Asteroid impact avoidance encompasses the methods by which near-Earth objects (NEO) on a potential collision course with Earth could be diverted away, preventing destructive impact events. An impact by a sufficiently large asteroid or other NEOs would cause, depending on its impact location, massive tsunamis or multiple firestorms, and an impact winter caused by the sunlight-blocking effect of large quantities of pulverized rock dust and other debris placed into the stratosphere. A collision 66 million years ago between the Earth and an object approximately 10 kilometers wide is thought to have produced the Chicxulub crater and triggered the Cretaceous–Paleogene extinction event that is understood by the scientific community to have caused the extinction of all non-avian dinosaurs.
The Infrared Astronomical Satellite (IRAS) was the first space telescope to perform a survey of the entire night sky at infrared wavelengths. Launched on 25 January 1983, its mission lasted ten months. The telescope was a joint project of the United States (NASA), the Netherlands (NIVR), and the United Kingdom (SERC). Over 250,000 infrared sources were observed at 12, 25, 60, and 100 micrometer wavelengths.
The Lincoln Near-Earth Asteroid Research (LINEAR) project is a collaboration of the United States Air Force, NASA, and the Massachusetts Institute of Technology's Lincoln Laboratory for the systematic detection and tracking of near-Earth objects. LINEAR was responsible for the majority of asteroid discoveries from 1998 until it was overtaken by the Catalina Sky Survey in 2005. As of 15 September 2011, LINEAR had detected 231,082 new small Solar System bodies, of which at least 2,423 were near-Earth asteroids and 279 were comets. The instruments used by the LINEAR program are located at Lincoln Laboratory's Experimental Test Site (ETS) on the White Sands Missile Range (WSMR) near Socorro, New Mexico.
A Schmidt camera, also referred to as the Schmidt telescope, is a catadioptric astrophotographic telescope designed to provide wide fields of view with limited aberrations. The design was invented by Bernhard Schmidt in 1930.
The Maui Space Surveillance Complex (MSSC) is a U.S. Space Force operating location for the 15th Space Surveillance Squadron and the Air Force Research Laboratory (AFRL) at Haleakala Observatory on Maui, Hawaii, with a twofold mission. First, it conducts the research and development mission on the Maui Space Surveillance System (MSSS) at the MSSC. Second, it oversees operation of the Maui High Performance Computing Center (MHPCC). AFRL's research and development mission on Maui was formally called Air Force Maui Optical Station (AMOS) and the Air Force Maui Optical and Supercomputing observatory; the use of the term AMOS has been widespread throughout the technical community for over thirty years and is still used today at many technical conferences. The main-belt asteroid 8721 AMOS is named after the project.
ROSAT was a German Aerospace Center-led satellite X-ray telescope, with instruments built by West Germany, the United Kingdom and the United States. It was launched on 1 June 1990, on a Delta II rocket from Cape Canaveral, on what was initially designed as an 18-month mission, with provision for up to five years of operation. ROSAT operated for over eight years, finally shutting down on 12 February 1999.
The United States Space Surveillance Network (SSN) detects, tracks, catalogs and identifies artificial objects orbiting Earth, e.g. active/inactive satellites, spent rocket bodies, or fragmentation debris. The system is the responsibility of United States Space Command and operated by the United States Space Force and its functions are:
The Kessler syndrome, proposed by NASA scientists Donald J. Kessler and Burton G. Cour-Palais in 1978, is a scenario in which the density of objects in low Earth orbit (LEO) due to space pollution is numerous enough that collisions between objects could cause a cascade in which each collision generates space debris that increases the likelihood of further collisions. In 2009, Kessler wrote that modeling results had concluded that the debris environment was already unstable, "such that any attempt to achieve a growth-free small debris environment by eliminating sources of past debris will likely fail because fragments from future collisions will be generated faster than atmospheric drag will remove them". One implication is that the distribution of debris in orbit could render space activities and the use of satellites in specific orbital ranges difficult for many generations.
The Midcourse Space Experiment (MSX) is a Ballistic Missile Defense Organization (BMDO) satellite experiment to map bright infrared sources in space. MSX offered the first system demonstration of technology in space to identify and track ballistic missiles during their midcourse flight phase.
The Space Fence is a second-generation space surveillance system operated by the United States Space Force in order to track artificial satellites and space debris in Earth orbit. It was constructed and designed by Lockheed Martin, Northrop Grumman, and Raytheon starting in 2009, with it being declared operational in March 2020. The budget is US$1.594 billion (FY15). The main facility is located at Kwajalein Atoll in the Marshall Islands.
The Medicina Radio Observatory is an astronomical observatory located 30 km from Bologna, Italy. It is operated by the Institute for Radio Astronomy of the National Institute for Astrophysics (INAF) of the government of Italy.
The Near Earth Object Surveillance Satellite (NEOSSat) is a Canadian microsatellite using a 15-cm aperture f/5.88 Maksutov telescope, with 3-axis stabilisation giving a pointing stability of ~2 arcseconds in a ~100 second exposure. It is funded by the Canadian Space Agency (CSA) and Defence Research and Development Canada (DRDC), and searches for interior-to-Earth-orbit (IEO) asteroids, at between 45 and 55 degree solar elongation and +40 to -40 degrees ecliptic latitude.
DFM Engineering is an American telescope and optics manufacturer founded in 1979 by Frank Melsheimer in Longmont, Colorado. DFM makes medium size Cassegrain telescopes and their associated systems including telescope optics, control systems, and mounts. A range of pre-designed telescopes are made, as are various custom installations. DFM produces its classical Cassegrain design in various apertures from 16 inches (0.4 m) to 50 inches (1.3 m) and larger. The base DFM 16-inch (40 cm) telescope system cost roughly 94 thousand USD in 2005.
Space domain awareness is the study and monitoring of satellites orbiting the Earth. It involves the detection, tracking, cataloging and identification of artificial objects, i.e. active/inactive satellites, spent rocket bodies, or fragmentation debris.
The Space Safety Programme, formerly the Space Situational Awareness (SSA) programme, is the European Space Agency's (ESA) initiative to monitor hazards from space, determine their risk, make this data available to the appropriate authorities and where possible, mitigate the threat.
Beam park is a radar mode used for space surveillance, particularly tracking space debris. In beam-park mode, a radar beam is kept in a fixed direction with respect to the Earth, while objects passing through the beam are tracked. In 24 hours, as a result of the Earth’s rotation, the radar effectively scans a narrow strip through 360° of the celestial sphere. The scattered waves are detected by a receiver and the measurements obtained during the observations can be used to determine object radar cross-section, time of peak occurrence, polarization ratio, doppler shift and object rotation. The obtained information for each object is then processed and matched against data from previously catalogued objects. The beam-park mode can be used to detect both previously known and uncatalogued objects at any altitude, provided that the reflected power captured by the receiver can be distinguished from the noise. This limits the use of radar-based beam park observations to objects in Low-Earth Orbit (LEO). Optical instruments, in turn, have very good performance for objects in Geostationary Earth Orbit (GEO) and in Geostationary Transfer Orbit (GTO). The radar technique typically outperforms optical facilities in LEO and can conduct observations for longer periods, both during day and night, independently of the weather and object illumination by sunlight.
Double Asteroid Redirection Test (DART) was a NASA space mission aimed at testing a method of planetary defense against near-Earth objects (NEOs). It was designed to assess how much a spacecraft impact deflects an asteroid through its transfer of momentum when hitting the asteroid head-on. The selected target asteroid, Dimorphos, is a minor-planet moon of the asteroid Didymos; neither asteroid poses an impact threat to Earth, but their joint characteristics made them an ideal benchmarking target. Launched on 24 November 2021, the DART spacecraft successfully collided with Dimorphos on 26 September 2022 at 23:14 UTC about 11 million kilometers from Earth. The collision shortened Dimorphos' orbit by 32 minutes, greatly in excess of the pre-defined success threshold of 73 seconds. DART's success in deflecting Dimorphos was due to the momentum transfer associated with the recoil of the ejected debris, which was substantially larger than that caused by the impact itself.
Asteroid impact prediction is the prediction of the dates and times of asteroids impacting Earth, along with the locations and severities of the impacts.
The Near Earth Object Survey TELescope is an astronomical survey and early-warning system for detecting near-Earth objects sized 40 metres and above a few weeks before they impact Earth.
Tip and cue, sometimes referred to as tip and que, tipping and cueing, or tipping and queing, is a method for satellite imagery and reconnaissance satellites to automatically coordinate tracking of objects across different satellites in real or near real-time. This technique ensures continuous tracking of targets as they move across different regions by handing them off between satellites, sharing satellite imagery and collateral across discrete satellites. The coordination between various satellites and their complementary sensors allows for more accurate and efficient data collection. This system is particularly useful in scenarios requiring real-time monitoring and rapid response; the method significantly improves situational awareness and operational effectiveness.
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