New Delhi: The Kargil War became a bitter lesson for India after the US denied GPS access to reveal the locations of the Pakistani Army. Though India emerged victorious, the ‘GPS denial’ episode pushed New Delhi to create the Navigation with India Constellation—our very own indigenous position tracker system.
However, 27 years after committing to its development, India has still not been able to make Navigation with India Constellation (NavIC) a fully functional system.
Last week, the Indian Space Research Organisation (ISRO) confirmed that the atomic clock on board the Indian Regional Navigational Satellite System-1F (IRNSS-1F)—the first generation of the NavIC satellites—had stopped functioning.
According to experts, for a navigation system to run, at least four satellites must be functional. This means that with the IRNSS-1F now completing its 10-year mission life, India’s indigenous navigational system is defunct.
NavIC, once envisioned as India’s answer to the satellite navigation systems run by the US, China, Russia and Europe, has now become a casualty of years of neglect, technical failures, ageing satellites and delayed replacement launches, pushing India further behind in a technology that now underpins both economic competitiveness and modern warfare.
ISRO’s focus on bigger missions like Gaganyaan, India’s first human spaceflight, and the Bharatiya Antariksh Station (BAS), has seemingly distracted the focus from essential strategic missions.
With no confirmation on the launch of the next set of satellites—the only way to revive NavIC to some form of functionality—India’s navigation system is stuck in limbo.
Ajey Lele, deputy director general at the Manohar Parrikar Institute for Defence Studies and Analyses (MP-IDSA), said that a single problem isn’t plaguing NavIC.
India now needs a serious strategy to get back in the race, he said, adding, “In the initial period, ISRO faced the problem of atomic clocks imported from abroad. Later, we have had problems ranging from the lack of ground support systems to launch failures.”
In the initial stage of the programme, ISRO had faced troubles with adequate ground support systems to fully realise the potential of the launched NavIC satellites. These ground systems are necessary for catching and translating signals from the satellites in orbit.
How does a navigation system work?
Satellite navigation systems work on two levels—regional and global.
For a regional network, at least three to four satellites—usually from medium earth orbit—need to transmit radio signals. This is the bare minimum requirement for operations.
For global systems such as the US’s GPS or Russia’s GLONASS, this satellite network requires at least 24 to 26 satellites.
GPS, for instance, has 31 operational satellites operating at a medium Earth orbit (MEO). These satellites operate at about 20,000 km in six orbital planes, inclined at about 50-55 degrees. China’s Beidou also has more than 40 satellites in MEO.
India’s NavIC, on the other hand, currently has only three operational satellites. In an ideal situation, NavIC requires seven functional satellites to get a decent view of a country’s land and its bordering areas.
NavIC was initially designed to operate as a regional navigation system, but the ambition was to later expand it for global coverage and use.
According to ISRO, the NavIC satellite constellation design will have three satellites placed in a geostationary orbit, at about 32.5 degrees E, 83 degrees E and 129.5 degrees E.
Four more satellites are designed to be placed in inclined geosynchronous orbit with equatorial crossing of 55 degrees E and 111.75 degrees E, with an inclination of 29 degrees. This comes to two satellites in each plane.
“The ground network consists of control centres, precise timing facilities, range and integrity monitoring stations, two-way ranging stations, etc,” states ISRO in its plan.
The original NavIC design offers two services—Standard Position Service (SPS) for civilian use and Restricted Service (RS) for military use. These services are backed by L5 bands—the most advanced and high-precision global navigation satellite system (GNSS) signal designed for civilian use—and S bands. This helps cover the Indian region and an area up to 1,500 kms beyond the Indian boundary.
“NavIC signals are designed to provide user position accuracy better than 20m (2s) and timing accuracy better than 50ns (2s). NavIC SPS signals are interoperable with the other global navigation satellite system (GNSS) signals, including GPS, Russia’s Glonass, Europe’s Galileo and China’s BeiDou,” the plan states.
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What went wrong?
The problems of NavIC are not new. The mission has faced hurdles since ISRO launched the first satellite in the IRNSS series, IRNSS-1A, in 2013. Just three years after its launch, ISRO’s then chairperson, AS Kiran Kumar, announced that the atomic clocks on IRNSS-1A had become dysfunctional.
He said that there were some “hardware issues” detected in the rubidium atomic clocks. The rubidium atomic clocks used in the first seven IRNSS series were sourced from Switzerland. It was the same atomic clocks which had also malfunctioned in the European Galileo constellation.
The problems for the mission did not end there.
ISRO’s attempt to replace IRNSS-1A on 31 August 2017, with IRNSS-1H also failed. The mission failed to insert the satellite into the desired orbit. According to ISRO, a heat shield that protects the satellite could not be detached on time during launch.
Last year, in response to a question in the Parliament, Union Minister of Science and Technology and Space confirmed that only 1B, 1F, 1I and 1J are fully operational. 1C was partially functional. Now that 1F is also out of order, only 1B, 1I, and IJ remain functional.
Last year, the Indian space agency was hit by another setback. The second-generation satellite series, NVS-02—incidentally ISRO’s 100th mission—also failed.
“From the next generation navigation satellites, which come under the NVS series, 1J is operational. The success of 1K, now known as NVS-02, could not be achieved,” the official said.
Ashwin Prasad, space technology expert and research analyst at the high-tech geopolitics programme at the Takshashila Institution, explained that in positioning, navigation and timing (PNT) technology, accuracy is of key importance. Atomic clocks provide the high-precision timing necessary for this technology.
“The problem is that ISRO is the sole centre of this programme,” Prasad said, adding that after the initial issues with the European atomic clocks, India started building its own clocks.
“So, that problem is taken care of. PNT is not a new technology that requires R&D. It is now a mature technology. We are in a position where private players can take on the role of building these segments. This will make the system smoother and ensure better success,” he said.
Prasad added that to revive NavIC, India now needs to ensure that the relaunch of NVS-2, along with subsequent launches of NVS-3 and NVS-4, is planned at the earliest.
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Where is India losing?
Experts said that India’s military agencies are at the biggest disadvantage due to the delay and mismanagement of NavIC.
With much of the global strategic scene now relying on space technologies, the failure of such important missions is not only crippling for India’s space programme but is also impacting the country’s military ambitions.
“Currently, for civilian purposes, commercial navigation systems are available. But it is for strategic use, when you want to rely on something homegrown, that NavIC would be the most useful,” Prasad said.
Other experts echoed the same sentiment.
Lele, who is also a retired Indian Air Force officer, said that India’s military assets currently rely on GPS and GLONASS for their military-grade navigation systems. All of India’s fourth and fifth-generation aircraft are complemented by the American and Russian systems.
“China, for instance, has its own navigation system (Beidou). Their military systems don’t have to rely on foreign navigation technology,” Lele said.
This year, another one of India’s strategic missions failed. The Polar Satellite Launch Vehicle C-62 (PSLV-C62) mission, carrying EOS-N1 or Anvesha—an earth observation satellite built by India’s Defence Research and Development Organisation (DRDO)—could not be placed into the intended orbit.
The satellite was a hyperspectral imaging satellite, designed to identify materials beneath multiple layers, such as camouflaged weapons and tanks, and to detect illegal movements around national borders. These details are missed by the human eye and even by conventional optical-imaging satellites.
(Edited by Saptak Datta)