The Indian Space Research Organisation successfully launched a record 104 satellites in one mission from Satish Dhawan Space Centre, Sriharikota by relying on its workhorse Polar Satellite Launch Vehicle rocket (PSLV). The name of rocket was PSLV C-37.

The satellites launched
1.    An earth observation Cartosat-2 series satellite and two other nano satellites were the only Indian satellites launched: the remaining were from the United States, Israel, the UAE, the Netherlands,   Kazakhstan and Switzerland. 

2.    Of the 101 foreign satellites launched, 96 were from the U.S. and one each from the other five countries. 

Previous records of multiple satellite launches
Till now Russia held the record of launching 37 satellites in a single mission, in 2014, while the National Aeronautics and Space Administration of the U.S. launched 29 satellites in one go in 2013. Last June, ISRO had come close to NASA’s record by launching 20 satellites in one mission. 

Significance of the launch
ISRO views the launch not as a mission to set a world record but as an opportunity to make full use of the capacity of the launch vehicle. The launch is particularly significant as ISRO now cements its position as a key player in the lucrative commercial space launch market by providing a cheaper yet highly reliable alternative. 

Details of the mission
1. At an orbital altitude of around 500 km, the vehicle takes about 90 minutes to complete one orbit. Though ISRO had sufficient time to put the satellites into orbit, it accomplished the task in about 12 minutes. Total payload of the mission is about 1500 kgs.

2. With the focus on ensuring that no two satellites collided with each other, the satellites were injected in pairs in opposite directions. Successive pairs of satellites were launched once the vehicle rotated by a few degrees, thereby changing the separation angle and time of separation to prevent any collision.

About Nano satellites
Besides setting the record for the most number of satellites launched in a single mission, the Indian space agency has launched two nano satellites weighing less than 10 kg , INS-1A and INS-1B, each weighing about 10 kg. They have a short lifespan of six to 12 months.

It is a technology demonstrator for a new class of satellites called ISRO nano satellites (INS). The main objective of the INS is to provide a platform on which payloads up to 5 kg from universities and R&D laboratories. 

Cartosat-2 Series
The main purpose of Mission PSLV-C37 is to put in space the fifth satellite in the fleet of the country’s high-resolution Earth observation spacecraft.The Cartosat-2 series is often said to be ISRO’s open secret for the military and the sharp-seeing eyes that keep vigil over the country.

The space agency literally averts its eyes whenever it is asked about it. The spacecraft’s cameras are said to have a resolution of 60 cm, if not better; it means they can spot any object or person, stationary or moving on ground and sized less than 1 metre. This is a key requisite for the security forces.

Four spacecrafts have been launched in the Cartosat-2 series since the first was put in orbit 10 years ago. ISRO said the new Cartosat-2A, when it starts working over the coming weeks, would detect changes in land use in cities, villages, coasts and farms, besides monitoring roads and water resources.

88 cubesats part of American satellites
The 88 cubesats are part of Planet’s earth observation constellation of 100 satellites. They weigh around 5 kg each and are called ‘Doves’ or Flock 3p.

For US based company Planet, it will be the record largest number of cubesats to be flown in a single launch, according to one of its executives.

What is Planet?
Planet, an earth observation company formed in 2010 by former NASA scientists, has chosen ISRO’s PSLV launch for the second time. It got its earlier set of 12 ‘Doves’ launched in June last year.

Combined with the 12 satellites of Flock 2p operating in a similar orbit, this launch will enable Planet’s 100-satellite ‘line scanner’ constellation of Doves.