SpaDeX Mission Lifts Off: ISRO Is Sending Spinach, Its First Biological Payload, To Space For Special Study

ISRO launched SpaDeX, an ambitious mission to demonstrate orbital docking capabilities. The mission aims to dock two satellites (SDX01, SDX02) and validate power transfer and payload operations post-docking.

SpaDeX Mission Lifts Off: The Indian Space Research Organisation (ISRO) on Monday launched its ambitious Space Docking Experiment (SpaDeX) onboard a PSLV-C60 rocket from the first launch pad at Sriharikota on Monday. The lift-off, initially scheduled for 9:58 pm, was rescheduled to 10 pm without specifying the reason for the delay. The experiment involves sending a spinach callus to space to study how plants behave in microgravity.

ISRO officials confirmed that the two spacecraft—Spacecraft A (SDX01) and Spacecraft B (SDX02)—separated successfully and were placed into their desired orbit of 475 km above Earth after over 15 minutes of flight. M. Jayakumar, Mission Director, confirmed that the PSLV-C60 mission had successfully placed the spacecraft in the right orbit.

The SpaDeX mission, hailed as a key milestone in India's space programme, aims to establish the country's capability in orbital docking, a critical technology for human spaceflight, satellite servicing, and future missions such as the Gaganyaan programme and establishment of the Bharatiya Antariksh Station -- India's own space station by 2035.

ISRO Chairman Dr. S. Somanath praised the achievement, stating, "The rocket has placed the satellites in the right orbit... the SpaDeX satellites have moved one behind the other, and over time, they will travel about 20 km apart before starting the rendezvous and docking process." He added that the docking is expected to occur around January 7.

The mission is a precursor to India’s ambitions in space, with SpaDeX marking a crucial milestone in mastering space docking technology, essential for satellite servicing and interplanetary missions. "This technology will also support future missions such as Chandrayaan-4 and the Bharatiya Antariksh Station," Dr. Somanath noted, as quoted by news agency ANI.

POEM-4—an experimental module—also carried 24 payloads from startups, academic institutions, and ISRO centres. These payloads are expected to be deployed later in the night, contributing to various scientific experiments.

The PSLV-C60 rocket, standing at 44.5 metres tall, carried the two 220-kg spacecraft, which will work in tandem for the docking process. The spacecraft, named Chaser (SDX01) and Target (SDX02), will travel together at the same speed and distance, and after a series of manoeuvres, will merge at an altitude of around 470 km.

These satellites, placed 5 km apart initially, will be manoeuvred to a separation of just 3 metres before merging to form a single unit. This intricate process will be attempted 10-14 days after the lift-off.  

In addition to SpaDeX, ISRO will also conduct the PSLV Orbital Experimental Module-4 (POEM-4) experiment, featuring 24 payloads from ISRO, industry, and academia. These payloads, utilising the PSLV's fourth stage, will remain operational for three to four months, exploring the microgravity environment in orbit.  

Former DRDO scientist and Director General for Amity Directorate of Science and Innovation, Dr W Selvamurthy, informed about ISRO's launch featuring the first biological payload in orbit, "Today, ISRO is launching the PSLV C-60 rocket with satellites as part of a very important space mission. The first biological payload in this mission is being sent by Amity University, Mumbai. The mission aims to explore providing fresh food to astronauts in space to meet their nutritional needs."

"The experiment involves sending a spinach callus to space to study how plants behave in microgravity, focusing on growth and plant physiology. This research will help identify challenges in growing vegetables in space," he told news agency PTI.

Union MoS Jitendra Singh Details Complexity Of SpaDeX

Jitendra Singh, Union Minister of State (Independent Charge) for Science and Technology, on Saturday spoke about the mission. "ISRO's year-end mission is going to be a historic one as it will seek the rare feat of docking or merging or joining together two satellites in space," he said, as quoted by news agency IANS. He added that the indigenous technology for this mission is named the "Bharatiya Docking System".  

The Union MoS highlighted the mission's complexity, stating, "ISRO will attempt to dock two satellites orbiting at speeds of 28,800 km/h, reducing their relative velocities to a mere 0.036 km/h." The experiment also includes validating power transfer between docked spacecraft and operating payloads post-undocking, with the satellites expected to have a two-year operational lifespan.  

SpaDeX's primary payloads include a high-resolution camera on SDX01 and a miniature multispectral payload along with a radiation monitor on SDX02. These will support applications such as resource monitoring and vegetation studies.  

Once successful, India will join an elite group of nations—the US, Russia, and China—that have mastered in-space docking technology. "SpaDEX will mark a milestone, showcasing India's expertise in spacecraft docking technology," Jitendra Singh had noted, emphasising its importance for future missions, including Chandrayaan-4 and the Gaganyaan human spaceflight mission slated for 2026.  

The PSLV-C60 mission, ISRO's last for 2024, also represents a technological leap as the first vehicle integrated up to the fourth stage at the newly established PSLV Integration Facility.