Cosmic dust called extraterrestrial dust or space dust, is dust which exists in outer space, or has fallen on Earth. Most cosmic dust particles are between a few molecules to 0.1 µm in size. Cosmic dust can be further distinguished by its astronomical location: intergalactic dust, interstellar dust, interplanetary dust and circumplanetary dust. In the Solar System, interplanetary dust causes the zodiacal light. Solar System dust includes comet dust, asteroidal dust, dust from the Kuiper belt, interstellar dust passing through the Solar System. Thousands of tons of cosmic dust are estimated to reach the Earth's surface every year, with each grain having a mass between 10−16 kg and 10−4 kg; the density of the dust cloud through which the Earth is traveling is 10−6/m3. Cosmic dust contains some complex organic compounds that could be created and by stars. A smaller fraction of dust in space is "stardust" consisting of larger refractory minerals that condensed as matter left by stars. Interstellar dust particles were collected by the Stardust spacecraft and samples were returned to Earth in 2006.
Cosmic dust was once an annoyance to astronomers, as it obscures objects they wish to observe. When infrared astronomy began, the dust particles were observed to be significant and vital components of astrophysical processes, their analysis can reveal information about phenomena like the formation of the Solar System. For example, cosmic dust can drive the mass loss when a star is nearing the end of its life, play a part in the early stages of star formation, form planets. In the Solar System, dust plays a major role in the zodiacal light, Saturn's B Ring spokes, the outer diffuse planetary rings at Jupiter, Saturn and Neptune, comets; the interdisciplinary study of dust brings together different scientific fields: physics, fractal mathematics, surface chemistry on dust grains) meteoritics, as well as every branch of astronomy and astrophysics. These disparate research areas can be linked by the following theme: the cosmic dust particles evolve cyclically; the evolution of dust traces out paths in which the Universe recycles material, in processes analogous to the daily recycling steps with which many people are familiar: production, processing, collection and discarding.
Observations and measurements of cosmic dust in different regions provide an important insight into the Universe's recycling processes. The astronomers accumulate observational ‘snapshots’ of dust at different stages of its life and, over time, form a more complete movie of the Universe's complicated recycling steps. Parameters such as the particle's initial motion, material properties, intervening plasma and magnetic field determined the dust particle's arrival at the dust detector. Changing any of these parameters can give different dust dynamical behavior. Therefore, one can learn about where that object came from, what is the intervening medium. Cosmic dust can be detected by indirect methods that utilize the radiative properties of the cosmic dust particles. Cosmic dust can be detected directly using a variety of collection methods and from a variety of collection locations. Estimates of the daily influx of extraterrestrial material entering the Earth's atmosphere range between 5 and 300 tonnes.
NASA collects samples of star dust particles in the Earth's atmosphere using plate collectors under the wings of stratospheric-flying airplanes. Dust samples are collected from surface deposits on the large Earth ice-masses and in deep-sea sediments. Don Brownlee at the University of Washington in Seattle first reliably identified the extraterrestrial nature of collected dust particles in the latter 1970s. Another source is the meteorites. Stardust grains are solid refractory pieces of individual presolar stars, they are recognized by their extreme isotopic compositions, which can only be isotopic compositions within evolved stars, prior to any mixing with the interstellar medium. These grains condensed from the stellar matter. In interplanetary space, dust detectors on planetary spacecraft have been built and flown, some are presently flying, more are presently being built to fly; the large orbital velocities of dust particles in interplanetary space make intact particle capture problematic. Instead, in-situ dust detectors are devised to measure parameters associated with the high-velocity impact of dust particles on the instrument, derive physical properties of the particles through laboratory calibration.
Over the years dust detectors have measured, among others, the impact light flash, acoustic signal and impact ionisation. The dust instrument on Stardust captured particles intact in low-density aerogel. Dust detectors in the past flew on the HEOS-2, Pioneer 10, Pioneer 11, Giotto and Cassini space missions, on the Earth-orbiting LDEF, EURECA, Gorid satellites, some scientists have utilized the Voyager 1 and 2 spacecraft as giant Langmuir probes to
The National Aeronautics and Space Administration is an independent agency of the United States Federal Government responsible for the civilian space program, as well as aeronautics and aerospace research. NASA was established in 1958; the new agency was to have a distinctly civilian orientation, encouraging peaceful applications in space science. Since its establishment, most US space exploration efforts have been led by NASA, including the Apollo Moon landing missions, the Skylab space station, the Space Shuttle. NASA is supporting the International Space Station and is overseeing the development of the Orion Multi-Purpose Crew Vehicle, the Space Launch System and Commercial Crew vehicles; the agency is responsible for the Launch Services Program which provides oversight of launch operations and countdown management for unmanned NASA launches. NASA science is focused on better understanding Earth through the Earth Observing System. From 1946, the National Advisory Committee for Aeronautics had been experimenting with rocket planes such as the supersonic Bell X-1.
In the early 1950s, there was challenge to launch an artificial satellite for the International Geophysical Year. An effort for this was the American Project Vanguard. After the Soviet launch of the world's first artificial satellite on October 4, 1957, the attention of the United States turned toward its own fledgling space efforts; the US Congress, alarmed by the perceived threat to national security and technological leadership, urged immediate and swift action. On January 12, 1958, NACA organized a "Special Committee on Space Technology", headed by Guyford Stever. On January 14, 1958, NACA Director Hugh Dryden published "A National Research Program for Space Technology" stating: It is of great urgency and importance to our country both from consideration of our prestige as a nation as well as military necessity that this challenge be met by an energetic program of research and development for the conquest of space... It is accordingly proposed that the scientific research be the responsibility of a national civilian agency...
NACA is capable, by rapid extension and expansion of its effort, of providing leadership in space technology. While this new federal agency would conduct all non-military space activity, the Advanced Research Projects Agency was created in February 1958 to develop space technology for military application. On July 29, 1958, Eisenhower signed the National Aeronautics and Space Act, establishing NASA; when it began operations on October 1, 1958, NASA absorbed the 43-year-old NACA intact. A NASA seal was approved by President Eisenhower in 1959. Elements of the Army Ballistic Missile Agency and the United States Naval Research Laboratory were incorporated into NASA. A significant contributor to NASA's entry into the Space Race with the Soviet Union was the technology from the German rocket program led by Wernher von Braun, now working for the Army Ballistic Missile Agency, which in turn incorporated the technology of American scientist Robert Goddard's earlier works. Earlier research efforts within the US Air Force and many of ARPA's early space programs were transferred to NASA.
In December 1958, NASA gained control of the Jet Propulsion Laboratory, a contractor facility operated by the California Institute of Technology. The agency's leader, NASA's administrator, is nominated by the President of the United States subject to approval of the US Senate, reports to him or her and serves as senior space science advisor. Though space exploration is ostensibly non-partisan, the appointee is associated with the President's political party, a new administrator is chosen when the Presidency changes parties; the only exceptions to this have been: Democrat Thomas O. Paine, acting administrator under Democrat Lyndon B. Johnson, stayed on while Republican Richard Nixon tried but failed to get one of his own choices to accept the job. Paine was confirmed by the Senate in March 1969 and served through September 1970. Republican James C. Fletcher, appointed by Nixon and confirmed in April 1971, stayed through May 1977 into the term of Democrat Jimmy Carter. Daniel Goldin was appointed by Republican George H. W. Bush and stayed through the entire administration of Democrat Bill Clinton.
Robert M. Lightfoot, Jr. associate administrator under Democrat Barack Obama, was kept on as acting administrator by Republican Donald Trump until Trump's own choice Jim Bridenstine, was confirmed in April 2018. Though the agency is independent, the survival or discontinuation of projects can depend directly on the will of the President; the first administrator was Dr. T. Keith Glennan appointed by Republican President Dwight D. Eisenhower. During his term he brought together the disparate projects in American space development research; the second administrator, James E. Webb, appointed by President John F. Kennedy, was a Democrat who first publicly served under President Harry S. Truman. In order to implement the Apollo program to achieve Kennedy's Moon la
Cape Canaveral Air Force Station Launch Complex 12
Launch Complex 12 at Cape Canaveral Air Force Station, Florida was a launch pad used by Atlas rockets and missiles between 1958 and 1967. It was the second-most southern of the pads known as Missile Row, between LC-11 to the south and LC-13 to the north. Along with Complexes 11, 13 and 14, 12 featured a more robust design than many contemporary pads, due to the greater power of the Atlas compared to other rockets of the time, it was larger, featured a concrete launch pedestal, 6 metres tall and a reinforced blockhouse. The rockets were delivered to the launch pad by means of a ramp on the southwest side of the launch pedestal. Atlas A, C and D missiles were tested from the site, it was used for orbital launches of Atlas-Able and Atlas-Agena rockets, two Project FIRE suborbital tests for Project Apollo, using Atlas D rockets. LC-12's first launch was Atlas 10A on January 10, 1958. During the second half of the year, a larger umbilical service tower was built in preparation for the C series Atlas tests, flown from December 1958 to August 1959.
On 24 September 1959, the first Atlas-Able, 9C, exploded during a static firing test at LC-12, after a turbopump on one of the engines failed to trigger a complete engine shutdown. The damaged turbopump continued feeding the fire beneath the vehicle. About a minute the rocket suffered a structural failure and exploded; the entire service tower and both umbilical towers were knocked over and the concrete launch stand caved in. Because damage to LC-12 was so extensive, it did not host another launch until Missile 56D in May 1960; the large service tower was not rebuilt following the explosion of Atlas 9C. It hosted more ICBM tests along with the second and third Atlas Able probes. In 1961, LC-12 was converted to support the Atlas-Agena rocket; the first Atlas-Agena launch from LC-12 was in August 1961. On 23 April 1962, Atlas-Agena B 133D launched Ranger 4, the first American spacecraft to reach the surface of the Moon, when it made a hard landing at an impact speed of 9,617 kilometres per hour. On 27 August 1962, Mariner 2 was launched by Atlas-Agena B 179D, the first spacecraft conduct a successful flyby of another planet when it flew past Venus on 14 December 1962.
On 28 July 1964, Atlas-Agena B 250D launched Ranger 7, the first successful Ranger mission. On 28 November 1964, Atlas-Agena D 288D launched with Mariner 4, which provided the first close-up pictures of Mars. In 1967, LC-12 became the third of the four Atlas pads to be deactivated. Following deactivation, the launch tower, mobile service structure and launch support equipment were dismantled, the site is no longer maintained. Encyclopedia Astronautica - LC12
Ranger 9 was a Lunar probe, launched in 1965 by NASA. It was designed to achieve a lunar impact trajectory and to transmit high-resolution photographs of the lunar surface during the final minutes of flight up to impact; the spacecraft carried six television vidicon cameras—two wide-angle and four narrow-angle —to accomplish these objectives. The cameras were arranged in two separate chains, or channels, each self-contained with separate power supplies and transmitters so as to afford the greatest reliability and probability of obtaining high-quality television pictures; these images were broadcast live on television to millions of viewers across the United States. No other experiments were carried on the spacecraft. Rangers 6, 7, 8, 9 were the so-called Block 3 versions of the Ranger spacecraft; the spacecraft consisted of a hexagonal aluminium frame base 1.5 m across on, mounted the propulsion and power units, topped by a truncated conical tower which held the TV cameras. Two solar panel wings, each 739 mm wide by 1537 mm long, extended from opposite edges of the base with a full span of 4.6 m, a pointable high-gain dish antenna was hinge mounted at one of the corners of the base away from the solar panels.
A cylindrical quasiomnidirectional antenna was seated on top of the conical tower. The overall height of the spacecraft was 3.6 m. Propulsion for the mid-course trajectory correction was provided by a 224-N thrust monopropellant hydrazine engine with four jet-vane thrust vectoring. Orientation and attitude control about three axes was enabled by 12 nitrogen gas jets coupled to a system of three gyroscopes, four primary Sun sensors, two secondary Sun sensors, an Earth sensor. Power was supplied by 9792 Si solar cells contained in the two solar panels, giving a total array area of 2.3 square meters and producing 200 W. Two 1,200 watt-hour batteries rated at 26.5 V with a capacity for 9 hours of operation provided power to each of the separate communication/TV camera chains. Two 1,000 watt-hour batteries stored power for spacecraft operations. Communications were through the quasiomnidirectional low-gain antenna and the parabolic high-gain antenna. Transmitters aboard the spacecraft included a 60 W TV channel F at 959.52 MHz, a 60 W TV channel P at 960.05 MHz, a 3 W transponder channel 8 at 960.58 MHz.
The telecommunications equipment converted the composite video signal from the camera transmitters into an RF signal for subsequent transmission through the spacecraft high-gain antenna. Sufficient video bandwidth was provided to allow for rapid framing sequences of both narrow and wide-angle television pictures; the Atlas 204D and Agena B 6007 boosters performed nominally, injecting the Agena and Ranger 9 into an Earth parking orbit at 185-kilometre altitude. A 90-second Agena second burn put the spacecraft into lunar transfer trajectory; this was followed by the separation of the Ranger. Seventy minutes after launch, the command was given to deploy solar panels, activate attitude control, switch from the omniantenna to the high-gain antenna; the accuracy of the initial trajectory enabled delay of the planned mid-course correction from 22 to 23 March when the maneuver was initiated at 12:03 UT. After orientation, a 31-second rocket burn at 12:30 UT, reorientation, the maneuver was completed at 13:30 UT.
Ranger 9 reached the Moon on 24 March 1965. At 13:31 UTC, a terminal maneuver was executed to orient the spacecraft so the cameras were more in line with the flight direction to improve the resolution of the pictures. 20 minutes before impact, the one-minute camera system warm-up began. The first image was taken at 13:49:41 UTC at an altitude of 2,363 kilometres. Transmission of 5,814 good contrast photographs was made during the final 19 minutes of flight; the final image taken before impact has a resolution of 0.3 metres. The spacecraft encountered the lunar surface with an incoming asymptotic direction at an angle of -5.6 degrees from the lunar equator. The orbit plane was inclined 15.6 degrees to the lunar equator. After 64.5 hours of flight, impact occurred at 14:08:19.994 UTC at 12.83 S latitude, 357.63 E longitude in the Alphonsus crater. Impact velocity was 2,670 metres per second; the spacecraft performance was excellent. Real-time television coverage with live network broadcasts of many of the F-channel images were provided for this flight.
Ranger program Timeline of Solar System exploration List of artificial objects on the Moon Lunar impact: A history of Project Ranger 1977 The Ranger 9 Flight Path And Its Determination From Tracking Data 1968 Millions watch space probe crash into Moon Photographs from Ranger 9 Live video from Ranger 9 NASA
Ranger 1 was a prototype spacecraft launched as part of the Ranger program of unmanned space missions. Its primary mission was to test the performance of those functions and parts necessary for carrying out subsequent lunar and planetary missions. Due to a launch vehicle malfunction, the spacecraft could only reach Low Earth orbit, rather than the high Earth orbit, planned, was only able to complete part of its mission; the spacecraft was of the Ranger Block I design and consisted of a hexagonal base 1.5-meter across upon, mounted a cone-shaped 4-meter-high tower of aluminum struts and braces. Two solar panel wings measuring 5.2 metres from tip to tip extended from the base. A high-gain directional dish antenna was attached to the bottom of the base. Spacecraft experiments and other equipment were mounted on the tower. Instruments aboard the spacecraft included a Lyman-alpha telescope, a rubidium-vapor magnetometer, electrostatic analyzers, medium-energy range particle detectors, two triple coincidence telescopes, a cosmic-ray integrating ionization chamber, cosmic dust detectors, solar X-ray scintillation counters.
There was no camera or midcourse correction engine on the Block I spacecraft. The communications system included the high-gain antenna and an omnidirectional medium-gain antenna and two transmitters, one at 960.1 MHz with 0.25 watts power output and the other at 960.05 MHz with 3 watts power output. Power was to be furnished by 8680 solar cells on the two panels, a 57-kilogram silver-zinc battery, smaller batteries on some of the experiments. Attitude control was provided by a solid-state timing controller and Earth sensors, pitch and roll jets; the temperature was controlled passively by gold plating, white paint, polished aluminum surfaces. The Ranger 1 spacecraft was designed to go into an Earth parking orbit and move into a 60,000-by-1,100,000-kilometre Earth orbit; the purpose of the mission was as an engineering test to verify the functionality of the Ranger hardware. Delay of the 1st countdown July 26: Trajectory information required by the Range Safety Officer was delayed. July 27: A guidance system malfunction in the Atlas booster.
July 28: Engineers found that the guidance program to be fed into the Cape computer contained an error. 1st countdown. July 29. 83 minutes before launch: Power interruptions occurred, requiring momentary holds to permit all stations to check and recover. 28 minutes before launch: Commercial electrical power failed. Inadequate allowance had been made for changes in cable sag caused by variations in temperature on the new power poles installed at Cape Canaveral Air Force Station. 2nd countdown. July 30. Engineers discovered a leak in Ranger's attitude control gas system. 3rd countdown. July 31. A valve malfunctioned in the liquid-oxygen tank on the Atlas booster. 4th countdown. August 1. Ground controllers turned on a spacecraft command applying high voltage to the scientific experiments for calibration purposes. All stations reported a major spacecraft failure. An electrical malfunction had triggered multiple commands from the central clock timer, Ranger 1 "turned on" as it had been programmed to do in orbit.
The explosive squibs fired, solar panels extended inside the shroud, all the experiments commenced to operate. Project engineers disengaged Ranger 1 from the Agena and hastily returned it to Hangar AE. Meantime, the launch was rescheduled for the next available opportunity. Subsequent tests and investigations determined the activating mechanism to have been a voltage discharge to the spacecraft frame. In the days that followed, they replaced and requalified the damaged parts and modified the circuitry to prevent a recurrence of this kind of failure. During the first half of 1961, Lockheed introduced the new Agena B stage which replaced the early test-model Agena A of 1959-60. Agena B had in-orbit restart capability, its first flight with the launch of Midas 3 on July 24 was successful. Several frustrating delays in Ranger 1's launch occurred, including one episode where the spacecraft's timer inadvertently activated on the pad, causing the solar panels to be deployed inside the payload shroud.
After removing Ranger 1 and repairing it, the launch was carried out at 6:04 AM EST on August 23. All went well up to orbital injection, but the planned Agena restart went awry when the engine shut down after only a few seconds, putting the probe in a 312x105 mile track. Subsequent investigation concluded that an electrical circuit in the Agena had overheated from exposure to the Sun; the unintended orbit made it difficult to operate Ranger 1's systems although ground controllers tried to work around it. The main problem they faced was with the solar panels. In addition, the antennas at NASA's various tracking stations had difficulty locking onto the probe due to its orbital plane. During this time, the computer system fired the attitude control jets in a vain attempt to lock onto the Sun with the effect that only one day after launch, the probe ran out of attitude control gas. At this point, it could not be stabilized and the solar panels lost their lock on the Sun. Ranger 1 thus reverted to battery power and continued transmitting until the batteries ran down on August 27 and all signals from the probe ceased.
It was not a total loss.
The orbital eccentricity of an astronomical object is a parameter that determines the amount by which its orbit around another body deviates from a perfect circle. A value of 0 is a circular orbit, values between 0 and 1 form an elliptic orbit, 1 is a parabolic escape orbit, greater than 1 is a hyperbola; the term derives its name from the parameters of conic sections, as every Kepler orbit is a conic section. It is used for the isolated two-body problem, but extensions exist for objects following a Klemperer rosette orbit through the galaxy. In a two-body problem with inverse-square-law force, every orbit is a Kepler orbit; the eccentricity of this Kepler orbit is a non-negative number. The eccentricity may take the following values: circular orbit: e = 0 elliptic orbit: 0 < e < 1 parabolic trajectory: e = 1 hyperbolic trajectory: e > 1 The eccentricity e is given by e = 1 + 2 E L 2 m red α 2 where E is the total orbital energy, L is the angular momentum, mred is the reduced mass, α the coefficient of the inverse-square law central force such as gravity or electrostatics in classical physics: F = α r 2 or in the case of a gravitational force: e = 1 + 2 ε h 2 μ 2 where ε is the specific orbital energy, μ the standard gravitational parameter based on the total mass, h the specific relative angular momentum.
For values of e from 0 to 1 the orbit's shape is an elongated ellipse. The limit case between an ellipse and a hyperbola, when e equals 1, is parabola. Radial trajectories are classified as elliptic, parabolic, or hyperbolic based on the energy of the orbit, not the eccentricity. Radial orbits hence eccentricity equal to one. Keeping the energy constant and reducing the angular momentum, elliptic and hyperbolic orbits each tend to the corresponding type of radial trajectory while e tends to 1. For a repulsive force only the hyperbolic trajectory, including the radial version, is applicable. For elliptical orbits, a simple proof shows that arcsin yields the projection angle of a perfect circle to an ellipse of eccentricity e. For example, to view the eccentricity of the planet Mercury, one must calculate the inverse sine to find the projection angle of 11.86 degrees. Next, tilt any circular object by that angle and the apparent ellipse projected to your eye will be of that same eccentricity; the word "eccentricity" comes from Medieval Latin eccentricus, derived from Greek ἔκκεντρος ekkentros "out of the center", from ἐκ- ek-, "out of" + κέντρον kentron "center".
"Eccentric" first appeared in English in 1551, with the definition "a circle in which the earth, sun. Etc. deviates from its center". By five years in 1556, an adjectival form of the word had developed; the eccentricity of an orbit can be calculated from the orbital state vectors as the magnitude of the eccentricity vector: e = | e | where: e is the eccentricity vector. For elliptical orbits it can be calculated from the periapsis and apoapsis since rp = a and ra = a, where a is the semimajor axis. E = r a − r p r a + r p = 1 − 2 r a r p + 1 where: ra is the radius at apoapsis. Rp is the radius at periapsis; the eccentricity of an elliptical orbit can be used to obtain the ratio of the periapsis to the apoapsis: r p r a = 1 − e 1 + e For Earth, orbital eccentricity ≈ 0.0167, apoapsis= aphelion and periapsis= perihelion relative to sun. For Earth's annual orbit path, ra/rp ratio = longest_radius / shortest_radius ≈ 1.034 relative to center point of path. The eccentricity of the Earth's orbit is about 0.0167.
Ranger 2 was a flight test of the Ranger spacecraft system of the NASA Ranger program designed for future lunar and interplanetary missions. Ranger 2 was designed to test various systems for future exploration and to conduct scientific observations of cosmic rays, magnetic fields, dust particles, a possible hydrogen gas "tail" trailing the Earth. Ranger 2 was of the Ranger Block 1 design and was identical to Ranger 1; the spacecraft consisted of a hexagonal base 1.5 m across, upon, mounted a cone-shaped 4-meter-high tower of aluminum struts and braces. Two solar panel wings measuring 5.2 m from tip to tip extended from the base. A high-gain directional dish antenna was attached to the bottom of the base. Spacecraft experiments and other equipment were mounted on the tower. Instruments aboard the spacecraft included a Lyman-alpha telescope, a rubidium-vapor magnetometer, electrostatic analyzers, medium-energy-range particle detectors, two triple coincidence telescopes, a cosmic-ray integrating ionization chamber, cosmic dust detectors, scintillation counters.
The communications system included the high-gain antenna and an omnidirectional medium-gain antenna and two transmitters at 960 MHz, one with 0.25 W power output and the other with 3 W power output. Power was to be furnished by 8680 solar cells on the two panels, a 53.5 kg silver-zinc battery, smaller batteries on some of the experiments. Attitude control was provided by a solid state timing controller and Earth sensors and pitch and roll jets; the temperature was controlled passively by gold plating, white paint, polished aluminum surfaces. Shortly after Ranger 1's unsuccessful mission, Atlas 117D and Agena 6002 were rolled out to LC-12 for the next attempt. Once again, getting the booster and spacecraft ready for flight proved a frustrating experience. On October 24, NASA received the news from the West Coast of the United States that a hydraulics failure had prevented Discoverer 33 from reaching orbit the previous day, which necessitated taking Agena 6002 down from the stack and giving it a thorough checkout.
The stage was found necessitating repair work. It took until mid-November before everything was ready. Liftoff took place at 3:12 AM EST on November 18. An improper autopilot signal resulted in Atlas BECO taking place 0.4 seconds early, thus the sustainer phase of flight was initiated with below nominal velocity, but the vehicle reached orbit since the guidance computer was programmed to not issue the SECO command until the proper velocity was achieved. The same malfunction had occurred on Atlas 105D/Midas 4 a month earlier and was traced to the location of the staging backup acceleration switch on the side of the LOX tank, causing the switch to be affected by the super-cold temperatures; the switch was moved to the fuel tank on subsequent Atlas-Agena vehicles. When it came time for the second Agena restart, the result was once again a burn lasting a few seconds; this time, the problem was traced to a defective rate gyro in the Agena which had gone undetected at launch. The control system caused the stage to rotate uncontrollably with the result that the propellants were pushed to the outer edge of the tanks by centrifugal force and could not drain down into the fuel feed lines properly.
Unlike with Ranger 1, the Agena had not operated long enough to achieve any significant ISP and so the probe was left in an lower orbit. Tracking antennas could not lock onto the probe or send it any commands, nor could the attitude control system stabilize it. Telemetry and instrument data were still received for a few hours, but the orbit decayed too low and after only one day and 19 orbits, Ranger 2 reentered the atmosphere and burned up. Ranger program Timeline of Solar System exploration List of artificial objects on the Moon "National Space Science Data Center - Ranger 2". National Air and Space Administration. Retrieved 19 June 2012. Space Flight Operations Memorandum - Ranger 2 Lunar impact: A history of Project Ranger 1977