India is a unique player in the space industry. Historically its space program has had a developmental focus that distinguishes it from the more militarily-oriented American and Russian programs. But India’s space focus is changing, as exemplified by Prime Minister Narendra Modi’s recent announcement of plans to carry out a manned space mission by 2020.
Recent years have seen several high-profile Indian missions. In 2008, India launched its Chandrayaan-1 to the moon. In 2014, its Mangalyaan spacecraft orbited Mars. More recently, India has developed its status as a launch services provider. A major driver of India’s growing space ambitions is its rivalry with China, which is also rapidly becoming a major space power.
Similar to the growth of private-public partnerships in the American space sector, the Indian Space Research Organization (ISRO) is increasingly looking to collaborate with private firms. A draft Space Activities Bill would facilitate firms’ participation in designing and launching satellites. Bringing in firms would develop local industry and allow ISRO to refocus its resources.
To learn more about India’s space industry, Filling Space spoke with Mayank Vahia, an astrophysicist working at the Tata Institute of Fundamental Research.
What drives India’s desires to develop its space program?
India is a large country with a vast mix of cultures, a growing economy, varied landscapes, and a challenging political environment. Reaching all corners of the country through ground communication and monitoring is therefore a mammoth task in terms of installation and maintenance costs. It is therefore obvious that India should want to use space to maximize a whole host of operational parameters of governance, monitoring, resource exploitation, disaster management, and national security.
How did India’s space program develop?
The program began with one of the great visionaries of India, Vikram Sarabhai. Encouraged by Homi Bhabha, who initiated India’s nuclear program and was supported by India’s first Prime Minister Jawaharlal Nehru, Sarabhai laid the foundation of the program. The program originally began with American assistance in sending up sounding rockets that went up to 100 kilometers. Sarabhai soon realized the need for complete indigenization. Today, India’s program owes no credit to any other nation. In its endeavor, the Indian program has made its mark with the reliable Polar Satellite Launch Vehicle (PSLV) launch vehicle and as a fine designer of satellites. India’s space program has made India nearly self-reliant in the exploration of space. We not only make and operate our own communication and Earth-observing satellites, we also participate in space programs to explore other worlds.
What are the main features of India’s space program?
India’s space program has two main components: rockets, the vehicles that take payloads into space; and satellites, the payloads that go into space. Rockets are tricky since they have to accelerate an object from rest to about 11 kilometers per second (km/s) in a matter of a few minutes. Few rocket engines can do this singlehandedly. So typically, the rocket that we see as one rocket is in fact three or four rockets sitting on top of each other. The lowest rocket carries the upper rockets to a certain height and then disengages so that the second rocket can be ignited to take the payload further into space and so on, until the payload or payloads that the rocket carries are put into their desired orbit.
Amongst the rockets, India’s work horse, the Polar Satellite Launch Vehicle (PSLV), can take a payload into an orbit up to 800 km. Originally designed to put payloads into polar orbit (rotating from North pole to South Pole), it has now been modified for a variety of uses. The PSLV recently had its 44th launch that met its objectives. It has launched national and international satellites and even holds a record for carrying multiple satellites in a single launch (104 in 2017). Costing about $25 million, the PSLV is one of the most cost-effective launch vehicles for a medium size payload.
However, the PSLV is not very large and can only take a maximum of 2,000 kg of objects into space. India is now in the final stages of testing and approving a far bigger Geosynchronous Satellite Launch Vehicle, or GSLV (Mark 3), which will carry about 5,000 kg into space. We will then be able to launch our own communication satellites which we currently launch using foreign rockets.
Turning to satellites, they have distinct challenges of their own. A satellite must withstand being accelerated from 0 km/s to 11 km/s in a matter of few minutes. It must be packed into an extremely small volume – typically a payload bay a couple of meters in diameter and height. Once in space, it must generate its own power through solar panels, and withstand the harsh environment of outer space. Once launched, a satellite, in general, cannot be repaired. So, it must also be extremely reliable.
Satellites may revolve around Earth or go on interplanetary missions. They may be used for observing Earth or observing space, free from interference of the atmosphere. When satellites observe Earth, it is preferable that they are kept in an orbit that goes from pole to pole so that as they complete their revolution, Earth, spinning under them, will allow the satellite to see the whole planet with minimal effort. Communications and weather monitoring satellites are slightly different; they need to be geostationary, meaning they should move with Earth so that they complete one rotation per day and thus appear stationary to us. They need to be at an altitude of about 36,000 km so that their revolution period is 24 hours.
India uses satellites in two kinds of global positioning systems, both of which are valuable. The first is GPS-aided GEO augmented navigation (GAGAN), which is used for civilian purposes to help guide aircrafts and ships in their navigation. GAGAN sits on the American GPS satellites and improves its accuracy from 10 meters to 3 meters using a series of ground stations and three geostationary satellites (GSAT 8, GSAT 10 and GSAT 15)
The second system is Navigation with Indian Constellation (NAVIC), also called Indian Regional Navigation Satellite System (IRNSS). NAVIC is entirely indigenous and uses a combination of five of our geostationary satellites (IRNSS 1A to 1G). Out of these, IRNSS 1C is geostationary while the others are geosynchronous. That is, they go around Earth once every 24 hours but are at an inclination to the equator that gives them a slight vertical motion. NAVIC can thus provide a highly accurate positioning system for all Indian needs in the civilian and defense arenas.
What are future plans for India’s space program?
India has a vibrant space exploration program and this will continue to grow. We have sent one mission each to the Moon and to Mars, flown astronomy payloads on several satellites, and now have a completely dedicated astronomy satellite. India’s Chandrayaan-1 mission was the first satellite that provided unequivocal evidence that there is water on the Moon – soaked in its soil like water in a sponge. Chandrayaan-1’s nine months of operation demonstrated India’s ability to use Earth’s gravity as an effective slingshot allowing us to send a mission to the Moon with much less fuel than other missions. Mangalyaan-1 again used Earth’s gravity as a slingshot, establishing our ability to send a mission even further; reaching Mars is like hitting a two-centimeter coin one kilometer away with a grain of sand moving at 24 km/s.
India is now looking forward to Chandrayaan-2 which will involve a rover, and also to the launch of Mangalyaan-2. India furthermore plans to put up an Aditya satellite to observe the Sun from the inner Lagrangian point. ISRO is providing excellent opportunities to Indian space explorers to learn about the universe. And it has an ambition of putting humans in space within the next four years. As mentioned above, India has now tested its next generation launch vehicle, the GSLV, which will serve future needs by being able to carry payloads of up to 5,000 kg. Finally, India is developing a unique program called Student Sat. It features small payloads, typically one-meter cubes with 10 watts of power that are designed by university students with the help of ISRO. This program helps students learn about the complexity of space.