Evolution of Gaganyaan:  What can happen to astronauts in space?

During interplanetary trips, astronauts can experience 16 sunrises and sunsets in 24 hours. This disrupts the circadian rhythm and their sleep patterns. (Representational photo by Mikhail Nilov via Pexels)

Indian Space Research Organization (ISRO) successfully launched the TV-D1 unmanned test mission from the Sriharikota launch pad on October 21, 2023. Launching a human crew into an orbit of 400 km and safely landing them in Indian sea waters is a goal of the Gaganyaan project, which aims to showcase ISRO's human spaceflight capacity.

Human spaceflight from India is scheduled for later in 2024, and the crew module (CM) that will transport them is now undergoing testing as part of the Test Vehicle Development Flight (TV-D1). For the TV-D1 test mission, an unmanned crew module was launched into orbit, brought back to Earth, and recovered in the Bay of Bengal.

Beginning of Gaganyaan project

India's space program is well-established and impressive. In 2014, India's Mars Mission successfully launched a satellite into Mars orbit at a fraction of the cost that NASA incurred to deliver the Maven spacecraft to the red planet. India is beginning the Gaganyaan project, which will likely be the next major success story in our space program, using information acquired from earlier space flights.

ISRO has come a long way since its humble beginnings with the launch of a single sound rocket in 1963 and is now actively preparing for human spaceflight. ISRO's Chandrayaan-2 mission, launched with the Mars mission on July 22, 2019, is now in lunar orbit. The spacecraft has already taken pictures of the Moon and Earth, which have been made public.

What is that Ku-band transponder?

Ku-band transponder capacity in Geostationary Orbit has increased, per ISRO claims. The frequency range known as the Ku-band (German: "Kurz-unten") consists of electromagnetic waves between 12 and 18 GHz. The GSAT-31's primary function is to facilitate satellite communications, which is why this band of the electromagnetic spectrum is so heavily exploited. With a geostationary satellite, India can enjoy increased Ku-band capacity since it orbits the Earth once every 24 hours.

A geostationary orbit is a 23-hour, 56-minute circle around Earth that matches its rotation. ISRO's primary mission has been, and continues to be, the successful application of space technology for national development. There are more plans in the future besides the Gaganyaan manned space travel mission.

What kind of physiological changes would happen?

Naturally, everyone's thoughts are occupied by such a difficult task. A lot of work goes into a mission like Gaganyaan, more than getting the spaceship into orbit and piloting it. In addition to the many physiological changes astronauts would experience, there are social, cultural, psychological, and mental health considerations are unique to interplanetary missions. Exposure to microgravity reduces performance and increases potential operational and health concerns during space travel to unexplored regions.

Sleep and Circadian Rhythms for Space Mission

It is well-established that people sleep differently in harsh conditions. The microgravity environment disrupts sleep and circadian rhythms during manned space travel missions. Humans' natural sleep patterns, regulated by the Earth's 24-hour rotation, are disrupted during interplanetary trips. There are 16 sunrises and sunsets for astronauts to experience in 24 hours, although they are still on Greenwich Mean Time (GMT).

Several considerations must be made when operating in space. Long periods of isolation and confinement (physical restrictions) are experienced by humans, for instance, during space travel. In addition to the effects of microgravity and other biological factors, the mission crew is also profoundly affected by intense environmental stimulus [i.e., an altered photoperiod or the rapid transition of the light/dark (LD) cycle and noise] in a unique and extreme environment, which leads to circadian dysregulation and other disturbances.

What are the other physiological factors?

Other physiological factors include:

- Motion sickness

- Awkward positions

- Varying levels of physical exertion

- The need to urinate

- Overexcitement (like seizing a once-in-a-lifetime opportunity)

- Issues with interpersonal relationships among crew members.

- Long durations of forced awake, operational pressures (such as an extended or irregular sleep-wake and work schedule), and other general malaise may also contribute to sleepiness, drowsiness, and impaired psychomotor function in space.

Adverse effects on sleep quality, mental clarity, mood, neurobehavioral function, critical thinking, and the ability to make sound decisions are only a few of the many consequences of these issues. The fact that there are differences before, during, and after a flight indicates the need for more study. A crew member's sleep/wake and work/rest patterns drastically differ from what one would experience on Earth.

What had happened to astronauts earlier?

Astronauts are susceptible to the adverse effects of sleep deprivation, poor sleep quality, insomnia, exhaustion, and decreased alertness. For a restful night's sleep, they must ensure a conducive physical (temperature, artificial lighting, airflow, noise, carbon dioxide) and social (positive crew interactions) setting. Space travel can have its own set of medical complications.

Conclusion

ISRO has just launched the test flight of the TV-D1 successfully. The Gaganyaan program, which intends to put humans into a Low Earth Orbit of 400 km for three days before returning them safely to Earth, is the successor of the test vehicle mission. Gaganyaan, India's planned human spaceflight demonstration mission, is set to take off in 2024. By 2035, the country plans to have a space station in operation and is also developing a Venus orbiter and a Mars lander.