Coming from someone who has been involved in the subject in one way or another for nearly 20 years, this might seem a strange question. Try to ask a planetary scientist what a "planet" is and you will see the dilemma. The term "planet" was officially defined (for now) by the International Astronomical Union (IAU) 10 years ago this month when the (now) dwarf planet Eris (formerly the Kuiper belt asteroid 2003UB313) was making major headlines and the (then) planet Pluto had metaphorical crosshairs placed upon it by those who thought that the tiny world was unfit for planet-hood. Getting back to the point of the article, the term "Space Surveillance" is one of those unfortunate nomenclatures that doesn't really describe what it actually does.

    First, let's split the term "Space Surveillance" into its two component parts, namely "space" and "surveillance". The "space" part implies all of space, namely everything outside of the Earth's atmosphere (or wherever space actually begins; another debate in itself). Therefore, "space" implies all orbiting satellites of Earth (including the Moon), the remaining solar system, the Milky Way, all of the galaxies (known and unknown) and ultimately the entire universe. Those who study the subject know that "Space Surveillance" deals mainly with all artificial objects orbiting the Earth, which obviously excludes the Moon and all other natural objects in the cosmos. This begs the question of where "Space Surveillance" ends and where "Astronomy" begins, since space and astronomy are intricately linked. Is "Space Surveillance" simply a branch of astronomy, or is it to be treated as an entirely different science?

    At the risk of being too general, astronomy deals with the science of the heavens and the cosmos, which could include the Earth in some respects, since the Earth is indeed a known member of our universe (at the risk of sounding too possessive). There are indeed braches of astronomy, such as stellar astronomy (stars), planetary astronomy (planets), galactic astronomy (galaxies), infrared astronomy (detecting and analyzing infra-red radiation from stars, galaxies, etc.), and many others that are much more specific than the general term "astronomy". Why is there not a branch of astronomy called "satellite astronomy" or "artificial satellite astronomy" that deals with the science of artificial satellite surveillance? Actually, the term "satellite astronomy" does exist, but it refers to using space-based telescopes (such as the Hubble Space Telescope) to study the heavens. Consequently, the term "ground-based astronomy" also exists to distinguish Earth-bound telescopes from their space-based counterparts.

    A possible reason for the missing "artificial satellite astronomy" discipline might stem from the political conditions from whence Space Surveillance began. On October 4, 1957, the Sputnik I satellite was launched from the (then) Soviet Union. On the other side of the world, Americans panicked, thinking that the delivery of nuclear payloads was just around the corner. The United States reacted by creating NASA and subsequently trained the country's radar installations, under the control of the U.S. military, to survey the skies for any artificial satellites (in addition to foreign aircraft and missiles). This mandate continued until the present day, even when the artificial satellite population grew from 2 tracked objects (Sputnik and the rocket that launched it) to nearly 20,000 tracked objects (too numerous to name here). "Space Surveillance" was likely a term coined by the U.S. military to describe its surveillance of any Earth-orbiting object. At that time, astronomy could not really participate to satellite surveillance in a meaningful way because the technology was not yet available to academia and certainly not to the general public. Most optical telescopes could not detect orbiting satellites because the detectors (film cameras) were not sensitive enough to detect and track quickly moving low Earth orbit (LEO) satellites unless the telescope apertures were very large. However, some worldwide programs existed that relied on visual observations to collect satellite tracking data (time and position measurements). Some of these programs existed into the 1970s.

    In the 1990's, the detection technology caught up with the demands of "Space Surveillance". The charge-coupled device (CCD) camera revolutionized astronomy and "Space Surveillance" alike, allowing amateur astronomers to collect satellite tracking data with much smaller-aperture telescopes. This is because the CCD had a quantum efficiency (percentage of light photons that were detected as electron current) many times larger than film. Instead of requiring aperture over one metre, a telescope of under 30cm was capable of detecting and tracking satellites. Retail computers were also much more capable than its earlier counterparts, allowing amateur astronomers to control their telescopes and CCDs with computers and to conduct satellite photometry and satellite astrometry. Automated and remotely controlled observatories were springing up all over the world, including Canada's first automated ground-based satellite tracking observatory, CASTOR, at the Royal Military College of Canada in late 1999, designed by yours truly.

    By the 1990's "Space Surveillance" was already a well-established term that generally meant the surveillance of all detectable artificial satellites orbiting the Earth. However, is the term now outdated? From the 1950s to the 1990s, the term was mainly in the realm of the military and government. Today, private companies are beginning their own satellite surveillance capabilities, possibly in response to the February 2009 Iridium-33 / Cosmos-2251 satellite collision. This web site is devoted to the subject of space surveillance because the author believes that the subject should be intensely studied by government, academia, industry and the public alike in order to solve the most pressing problems posed by the overpopulation of satellites. Today, there should be few secrets in space because we cannot afford to hide critical information that could be used to prevent the next major collision or to prevent terrorist acts in space. Now that "Space Surveillance" includes participants from all walks of life (from the top of government down to a private citizen), does the term really define what is happening now? Is it only "surveillance", or is there much more?

    This leads us to the "surveillance" part of the term. "Surveillance" implies watching or observing. Are all "space surveillance" professionals really observing satellites all the time? Some are theorists that do not observe in any way. Some are astrodynamicists who study the motions of satellites but do not observe them. Another phrase can be used: "space science". Again, this sounds too general (the general "space" part is still there), but at least "surveillance" has been replaced with "science" and therefore is more inclusive of everyone involved.

    If we assume that "Space Surveillance" is restricted to observing satellites in some manner and possibly analyzing these observations, whether to determine a satellite's orbit, attitude, identity, or other characteristic, does the term really convey all of that information? When satellites were simply tracked to determine their orbits from the 1950s to the 1990s, the term "Space Surveillance" could convey all that was actually done. Now that we can study satellites in so much more detail and in some cases resolve the satellite themselves, should this term be expanded, changed or left alone? Like the term "planet", the definition has been forcibly changed to fit the times. Is this like stuffing too much toothpaste into a tube of limited volume?

    The terms "Space Surveillance" and "Space Science" sound too general to describe what is actually happening. Perhaps a name change is in order. Perhaps creating sub-categories (like those created for astronomy) would be better. Terms such as "satellite tracking", "satellite identification" and "satellite photometry", to name just a few, can replace the overall general term. Perhaps "satellite science" can adopted. Of course, this is all wishful thinking, but if Sputnik caused the term "space surveillance" to come into being, maybe another equally important satellite event will cause another term to be adopted and make us think about the individual scientific aspects of space surveillance.

    What does the term "Space Surveillance" really stand for today? This would likely depend on who you ask, which is a problem, since nobody will know what it truly means unless the person is involved with it in some manner and defines the term in his/her own way. Maybe the meaning of the term should be more objective, much like the term "planet" was prior to August 2006, until the subject matures a little more. "Space Surveillance" is, after all, the infant sibling of astronomy and therefore should be allowed to grow and develop naturally with the times.