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Mariner (1962-1975) Pioneer | Mariner | Viking | Voyager | Magellan | Pathfinder | Galileo | Mars Global Surveyor
Overview The Mariner mission was a space program in the 1960's and '70's whose purpose was to visit the inner solar system and the three planets other than Earth: Mercury, Venus, and Mars. Total research, development, launch, and support costs for the Mariner series of spacecraft (Mariners 1 through 10) was approximately $554 million. Mariner 1
The failure was apparently caused by a combination of two factors: Improper operation of the Atlas airborne beacon equipment resulted in a loss of the rate signal from the vehicle for a prolonged period. The airborne beacon used for obtaining rate data was inoperative for four periods ranging from 1.5 to 61 seconds in duration. Additionally, the Mariner 1 Post Flight Review Board determined that the omission of a hyphen in coded computer instructions in the data-editing program allowed transmission of incorrect guidance signals to the spacecraft. During the periods the airborne beacon was inoperative the omission of the hyphen in the data-editing program caused the computer to incorrectly accept the sweep frequency of the ground receiver as it sought the vehicle beacon signal and combined this data with the tracking data sent to the remaining guidance computation. This caused the computer to swing automatically into a series of unnecessary course corrections with erroneous steering commands which finally threw the spacecraft off course. Mariner 2
This was a backup craft for Mariner 1. After launch and termination of the Agena first burn, the Agena-Mariner was in a 118 km altitude Earth parking orbit. The Agena second burn some 980 seconds later followed by Agena-Mariner separation injected the Mariner 2 spacecraft into a geocentric escape hyperbola at 26 minutes 3 seconds after lift-off. Solar panel extension was completed about 44 minutes after launch. On August 29, 1962, cruise science experiments were turned on. The midcourse maneuver was initiated at 22:49:00 UT on September 4 and completed at 2:45:25 UT September 5. On September 8 at 17:50 UT, the spacecraft suddenly lost its attitude control, which was restored by the gyroscopes 3 minutes later. The cause was unknown but may have been a collision with a small object. On October 31 the output from one solar panel deteriorated abruptly, and the science cruise instruments were turned off. A week later the panel resumed normal function and instruments were turned back on. The panel permanently failed on November 15, but Mariner 2 was close enough to the sun that one panel could supply adequate power. On December 14 the radiometers were turned on. Mariner 2 approached Venus from 30° above the dark side of the planet, and it passed below the planet at its closest distance of 34,773 km at 19:59:28 UT December 14, 1962. After the encounter, cruise mode resumed. Spacecraft perihelion occurred on December 27 at a distance of 105,464,560 km. The last transmission from Mariner 2 was received on January 3, 1963 at 07:00 UT. Mariner 2 remains in heliocentric orbit. Mariner 2, in December of 1962, was the first successful probe to flyby Venus. It confirmed that Venus' surface temperature was very hot (it read about 800 °F, which has been revised to 900 °F - hot enough to melt lead). This disproved the previous theory that there were oceans on Venus. It also confirmed that Venus was cloud-covered, its atmosphere was comprised mostly of carbon dioxide (CO2), and that the clouds topped out at about 60 km. Mariner 2 discovered that Venus had a slow retrograde rotation and no detectable magnetic field. It was found that cosmic dust density was much lower than near Earth, and more accurate estimates of Venus' mass and the Astronomical Unit were completed. Mariner 3
Mariner 4
Mariner 4 was the sister probe of Mariner 3. It reached Mars in 1965 and took the first 21 pictures ever taken close-up of Mars. It showed that Mars was heavily cratered and had a thinner atmosphere that previously thought. Most scientists concluded that Mars was dead geologically and biologically from these initial scans. It was designed to conduct close up scientific observations of Mars and to transmit these observations to earth. Other mission objectives were to perform field and particle measurements in interplanetary space in the vicinity of Mars and to provide experience in and knowledge of the engineering capabilities for interplanetary flights of long duration. After launch, the protective shroud covering Mariner 4 was jettisoned and the Agena D/Mariner 4 combination separated from the Atlas D booster at 14:27:23 UT on November 28, 1964. The Agena D first burn from 14:28:14 to 14:30:38 put the spacecraft into an Earth parking orbit and the second burn from 15:02:53 to 15:04:28 injected the craft into a Mars transfer orbit. Mariner 4 separated from the Agena D at 15:07:09 and began cruise mode operations. The solar panels deployed and the scan platform was unlatched at 15:15:00 and Sun acquisition occurred 16 minutes later. After 7.5 months of flight involving one midcourse maneuver on December 5, 1964, the spacecraft flew by Mars on July 14 and 15, 1965. Planetary science mode was turned on at 15:41:49 UT on July 14. The camera sequence started at 00:18:36 UT on July 15 and 21 pictures and 21 lines of a 22nd picture were taken. The images covered a discontinuous swath of Mars starting near 40 N, 170 E, down to about 35 S, 200 E, and then across to the terminator at 50 S, 255 E, representing about 1% of the planet's surface. The closest approach was 9,846 km from the Martian surface at 01:00:57 UT July 15, 1965. The images taken during the flyby were stored in the onboard tape recorder. At 02:19:11 UT, Mariner 4 passed behind Mars as seen from Earth and the radio signal ceased. The signal was reacquired at 03:13:04 UT when the spacecraft reappeared. Cruise mode was then re-established. Transmission of the taped images to Earth began about 8.5 hours after signal reacquisition and continued until August 3. All images were transmitted twice to insure no data was missing or corrupt. The spacecraft performed all programmed activities successfully and returned useful data from launch until 22:05:07 UT on October 1, 1965, when the distance from Earth (309.2 million km) and the antenna orientation temporarily halted signal acquisition. Data acquisition resumed in late 1967. The cosmic dust detector registered 17 hits in a 15 minute span on September 15, part of an apparent micrometeoroid shower which temporarily changed the spacecraft attitude and probably slightly damaged the thermal shield. On December 7 the gas supply in the attitude control system was exhausted, and on December 10 and 11 a total of 83 micrometeoroid hits were recorded which caused perturbation of the attitude and degradation of the signal strength. On December 21, 1967, communications with Mariner 4 were terminated. The total data returned by the mission was 5.2 million bits. All experiments operated successfully with the exception of the ionization chamber/Geiger counter which failed in February 1965, and the plasma probe, which had its performance degraded by a resistor failure on December 6, 1964. The images returned showed a Moon-like cratered terrain (which later missions showed was not typical for Mars, but only for the more ancient region imaged by Mariner 4). A surface atmospheric pressure of 4.1 to 7.0 mb was estimated and no magnetic field was detected Mariner 5
The spacecraft passed 4,000 km from Venus on October 19, 1967. The spacecraft instruments measured interplanetary magnetic fields, charged particles, and plasmas, as well as the radio refractivity and UV emissions of the Venusian atmosphere. The mission was termed a success. Mariner 6
Mariner 6 was launched from Launch Complex 36B at Cape Kennedy (Mariner 7 was launched 31 days later). It represented the first mission launched on the Atlas/Centaur, (AC20, spacecraft 69-3) consisting of a 1 1/2 stage Atlas SLV-3C and a restartable Centaur stage. The main booster was jettisoned 4 minutes 38 seconds after launch followed by a 7.5 minute Centaur burn to inject the spacecraft into Mars direct-ascent trajectory. After Mariner 6 separated from the Centaur the solar panels were deployed. A midcourse correction involving a 5.35 second burn of the hydrazine rocket occurred on March 1, 1969. A few days later the explosive valves were deployed to unlatch the scan platform. Some bright particles released during the explosion distracted the Canopus sensor, and attitude lock was lost temporarily. It was decided to place the spacecraft on inertial guidance for the Mars flyby to prevent a similar occurrence. On July 29, 50 hours before closest approach, the scan platform was pointed to Mars and the scientific instruments turned on. Imaging of Mars began two hours later. For the next 41 hours, 49 approach images (plus a 50th fractional image) of Mars were taken through the narrow-angle camera. At 05:03 UT on July 31 the near-encounter phase began, including collection of 26 close-up images. Due to a cooling system failure, channel 1 of the IR spectrometer did not cool sufficiently to allow measurements from 6 to 14 µm, so no infrared data were obtained over this range. Closest approach occurred at 05:19:07 UT at a distance of 3431 km from the martian surface. 11 minutes later Mariner 6 passed behind Mars and reappeared after 25 minutes. X-band occultation data were taken during the entrance and exit phases. Science and imaging data were played back and transmitted over the next few days. The spacecraft was then returned to cruise mode which included engineering and communications tests, star photography TV tests, and UV scans of the Milky Way and an area containing comet 1969-B. Periodic tracking of the spacecraft in its heliocentric orbit was also done. As a historical note, 10 days before the scheduled launch of Mariner 6 while it was mounted on top of the Atlas/Centaur booster, a faulty switch opened the main valves on the Atlas stage. This released the pressure which supported the Atlas structure, and as the booster deflated it began to crumple. Two ground crewman started pressurizing pumps, saving the structure from further collapse. The Mariner 6 spacecraft was removed, put on another Atlas/Centaur, and launched on schedule. The two ground crewman, who had acted at risk of the 12-story rocket collapsing on them, were awarded Exceptional Bravery Medals from NASA. The total data return for Mariners 6 and 7 was 800 million bits. Mariner 6 returned 49 far encounter and 26 near encounter images of Mars, and Mariner 7 returned 93 far and 33 near encounter images. Close-ups from the near encounter phases covered 20% of the surface. The spacecraft instruments measured UV and IR emissions and radio refractivity of the Martian atmosphere. Images showed the surface of Mars to be very different from that of the Moon, in some contrast to the results from Mariner 4. The south polar cap was identified as being composed predominantly of carbon dioxide. Atmospheric surface pressure was estimated at between 6 and 7 mb. Radio science refined estimates of the mass, radius and shape of Mars. Mariner 7
At 09:32:33 UT on August 2, 1969, Mariner 7 began the far-encounter sequence involving imaging of Mars with the narrow angle camera. Over the next 57 hours, ending about 5 hours before closest approach, 93 images of Mars were taken and transmitted. The spacecraft was reprogrammed as a result of analysis of Mariner 6 images. The new sequence called for the spacecraft to go further south than originally planned, take more near-encounter pictures, and collect more scientific data on the lighted side of Mars. Data from the dark side of Mars were to be transmitted directly back to Earth but there would be no room on the digital recorder for backup due to the added dayside data. At closest approach, 05:00:49 UT on August 5, Mariner 7 was 3430 km above the martian surface. Over this period, 33 near-encounter images were taken. About 19 minutes after the flyby, the spacecraft went behind Mars and emerged roughly 30 minutes later. X-band occultation data were taken during the entrance and exit phases. Science and imaging data were played back and transmitted over the next few days. The spacecraft was then returned to cruise mode which included engineering and communications tests, star photography TV tests, and UV scans of the Milky Way and an area containing comet 1969-B. Periodic tracking of the spacecraft in its heliocentric orbit was also done. Mariner 8
Mariner 8 was (along with Mariner 9) part of the Mariner Mars 71 project. It was intended to go into Mars orbit and return images and data. Mariner 8 was launched on an Atlas-Centaur SLV-3C booster (AC-24). The main Centaur engine was ignited 265 seconds after launch, but the upper stage began to oscillate in pitch and tumbled out of control. The Centaur stage shut down 365 seconds after launch due to starvation caused by the tumbling. The Centaur and spacecraft payload separated and re-entered Earth's atmosphere approximately 1500 km downrange and fell into the Atlantic Ocean about 560 km north of Puerto Rico. The Mariner Mars 71 project consisted of two spacecraft (Mariners H and I), each of which would be inserted into a Martian orbit, and each of which would perform a separate but complementary mission. Either spacecraft could perform either of the two missions. The two spacecraft would have orbited the planet Mars a minimum of 90 days, during which time data would be gathered on the composition, density, pressure, and temperature of the atmosphere, and the composition, temperature, and topography of the surface. Approximately 70% of the planetary surface was to be covered, and temporal as well as spatial variations would be observed. Some of the objectives of the Mariner-H mission were successfully added to the Mariner-I (Mariner 9) mission profile. Mariner 9
Mariner 9 was launched on a 398 million km direct ascent trajectory to Mars by an Atlas-Centaur SLV-3C booster (AC-23). Separation from the booster occurred at 22:36 UT, 13 minutes after launch. The four solar panels were deployed at 22:40 UT. The sensors locked onto the sun at 23:16, shortly after the spacecraft left Earth's shadow and Canopus acquisition was achieved at 02:26 UT May 31. A planned midcourse maneuver was executed on June 5. Mariner 9 arrived at Mars on November 14, 1971, after a 167 day flight. A 15 minute 23 second rocket burn put the spacecraft into Mars orbit, making Mariner 9 the first spacecraft to orbit another planet. The insertion orbit had a periapsis of 1398 km and a period of 12 hr, 34 min. Two days later, a 6 second rocket burn changed the orbital period to just under 12 hours with a periapsis of 1387 km. A correction trim maneuver was made on 30 December on the 94th orbit which raised the periapsis to 1650 km and changed the orbital period to 11:59:28 so that synchronous data transmissions could be made to the Goldstone 64-m DSN antenna. Imaging of the surface of Mars by Mariner 9 was delayed by a dust storm which started on September 22, 1971, in the Noachis region. The storm quickly grew into one of the largest global storms ever observed on Mars. By the time the spacecraft arrived at Mars no surface details could be seen except the summits of Olympus Mons and the three Tharsis volcanoes. The storm abated through November and December and normal mapping operations began. The spacecraft gathered data on the atmospheric composition, density, pressure, and temperature and also the surface composition, temperature, gravity, and topography of Mars. A total of 54 billion bits of scientific data were returned, including 7329 images covering the entire planet. After depleting its supply of attitude control gas, the spacecraft was turned off on October 27, 1972. Mariner 9 was left in an orbit which should not decay for at least 50 years, after which the spacecraft will enter the martian atmosphere. The mission resulted in a global mapping of the surface of Mars, including the first detailed views of the martian volcanoes, Valles Marineris, the polar caps, and the Martian moons Phobos and Deimos. It also provided information on global dust storms, the triaxial figure of Mars, and the rugged gravity field as well as evidence for surface aeolian activity. Mariner 10
Mariner 10 was placed in a parking orbit after launch for approximately 25 minutes, then placed in orbit around the sun en route to Venus. The protective cover of the sunward-facing electrostatic analyzers did not open fully after launch, and these instruments, part of the Scanning Electrostatic Analyzer and Electron Spectrometer experiment, could not be used. It was also discovered that the heaters for the television cameras had failed, so the cameras were left on to prevent low temperatures from damaging the optics. A trajectory correction maneuver was made 10 days after launch. Immediately following this maneuver the star-tracker locked onto a bright flake of paint which had come off the spacecraft and lost lock on the guide star Canopus. An automated safety protocol recovered Canopus, but the problem of flaking paint recurred throughout the mission. The on-board computer also experienced unscheduled resets occasionally, which would necessitate reconfiguring the clock sequence and subsystems. Periodic problems with the high-gain antenna also occurred during the cruise. In January 1974 Mariner 10 made ultraviolet observations of Comet Kohoutek and another mid-course correction was made on January 21. The spacecraft passed Venus on February 5, 1974, at a closest range of 5768 km at 17:01 UT and returned the first close-up images of Venus. This also marked the first time a spacecraft used a gravity assist from one planet to help it reach another. En route to Mercury an attitude control anomaly occurred for the second time, using up attitude control gas. Some new procedures were used from that point on to orient the spacecraft, including Sun-line maneuvers and the use of solar wind on the solar panels to orient the spacecraft. Mariner 10 crossed the orbit of Mercury on March 29, 1974, at 20:46 UT, at a distance of about 704 km from the surface. A second encounter with Mercury, when more photographs were taken, occurred on September 21, 1974, at an altitude of 48,069 km. Unfortunately the lighted hemisphere was almost the same as the first encounter, so a large portion of the planet remained un-imaged. A third and last Mercury encounter at an altitude of 327 km, with additional photography of about 300 frames and magnetic field measurements occurred on March 16, 1975. Engineering tests were continued until March 24, 1975, when the supply of attitude-control gas was depleted and the mission was terminated. Mariner 10 results showed a Hadley-type circulation existed in Venus' atmosphere and showed that Venus had at best a weak magnetic field, and the ionosphere interacted with the solar wind to form a bow shock. At Mercury, it was confirmed that Mercury had no atmosphere and a cratered, dormant Moon-like surface was shown in the images. Mercury was shown to have a small magnetic field and a relatively large iron-rich core. The total cost of the Mariner 10 mission was roughly $100 million. 
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This
craft was intended to perform a Venus flyby but destined for destruction, for
it was destroyed by the Range Safety Officer 293 seconds after launch at 09:26:16
UT when it veered off course. The booster had performed satisfactorily until an
unscheduled yaw-lift (northeast) maneuver was detected by the range safety officer.
Faulty application of the guidance commands made steering impossible and were
directing the spacecraft towards a crash, possibly in the North Atlantic shipping
lanes or in an inhabited area. The destruct command was sent 6 seconds before
separation, after which the launch vehicle could not have been destroyed. The
radio transponder continued to transmit signals for 64 seconds after the destruct
command had been sent.
Mariner
3 was destined for Mars, but it was lost when its protective shield failed to
eject. It was a solar-cell and battery-powered spacecraft that was designed to
take measurements in the vicinity of Mars and obtain photographs of the planet's
surface and transmit them to Earth. The trip was to take a little less than eight
months, but when the shield failed to eject, the craft was unable to use its solar
panels to collect energy, so its batteries soon died out. It is now in solar orbit.
Mariner 5 was a refurbished backup spacecraft for the Mariner 4 mission and was
converted from a Mars mission to a Venus mission. The craft was fully attitude
stabilized, using the sun and Canopus as references. A central computer and sequencer
subsystem supplied timing sequences and computing services for other spacecraft
subsystems.
Mariner
6 and 7 comprised a dual-spacecraft mission to Mars, the sixth and seventh missions
in the Mariner series of spacecraft used for planetary exploration in the flyby
mode. The primary objectives of the missions were to study the surface and atmosphere
of Mars during close flybys to establish the basis for future investigations,
particularly those relevant to the search for extraterrestrial life, and to demonstrate
and develop technologies required for future Mars missions and other long-duration
missions far from the sun. Mariner 6 also had the objective of providing experience
and data which would be useful in programming the Mariner 7 encounter 5 days later.
Each spacecraft carried a wide- and narrow-angle television camera, an infrared
spectroscope, an infrared radiometer, and an ultraviolet spectroscope. The spacecraft
were oriented entirely to planetary data acquisition, and no data were obtained
during the trip to Mars or beyond Mars.
The
Mariner Mars 71 mission was planned to consist of two spacecraft on complementary
missions, but due to the failure of Mariner 8 to launch properly, only one spacecraft
was available. Mariner 9 combined mission objectives of both Mariner 8 (mapping
70 % of the Martian surface) and Mariner 9 (a study of temporal changes in the
Martian atmosphere and on the Martian surface). For the survey portion of the
mission, the planetary surface was to be mapped with the same resolution as planned
for the original mission, although the resolution of pictures of the polar regions
would be decreased due to the increased slant range. The variable features experiments
were changed from studies of six given areas every 5 days to studies of smaller
regions every 17 days.
Mariner
10 was the seventh successful launch in the Mariner series, the first spacecraft
to use the gravitational pull of one planet (Venus) to reach another (Mercury),
and the first spacecraft mission to visit two planets. Mariner 10 was the first
(and as of 2003 the only) spacecraft to visit Mercury. The spacecraft flew by
Mercury three times in a retrograde heliocentric orbit and returned images and
data on the planet. Mariner 10 returned the first-ever close-up images of Venus
and Mercury. The primary scientific objectives of the mission were to measure
Mercury's environment, atmosphere, surface, and body characteristics and to make
similar investigations of Venus. Secondary objectives were to perform experiments
in the interplanetary medium and to obtain experience with a dual-planet gravity-assist
mission.