Recently the reusable rocket technology has gained importance around the sustainable use of space.
What is the status of space technology?
Past scenario – For nearly four decades, space exploration was dominated by government agencies, with missions driven largely by strategic, scientific, and prestige considerations.
Present status – The space sector has entered a commercial phase, led by private companies that invest, innovate, and compete to reduce costs and increase launch frequency.
Today, space is one of the fastest-growing industries in the world and is projected to exceed $1 trillion in value by 2030.
Transformative innovation – At the heart of this transformation lies a single disruptive innovation: Reusable rocket technology, which is redefining sustainability and cost-effectiveness in access to space.
The economics of launch costs – Traditionally, rockets were expendable, meaning each launch destroyed the launch vehicle after a single use.
This made space access extremely expensive, with costs running into tens of thousands of dollars per kilogram of payload.
Low launch of costs – The introduction of partial reusability by private players has reduced the cost of access to space by 5 to 20 times, fundamentally altering the economics of spaceflight.
Lower launch costs have multiple downstream effects:
Increased launch frequency
Expansion of satellite constellations
Greater accessibility for developing countries and private firms
New commercial applications such as space tourism and in-orbit servicing
This shift has moved the industry from a “disposable” model to a transportation model, similar to aviation.
Why spaceflight is technically challenging?
Physical barriers – Launching a rocket into orbit requires overcoming two major physical barriers:
Gravity
Aerodynamic drag.
Unlike aircraft, rockets cannot push against air or ground and must propel themselves forward by ejecting exhaust gases backward at supersonic speeds.
The fundamental physics governing rocket motion is explained by the Tsiolkovsky rocket equation, which links a rocket’s velocity to its mass and fuel consumption.
This equation highlights a major limitation: fuel itself is extremely heavy.
As a result, more than 90% of a rocket’s mass at liftoff is typically propellant and tanks, while less than 4% is the actual payload.
This “weight problem” is the core reason spaceflight is expensive.
Role of rocket staging –To address the limitations, rockets are designed with multiple stages.
Each stage is an independent propulsion unit that is discarded once its fuel is exhausted, allowing the rocket to shed dead weight mid-flight.
This improves efficiency and makes orbital insertion possible.
Traditional launch vehicles such as PSLV and LVM-3 use expendable staging, where discarded stages fall into the ocean and are never recovered.
While effective, this approach locks in high recurring costs because each launch requires a completely new vehicle.
Reusability –Reusable rockets aim to recover and reuse the most expensive components, particularly the first stage, which contains engines, avionics, and fuel tanks.
SpaceX has pioneered this approach with its Falcon 9 rocket.
After separation, the first stage performs a controlled descent using:
Engine re-ignition (retro-propulsion) to reduce speed
Aerodynamic drag during atmospheric re-entry
Precision guidance and autonomous landing on land or ocean platforms
This innovation has dramatically reduced costs and increased launch cadence.
SpaceX has successfully recovered Falcon 9 first stages over 520 times, with some boosters reused more than 30 times.
Fully Reusable Launch Vehicles – While partial reusability is now proven, the next major leap is full reusability, where both stages of a rocket are recovered and reused.
SpaceX’s Starship represents this ambition.
Designed as a fully reusable, heavy-lift vehicle, Starship is intended to carry crew and cargo not only to Earth orbit but also to the Moon and Mars.
Other global players:
Blue Origin has demonstrated vertical booster recovery for its New Glenn rocket.
Chinese commercial space firms, such as LandSpace, are attempting recovery technologies for orbital-class rockets.
These developments indicate that reusability is fast becoming an industry norm rather than an exception.
What are the limits to reusability?
Practical limitations – Rocket stages are subjected to extreme stresses:
Cryogenic temperatures from propellants
Intense heat during combustion and re-entry
High pressure, vibration, and g-forces
Over multiple flights, these conditions cause material fatigue and microfractures, especially in engines and fuel tanks.
Other concerns – Beyond a point, the cost and time required for inspection, refurbishment, and replacement of components can outweigh the savings from reuse.
Thus, the feasible number of reuses is determined not only by engineering durability but also by refurbishment economics and acceptable risk levels.
What is the human spaceflight vs satellite missions?
Human space missions – These are significantly more expensive than uncrewed satellite launches, often costing three to five times more. This is due to stringent requirements for:
Life support systems
Crew safety and redundancy
Escape mechanisms and reliability standards
Satellite missions – They are typically one-way, with simpler hardware and software architectures.
Reusability helps reduce costs in both cases but is especially transformative for high-frequency satellite launches.
India’s Position in the Reusable Space Race – India, through ISRO, has recognised the strategic importance of reusability and is actively developing relevant technologies.
Two major approaches are being pursued:
Reusable Launch Vehicle (RLV) – A winged, shuttle-like vehicle capable of re-entering the atmosphere and landing on a runway.
Stage Recovery Systems – Using aerodynamic drag and retro-propulsion to recover spent rocket stages on land or sea platforms.
While India has traditionally focused on cost-effective expendable launch systems, the rapidly evolving global market makes reusability a necessity rather than a choice.
What lies ahead?
Future launch vehicles must be designed with reuse as a non-negotiable design driver.
Advances in propellant density and engine efficiency now allow two-stage systems to perform missions that once required three or more stages.
Key focus areas should include:
Optimised stage energy distribution
High-performance, compact engines
Rapid and economical refurbishment
Increased launch cadence.
Reusable rocket technology represents a paradigm shift in space access, making it more affordable, sustainable, and inclusive.
As space becomes a critical domain for economic growth, national security, and technological leadership, countries that fail to adapt risk being left behind.
For India, timely induction of disruptive technologies and policy support for reusable systems will be crucial to remaining competitive in the emerging global space economy.
