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66-578: The Mars Climate Orbiter (formerly the Mars Surveyor '98 Orbiter ) was a robotic space probe launched by NASA on December 11, 1998, to study the Martian climate , Martian atmosphere , and surface changes and to act as the communications relay in the Mars Surveyor '98 program for Mars Polar Lander . However, on September 23, 1999, communication with the spacecraft was permanently lost as it went into orbital insertion . The spacecraft encountered Mars on

132-418: A 3-panel solar array , providing an average of 500 W (0.67 hp) at Mars. Deployed, the solar array measured 5.5 meters (18 ft 1 in) in length. Power was stored in 12-cell, 16-amp-hour nickel-hydrogen batteries . The batteries were intended to be recharged when the solar array received sunlight and power the spacecraft as it passed into the shadow of Mars. When entering into orbit around Mars,

198-464: A POWER1 ISA capable of 5, 10 or 20 MHz operation. Data storage was to be maintained on 128 MB of random-access memory (RAM) and 18 MB of flash memory . The flash memory was intended to be used for highly important data, including triplicate copies of the flight system software. The Pressure Modulated Infrared Radiometer (PMIRR) uses narrow-band radiometric channels and two pressure modulation cells to measure atmospheric and surface emissions in

264-400: A service life of 15 years or more at 80% depth of discharge (DOD) The energy density is 75  Wh / kg , 60 Wh/dm specific power 220 W/kg. The open-circuit voltage is 1.55  V , the average voltage during discharge is 1.25 V. While the energy density is only around one third as that of a lithium battery , the distinctive virtue of the nickel–hydrogen battery

330-520: A 1.3-meter (4-foot-3-inch) high-gain antenna to transceive data with the Deep Space Network over the x band . The radio transponder designed for the Cassini–Huygens mission was used as a cost-saving measure. It also included a two-way UHF radio frequency system to relay communications with Mars Polar Lander upon an expected landing on December 3, 1999. The space probe was powered with

396-580: 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

462-522: 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

528-549: 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,

594-412: A few days' storage. Self-discharge is less at lower temperature. Compared with other rechargeable batteries, a nickel–hydrogen battery provides good specific energy of 55–60 watt-hours/kg, and very long cycle life (40,000 cycles at 40% DOD) and operating life (> 15 years) in satellite applications. The cells can tolerate overcharging and accidental polarity reversal, and the hydrogen pressure in

660-422: A new Mars Surveyor program began as a set of missions designed with limited objectives, low costs, and frequent launches. The first mission in the new program was Mars Global Surveyor , launched in 1996 to map Mars and provide geologic data using instruments intended for Mars Observer . Following Mars Global Surveyor, Mars Climate Orbiter carried two instruments, one originally intended for Mars Observer, to study

726-433: 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

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792-611: 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

858-450: A trajectory that brought it too close to the planet, and it was either destroyed in the atmosphere or escaped the planet's vicinity and entered an orbit around the Sun. An investigation attributed the failure to a measurement mismatch between two measurement systems: SI units (metric) by NASA and US customary units by spacecraft builder Lockheed Martin . After the loss of Mars Observer and

924-441: 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,

990-710: Is its long life: the cells handle more than 20,000 charge cycles with 85% energy efficiency and 100% faradaic efficiency . NiH 2 rechargeable batteries possess properties which make them attractive for the energy storage of electrical energy in satellites and space probes . For example, the ISS , Mercury Messenger , Mars Odyssey and the Mars Global Surveyor are equipped with nickel–hydrogen batteries. The Hubble Space Telescope , when its original batteries were changed in May 2009 more than 19 years after launch, led with

1056-457: 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

1122-419: 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

1188-426: 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

1254-600: 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

1320-531: The Cape Canaveral Air Station in Florida, aboard a Delta II 7425 launch vehicle. The complete burn sequence lasted 42 minutes bringing the spacecraft into a Hohmann transfer orbit , sending the probe into a 9.5-month, 669 million km (416 million mi) trajectory. At launch, Mars Climate Orbiter weighed 638 kg ( 1 407  lb) including propellant. Mars Climate Orbiter began

1386-777: 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

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1452-496: The Mars Climate Orbiter Mishap Investigation Board released a Phase I report, detailing the suspected issues encountered with the loss of the spacecraft. Previously, on September 8, 1999, Trajectory Correction Maneuver-4 (TCM-4) was computed, and was then executed on September 15, 1999. It was intended to place the spacecraft at an optimal position for an orbital insertion maneuver that would bring

1518-470: 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

1584-447: 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

1650-549: The Martian surface and atmosphere. Under proper conditions, resolutions up to 1 kilometer ( 3 300  ft) are possible. The principal investigator on this project was Michael Malin at Malin Space Science Systems and the project was reincorporated on Mars Reconnaissance Orbiter . Its objectives: The Mars Climate Orbiter probe was launched on December 11, 1998, at 18:45:51 UTC by NASA from Space Launch Complex 17A at

1716-640: 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,

1782-406: 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

1848-514: The SIS. Specifically, software that calculated the total impulse produced by thruster firings produced results in pound-force seconds . The trajectory calculation software then used these results – expected to be in newton-seconds (incorrect by a factor of 4.45) – to update the predicted position of the spacecraft. Still, NASA does not place the responsibility on Lockheed for the mission loss; instead, various officials at NASA have stated that NASA itself

1914-566: 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

1980-465: The atmosphere or re-entered heliocentric space after leaving Mars' atmosphere. Mars Reconnaissance Orbiter has since completed most of the intended objectives for this mission. The problem here was not the error; it was the failure of NASA's systems engineering, and the checks and balances in our processes, to detect the error. That's why we lost the spacecraft. —Edward Weiler, NASA associate administrator for space science On November 10, 1999,

2046-444: The cell provides a good indication of the state of charge. However, the gaseous nature of hydrogen means that the volume efficiency is relatively low (60-100 Wh/L for an IPV (individual pressure vessel) cell), and the high pressure required makes for high-cost pressure vessels. The positive electrode is made up of a dry sintered porous nickel plaque, which contains nickel hydroxide . The negative hydrogen electrode utilises

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2112-421: The climate and weather of Mars. The primary science objectives of the mission included: The Mars Climate Orbiter bus measured 2.1 meters (6 feet 11 inches) tall, 1.6 meters (5 feet 3 inches) wide and 2 meters (6 feet 7 inches) deep. The internal structure was largely constructed with graphite composite/aluminum honeycomb supports, a design found in many commercial airplanes . With

2178-450: 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

2244-453: 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

2310-483: The denser-than-expected atmosphere, and it was either destroyed in the atmosphere, or re-entered heliocentric space. The primary cause of this discrepancy was that one piece of ground software supplied by Lockheed Martin produced results in a United States customary unit , contrary to its Software Interface Specification (SIS), while a second system, supplied by NASA, expected those results to be in SI units , in accordance with

2376-713: 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 ,

2442-455: The exception of the scientific instruments, battery and main engine, the spacecraft included dual redundancy on the most important systems. The spacecraft weighed 638-kilogram (1,407 lb). The spacecraft was 3-axis stabilized and included eight hydrazine monopropellant thrusters: four 22 N (4.9 lb f ) thrusters to perform trajectory corrections and four 0.9 N (3.2 ozf) thrusters to control attitude . Orientation of

2508-455: 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,

2574-598: 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

2640-450: The highest number of charge and discharge cycles of any NiH 2 battery in low Earth orbit . The development of the nickel hydrogen battery started in 1970 at Comsat and was used for the first time in 1977 aboard the U.S. Navy's Navigation technology satellite-2 (NTS-2). Currently, the major manufacturers of nickel–hydrogen batteries are Eagle-Picher Technologies and Johnson Controls, Inc. The nickel–hydrogen battery combines

2706-415: The hydrogen present in the cell and forms water; as a consequence the cells can withstand overcharging as long as the heat generated can be dissipated. The cells have the disadvantage of relatively high self-discharge rate, i.e. chemical reduction of Ni(III) into Ni(II) in the cathode: which is proportional to the pressure of hydrogen in the cell; in some designs, 50% of the capacity can be lost after only

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2772-521: 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

2838-427: 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,

2904-402: 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

2970-505: The onset of the rising costs associated with the future International Space Station , NASA began seeking less expensive, smaller probes for scientific interplanetary missions. In 1994, the Panel on Small Spacecraft Technology was established to set guidelines for future miniature spacecraft. The panel determined that the new line of miniature spacecraft should be under 1 000  kg ( 2 200 pounds) with highly focused instrumentation. In 1995,

3036-411: The planned orbital insertion maneuver on September 23, 1999, at 09:00:46 UTC. Mars Climate Orbiter went out of radio contact when the spacecraft passed behind Mars at 09:04:52 UTC, 49 seconds earlier than expected, and communication was never reestablished. Due to complications arising from human error , the spacecraft encountered Mars at a lower-than-anticipated altitude and it was either destroyed in

3102-415: The positive nickel electrode of a nickel–cadmium battery and the negative electrode, including the catalyst and gas diffusion elements, of a fuel cell . During discharge, hydrogen contained in the pressure vessel is oxidized into water while the nickel oxyhydroxide electrode is reduced to nickel hydroxide. Water is consumed at the nickel electrode and produced at the hydrogen electrode, so the concentration of

3168-428: The potassium hydroxide electrolyte does not change. As the battery discharges, the hydrogen pressure drops, providing a reliable state of charge indicator. In one communication satellite battery, the pressure at full charge was over 500 pounds/square inch (3.4 MPa), dropping to only about 15 PSI (0.1 MPa) at full discharge. If the cell is over-charged, the oxygen produced at the nickel electrode reacts with

3234-408: 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

3300-536: 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

3366-531: The solar array was to be utilized in the aerobraking maneuver, to slow the spacecraft until a circular orbit was achieved. The design was largely adapted from guidelines from the Small Spacecraft Technology Initiative outlined in the book, Technology for Small Spacecraft . In an effort to simplify previous implementations of computers on spacecraft, Mars Climate Orbiter featured a single computer using an IBM RAD6000 processor utilizing

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3432-533: 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

3498-461: The spacecraft around Mars at an altitude of 226 km (140 miles) on September 23, 1999. However, during the week between TCM-4 and the orbital insertion maneuver, the navigation team reported that it appeared the insertion altitude could be much lower than planned, at about 150 to 170 km (93 to 106 miles). Twenty-four hours prior to orbital insertion, calculations placed the orbiter at an altitude of 110 km (68 miles). 80 km (50 miles)

3564-408: 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

3630-414: 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

3696-494: The spacecraft was determined by a star tracker , two Sun sensors and two inertial measurement units . Orientation was controlled by firing the thrusters or using three reaction wheels . To perform the Mars orbital insertion maneuver, the spacecraft also included a LEROS 1B main engine rocket, providing 640 N (140 lb f ) of thrust by burning hydrazine fuel with nitrogen tetroxide (NTO) oxidizer. The spacecraft included

3762-464: The thermal infrared and a visible channel to measure dust particles and condensates in the atmosphere and on the surface at varying longitudes and seasons. Its principal investigator was Daniel McCleese at JPL/CALTECH. Similar objectives were later achieved with Mars Climate Sounder on board Mars Reconnaissance Orbiter . Its objectives: The Mars Color Imager (MARCI) is a two-camera (medium-angle/wide-angle) imaging system designed to obtain pictures of

3828-423: 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

3894-477: 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,

3960-531: 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

4026-437: 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,

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4092-550: Was at fault for failing to make the appropriate checks and tests that would have caught the discrepancy. The discrepancy between calculated and measured position, resulting in the discrepancy between desired and actual orbit insertion altitude, had been noticed earlier by at least two navigators, whose concerns were dismissed because they "did not follow the rules about filling out [the] form to document their concerns". A meeting of trajectory software engineers, trajectory software operators (navigators), propulsion engineers, and managers

4158-853: Was convened to consider the possibility of executing Trajectory Correction Maneuver-5, which was in the schedule. Attendees of the meeting recall an agreement to conduct TCM-5, but it was ultimately not done. According to NASA, the cost of the mission was $ 327.6 million ($ 571.41 million in 2023) total for the orbiter and lander, comprising $ 193.1 million ($ 336.81 million in 2023) for spacecraft development, $ 91.7 million ($ 159.95 million in 2023) for launching it, and $ 42.8 million ($ 74.65 million in 2023) for mission operations. 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

4224-576: 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". Nickel%E2%80%93hydrogen battery NiH 2 cells using 26% potassium hydroxide (KOH) as an electrolyte have shown

4290-495: 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

4356-442: Was the minimum altitude that Mars Climate Orbiter was thought to be capable of surviving during this maneuver. During insertion, the orbiter was intended to skim through Mars' upper atmosphere, gradually aerobraking for weeks, but post-failure calculations showed that the spacecraft's trajectory would have taken it within 57 km (35 miles) of the surface. At this altitude, the spacecraft would likely have skipped violently off

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