Technology

DRDO Seeks Indian Firms for Air-Breathing Propulsion on VLEO Satellites

2026-09-13 - ABikram Mondal

DRDO Opens Bids for a New Kind of Satellite Engine

Defence Research and Development Organisation has floated a request for proposals under its Technology Development Fund programme. The goal is an indigenous air-breathing electric propulsion system built for satellites in very low Earth orbit. Indian companies and research groups can now submit ideas that meet a detailed list of performance targets.

The system must run between 180 km and 230 km altitude. It needs to produce thrust from 12 mN to 25 mN while drawing under 1,500 watts and staying below 40 kg total mass. Operational life should reach at least three years. At least 75 percent of the content must come from Indian sources.

DRDO prefers a Hall-effect thruster design. The unit will draw ambient atmospheric particles in that thin layer of sky and mix them with xenon propellant. This hybrid approach aims to cut reliance on stored fuel and stretch mission times.

The RFP appeared in early September. Responses will shape the next round of prototype work. Successful bidders stand to supply hardware for future surveillance and observation constellations that need closer, sharper views of Earth.

Why Very Low Earth Orbit Matters for India

Satellites lower than usual orbits deliver higher resolution images and shorter signal delays. Those gains help disaster response teams, farmers tracking crops, and defence planners watching borders. The trade-off is stronger atmospheric drag that pulls satellites down faster.

Standard electric thrusters carry all their propellant from the ground. In VLEO the air itself becomes part of the fuel supply. DRDO wants the new engine to scoop that thin gas and ionise it alongside xenon. The result should keep the satellite stable without constant refuelling.

India currently operates 56 satellites. Demand is rising fast. ISRO Chairman V Narayanan has said the country needs 200 to 300 new satellites over the next six or seven years. Many of those could fly in VLEO if the propulsion problem is solved.

Longer endurance in these orbits also reduces the number of replacement launches. Fewer rockets mean lower costs and less orbital debris over time.

Technical Targets Laid Out in the RFP

The document lists clear numbers. Altitude stays between 180 km and 230 km. Thrust range runs 12 mN to 25 mN. Power draw must stay below 1,500 watts. Whole system mass cannot exceed 40 kg. Minimum life is three years. Indigenous content floor is 75 percent.

Hall-effect thrusters already fly on many commercial satellites. They ionise propellant and accelerate the ions with crossed electric and magnetic fields. Efficiency stays high at low thrust levels, which suits the drag compensation job in VLEO.

DRDO adds the air-breathing element on top. Ambient molecules supplement the xenon. This cuts the xenon tank size and stretches the time between refills or end of mission.

Power processing units, cathodes, anodes, and high-performance ceramics all form part of the supply chain that Indian firms must develop or source locally.

Comparison with Existing Electric Propulsion Options

The table below places the DRDO targets next to typical performance figures reported for two established Hall-effect systems used on other satellites. Exact rival data for air-breathing versions remains limited in public records.

Parameter	DRDO Target	Typical 1 kW Hall Thruster	Typical 2 kW Hall Thruster
Thrust	12-25 mN	40-60 mN	80-120 mN
Power	<1,500 W	~1,000 W	~2,000 W
System Mass	<40 kg	~15-25 kg	~25-35 kg
Propellant	Air + Xenon	Xenon only	Xenon only
Altitude Focus	180-230 km	300+ km	300+ km
Indigenous Content	75% minimum	Mostly imported	Mostly imported

Numbers for rival systems come from manufacturer datasheets and mission reports already in the public domain. The DRDO specification adds the air-breathing requirement and the strict local-content rule that most existing units do not carry.

What the Spec Sheet Leaves Out

The RFP gives performance numbers but does not detail thermal management at those altitudes or how the intake will handle varying atmospheric density. Lifetime claims of three years assume steady operation without major degradation from atomic oxygen erosion.

Integration with small satellite buses also remains open. The 40 kg mass budget includes the thruster, power unit, and propellant tanks, yet real spacecraft carry additional structure and payloads that eat into the allowance.

Cost targets and production volumes sit outside the published requirements. Indian firms will need to price the system competitively while meeting the 75 percent local content rule.

Testing in actual VLEO conditions will come only after ground qualification. Vacuum chambers can simulate the environment but cannot fully replicate the continuous flow of atmospheric particles at orbital speeds.

Who Stands to Gain from This Work

Indian startups and mid-sized aerospace suppliers now have a clear path to develop and own propulsion intellectual property. The 75 percent indigenous rule pushes component makers in ceramics, power electronics, and precision machining to step up.

Defence and space programmes gain a domestic source for a capability that currently relies on foreign suppliers. Long-duration VLEO satellites could feed higher-resolution imagery into existing networks without waiting for new foreign launches.

Academic groups working on plasma physics and electric propulsion also receive a concrete target. Collaboration between DRDO labs, private firms, and universities can accelerate the timeline.

Success here would mark another step in building a closed-loop Indian space supply chain that starts with design and ends with on-orbit performance.

Next Steps After the RFP Closes

DRDO will evaluate proposals and shortlist teams for prototype development. Funding under the Technology Development Fund covers initial hardware and testing. Later phases could move to flight demonstration on a technology satellite.

Parallel work on xenon production and storage inside India would further reduce import dependence. The same supply chain could support other electric propulsion projects already under way.

Timeline details have not been released. Past DRDO technology development programmes have moved from RFP to first hardware in 18 to 36 months when priorities align.

The outcome will show whether Indian industry can deliver a complete propulsion package that meets the demanding combination of low mass, modest power, and air-breathing operation in one of the harshest orbital regimes.

The short version. DRDO is asking Indian industry to build an air-breathing electric thruster that keeps satellites stable at 180-230 km altitude with under 40 kg mass and at least 75 percent local content.

Sources

Reported from the sources above on 2026-09-13. Figures are as published at the time of writing. If something here has moved on, the linked source is the one to trust.

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