Building India's first solar spacecraft: Why the Aditya-L1 site was a no-perfume zone

In the quest to unlock the Sun's mysteries, the team behind India's Aditya-L1 mission took extraordinary measures to maintain the utmost precision. The Indian Institute of Astrophysics (IIA), responsible for building Aditya's main payload, the Visible Emission Line Coronagraph (VELC), left no room for error, even when it came to personal grooming choices.

The core of VELC operations was the state-of-the-art vibration and thermotech facility located in Hoskote near Bengaluru. Here, the team conducted component-level vibrations, a crucial step in integrating detectors and optical elements.

Ahead of this integration, a meticulous calibration process unfolded within a pristine cleanroom. Inside this controlled environment, the dedicated team, donned in futuristic explorer-like suits, took precautions against electrostatic discharge and contamination. To maintain the pristine conditions, the use of perfumes was strictly prohibited, and every single screw underwent ultrasonic cleaning.


These suits acted as protective shields for the sensitive sensors and optics, while the cleanroom itself was deemed a "sanctuary." Nagabushana S, the head of the VELC technical team, told TOI, emphasizing the critical cleanliness standards, stating, "It (the cleanroom) had to be kept 1-lakh times cleaner than a hospital ICU."

To achieve this, the team utilized HEPA (high-efficiency particulate air) filters, 99% concentrated isopropyl alcohol, and stringent protocols to prevent foreign particles from causing any disruptions. Even medicinal sprays were avoided, as a single particle discharge could have undone days of painstaking work.

TOI spoke with several ISRO scientists experienced in working within cleanrooms for various satellite projects. While acknowledging the importance of maintaining pristine conditions, none of them had gone to the extent of forgoing perfumes. One scientist suggested that perhaps the IIA scientists were taking extra precautions due to the sensitivity of their mission.

India's first-ever space expedition to study the Sun, the Aditya-L1 blasted off at 11:50 am on Saturday from the Satish Dhawan Space Centre (SDSC-SHAR) in Andhra Pradesh's Sriharikota. "Launch successful, all normal," an Indian Space Research Organisation (ISRO) official announced from mission control as the vessel made its way to the upper reaches of the Earth's atmosphere.