Isro launch: Here's everything you need to know about the 20 satellites

The details on the 20 satellites that ISRO launched with the PSLV-C34.

Isro just launched a record setting 20 satellites on the Polar Satellite Launch Vehicle rocket, which has a flawless, two decade long record. The launch took place from the Satish Dhawan Space Centre in Sriharikota. The nation followed the launch, and the Prime Minister and President sent out congratulatory tweets to Isro.

The payload was 20 satellites from all around the world. Satellites from Germany, Canada, USA and Indonesia shared space with three Indian satellites. The total weight of all twenty satellites on board was 1,288 kg. The heaviest passenger was the Cartosat-2 weighing in at 727.5 kg. All the twenty satellites were housed in a heat shield, two halves of which closed.

Isro launch: Heres everything you need to know about the 20 satellites

The satellites integrated with the PSLV-C34. The heat shield can also be seen. Image: ISRO

Below is a cross-section view of how the satellites were placed inside the launch vehicle. The primary satellite was on the top. There were three clusters of four Dove satellites each on the bottom. The rest sat in the middle.

Image: ISRO

Image: ISRO

Cartosat 2C: The Cartosat 2C was the first satellite to be released from the launch vehicle, as well as the primary payload in the mission. The Cartosat series of satellites are indigenously developed. This is the fourth Cartosat 2 series satellite to be launched, after 2, 2A and 2B.

While similar in design and function to the previous satellites, this iteration is heavier than the Cartosat 2B, and technically more advanced. The satellite was injected into a polar sun synchronous orbit 550km above the surface of the earth. The Cartosat 2C is an earth observation satellite and is equipped with panchromatic and multi-spectral image sensors for that purpose.

The imaging resolution is less than a meter, which makes it one of the most powerful imaging satellites launched by India. It is powered by two solar panels and lithium-ion batteries. The Cartosat 2C has an expected life span of 5 years.

The Cartosat 2C Solar panel deployment test in Bengaluru. Image: ISRO

The Cartosat 2C Solar panel deployment test in Bengaluru. Image: ISRO

Sathyabamasat and Swayam: Sathyabamasat and Swayam were two amateur Indian satellites built by students. Prime Minister Narendra Modi had congratulatory Tweets just for the students who built the satellites that were launched.

The Sathyabamasat was built by the students of Sathyabama University in Chennai. This satellites monitors greenhouse gas emissions. It is fairly advanced and functional for an amateur satellite, monitoring more greenhouse gases than other greenhouse gas monitoring satellites that were its co-passengers in the same launch vehicle. The Sathyabamasat can detect levels of water vapour, carbon dioxide, carbon monoxide, methane and hydrogen fluoride in the atmosphere. This is impressive considering that the satellite weighs less than 1.5 kg.

Swayam, made by students from the College of Engineering, Pune, weighs less than 1 kg. Swayam is meant to provide point-to-point messaging services to the amateur radio HAM network. The two Indian satellites made by students are categorized as nano satellites because of their tiny size.


Sathyabamasat on the right and Swayam on the left. Image: ISRO

LAPAN-A3: LAPAN stands for Lembaga Penerbangan dan Antariksa Nasional, which is the national space agency of Indonesia. The LAPAN-A3 is a multitasking satellite, similar to the LAPAN-A2. The LAPAN design is a cost effective micro-satellite. The LAPAN A3 is designed for both communication and earth observation functions. The LAPAN will be used to monitor the environment and consumption of food resources in Indonesia.

The satellite will be used for surveying and anticipating the conditions in the world's largest archipelago, Indonesia. Studying land use and environmental degradation are its key functions. The spacecraft weighs 115 kg. There is a panchromatic digital space camera on board with a resolution of 5 metres, and a 1,000mm lens. Another key payload on the satellite is the Automatic Identification System. The system will be used by ships in open seas for position, course and speed information, as well as for predicting and avoiding collisions. The satellite was launched in a sun synchronous circular orbit, at an altitude of 637 km.

The LAPAN A3. Image: LAPAN

The LAPAN A3. Image: LAPAN

BIROS: BIROS and LAPAN-A3 were the two satellites deployed together after the three Indian satellites. BIROS stands for Berlin Infrared Optical System, which is part of the Firebird constellation of fire detecting satellites. BIROS is designed by DLR, the German space agency. There are two satellites in the constellation, the TET-1 is already functional. BIROS has a cold gas propulsion system, whereas the TET-1 has none. The BIROS weighs 130 kg.

The BIROS is meant primarily for detecting forest fires, and the data collected will be available openly to the scientific community. The BIROS will be operational in a sun synchronous orbit at an altitude of 510 km. The satellite has an OSIRIS payload, which stands for Optical high Speed Infrared Interlink System. The BIROS is a smart satellite, as in it directly beams down processed information, instead of just raw data. The BIROS is very agile at maneuvering because of newly developed actuators for steering the satellite. It's designed to  function autonomously.

Image: DLR


M3MSat: Next in line were the Maritime Monitoring and Messaging Microsatellite and the SkySat Gen 2-1. The M3MSat is from the CSA (Canadian Space Agency). The small satellite has a number of cutting edge technologies developed in Canada, and this is meant to be a technology demonstration. Similar to the communications role of the LAPAN-A3, the M3MSat has an Automatic Identification System. The system will be used by ships and maritime authorities for safety and monitoring traffic in the open seas.

The satellite will also test technologies to monitor greenhouse gas emissions from industrial complexes. The M3MSat is a collaboration between CSA and the Defence Research and Development Canada agency. The M3MSat has installed a tool to evaluate the health of the satellite, called Dielectric Deep Charge Monitor. This tool measures the static electricity charge build up on the satellite and could pave the way for improvements in the ways satellites monitor themselves. The M3MSat will be in a pole to pole orbit at 505 km.

Image: Janice Lang, DRDC

Image: Janice Lang, DRDC

SkySat Gen 2-1: The SkySat Gen 2-1 from the US was deployed with the M3MSat. SkySat Gen2-1 belongs to Terra Bella, a Google owned company that changed its name from Skybox Imaging. Terra Bella has already launched the SkySat A and the SkySat B, and plans to have at least 20 satellites in orbit by 2017. The SkySat Gen 2-1 is also designated as the SkySat C, and is part of a growing constellation of SkySat satellites. The SkySat Gen 2-1 has a mass of 110 kg according to ISRO, but the Terra Bella site lists SkySat satellites at less than 100 kg.

The small satellite is cost effective to build, and is packed with next generation satellite imaging technologies for capturing sub meter resolution images. The satellites will be used for commercially providing high resolution satellite imagery. SkySat satellites are the first to enable commercial videos captured from orbit. There is no propulsion module on this SkySat, but future SkySat satellites are expected to include propulsion technologies as well.

Image: Terra Bella

SkySat blueprint Image: Terra Bella

GHGSat-D: The GHGSat-D actually has an easy to use name, Claire. Claire was next in line, another Canadian passenger weighing just 25.5 kg according to ISRO, and less than 15 kg according to GHGSat. The satellite is designed to monitor greenhouse gas emissions. Claire monitors the distribution of greenhouse gases in the atmosphere by studying the spectral fingerprint of these gases using sunlight. The satellite will monitor specific high risk sites all across the world, including oil wells in the US, power plants in Europe, coal mines in China and rice fields in Vietnam.

GHGSat: Claire 640x480 from Stephane Germain on Vimeo.

Claire will measure the levels of carbon dioxide and methane across the world. It's the size of a regular microwave and is expected to stay functional for a period of 5 years. Claire is the first satellite in a constellation of satellites from GHGSat, which aims to give customers around the world on-demand access to satellite monitoring of greenhouse gas emissions. As such, it is a technological demonstration with more advanced models in the pipeline.

Image: GHG Sat

Claire. Image: GHGSat

Dove Flock 2p: The final satellites to be deployed were a cluster of 12 Doves from Planet Labs. Dove satellites are deployed in multiple constellations known as Flocks. The Doves released by the PSLV in this launch are collectively known as Flock 2p. The 12 satellites were released over a period of 7 minutes. The satellites were launched in a sun synchronous orbit at 500 km altitude. These were housed in three QuadPack dispensers on board the launch vehicle. Each QuadPack dispenser had 4 Dove satellites. The weight of each satellite is 4.7 kg, making them the lightest passengers in the launch.

These were the first sun synchronous orbit launches for Planet Labs this year. The imagery gathered by Flock 2p will be easier to process by machines and humans because of the mid-morning pass timing that gives ideal lighting situations at every pass. This is the first time that Planet Labs has used ISRO's PSLV for launching satellites.

The Dove 2 Spacecraft. Image: Planet Labs Inc.

The Dove 2 Spacecraft. Image: Planet Labs Inc.

For those who missed the action, DoorDarshan has uploaded the entire launch.

The launch had a lot of environmentally conscious passengers. Sathyabamasat, Claire, GHGSat-D, M3MSat all monitor greenhouse gas emissions. LAPAN A3 and the BIROS observe natural resources, and the effect of humans on them. The number of environment monitoring satellites in the launch is thematically in tune with efforts by Indian and French space agencies to gather big space data on climate change.

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