One Indian Rocket Put 104 Satellites Into Orbit on 15 February 2017, Nearly Triple the Old Record of 37

At 09:28 IST on Wednesday, 15 February 2017, the Polar Satellite Launch Vehicle PSLV-C37 lifted off from the First Launch Pad at Sriharikota with 104 satellites on board. ISRO says the rocket reached orbit after 16 minutes 48 seconds, and over the next 12 minutes every satellite separated from its fourth stage. The earlier record for one rocket was 37, set by a Russian Dnepr in June 2014.

What was on the rocket

One satellite was large. Cartosat-2D, called the Cartosat-2 series satellite in ISRO’s launch pages, weighed 714 kg and carried panchromatic (black-and-white) and multispectral cameras for remote sensing. The other 103 were small. ISRO puts their combined mass at about 663 kg, less than Cartosat-2D alone, and the whole load at about 1,378 kg.

Two of the 103 were Indian technology demonstrators, INS-1A and INS-1B, at 8.4 kg and 9.7 kg. The other 101 belonged to foreign customers. Ninety-six were American: 88 Dove satellites from the company Planet, which ISRO lists as Flock-3p, and eight Lemur-2 satellites from the company Spire. The remaining five were Al-Farabi-1 from Kazakhstan, BGUSat from Israel, DIDO-2 from Switzerland, Nayif-1 from the United Arab Emirates and PEASS from the Netherlands.

A rocket in its XL form

PSLV-C37 was the 39th PSLV flight and the 16th in the XL configuration, which adds six solid-fuel strap-on boosters to the core stage, according to ISRO and The Wire. ISRO described it as the 38th consecutively successful PSLV mission.

The target was a polar Sun-synchronous orbit, one that passes over any given place at the same local time each day. ISRO reported 506 km altitude and an inclination of 97.46 degrees to the equator, and said the result was very close to the intended orbit.

Twenty-nine minutes from liftoff to the last release

Adding ISRO’s two figures gives about 29 minutes between liftoff and the final separation. Cartosat-2D went first. INS-1A and INS-1B followed, and then the 101 foreign satellites, all in a predetermined sequence. Cartosat-2D’s solar panels opened automatically, and ISRO’s tracking network in Bangalore took over control of it.

The hard part was keeping 104 objects from touching one another as they left the same stage. Mission director B. Jayakumar told ROOM Space Journal that avoiding collisions during separation was a key challenge and that a new separation technology had been used and worked efficiently. The ISRO pages cited here give no release time for individual satellites and no description of the hardware, so the sequence is known in order but not in seconds.

Who paid for the seats

ISRO says the 101 foreign satellites flew under commercial arrangements between Antrix Corporation Limited, a Department of Space company that serves as ISRO’s commercial arm, and the customers. By ISRO’s count after the flight, PSLV had launched 46 Indian satellites and 180 foreign customer satellites. This single flight supplied 101 of those 180.

No official cost for the flight appears on the ISRO pages cited here. The Christian Science Monitor, citing a Moneycontrol report, said ISRO charged an average of about $3 million per satellite between 2013 and 2015, and that private launches brought 230 crore rupees (about $34 million) to ISRO’s commercial arm the year before. That price level is the sort of number behind the reputation described in our profile of ISRO as a frugal space power.

A later total comes from a written Lok Sabha reply by Minister of State Jitendra Singh, reported by ANI on 14 March 2025. It said 393 foreign satellites and three Indian customer satellites were launched commercially on PSLV, LVM3 and SSLV between January 2015 and December 2024, earning $143 million in foreign exchange. The reply also said India has launched satellites for 34 countries since 2014. The private companies now entering the same market are covered in our piece on India’s NewSpace startups.

What the record counted

A record for the number of satellites says nothing about their mass. The Dnepr flight of 19 June 2014 carried 37 satellites, among them Deimos 2 at 300 kg and KazEOSat 2 at 180 kg, according to Spaceflight Now. Thirty-three were released in a timed sequence and four stayed inside the UniSat-6 mothership for later release. All of PSLV-C37’s 104 separated from the fourth stage, per ISRO. Planet, whose Doves filled most of the 2017 manifest, had also put 11 CubeSats on that 2014 Dnepr.

By ISRO’s own list, each Dove weighs 4.7 kg and each Lemur 4.6 kg. Multiplying out, the 96 American satellites come to roughly 450 kg, about a third of the 1,378 kg total. Cartosat-2D alone outweighed all 103 passengers.

ISRO’s chairman A.S. Kiran Kumar rejected the idea that the flight was a race for a title. As ROOM Space Journal reports it, the aim was to use about 600 kg of spare capacity on the rocket and improve returns. The Wire’s pre-launch report said the same about keeping spending down.

SpaceX ended the record on 24 January 2021, when a Falcon 9 launched 143 satellites, 10 of them its own Starlink craft. Advanced Television reported that around 133 of the 143 were CubeSats and microsatellites.

Ten in 2008, twenty in 2016, and the flights since

PSLV-C37 had two earlier steps. On 28 April 2008 PSLV-C9 carried ten satellites: the 690 kg Cartosat-2A, the 83 kg IMS-1 and eight foreign nanosatellites weighing about 50 kg together. It was the vehicle’s 13th flight and its third without strap-on boosters. PSLV-C34 on 22 June 2016 carried 20, which Universe Today reports as the PSLV’s best before February 2017.

Since then the rocket has had failures. ISRO’s list marks PSLV-C39, flown on 31 August 2017 with the navigation satellite IRNSS-1H, as unsuccessful. PSLV-C61 on 18 May 2025, the 63rd flight, performed normally until the second stage, and ISRO says an observation in the third stage meant the mission could not be accomplished. The Week reports that PSLV-C62 on 12 January 2026 lost its main satellite EOS-N1 and 15 smaller ones to a third-stage fault. ISRO’s launch list, as checked for this article, ends at PSLV-C62. A PSLV had also carried Mangalyaan to Mars orbit in 2013.

The tracking worry and the stage that stayed behind

G. Madhavan Nair, a former ISRO chairman, raised a concern in comments carried by ROOM on 15 February 2017. Tiny satellites last perhaps one or two years, he said, and because of their size they “may not be amenable for tracking and finding out their positions.”

The fourth stage that released the 104 satellites stayed in orbit for more than seven years. ISRO’s notice says it re-entered over the North Atlantic on 6 October 2024, within the 25-year limit in the Inter-Agency Space Debris Coordination Committee guideline.