From the archives: Wanted: traffic policemen for space

[Reposted from the Nature India archives. Eminent scientist, India's ex-President and author of this article APJ Abdul Kalam passed away on 27 July, 2015 of cardiac arrest while delivering a lecture at Indian Institute of Management, Shillong.]

The geo-synchronous orbit is full with 240 satellites sent to space by many countries across the world. Add to that over 800 active satellites in various other orbits. It’s an astounding satellite population out there – let’s not forget the number of military satellites for communication and reconnaissance. These high-value technological assets need fierce protection to ensure continuous service. And the global space community has to have a vision to keep these satellites safe and going.

As I embark on my discussion on space safety and security, I am reminded of my joint family in Rameswaram, a small island in southern part of India, where a number of us brothers and a sister lived together. I was the last fellow. I keenly witnessed my mother keep all her children connected in spite of their varying needs and personalities. I used to ask myself, how does she keep us united despite such amazing diversity? It was only through the inherent pure love of the mother.

During the last five decades, I have seen how many successes and a few failures of space programmes helped connect countries around the globe. Whenever a major space event takes place – man landing on the moon, first series of communication satellites in the geo-synchronous orbit or remote sensing satellites in polar orbit, NASA astronauts, including Sunita Williams, descending on earth on a rainy day – it captures the attention of the entire planet. Events in space have in a way integrated the world, like the mother unifying the family. The question is: can we use space to transform earth into a homogenously prosperous place without poverty or fear of war?

Comprehensive Space Security

When enormous societal and economic commitments have been made by nations with space infrastructure, the main security concern is that outer space should be free of weapons. Countries must recognize the necessity for the world space community to avoid terrestrial geo-political conflicts to be drawn into outer space thus threatening space assets belonging to humanity.

Multilateral approaches are required to ensure that the use of outer space is in conformity with international law and in the interest of maintaining peace and security and promoting international cooperation. To this end, I can envisage creation of an International Space Force (ISF) by all space faring nations, which will enable peaceful use of space on a global cooperative basis.

I am of the view that the present capabilities of major space faring nations are not optimally utilized. The launch vehicles, spacecraft, application potential and scientific research potential of the world call for a paradigm shift in national policies to nurture collaborations. The huge costs involved also make it a fit case for collaboration. My experience says this can happen only if nations involved contribute substantially by way of technology and resources.

The next 50 years

Here, I cite two successful Indian experiences in international cooperation – one, a joint venture between India and Russia with the shared funding of $300 million that has resulted in the production of the world’s first super sonic cruise missile Brahmos. Second is the pan-African e-network initiative worth $100 million, to connect 53 pan African nations to provide education, healthcare and e-governance services.

USA, Europe and other countries have many similar experiences in hard cooperation. These experiences give me the confidence that hard international cooperation can indeed accelerate the application of space science and technology leading to fast results for societal application.

This in itself will aid the security dimension in space. In an ideal situation, two international teams could be formed to come up with alternative proposals and investments to achieve the goal of low cost access to space. This would enable taking up mass missions that are not in the realm of individual nations. A world space vision can trigger many young minds towards hitherto "impossible" challenges.

With the background and strength of technological progress in space systems in the world, we must have in place a World Space Vision 2050 that takes into account the components of large scale societal missions and low cost access to space, comprehensive space security, exploration and current application missions.

In this context, I suggest the international space community to consider creation of a World Space Council to formulate and implement the World Space Vision. The council with global participation could oversee the planning and implementation of exploration, space security and societal missions. Such a unified approach will enable the world to see a quantum jump in the progress in space science and technology for the benefit of all.

Indian space studies

Studies in India have shown that the smallest size reusable space launch vehicle, weighing about 25-30 tonnes can be developed with high payload fractions. This can gather air in the cruise phase, liquefy it and then separate the liquid oxygen for on-board storage while the spacecraft ascends directly from earth to orbit. These studies suggest that an "aerobic" space transportation vehicle can have a 15 per cent payload fraction for a launch weight of 270 tonnes. This type of trans-atmospheric space transportation system has the potential to increase the payload fraction to 30 per cent for higher take off weight.

India is working on both single and two-stage reusable launch vehicles with the goal of reducing the cost of access to space by one or two orders of magnitude. Scientific breakthrough, for example, in air breathing propulsion systems may lead to a revolution in space transportation. Space communities of the world have a huge stake in such breakthrough research in advanced inter-disciplinary and inter-institutional collaboration.

More critical technology needed

The real value of future societal space missions, like energy from space and seawater desalination using space solar power can only be realized if we build fully reusable space transportation systems with very high payload efficiency. Several technologies such as in-flight air collection and oxygen liquefaction technology, ram or scramjet engines, ascent turbojets and advanced light weight high temperature materials need to be developed.

It is essential that these new technologies are flight-tested comprehensively over the entire speed and height regimes that are common to the role of trans-atmospheric vehicles in space transportation. A multi-role system architecture is required. Such vehicles will have to comprehensively demonstrate all special attributes of fully reusable space transportation for a safe, affordable flight to space, as well as those attributes related to intercontinental passenger aviation.

Spacecraft orbiting the Geosynchronous Equatorial Orbit (GEO) are very high value resources. However, the life of these spacecraft is a function of component failure, capacity of fuel, internal energy systems and space environment. While new design practices and technologies are constantly increasing the life of satellite, there is a requirement for extending the life of satellite through in-orbit maintenance such as diagnosis, replacement, recharging, powering, refueling or de-boosting after use.

This calls for creation of space satellite service stations for all the spacecraft in the GEO as a permanent international facility. Future satellites and payloads will also have to be designed with self-healing capability and midlife maintenance.