Small launchers are compact rockets built to put satellites of a few hundred kilograms into low orbit quickly, instead of waiting for a ride on a big rocket.
Many modern satellites are small — a few kilograms to a few hundred. They can share a ride on a big rocket, but then they must wait for its schedule and accept its orbit. A small launcher is sized for them, so a small satellite can go where it needs, when it needs.
ISRO's Small Satellite Launch Vehicle (SSLV) is 34 m long, 2 m wide and weighs about 120 tonnes at lift-off — under half of PSLV-XL's 320 tonnes. It can place a single satellite of up to 500 kg into a 500 km orbit.
It has three solid stages and a small liquid Velocity Trimming Module on top for fine-tuning the final orbit. ISRO describes it as low-cost, quick to prepare and able to launch on demand.
SSLV's first flight in August 2022 failed. After fixes, SSLV-D3 placed EOS-08 precisely in orbit on 16 August 2024. That flight completed the development project and opened the way for operational flights by Indian industry and NSIL.
ISRO is building an SSLV Launch Complex at Kulasekarapattinam in Tamil Nadu. The Prime Minister laid its foundation stone on 28 February 2024 and construction began on 5 March 2025. It is meant mainly for SSLV launches into polar orbits, aimed at the market for satellites up to 500 kg. The first buildings are assembly halls for SSLV's upper stages and a Launch Service Building.
Indian companies are now building their own small rockets. On 18 November 2022, Skyroot Aerospace of Hyderabad flew Vikram-S on mission Prarambh from the sounding-rocket complex at Sriharikota. It was a suborbital flight that reached about 89.5 km. ISRO called it the first launch of a launch vehicle built by a private company in India.
Reaching about 90 km and coming back down is far easier than reaching orbit — but it is the first step.
Follow SSLV from its failed first flight in 2022 to the 2024 flight that completed its development. See SSLV's flights
Payload fraction. SSLV: 500 kg ÷ 120,000 kg ≈ 0.42% to a 500 km orbit. PSLV-XL: 1,750 kg ÷ 320,000 kg ≈ 0.55% to a 600 km sun-synchronous orbit. Here the smaller rocket has the lower payload fraction.
SSLV stage by stage (ISRO maximum vacuum thrust × burn time, an upper bound on impulse):
Suborbital vs orbital. To coast up to 89.5 km after the engine stops, a rocket needs a vertical speed of about √(2gh) = √(2 × 9.81 × 89,500) ≈ 1.3 km/s (ignoring drag and the small drop in g). To stay in a 500 km orbit it needs v = √(GM/r) = √(398,600 / 6,878) ≈ 7.61 km/s sideways. Kinetic energy scales with v², so orbit needs roughly (7.61/1.33)² ≈ 33 times more energy per kilogram than the suborbital hop. That is the gap between a first private sounding flight and a private orbital launch.
Why a southern spaceport. ISRO built the Kulasekarapattinam complex primarily for SSLV polar launches.
A single satellite of up to 500 kg into a 500 km orbit.
The 18 November 2022 suborbital flight of Skyroot Aerospace's Vikram-S from Sriharikota, which reached about 89.5 km — the first launch of a rocket built by a private Indian company.
A 90 km hop needs about 1.3 km/s of vertical speed, but staying in a 500 km orbit needs about 7.6 km/s of sideways speed — roughly 33 times the kinetic energy per kilogram.