spacecraft. The two spacecraft completed China’s first automatic rendezvous and docking on 3 November 2011. About 9 months later, Tiangong 1 completed the first manual rendezvous and docking with Shenzhou 9, which also carried China’s first female astronaut Liu Yang.
In September 2016, Tiangong 2 was launched into orbit. It was a space laboratory with more advanced functions and equipment than Tiangong 1. A month later, two astronauts entered Tiangong 2 and were stationed for about 30 days, verifying the viability of astronauts’ medium-term stay in space. In April 2017, China’s first cargo spacecraft, Tianzhou 1 docked with Tiangong 2 and completed multiple in-orbit propellant refuelling tests.
The final phase of building China’s own space station “Tiangong” began in 2020. Since June 2021, there have been ten crewed missions to the Space Station, and many unscrewed ones.
The basic Chinese space station was completed on Nov. 5, 2022, and has since entered the application and development phase, which is poised to last for no less than 10 years. The Chinese space station is much smaller than the ISS with only three modules, compared with 16 modules on the ISS.
As of April 2025, a total of 26 Chinese nationals have travelled to space. In 2025, China and Pakistan signed an agreement to send the first foreign Astronaut to the Tiangong Space Station.
Commercial Private Human Spaceflights
Since the early 2000s, a variety of private spaceflight ventures have been undertaken. As of November 2024, SpaceX and Boeing have launched humans to orbit, while Blue Origin has launched 8 crewed flights, six of which crossed the Kármán line (100 km).
Virgin Galactic has launched crew to a height above 80 km on a suborbital trajectory. SpaceX, Boeing, Blue Origin, and Virgin Galactic plan to fly commercial passengers in the emerging space tourism market.
Indian Human Spaceflight Program
The Indian Human Spaceflight programme “Gaganyaan” is an ongoing programme of ISRO to develop the technology needed to launch crewed orbital spacecraft into low Earth orbit. Three uncrewed flights, named Gaganyaan-1, Gaganyaan-2 and Gaganyaan-3 are scheduled to launch in 2025 and 2026, followed by crewed flight in 2027 on a human-rating HLVM3 rocket.
Before the Gaganyaan mission announcement in August 2018, human spaceflight was not a priority for ISRO, though related technologies were developed since 2007, and it performed a Crew Module Atmospheric Re-entry Experiment and a Pad Abort Test for the mission.
In December 2018, the Indian government approved a further ₹10,000 Crore (US$1.5 billion) for a 7-day crewed flight of 2–3 astronauts. Total program cost is currently estimated to be ₹20,193 crore (US$2.4 billion).
When completed successfully, India will become the fourth nation to conduct independent human spaceflight after the Soviet Union, United States, and China. After conducting the first crewed spaceflights, ISRO intends to start a space station programme, crewed lunar landings, and crewed interplanetary missions in the long term.
The first phase of this programme is to develop and fly the 3.7-ton spacecraft called Gaganyaan with the capacity to carry a 3-member crew in low Earth orbit and safely return to Earth after a mission duration of a few orbits in two days. The extendable version of the spaceship will allow flights up to seven days, rendezvous and docking capability.
In the next phase, enhancements will lead to the development of a small habitat, allowing spaceflight duration of 30 to 40 days in one single mission. Further advances based on experience will subsequently lead to development of a bigger space station.
On July 5, 2018, ISRO successfully conducted the critical “crew bailout test” called the ISRO Pad Abort Test to see how fast and effectively the crew module could be released safely in the event of an emergency. Multiple in-flight abort tests are being carried out.
ISRO is targeting more than 99.8 percent reliability for its crew escape system. ISRO plans to launch its crewed orbiter Gaganyaan atop the Launch Vehicle Mark 3 (LVM3). The capsule would return for a splashdown in the Arabian Sea near the Gujarat coastline. The design of the crew module is complete. The spacecraft will be flown twice uncrewed for validation before conducting actual human spaceflight.
The spacecraft will carry one crew in its maiden crewed mission to an orbit of 400 km. The first uncrewed flight will involve the launch of a 5,000 kg module which, after orbiting will re-enter the atmosphere and decelerate at an altitude of 7 km (4.3 mi) before splash down.
India’s Human Space Flight Centre, a proposed 140 acres facility near Kempegowda International Airport in Devanahalli, Karnataka is being created in Bengaluru for training astronauts.
The ₹1,000 crore (US$118.3 million) centre will train the selected astronauts in rescue and recovery operations, operations in a zero-gravity environment, and monitoring of the radiation environment. A dedicated campus has been planned. The facility will include offices, housing, testing and integration facilities and will also employ a workforce of 1,000 people in the long term.
India plans to deploy Bharatiya Antariksha Station, a 52-tonne space station, as a follow-up program to the Gaganyaan missions. Final approval is expected to be given to the program by the Indian government only after the completion of the Gaganyaan missions. ISRO is working to develop spacecraft docking and berthing technology.
A Space Docking Experiment, or SPADEX, is under development. ISRO has plans for first space station module in 2028 and complete the station by 2035.
