A praiseworthy article on the successful Landing Experiment (LEX) of the Reusable Launch Vehicle Tech Demonstrator yesterday, 2nd April 2023, will not fully express the greatness of what has transpired. Putting together in perspective the earlier Hypersonic Experiment (HEX) of 2016, and the recent LEX, India has demonstrated that it can launch a fixed-wing space drone to a suborbital altitude of 65 km, making it attain hypersonic speeds up to Mach 5 and eventually decelerate to subsonic speeds and make a controlled landing on an airstrip. ISRO Chairman Dr Somanath has already confirmed that after a few more rounds of LEX, the final goal of the experimental cycle is taking the RLV into the Earth’s orbit and making it endure the gruelling atmospheric re-entry.
Euphoria aside, what makes LEX so unique? The great opportunity has come through a multi-stakeholder approach – the ISRO, DRDO, and the Indian Air Force came together for it. Let me take you back to a nebulous event in our collective memories. It dates back to May 2017. The Late Manohar Parrikar, by then, had returned to becoming the Chief Minister of Goa after being India’s Defence Minister in March 2017. India’s Defence ministership had gone to the Late Arun Jaitley. Jaitley inaugurated the Chitradurga ATR, and in his public statement, he said, “The Aeronautical Test Range is a first-of-its-kind. You need an area (for an ATR-like facility) that is secluded. And the entire gamut of aeronautical defence preparedness gets tested in these areas. India is a country geographically located in a region which is not free from trouble. We have a neighbour who, for the past seven decades, has perpetuated a security threat. And therefore, our level of defence preparedness is always to be optimum.”
Since 2017, the Chitradurga ATR has seen some prominent and rigorous tests of various uncrewed aeronautical platforms, be it the miniaturised version of the GHATAK stealth uncrewed aerial vehicle or the Rustom-2 UAV. Chitradurga fascinated many in the overseas media and think tanks in these six-odd years, especially our Western neighbour who scratched its heads in comprehending why the Chitradurga ATR’ runway was being extended. The conspiracy-minded effort in that report suggested the runway expansion be deliberately done for the upgraded UAVs from the Rustom series. However, the writer from our Western neighbour could not find an essay where the editor of Interstellar, in 2016, had written that RLV would eventually need a longish runway, without naming Chitradurga, as it descends into the atmosphere at hypersonic speeds.
Let us not equate the RLV testbed immediately with the US Space Shuttle or the Soviet Buran. RLV is actually in the league of the uncrewed American X-37 and the Chinese Shenlong. Once it goes orbital, the RLV could carry out a variety of long-duration scientific experiments of interest to a wide variety of end users and those meant to last long durations for tens of months. It is likely not to be immediately graduated for crew rating, as the Gaganyaan capsule will be the preferred choice for crew transportation even when the preparations for the space station formally commence in the 2030s. However, the uncrewed and space-proven variants of the RLV may carry logistics cost-effectively to an Indian or any commercial space station.
So what is the future of RLV, and why should we be excited about it? RLV’s reusability lies in it being the upper reusable stage of a two-stage-to-orbit (TSTO) system. ISRO’s proposed ADMIRE, a vertical-take-off-vertical landing system, may result in spinoffs, creating a reusable bottom stage of an RLV-consisting TSTO. So, with a reusable bottom stage and a reusable top stage, India is entering into a new RRR space race of ‘renewable, re-entry and reusable’ launch vehicles, for which the techno-political stage has already been set up.
The French government organises a track-1.5 diplomatic event called the Paris Peace Forum. In 2021, the Forum announced the Net Zero Space initiative calling stakeholders worldwide to take firm actions to reduce debris orbiting the Earth and use outer space sustainably. Where does sustainable use of outer space begin? It begins with the RRR of launch vehicles, emphasising cleaner fuels, vehicles that can re-enter Earth’s atmosphere piggybacking payloads (either humans, logistics, accumulated space debris, extraterrestrial materials, or experimented materials and matter), and reusable vehicles. Many space companies have pledged to abide by sustainable use of outer space, and in the coming years, RRR could become mandatory. Renewable and clean fuels may perhaps become mandatory. This provision could, for once, discontinue using solid fuels like the unsymmetrical dimethylhydrazine (UDMH) or the soot-generating Rocket Propellant-1, both may face growing global opposition. RRR, in no matter of time, has already become a political issue, and efforts are to be invested in graduating to sustainable launch options.
The RLV is not a gliding space drone but a high-hypersonic platform. During its suborbital HEX experimental flight, the RLV has only tested the space drone up to Mach 5. But once the Orbital Re-entry Experiment preparations begin, the vehicle will be modified for atmospheric re-entry testing, where it could reach enormously high Mach 20+ speeds during descent. Atmospheric reentry platforms are highly coveted as a must-have civilian and military paraphernalia, and India’s global stature is rising. In March 2023, the Australian Strategy Policy Institute (ASPI) released a report measuring the top 5 country positions in 44 cutting-edge technologies. India ranked in the top 5 in 29 different advanced technologies. Related to RLV, India ranked third in hypersonic engines and fourth in drone technologies. The RLV LEX test further consolidates India’s position in these rankings and on the global space power pedestal. India must keep pace with RRR, time is no more a luxury, secure its industrial and R&D ecosystem, and ensure that a fully reusable TSTO option is ready to serve India’s aspirations and future security needs. The world watches us closely as we inch towards the apex of two of the few holy grail technologies with a high-hypersonic space drone.