United States
2007 – Probes
There are ## scientific satellites in orbit around Earth, as designated by the AGI satellite database. This number may vary slightly by source, as some satellites may be alternatively classified as either “scientific” or “remote sensing.”
2007 – Landers/Rovers
Surface systems include all systems that operate on the surface of an asteroid, comet, or planet other than Earth, for instance, NASA’s Mars Rovers, Spirit and Opportunity. The planned 90-day mission for these vehicles has lasted for 45 months, greatly increasing scientific knowledge of Mars.
2007 – GPS
The U.S. Navigation Signal Timing and Ranging Global Positioning System (NAVSTAR GPS or GPS) continues to be the only fully operational navigation constellation and therefore the most popular. GPS consists of ## active satellites in ## medium Earth orbit planes. According to the Department of Defense (DoD), “the fundamental concept of GPS is to use simultaneous distance measurements from ## satellites to compute the position and time of any receiver.” The GPS signal is available at no cost to users around the world and has spawned many commercial applications.
2007 – Human Settlements
NASA’s future exploration plans include outposts on the Moon, though many of the details and specifications for these habitats are yet to be determined. According to NASA: “Astronauts will set up a lunar outpost — possibly near a south pole site called Shackleton Crater — where they’ll conduct scientific research, as well as test technologies and techniques for possible exploration of Mars and other destinations.”
2007 – Bigelow Space Stations
An entrepreneurial company, Bigelow Aerospace, is developing an in-space platform based on inflatable technology originally conceived in NASA’s TransHab program. It is building modules that can be used as platforms for in-orbit accommodations, research, and training. Bigelow has launched two prototypes into orbit: Genesis I in July 2006 and Genesis II in June 2007.
2007 – ISS
The largest in-space platform ever constructed is the International Space Station (ISS). The development of the ISS, led by the United States, “draws upon the scientific and technological resources of 16 nations: the United States, Canada, Japan, Russia, 11 nations of the European Space Agency, and Brazil,” according to NASA.[
2007 – Military Reconnaissance
AGI designates remote sensing satellites as surveillance/military satellites. Exhibit 3p (below) provides the number of these satellites by country. AGI reports ## active U.S. surveillance/military satellites that it designates as having “unavailable” orbital parameters. In addition, the line between some remote sensing and Earth science satellite classifications is not always clear-cut.
2007 – Land Imaging
Remote sensing satellites provide images of the Earth for civil, scientific, military, and intelligence applications using a number of different technologies.
2007 – ICBMs and SLBMs
Long-range missiles travel through space, reaching apogees of 950-1100 kilometers, or about five times the altitude of what is generally considered the threshold of low Earth orbit. Intercontinental Ballistic Missiles (ICBM) and Submarine Launched Ballistic Missiles (SLBM) are intended to carry a warhead, typically nuclear, as a payload on a suborbital ballistic trajectory. In the United States, ICBMs fall under the purview of U.S. Air Force Space Command. Funding for their maintenance and operation falls within the major force program for DoD space spending.
2007 – Orbital Launch Reports and Forecasts
The FAA’s Office of Commercial Space Transportation (FAA/AST) and the Commercial Space Transportation Advisory Committee (COMSTAC) prepare an annual forecast of global demand for commercial launch services. COMSTAC is a group of senior executives from space transportation, satellite, and government organizations.