Space Situational Awareness (SSA) can be described in the broadest sense as knowledge of the energy and particle fluxes in near-Earth area, as well as natural and manmade objects travelling through or orbiting inside this space, as well as their past, present, and future states. At this point, the region of near-Earth space may be left a little hazy. Space Situational Awareness (SSA) refers to the ability to view, comprehend, and forecast the physical location of natural and manmade objects.
Space Situational Awareness (SSA) is critical to ensuring that space activities are carried out safely and in conformity with national and international laws, rules, and other guidelines. It entails being aware of potential hazards to space activities as well as knowing the space environment. Issues such as orbital collisions between space objects and space debris can be avoided with SSA. Operators must be aware of their legal responsibilities, which include liability, ownership, and control over space objects.
Operators can carry out missions securely, decrease the chance of collisions, and prevent interfering with the space activities of other entities or nations by knowing where space objects are positioned in orbit, their orbital trajectories, and their status. SSA also entails spotting potentially damaging natural phenomena in space, such as electro-magnetic interference and asteroids posing a threat to spacecraft.
A variety of existing technologies and SSA services can be used to achieve SSA. The tracking of space objects via ground stations, accessing space-object tracking databases, and the launch of space-based SSA hardware are all examples of such technologies and services. These techniques allow operators to achieve various levels of awareness that are tailored to their specific needs and goals.
SSA is critical for maintaining dominance is space. Observation of hostile space operations, such as undeclared satellite launches, parasitic satellites, orbital parameters, in-orbit purposeful moves during a war scenario, space robotic activities, and the use of satellites. Monitoring the launches of hostile missiles in order to improve ballistic missile defence warning system is another critical aspect as the emerging threats such as supersonic missiles is rising. SSA is also involves identify orbiting space objects, assess their danger, determine ownership, and estimate an adversary’s likely intention and use. Communication Intelligence (COMINT) and Electronic Intelligence (ELINT) of opponents’ space assets are included in Signal Intelligence (SIGINT) and is vital for cataloguing all the opponents’ space assets and their capabilities.
Japan has an issue of aging SSA systems, its radar and telescopes are more than 10 years old. Current radar system can old observe about 5% of the space debris. Is LEO. Japanese space agency JAXA is planning to induct new observational radar to detect LEO debris. JAXA is also refurbishing its ground based telescopes to maintain its capability. JAXA is also overhauling the analysis system to process observations data and enable quicker collision avoidance.
Through its global Space Surveillance Network, which includes terrestrial radar and optical sensors as well as space-based sensors, the US military maintains the most modern SSA capacity. In the United States Marshall Islands, a second-generation space surveillance system known as Space Fence became active in 2020. Using radar, the number of objects that may be tracked is greatly increased, and many smaller objects can be detected in LEO.
The Russian Military Space Surveillance Network has a wide range of capabilities. It has been upgraded throughout time and now comprises ground-based electro-optical telescopes as well as phased array radars. The Automated Warning System on Hazardous Situations in Outer Space, operated by the Russian civilian space agency Roscosmos, uses data from the International Scientific Optical Network (ISON) and other Russian SSA assets. Russian radars cover the whole landmass of the former Soviet Union. Russian sensors are predominantly ground-based, with ship-based sensors supplementing them. Sensors mounted on ships give them flexibility and redundancy. Their SSA sensors are placed in Azerbaijan, Belarus, Kazakhstan, and Tajikistan, in addition to the Russian mainland.
China has significant tracking, telemetry, and control assets for satellites. It operates four telescopes at Nanjing’s Purple Mountain Observatory. China established a tracking station at Ngari in the Tibetan Autonomous Region (TAR) in 2013, allowing them to follow all Indian satellites11. China has also built a similar facility in Patagonia, Argentina, which is suspected of being used to track US military satellites. China has also built the world’s largest radio telescope with an aperture of 500 m here, dubbed ‘Heavenly Eye’ or ‘Tinyan.’
A long-range telescope in Leh, a radar in India’s northeast, and a Multi-Object Tracking Radar (MOTR) in Sriharikota, in southern India, will be among India’s SSA capabilities. There are optical-infrared observatories in India, including those in Bangalore, Pune, Mt. Abu, Nainital, and Hanle. MOTR has already been used for space debris proximity analysis throughout the powered and orbital phases of satellite launch, debris re-entry prediction, and TLE catalogue development. In actuality, the Indian GSAT-6A satellite was tracked using a telescope from the ARIES Devasthal Observatory.
Though SSA data involved data of military significance, various private companies have operate terrestrial telescopes and radar to collect SSA data. The sheer number of objects in space presents a huge challenge for SSA data collection and its accuracy.