The 'Pushpak' Takes Flight and Lands Itself
ISRO has successfully completed a series of crucial landing experiments (LEX) for its Reusable Launch Vehicle (RLV) Technology Demonstrator, nicknamed 'Pushpak'. In these tests, most recently conducted at Aeronautical Test Range in Chitradurga, Karnataka,
the uncrewed, winged spaceplane was lifted to an altitude of 4.5 kilometres by an Indian Air Force Chinook helicopter and released. From there, Pushpak had to find its own way home. Using its onboard computers and a suite of indigenous navigation systems, the vehicle autonomously glided, corrected its course, and executed a perfect, high-speed landing on the runway, touching down at around 350 kmph. The latest tests were designed to be even more challenging, releasing Pushpak from an off-nominal position to test its ability to handle dispersions and make complex manoeuvres to align with the runway.
Why Reusability is the Holy Grail of Spaceflight
Traditionally, launching a satellite is an incredibly expensive, single-use affair. Most parts of a rocket, including its powerful and costly engines, are discarded and burn up or fall into the ocean after just one flight. This is like building a brand-new aeroplane for every single trip you take. Reusability changes this entire economic model. The goal is to dramatically reduce the cost of launching a kilogram of payload into orbit, potentially by up to 80 percent. Current estimates peg the cost at thousands of dollars per kilogram; ISRO's vision is to bring that down to a few hundred. By recovering and reusing the most expensive components of a launch vehicle, agencies and companies can fly missions more frequently and affordably, opening up space for more scientific research, commercial ventures, and exploration.
ISRO's Unique Approach: A Spaceplane, Not a Rocket
While private companies like SpaceX have mastered vertical landings where rocket boosters return to Earth under power, ISRO is pursuing a different, but equally valid, method. Pushpak is designed to re-enter the atmosphere and land horizontally on a runway, much like the US Space Shuttle once did. This winged-body design has its own set of complex challenges, particularly in managing the extreme heat of re-entry and mastering the aerodynamics of a high-speed glide. The successful landing experiments are a testament to ISRO's mastery over autonomous navigation, guidance, and control systems. The project integrates several homegrown technologies, including a Ka-band Radar Altimeter, the NavIC receiver, and specialized landing gear designed to handle the precise, high-speed touchdown.
The Road to a Fully Reusable Rocket
Pushpak itself is not the final launch vehicle. It is a vital technology demonstrator, a scaled-down version designed to test and perfect the critical technologies needed for a future Two-Stage-To-Orbit (TSTO) launch vehicle. The successful completion of the Landing Experiment (LEX) series is a crucial phase. The next major step is the Orbital Re-entry Experiment (OREX). This will involve launching Pushpak into orbit on a rocket, having it circle the Earth, re-enter the atmosphere at hypersonic speeds, and then perform its autonomous glide and landing. This will test the vehicle's thermal protection systems and its ability to handle the full mission profile. These tests are all building blocks for India's next-generation launch vehicle, designed to be partially reusable and capable of lifting heavy payloads, securing India's future in the competitive global launch market.
