AIR POWER DEVELOPMENT CENTRE BULLETIN

Space Situational awareneSS

Since 1957, when the first man-made object was placed into earth’s orbit, space has increasingly become a key enabler for nearly all military, governmental, commercial, and individual operations. From mobile phones to precision weapons, the explosion of electronics into almost all facets of modern-life has placed increasingly greater importance on space-based capabilities.

However, space—though an isolated and seemingly empty region—is becoming increasingly congested with active satellites and discarded space junk. Maintaining an awareness of the position and trajectory of these objects is important when the relative speed of closure between objects can be as high as 14 kilometres per second. The vulnerability of a space asset to a collision with even a minute piece of space junk makes Space Situational Awareness (SSA) an absolute necessity to successful operations in the space domain.

Military forces around the world are increasingly reliant on space based capabilities for communications, positioning, timing, and surveillance to enable the delivery of their primary effects. SSA provides the operators of space-based capabilities the ability to anticipate the influence of other space objects and take action to ensure continued and unimpeded operation of space vehicles. Commanders and decision makers use SSA to leverage the capabilities of space-based

systems while exploiting the associated vulnerabilities of an adversary. SSA is provided through the tracking, classification, and identification of space-based objects.

Air power is heavily dependent on space-based technology. Satellite communications deliver information in a timely manner to deployed forces to ensure mission effectiveness. Global Navigation Satellite Systems, primarily the US Global Positioning System, provide accurate positioning, navigation and

timing information to support Australian Defence Force (ADF) operations. Intelligence, surveillance and reconnaissance activities provide remote sensing products—such as imagery, missile and other threat warnings—and signals intelligence products as an enabler in creating air power and joint operations effects. Meteorological services are also reliant on space based products, with these products providing vital information that enhance air, land and maritime operations. The loss of all or any one of these space-based services,

and their associated products, will have a detrimental effect on joint operations through a reduction in mission effectiveness.

The growing dependence on space systems within the ADF, the increasing number of foreign space systems, and the rapidly increasing amount of space debris, constitute a growing vulnerability to operations. SSA provides the foundation for safe and responsible space

Issue 193, February 2013

The space environment has become increasingly congested, contested and competitive. Operating within space is correspondingly more uncertain than ever in our past. Addressing the changes in the environment requires strategically rethinking our processes, integrating extra flexibility in our planning, improving our awareness of the space environment and expanding our collaboration with all space faring nations and corporations.

—Lieutenant General Susan J. Helms, Commander US Joint Functional Component Command for Space, March 2011.

A Defence payload on an Intelsat communications satellite launched on 25 March 2012.

operations. SSA is the fusion of many sources of data to predict, detect and provide warnings of any threats to space assets in order to ensure access to and protection of critical space capabilities. So what is involved in SSA? The various elements of SSA include: surveillance of space objects; knowledge of space weather; space object identification; and intelligence on space object capabilities and intent.

One of the key elements of SSA is the knowledge of the location of objects in Earth orbit. This is achieved through surveillance of space, which is the observation (both passive and/or active) of objects in orbit around the Earth. Surveillance of space involves the detection, tracking, identification and cataloguing of space objects using a global network of space surveillance sensors. Radars, both conventional and phased-array, provide the backbone of any space surveillance network. They are capable of providing 24-hour operations in nearly all weather conditions. Phased array systems are capable of tracking multiple objects simultaneously and scanning large portions of space rapidly. Optical telescopes provide the second major type of space surveillance sensor. They are passive systems which rely upon the light reflected from a space object that is incident upon the sensor, typically a digital camera. Optical telescopes are able to cover large areas of space quickly and have a greater range than radars. However, they are not capable of 24-hour operations as they are affected by daylight and weather.

In addition to the traditional radar and optical tracking sensors, there are also other more specialised sensors which contribute to SSA. These include lasers for very accurate distance measurements, infrared sensors which detect heat, telescopes which take pictures of space objects, sensors which detect electronic emissions from space objects, and specialised imaging radars which create images of the objects. All of these various passive and active sensors can be located on the Earth, or onboard satellites in orbit.

There are several space surveillance networks involving amateur satellite observers, the scientific community and the military. The most prominent of these networks is the US Air Force Space Surveillance Network (SSN), which maintains the most complete catalogue of space objects. This is a network of 29 radar and optical sensors, and includes a US military operated space-based telescope onboard the Space-Based Surveillance Satellite. However, there is a limitation in the SSN, in that there is little to no coverage from the Southern Hemisphere and Asia.

Once positional data is obtained from the SSN, it is fused with the other elements of SSA to form an overall space picture (analogous to the air and sea picture). This space picture includes intelligence data on the capabilities, limitations, vulnerabilities of the system, and the doctrine and tactics of the state that owns and operates the system. Additionally, the environmental conditions are monitored and analysed, in order to anticipate terrestrial and space weather events, solar activity, and atmospheric weather effects. SSA also looks for any natural near-earth objects or potentially hazardous asteroids that may pose a threat to space objects and capabilities.

In 2010, Australia and the US signed an SSA Partnership Statement of Principles that recognises the importance of SSA to protect national interests, and support global peace and security. At the 2012 Australia-US Ministerial consultations, both nations affirmed their intention to relocate two space surveillance sensors—a C-Band space surveillance radar and a highly advanced Space Surveillance Telescope—from the US to Australia to strengthen the SSN’s ability to track space objects and debris.

Within the ADF, the Australian Space Operations Centre (AUSSpOC) provides operational SSA utilising indigenous and coalition space assets to Government and operational commanders. AUSSpOC is located in the Air and Space Operations Centre within the Headquarters Joint Operations Command.

Space continues to be an essential enabler for the ADF in general and the Air Force specifically. Nearly every air power effect delivered by the Air Force is enabled by space operations to some degree. SSA is central to the continued delivery of space capabilities and its importance to air power continues to grow.

Key points• Space is becoming more congested, contested and

competitive from over 50 years of space activities and the significant increase in space debris.

• Surveillance of space is conducted by a network of sensors.

• In 2012, Australia and the US agreed to locate a C-Band space surveillance radar and a highly advanced Space Surveillance Telescope to Australia, enhancing their joint SSA capabilities.

Air Power Development CentreF3-GF, PO Box 7932, Department of Defence

CANBERRA BC ACT 2610Ph: 02 6128 7041 Fax: 02 6128 7053

Email: airpower@defence.gov.auWeb: www.airforce.gov.au/airpower

Disclaimer: The views in this Pathfinder are not necessarily those of the RAAF