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62-590: The Lunar Reconnaissance Orbiter ( LRO ) is a NASA robotic spacecraft currently orbiting the Moon in an eccentric polar mapping orbit . Data collected by LRO have been described as essential for planning NASA's future human and robotic missions to the Moon. Its detailed mapping program is identifying safe landing sites, locating potential resources on the Moon, characterizing the radiation environment, and demonstrating new technologies. Launched on June 18, 2009, in conjunction with

124-580: A 58-centimeter (23 in) sphere which weighed 83.6 kilograms (184 lb). Explorer 1 carried sensors which confirmed the existence of the Van Allen belts, a major scientific discovery at the time, while Sputnik 1 carried no scientific sensors. On 17 March 1958, the US orbited its second satellite, Vanguard 1 , which was about the size of a grapefruit, and which remains in a 670-by-3,850-kilometre (360 by 2,080 nmi) orbit as of 2016 . The first attempted lunar probe

186-522: A considerable amount of time, is to follow a trajectory on the Interplanetary Transport Network . A space telescope or space observatory is a telescope in outer space used to observe astronomical objects. Space telescopes avoid the filtering and distortion of electromagnetic radiation which they observe, and avoid light pollution which ground-based observatories encounter. They are divided into two types: satellites which map

248-549: A descent through that atmosphere towards an intended/targeted region of scientific value, and a safe landing that guarantees the integrity of the instrumentation on the craft is preserved. While the robotic spacecraft is going through those parts, it must also be capable of estimating its position compared to the surface in order to ensure reliable control of itself and its ability to maneuver well. The robotic spacecraft must also efficiently perform hazard assessment and trajectory adjustments in real time to avoid hazards. To achieve this,

310-433: A positively charged atom. The positively charged ions are guided to pass through positively charged grids that contains thousands of precise aligned holes are running at high voltages. Then, the aligned positively charged ions accelerates through a negative charged accelerator grid that further increases the speed of the ions up to 40 kilometres per second (90,000 mph). The momentum of these positively charged ions provides

372-611: A pre-programmed list of operations that will be executed unless otherwise instructed. A robotic spacecraft for scientific measurements is often called a space probe or space observatory . Many space missions are more suited to telerobotic rather than crewed operation, due to lower cost and risk factors. In addition, some planetary destinations such as Venus or the vicinity of Jupiter are too hostile for human survival, given current technology. Outer planets such as Saturn , Uranus , and Neptune are too distant to reach with current crewed spaceflight technology, so telerobotic probes are

434-553: A region in the lunar highlands south of Mare Nubium ( Sea of Clouds ). The total cost of the mission is reported as US$ 583 million, of which $ 504 million pertains to the main LRO probe and $ 79 million to the LCROSS satellite. LRO has enough fuel to continue operations until at least 2026. Developed at NASA's Goddard Space Flight Center , LRO is a large (1,916 kg/4,224 lb) and sophisticated spacecraft. Its mission duration

496-410: Is eroded and uneven, with prominent ridges at the northern and southern ends. A small crater lies across the northeastern rim and there is 10–11 km crater on the interior floor near the west-southwestern rim. Near the center of the crater floor is a small ridge. The floor of the crater has an average depth of 4 km and it is 60 km across. The slope of the crater walls is 10–15°. Because of

558-441: Is increased fuel consumption or it is a physical hazard such as a poor landing spot in a crater or cliff side that would make landing very not ideal (hazard assessment). In planetary exploration missions involving robotic spacecraft, there are three key parts in the processes of landing on the surface of the planet to ensure a safe and successful landing. This process includes an entry into the planetary gravity field and atmosphere,

620-457: Is not one universally used propulsion system: monopropellant, bipropellant, ion propulsion, etc. Each propulsion system generates thrust in slightly different ways with each system having its own advantages and disadvantages. But, most spacecraft propulsion today is based on rocket engines. The general idea behind rocket engines is that when an oxidizer meets the fuel source, there is explosive release of energy and heat at high speeds, which propels

682-419: Is the same as that of monopropellant propulsion system: very dangerous to manufacture, store, and transport. An ion propulsion system is a type of engine that generates thrust by the means of electron bombardment or the acceleration of ions. By shooting high-energy electrons to a propellant atom (neutrally charge), it removes electrons from the propellant atom and this results in the propellant atom becoming

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744-426: Is unique because it requires no ignition system, the two liquids would spontaneously combust as soon as they come into contact with each other and produces the propulsion to push the spacecraft forward. The main benefit for having this technology is because that these kinds of liquids have relatively high density, which allows the volume of the propellent tank to be small, therefore increasing space efficacy. The downside

806-600: The Sun similar to the Earth's orbit. To reach another planet, the simplest practical method is a Hohmann transfer orbit . More complex techniques, such as gravitational slingshots , can be more fuel-efficient, though they may require the probe to spend more time in transit. Some high Delta-V missions (such as those with high inclination changes ) can only be performed, within the limits of modern propulsion, using gravitational slingshots. A technique using very little propulsion, but requiring

868-777: The International Space Station (ISS), and the Tiangong space station . Currently, the ISS relies on three types of cargo spacecraft: the Russian Progress , along with the American Cargo Dragon 2 , and Cygnus . China's Tiangong space station is solely supplied by the Tianzhou . The American Dream Chaser and Japanese HTV-X are under development for future use with the ISS. The European Automated Transfer Vehicle

930-681: The Lunar Crater Observation and Sensing Satellite (LCROSS), as the vanguard of NASA's Lunar Precursor Robotic Program , LRO was the first United States mission to the Moon in over ten years. LRO and LCROSS were launched as part of the United States's Vision for Space Exploration program. The probe has made a 3-D map of the Moon's surface at 100-meter resolution and 98.2% coverage (excluding polar areas in deep shadow), including 0.5-meter resolution images of Apollo landing sites. The first images from LRO were published on July 2, 2009, showing

992-642: The Lunar south pole . On 28 September 2009, Cabeus proper was selected as the impact target for the LCROSS mission, switching the target from satellite crater Cabeus A. The change was made after review of the latest data gathered by other lunar exploration craft, which indicated that Cabeus proper had a higher concentration of hydrogen than Cabeus A. At 11:31 UTC on 9 October 2009 the Centaur upper stage of its Atlas V carrier rocket impacted Cabeus, followed shortly thereafter by

1054-657: The Mare Tranquillitatis (Sea of Tranquility), the ancient lava plain where the Apollo 11 astronauts Neil Armstrong and Buzz Aldrin first set foot on the moon. The mission maintains a full list of publications with science results on its website. Robotic spacecraft Uncrewed spacecraft or robotic spacecraft are spacecraft without people on board. Uncrewed spacecraft may have varying levels of autonomy from human input, such as remote control , or remote guidance. They may also be autonomous , in which they have

1116-470: The United States Air Force considers a vehicle to consist of the mission payload and the bus (or platform). The bus provides physical structure, thermal control, electrical power, attitude control and telemetry, tracking and commanding. JPL divides the "flight system" of a spacecraft into subsystems. These include: The physical backbone structure, which This is sometimes referred to as

1178-413: The solar wind or out-gassing. This crater is sufficiently large that the temperature within the shaded region is below 100 K (−173 °C). This would allow water ice to remain on or near the crater surface for billions of years without sublimating. The United States National Aeronautics and Space Administration launched the LCROSS , impactor spacecraft on 18 June 2009, to look for water at

1240-447: The telecommunications subsystem include radio antennas, transmitters and receivers. These may be used to communicate with ground stations on Earth, or with other spacecraft. The supply of electric power on spacecraft generally come from photovoltaic (solar) cells or from a radioisotope thermoelectric generator . Other components of the subsystem include batteries for storing power and distribution circuitry that connects components to

1302-563: The 1651 work Almagestum Novum by Giovanni Riccioli , who named it after Niccolò Cabeo . However, the position of the Cabeus crater was in the location later assigned to Newton crater . The official name and location for this crater was adopted by the IAU Commission 17, as established in the 1935 work Named Lunar Formations by Mary A. Blagg and Karl Müller. This crater is a worn formation that has been eroded by subsequent impacts. The rim

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1364-501: The Lunar Reconnaissance Orbiter entered into orbit around the Moon after a four-and-a-half-day journey from the Earth. When launched, the spacecraft was aimed at a point ahead of the Moon's position. A mid-course correction was required during the trip in order for the spacecraft to correctly enter Lunar orbit. Once the spacecraft reached the far side of the Moon , its rocket motor was fired in order for it to be captured by

1426-614: The Moon is so close, LRO has its own dedicated ground station, and it doesn't have to share time on the Deep Space Network . Among the latest products is a global map with a resolution of 100 m/pixel (330 ft/pixel) from the Lunar Reconnaissance Orbiter Camera (LROC). In March 2015, the LROC team reported having imaged the location of an impact whose flash was observed from Earth on March 17, 2013. The team found

1488-479: The Moon to date. It will continue to be updated as more data is acquired. On March 15, 2011, the final set of data from the exploration phase of the mission was released to the NASA Planetary Data System . The spacecraft's seven instruments delivered more than 192 terabytes of data. LRO has already collected as much data as all other planetary missions combined. This volume of data is possible because

1550-593: The Moon two years later. The first interstellar probe was Voyager 1 , launched 5 September 1977. It entered interstellar space on 25 August 2012, followed by its twin Voyager 2 on 5 November 2018. Nine other countries have successfully launched satellites using their own launch vehicles: France (1965), Japan and China (1970), the United Kingdom (1971), India (1980), Israel (1988), Iran (2009), North Korea (2012), and South Korea (2022). In spacecraft design,

1612-472: The Moon's gravity into an elliptical lunar orbit. A series of four rocket burns over the next four days put the satellite into its commissioning phase orbit where each instrument was brought online and tested. On September 15, 2009, the spacecraft started its primary mission by orbiting the Moon at about 50 km (31 mi) for one year. After completing its one-year exploration phase, in September 2010, LRO

1674-406: The Moon; travel through interplanetary space; flyby, orbit, or land on other planetary bodies; or enter interstellar space. Space probes send collected data to Earth. Space probes can be orbiters, landers, and rovers. Space probes can also gather materials from its target and return it to Earth. Once a probe has left the vicinity of Earth, its trajectory will likely take it along an orbit around

1736-611: The Next Generation Satellite Laser Ranging (NGSLR) station at NASA's Goddard Space Flight Center in Greenbelt, Maryland. In May 2015, LRO's orbit was altered to fly 20 km (12 mi) above the Moon's south pole, allowing higher resolution data to be obtained from the Lunar Orbiter Laser Altimeter (LOLA) and Diviner instruments over the permanently shadowed craters there. In 2019, LRO found

1798-518: The Soviet Venera 4 was the first atmospheric probe to study Venus. Mariner 4 's 1965 Mars flyby snapped the first images of its cratered surface, which the Soviets responded to a few months later with images from on its surface from Luna 9 . In 1967, America's Surveyor 3 gathered information about the Moon's surface that would prove crucial to the Apollo 11 mission that landed humans on

1860-450: The combustion of the fuel can only occur due to a presence of a catalyst . This is quite advantageous due to making the rocket engine lighter and cheaper, easy to control, and more reliable. But, the downfall is that the chemical is very dangerous to manufacture, store, and transport. A bipropellant propulsion system is a rocket engine that uses a liquid propellant. This means both the oxidizer and fuel line are in liquid states. This system

1922-453: The command and data subsystem. It is often responsible for: This system is mainly responsible for the correct spacecraft's orientation in space (attitude) despite external disturbance-gravity gradient effects, magnetic-field torques, solar radiation and aerodynamic drag; in addition it may be required to reposition movable parts, such as antennas and solar arrays. Integrated sensing incorporates an image transformation algorithm to interpret

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1984-650: The crash site of Indian moon lander Vikram . In 2020, software was tested to use star trackers instead of the Miniature Inertial Measurement Unit that had been turned off in 2018 (as it was degrading). LRO and the Chandrayaan-2 orbiter were expected to come dangerously close to each other on 20 October 2021 at 05:45 UTC over the Lunar North pole. Chandrayaan-2 orbiter performed a collision avoidance manoeuvre at 14:52 UTC on 18 October 2021 to avert

2046-521: The crater by going back to images taken in the first year or two and comparing them to images taken after the impact, called temporal pairs. The images revealed splotches, small areas whose reflectance is markedly different from that of the surrounding terrain, presumably from disruption of the surface by recent impacts. By September 2015, LROC had imaged nearly three-fourths of the lunar surface at high resolution, revealing more than 3,000 lobate scarps . Their global distribution and orientation suggests that

2108-589: The crater's location near the lunar south pole, the main part of the crater is illuminated by the Sun during only 25% of each lunar day. The inner walls receive illumination for 30% of a lunar day, while part of the western end of the crater is in permanent shadow. The south polar region of the Moon was surveyed by the Lunar Prospector spacecraft and a hydrogen signature was detected. Potential sources for this hydrogen include water deposits from comet or meteorite impacts,

2170-713: The entire sky ( astronomical survey ), and satellites which focus on selected astronomical objects or parts of the sky and beyond. Space telescopes are distinct from Earth imaging satellites , which point toward Earth for satellite imaging , applied for weather analysis , espionage , and other types of information gathering . Cargo or resupply spacecraft are robotic vehicles designed to transport supplies, such as food, propellant, and equipment, to space stations. This distinguishes them from space probes, which are primarily focused on scientific exploration. Automated cargo spacecraft have been servicing space stations since 1978, supporting missions like Salyut 6 , Salyut 7 , Mir ,

2232-455: The fall of 1951. The first artificial satellite , Sputnik 1 , was put into a 215-by-939-kilometer (116 by 507 nmi) Earth orbit by the USSR on 4 October 1957. On 3 November 1957, the USSR orbited Sputnik 2 . Weighing 113 kilograms (249 lb), Sputnik 2 carried the first animal into orbit, the dog Laika . Since the satellite was not designed to detach from its launch vehicle 's upper stage,

2294-466: The faults are created as the Moon shrinks, with influence by gravitational tidal forces from Earth. In March 2016, the LROC team reported the use of 14,092 NAC temporal pairs to discover over 47,000 new splotches on the Moon. In July 2024, the analysis of the radar data obtained by LRO confirmed the presence of an underground cave on the moon accessible from the surface. The cave is said to be about 45 metres wide and at least 80 metres long, and present in

2356-598: The ground. Increased autonomy is important for distant probes where the light travel time prevents rapid decision and control from Earth. Newer probes such as Cassini–Huygens and the Mars Exploration Rovers are highly autonomous and use on-board computers to operate independently for extended periods of time. A space probe is a robotic spacecraft that does not orbit Earth, but instead, explores further into outer space. Space probes have different sets of scientific instruments onboard. A space probe may approach

2418-428: The highly accurate landing site of the first successful Japanese SLIM soft landing. The orbiter carries a complement of six instruments and one technology demonstration: Prior to the LRO's launch, NASA gave members of the public the opportunity to have their names placed in a microchip on the LRO. The deadline for this opportunity was July 31, 2008. About 1.6 million names were submitted. On June 23, 2009,

2480-521: The immediate imagery land data, perform a real-time detection and avoidance of terrain hazards that may impede safe landing, and increase the accuracy of landing at a desired site of interest using landmark localization techniques. Integrated sensing completes these tasks by relying on pre-recorded information and cameras to understand its location and determine its position and whether it is correct or needs to make any corrections (localization). The cameras are also used to detect any possible hazards whether it

2542-466: The impact of the LCROSS spacecraft itself. The impact of the Centaur was intended to throw up a plume of lunar surface material to be sampled by sensors carried on the LCROSS spacecraft as it traversed the plume. But the debris plumes were smaller than predicted. Preliminary data from the LCROSS spectrometer measurements of the impact plume appeared to confirm the presence of water in the crater. Analysis of

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2604-485: The instrument is being used to collect bistatic radar observations using radar transmissions from the Earth. The Mini-RF instrument has already met its science mission success criteria by collecting more than 400 strips of radar data since September 2010. In January 2013, NASA tested one-way laser communication with LRO by sending an image of the Mona Lisa to the Lunar Orbiter Laser Altimeter (LOLA) instrument on LRO from

2666-478: The lighting environment; characterization of deep space radiation in lunar orbit; and high-resolution mapping, at a maximum resolution of 50 cm/pixel (20 in/pixel), to assist in the selection and characterization of future landing sites. In addition, LRO has provided images and precise locations of landers and equipment from previous and current lunar missions, including the Apollo sites. In 2024, it confirmed

2728-427: The most powerful form of propulsion there is. For a propulsion system to work, there is usually an oxidizer line and a fuel line. This way, the spacecraft propulsion is controlled. But in a monopropellant propulsion, there is no need for an oxidizer line and only requires the fuel line. This works due to the oxidizer being chemically bonded into the fuel molecule itself. But for the propulsion system to be controlled,

2790-402: The only way to explore them. Telerobotics also allows exploration of regions that are vulnerable to contamination by Earth micro-organisms since spacecraft can be sterilized. Humans can not be sterilized in the same way as a spaceship, as they coexist with numerous micro-organisms, and these micro-organisms are also hard to contain within a spaceship or spacesuit. The first uncrewed space mission

2852-460: The plume observations supports the presence of water in the regolith. Absorption in the near-infrared can be attributed to ice and water vapor, while emissions in the ultraviolet indicate the presence of hydroxyl radicals, which also supports the likelihood of water. The estimated total amount of water vapor and ice in the plume is up to 155 ± 12 kg , or an estimated 5.6 ± 2.9% by mass. The spectral signatures of other volatiles were observed, matching

2914-524: The possible conjunction event. On August 21, 2009, the spacecraft, along with the Chandrayaan-1 orbiter, attempted to perform a bistatic radar experiment to detect the presence of water ice on the lunar surface, but the test was unsuccessful. On December 17, 2010, a topographic map of the Moon based on data gathered by the LOLA instrument was released to the public. This is the most accurate topographic map of

2976-408: The power sources. Spacecraft are often protected from temperature fluctuations with insulation. Some spacecraft use mirrors and sunshades for additional protection from solar heating. They also often need shielding from micrometeoroids and orbital debris. Spacecraft propulsion is a method that allows a spacecraft to travel through space by generating thrust to push it forward. However, there

3038-536: The robotic spacecraft requires accurate knowledge of where the spacecraft is located relative to the surface (localization), what may pose as hazards from the terrain (hazard assessment), and where the spacecraft should presently be headed (hazard avoidance). Without the capability for operations for localization, hazard assessment, and avoidance, the robotic spacecraft becomes unsafe and can easily enter dangerous situations such as surface collisions, undesirable fuel consumption levels, and/or unsafe maneuvers. Components in

3100-533: The space stations Salyut 7 and Mir , and the International Space Station module Zarya , were capable of remote guided station-keeping and docking maneuvers with both resupply craft and new modules. Uncrewed resupply spacecraft are increasingly used for crewed space stations . The first robotic spacecraft was launched by the Soviet Union (USSR) on 22 July 1951, a suborbital flight carrying two dogs Dezik and Tsygan. Four other such flights were made through

3162-408: The spacecraft forward. This happens due to one basic principle known as Newton's Third Law . According to Newton, "to every action there is an equal and opposite reaction." As the energy and heat is being released from the back of the spacecraft, gas particles are being pushed around to allow the spacecraft to propel forward. The main reason behind the usage of rocket engine today is because rockets are

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3224-414: The spacecraft is robotic. Robotic spacecraft use telemetry to radio back to Earth acquired data and vehicle status information. Although generally referred to as "remotely controlled" or "telerobotic", the earliest orbital spacecraft – such as Sputnik 1 and Explorer 1 – did not receive control signals from Earth. Soon after these first spacecraft, command systems were developed to allow remote control from

3286-423: The thrust to propel the spacecraft forward. The advantage of having this kind of propulsion is that it is incredibly efficient in maintaining constant velocity, which is needed for deep-space travel. However, the amount of thrust produced is extremely low and that it needs a lot of electrical power to operate. Mechanical components often need to be moved for deployment after launch or prior to landing. In addition to

3348-421: The total mass in orbit was 508.3 kilograms (1,121 lb). In a close race with the Soviets , the United States launched its first artificial satellite, Explorer 1 , into a 357-by-2,543-kilometre (193 by 1,373 nmi) orbit on 31 January 1958. Explorer I was an 205-centimetre (80.75 in) long by 15.2-centimetre (6.00 in) diameter cylinder weighing 14.0 kilograms (30.8 lb), compared to Sputnik 1,

3410-531: The use of motors, many one-time movements are controlled by pyrotechnic devices. Robotic spacecraft are specifically designed system for a specific hostile environment. Due to their specification for a particular environment, it varies greatly in complexity and capabilities. While an uncrewed spacecraft is a spacecraft without personnel or crew and is operated by automatic (proceeds with an action without human intervention) or remote control (with human intervention). The term 'uncrewed spacecraft' does not imply that

3472-437: Was Sputnik , launched October 4, 1957 to orbit the Earth. Nearly all satellites , landers and rovers are robotic spacecraft. Not every uncrewed spacecraft is a robotic spacecraft; for example, a reflector ball is a non-robotic uncrewed spacecraft. Space missions where other animals but no humans are on-board are called uncrewed missions. Many habitable spacecraft also have varying levels of robotic features. For example,

3534-402: Was handed over to NASA's Science Mission Directorate to continue the science phase of the mission. It would continue in its 50 km circular orbit, but eventually would be transitioned into a fuel-conserving "quasi-frozen" elliptical orbit for the remainder of the mission. NASA's LCROSS mission culminated with two lunar impacts at 11:31 and 11:36 UTC on October 9. The goal of the impact

3596-528: Was planned for one year, but has since been extended numerous times after review by NASA. After completing a preliminary design review in February 2006 and a critical design review in November 2006, the LRO was shipped from Goddard to Cape Canaveral Air Force Station on February 11, 2009. Launch was planned for October 2008, but this slid to April as the spacecraft underwent testing in a thermal vacuum chamber. Launch

3658-519: Was previously used between 2008 and 2015. Solar System   → Local Interstellar Cloud   → Local Bubble   → Gould Belt   → Orion Arm   → Milky Way   → Milky Way subgroup   → Local Group → Local Sheet → Virgo Supercluster → Laniakea Supercluster   → Local Hole   → Observable universe   → Universe Each arrow ( → ) may be read as "within" or "part of". Cabeus (crater) The crater name Cabeus first appeared in

3720-508: Was rescheduled for June 17, 2009, because of the delay in a priority military launch, and happened one day later, on June 18. The one-day delay was to allow the Space Shuttle Endeavour a chance to lift off for mission STS-127 following a hydrogen fuel leak that canceled an earlier planned launch. Areas of investigation include selenodetic global topography ; the lunar polar regions , including possible water ice deposits and

3782-495: Was the Luna E-1 No.1 , launched on 23 September 1958. The goal of a lunar probe repeatedly failed until 4 January 1959 when Luna 1 orbited around the Moon and then the Sun. The success of these early missions began a race between the US and the USSR to outdo each other with increasingly ambitious probes. Mariner 2 was the first probe to study another planet, revealing Venus' extremely hot temperature to scientists in 1962, while

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3844-561: Was the search for water in the Cabeus crater near the Moon's south pole, and preliminary results indicated the presence of both water and hydroxyl , an ion related to water. On January 4, 2011, the Mini-RF instrument team for the Lunar Reconnaissance Orbiter (LRO) found that the Mini-RF radar transmitter had suffered an anomaly. Mini-RF has suspended normal operations. Despite being unable to transmit,

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