Spacecraft Propulsion in India: Green Thrust and Propellant-Free Agility

The problems being solved

Spacecraft don't just coast—they nudge, rotate, and fine-tune their paths. The challenge is doing that with surgical precision, often needing multiple discrete thrust levels that traditional reaction control systems struggle to deliver flexibly.

Then there's the propellant itself. Carrying a single, safe, storable fuel that can handle both high-thrust escapes and low-thrust station-keeping would slash complexity, but most systems still rely on separate, often toxic, chemical cocktails.

A more radical itch: what if a spacecraft could maneuver without any propellant at all? Eliminating fuel mass and storage would rewrite the rules of satellite design, yet practical, scalable solutions remain elusive.

How the field is solving it

Indian patent filings reveal three distinct technical bets, each attacking a different piece of the propulsion puzzle.

One approach uses a vortex thruster fed by decomposing a monopropellant, then injects a secondary propellant to toggle between thrust levels. The swirling flow stabilises combustion and enables the kind of multi-mode responsiveness needed for delicate orbital adjustments.

Another path embraces water as the sole propellant. A dual-mode system splits operation into high-thrust and low-thrust parts—possibly through electrolysis or thermal decomposition—offering a green, non-toxic, and easily storable alternative that sidesteps the hazards of hydrazine.

A third concept does away with fluids entirely: extendable arms on the spacecraft surface push against nothing but inertia. By rhythmically extending and retracting, they generate net movement without expelling mass, a mechanical dance that could one day propel small platforms.

• Vortex thruster with secondary injection for multiple thrust levels
• Dual-mode water propulsion for safe, single-propellant operation
• Extendable arms for propellant-free maneuvering via momentum transfer

Where the market is heading

The global space propulsion market is on a steep climb—valued in the low single-digit billions today, it is projected to roughly double by the early 2030s, growing at a double-digit annual rate, according to MarketsandMarkets. Supply chains, however, are straining under the weight of demand for radiation-hardened chips and precision valves, as reported by SpaceNews.

Electric and green propulsion are no longer niche. Large sovereign constellation programmes and private crewed missions beyond low Earth orbit are pulling advanced thrusters into the mainstream, with electric systems promising to slash fuel mass and comply with tightening environmental norms.

India's own space ecosystem has transformed. Policy continuity—anchored by the Indian Space Policy 2023, liberalised foreign direct investment, and dedicated seed and venture funds—has fuelled a surge in entrepreneurial activity. Private players are moving from engine test-fires to deployment, and investment in Indian space startups has crossed the half-a-billion-dollar mark, creating a fertile ground for propulsion breakthroughs.

The white space

While current patent activity clusters around chemical and water-based thrusters, deep-space ambitions demand high-thrust, long-duration options that go beyond these. Nuclear thermal propulsion and high-power electric systems remain largely unexplored in India's innovation landscape, opening a frontier for those willing to tackle extreme engineering.

Small satellites and CubeSats, with their tight mass and volume budgets, need miniaturised propulsion modules that are conspicuously absent from recent filings. A compact, plug-and-play thruster purpose-built for these platforms would unlock new mission profiles for Earth observation and communication swarms.

Propellant-less concepts like extendable arms are elegant but must prove they can scale. The opportunity lies in demonstrating that such mechanical systems can deliver meaningful impulse for larger spacecraft or sustain operation over years, not just minutes.

• High-thrust nuclear or electric propulsion for deep-space missions
• Miniaturised propulsion modules tailored for small satellites and CubeSats
• Scaling propellant-free mechanical systems to larger, long-duration platforms

Explore the innovators

The specific inventors, patents, and companies working on these propulsion challenges in India can be explored on Deeptech Navigator. From the fluid dynamics of vortex thrusters to the control algorithms of water-based dual-mode engines and the kinematics of extendable arms, the technical details are waiting to be discovered—no names, no counts, just the ideas shaping tomorrow's orbital agility.

In our data

Sources

• Spacecraft propulsion ↗
• 4.0 In-Space Propulsion - NASA ↗
• How does a rocket work in space where there is no air to push against? ↗
• Spacecraft propulsion - supply chain hub ↗
• Space boom strains supply chain, industry report warns ↗
• The Hidden Supply Chain of the Space Economy ↗
• Satellite Propulsion Market worth $5.19 billion by 2030 ↗
• Space Propulsion Market Size, Share, Forecast 2031 ↗