Out of the 104 satellites, only 3 were Indian. The rest 101 satellites belonged to USA, Netherlands, Israel, Switzerland, and Kazakhstan.
Of them, ISRO’s Cartosat 2 was the heaviest with a mass of 714 Kgs. The remaining 103 satellites were nano satellite and together they weighed 666 kgs.
The reason for this is that nano satellites are small in size and relatively cheap to build in launch. They are usually piggybacked on missions with larger satellites.
To put that in perspective, majority of the satellites were of a U.S based company Planet (88 satellite) and their dimensions are just 30x10x10 cm. They each weigh around 4.5kgs.
The satellites were launched by ISRO’s PSLV and this was its 39th mission. India's 3 satellites- the largest Cartosat 2 and 2 nano satellites were launched first axially at a height of 505 kms.
The next 81 were launched radially away from the vehicle at different angles.
Axially means along the body of the vehicle whereas radial means along the circumference.
After these were cleared, remaining 20 satellites were launched.
The entire mission was of 28 minutes, with the first satellite launched at the 17th minute and the remaining following soon after that.
It was a significant achievement for ISRO. The previous record for the most number of satellites launched in a single launch was 37 and was made by the Russian space agency in 2014.
Source: Quora
