What's New Updates by Chapter Astro Pages Ordering
Links to the Mars Pathfinder Web Pages
Past Missions to Mars
National Space Science Data Center Mars Photo Gallery
Spaceviews Mars Pathfinder Mission
Jet Propulsion Lab's Future Mars Mission
University of Arizona's Lunar and Planetary Lab Imager
Passport to Knowledge Mars Mission Home Page
Mars Today Poster of Current Conditions on Mars
Viking Mission Home Page
Center for Mars Exploration
Manned Mission to Mars Home Page
The Mars Pathfinder landed on Mars on July 4, 1997.
The best ever photograph of Mars from Hubble has just been released. [hotlink to the photo]
Here is JPL's briefing as of March 20, 1997, about Mars Global Surveyor:
Today Mars Global Surveyor performed the second of four planned trajectory correction maneuvers at 10 a.m. Pacific Standard Time. The 26-second burn, designed to refine Surveyor's flight path to Mars, achieved a change in spacecraft velocity of about 3.87 meters per second (about 14 kilometers per hour or 8.6 miles per hour). The burn was performed in two stages, in which flight controllers first commanded the spacecraft to fire its small thrusters for 20 seconds, then to fire its main engine for another six seconds.
One of the spacecraft's solar arrays remains tilted at about 20.5 degrees from its fully deployed position. After completion of a series of very slight maneuvers in January and February to characterize the situation, which is believed to be caused by a broken damper arm wedged in the panel's joint, the flight team turned its attention to analyzing the possibility of carrying out the mission in Surveyor's current configuration. A decision is expected to be reached in early April by NASA Headquarters, the JPL flight team and their partners at Lockheed Martin Astronautics in Denver. Initial results indicate that the array, in its current state, will not be a significant problem in accomplishing the aerobraking operations at Mars. Mars Global Surveyor will use the aerobraking technique to dip slightly into the top of the Martian atmosphere in order to progressively slow the craft's orbital speed and thus maneuver it into the desired orbit from which to map the surface of the planet.
All systems onboard Mars Global Surveyor continue to operate normally. Currently the spacecraft is about 47 million kilometers (29 million miles) from Earth, traveling at a speed of about 93,600 kilometers per hour (59,000 miles per hour) with respect to the Sun.
The next flight path correction maneuver is scheduled for April 19, although flight controllers said the maneuver may not be necessary.
At 133 days into its flight to Mars, Mars Global Surveyor is presently on target to intercept the orbit of Mars on Sept. 12, 1997.
The sharpest view of Mars ever taken from Earth, was obtained by the recently refurbished Hubble Space Telescope (HST). This stunning portrait was taken with HST's Wide Field Planetary Camera-2 (WFPC2) on March 10, 1997, just before Mars opposition, when the red planet made one of its closest passes to the Earth (about 60 million miles or 100 million km). At this distance, a single picture element (pixel) in WFPC2's Planetary Camera spans 13 miles (22 km) on the Martian surface.
These images show the planet during the transition between spring and summer in the northern hemisphere (just before summer solstice). The annual north polar carbon dioxide frost (dry ice) cap is rapidly sublimating (evaporating from solid to gas), revealing the much smaller permanent water ice cap, along with a few nearby detached regions of surface frost. Bright water ice clouds can be seen in the giant impact basin, Hellas (near bottom of the image).
Hubble is being used to monitor dust storm activity to support the Mars Pathfinder and Mars Global Surveyor Orbiter Missions, which are currently en route to Mars. Hubble's "weather report" from these images, is invaluable for Mars Pathfinder, which is scheduled for a July 4 landing. Fortunately, these images show no evidence for large-scale dust storm activity, which plagued a previous Mars mission in the early 1970s.
The WFPC2 was used to observe Mars in nine different colors spanning the ultraviolet to the near infrared. The specific colors were chosen to clearly discriminate between airborne dust, ice clouds, and prominent Martian surface features. This picture was created by combining images taken in blue (433 nm), green (554 nm), and red (763 nm) colored filters.
Two miniaturized instruments designed and built by the University of Colorado at Boulder have been installed on Russia's Mars '96 spacecraft, now slated for launch from the Baikonur Cosmodome in Kazakhstan on Nov. 16.
Both instruments are photometers that will be used to gather light for studies of atmospheric and lunar dust, said Larry Esposito, a research associate at CU-Boulder's Laboratory for Atmospheric and Space Physics.
One photometer will ride on the main orbiting spacecraft. The second one will be deployed on a missile-like device, known as a penetrator, that will hurtle toward the planet at more than 3,000 miles per hour before penetrating the Martian surface up to 20 feet.
Involving about 20 nations, Mars '96 is one of the most ambitious planetary missions ever mounted, said Esposito. The 7-ton orbiting spacecraft, which will carry 18 instruments and four astrophysical experiments, also will deploy two soft-landing vehicles and two penetrators on the planet's surface.
The 15-foot-long penetrators, shaped like giant ice-cream cones and originally developed for military use, each carry 10 tiny instruments. A meteorological package on the rear of one of the penetrators designed by a Russian-Finnish team will carry the CU-Boulder photometer to measure sky brightness.
"We are interested in the weather on Mars," said Esposito. "The amount of sunlight on the surface can tell us how much cloud cover there is and how much dust is in the atmosphere. We should be able to calculate the abundance, size and composition of these dust particles, and learn more about how the dust concentrations affect the Martian climate."
Although the photometer will remain on the surface of Mars for years, it will gather data for only a few seconds each day, he said. Over time, the instrument should provide Esposito and his colleagues with seasonal and annual information on Martian dust and its impact on the planet's climate.
The primary scientific focus of Mars '96 will be to study the processes responsible for the evolution of the Martian surface, atmosphere and climate. The 60-million mile journey will include two loops past Earth before arriving at the Red Planet in December 1997.
Mars Pathfinder, the second in NASA's decade-long program of missions to Mars, blasted into space at 1:58:06 a.m. Eastern time today on December 4th.
Launched about a month after NASA's Mars Global Surveyor, Pathfinder successfully separated from the Delta launch vehicle at about 500 miles above Earth and was sent on its way to Mars. The spacecraft is on a fast track to Mars that will place it on the surface of the planet on July 4, 1997.
Mars Pathfinder is the second of NASA's Discovery program missions, designed to send low-cost spacecraft with highly focused science goals into space. The Spacecraft will be the first to land on the surface of Mars since the Viking landers of the mid-1970s.
The Mars '96 mission to Mars was launched by the Russians on November 17, but a problem with the fourth stage left it in Earth orbit unable to escape to Mars. The orbit will decay over a few weeks and the spacecraft will burn up in the Earth's atmosphere.
Mars Global Surveyor sailed into a cloudless sky atop a Delta II launch vehicle at 12:00:49.99 p.m. Eastern time (9 a.m. Pacific time) November 7, 1996, from launch pad 17A at Cape Canaveral Air Station, FL. The launch was delayed a day due to clouds and upper-level winds on the first day of the launch window on Wednesday, November 6.
Automated Delta rocket operations went just as planned following launch. The three-stage Delta vehicle and its nine solid-fuel strap-on boosters lifted the spacecraft to an altitude of 115 kilometers (70 miles) above Earth. The second stage boosted the payload to a circular parking orbit 185 kilometers (115 miles) above Earth about 10 minutes after launch, where the spacecraft coasted for about 30 minutes before reaching its proper position over the eastern Indian Ocean. The Delta's third stage fired for about 90 seconds to spin up Mars Global Surveyor to 60 rpm and send the Mars craft on its way.
The spacecraft's solar arrays were deployed at about 5:52 Universal Time (9:52 a.m. Pacific time). Telemetry indicated that one of the solar panels did not fully open, but the spacecraft team expects to have the array fully unfolded within the next day. Surveyor's radio signal was acquired on time, about 70 minutes after launch, at about 6:11 Universal Time (10:11 a.m. Pacific time), by the 34-meter (112-foot) antenna of NASA's Deep Space Network at Canberra, Australia.
The next major spacecraft event will occur seven days from now, when the propellant tanks are pressurized. Eight days later, Surveyor will fire its main engine in the first of four trajectory correction maneuvers to fine-tune its flight path to the red planet.
The United States and Russia return to Mars this fall with the launch of three missions destined to explore Earth's planetary neighbor in greater detail than has ever before been accomplished.
NASA's Mars Global Surveyor and Mars Pathfinder and Russia's Mars '96 mission are scheduled for three separate launches in November and December 1996. Mars Global Surveyor, an orbiter carrying six scientific instruments to study the atmosphere,surface and interior of Mars, will be launched Nov. 6. It will be followed by Russia's Mars '96, an orbiter carrying 12 instruments plus two small landers and two penetrators, which will lift off Nov. 16. Mars Pathfinder will carry a lander and small rover robot when it is lofted into space Dec. 2.
Launch of the NASA spacecraft marks the beginning of a new era in Mars exploration and an ambitious new initiative by the United States to send pairs of spacecraft to the red planet every 26 months through the year 2005.
NASA's new decade-long program of robotic exploration known as the Mars Surveyor program takes the next step in expanding scientists' knowledge of Mars. The program is focused on three major areas of investigation: the search for evidence of past life on Mars; understanding the Martian climate and its lessons for the past and future of Earth's climate; andunderstanding the geology and resources that could be used to support future human missions to Mars.
The unifying theme of the Mars exploration program is the search for water, which is a key requirement for life, a driver of climate and a vital resource. Early missions will thus focus partially on finding and understanding the past and present state of water on Mars. Mars Global Surveyor and Mars Pathfinder will be the forerunners in this quest, becoming the precursors to a series of missions that may culminate in the first few years of the next century with robotic return of a Martian soil sample to Earth, followed by eventual human exploration.
NASA's 1996 missions to Mars further the global explorations of the planet begun in 1965 with the Mariner 4 mission to Mars and continued in the mid-'70s by the Viking lander missions.
From earlier investigations, scientists have compiled a portrait of Mars full of stark contrasts. Mars' surface features range from ancient, cratered terrain like Earth's Moon to immense volcanoes that would dwarf Mt. Everest and a canyon that would stretch across the United States.
Mars' atmosphere is less than 1 percent as thick as Earth's, but there are permanent polar caps with reservoirs of water ice. Closeup shots of Mars' terrain resemble that of an Earthly desert, with surface features that look like river channels carved long ago by flowing water.
The next step in Mars exploration, according to scientists, is to obtain an overview of the entire planet and to verify remote observations with measurements taken from the ground. Mars Global Surveyor is designed to study the atmosphere, surface and interior systematically over a full Martian year. The Russian Mars '96 orbiter has similar objectives, but will also characterize the uppermost atmosphere and its interactions with the solar wind.
To obtain "ground truth" -- observations on the surface verifying those made from space -- the Russian Mars '96 spacecraft will deploy two landers that will touch down in the northern hemisphere in a region called Amazonis Planitia and two penetrators that will impact and lodge themselves anywhere from 1 to 6 meters (3 to 20 feet) underground. These probes will furnish details of the atmosphere and surface at the specific locations in which they land. NASA is contributing two experiments to Mars '96: the Mars Oxidation Experiment, which will measure the oxidation rate of the Martian environment, and the Tissue- Equivalent Proportional Counter, which will study the radiation environment in interplanetary space and near Mars.
Mars Pathfinder will deploy a mobile rover that will characterize rocks and soil in a landing area over hundreds of square meters (yards) on Mars. Pathfinder's instruments and mobile rover are designed to provide an in-depth portrait of Martian rocks and surface materials over a relatively large landing area, thereby giving scientists an immediate look at the crustal materials that make up the red planet.
Although the last to leave Earth, Mars Pathfinder takes a shorter flight path and will be the first of the three spacecraft to arrive at Mars, touching down in Ares Vallis on July 4, 1997.
Pathfinder is designed to demonstrate an innovative approach to landing a spacecraft and rover on the surface of Mars. Pathfinder will dive through the upper atmosphere of Mars on a parachute, then inflate a huge cocoon of airbags to cushion its impact. The spacecraft will collect engineering and atmospheric science data along its descent to the ground.
The primary objective of the mission is to test this low- cost method of delivering a spacecraft, science payload and free- ranging rover to the surface of the red planet. Landers and rovers of the future will share the heritage of spacecraft designs and technologies that evolve from this pathfinding mission.
Once on the surface, the lander's first task will be to transmit engineering and science data collected during descent through the thin atmosphere of Mars. Then its camera will take a panoramic image of its surroundings and begin transmitting the data directly to Earth at a few thousand bits per second. Much of Pathfinder's mission after this will be focused on collecting atmospheric and surface composition data, and supporting the rover by storing and transmitting images captured by its cameras. Pathfinder's nominal mission lifetime is approximately 30 "sols," or Martian days (about the same number of Earth days).
Pathfinder's rover, Sojourner, will be carried to Mars in a stowed configuration with its chassis and wheels folded up like an accordion. Once its solar cells are exposed to the Sun, the rover will power up and stand to its full height before leaving the lander. Driving off onto the floor of an ancient flood plain believed to contain a wide variety of rocks, Sojourner will explore the surface independently, relying on the lander primarily for communications with Earth.
Two months later, NASA's Mars Global Surveyor and Russia's Mars '96 orbiter will arrive at Mars on September 11 and 12, 1997, respectively.
At first, Mars Global Surveyor will be in a highly elliptical orbit and spend four months dipping lower and lower into Mars' upper atmosphere using a technique called aerobraking to bring it into a low-altitude, nearly circular mapping orbit over the poles. By March 1998, Surveyor will be ready to begin data collection, compiling a systematic database as it surveys the Martian landscape and photographs unique features, such as the polar caps and Mars' network of sinuous, intertwining river channels.
Mars '96 carries a dozen instruments and a dozen smaller devices designed to study the evolution of the Martian atmosphere, surface and interior. In addition to meteorological and seismic instruments, the spacecraft carries instruments to image the Martian surface, explore the chemistry and water content of rocks and attempt to detect and measure the Martian magnetic field.
Two miniaturized instruments designed and built by the University of Colorado at Boulder have been installed on Russia's Mars '96 spacecraft, now slated for launch from the Baikonur Cosmodome in Kazakhstan on Nov. 16.
Both instruments are photometers that will be used to gather light for studies of atmospheric and lunar dust, said Larry Esposito, a research associate at CU-Boulder's Laboratory for Atmospheric and Space Physics.
One photometer will ride on the main orbiting spacecraft. The second one will be deployed on a missile-like device, known as a penetrator, that will hurtle toward the planet at more than 3,000 miles per hour before penetrating the Martian surface up to 20 feet.
The CU instrument team includes Esposito, LASP senior researcher George Lawrence and former LASP graduate student Justin Maki, now a post-doctoral researcher at the University of Arizona. Designed and developed with funding and support from NASA, the photometers were built for about $13,000 each.
Involving about 20 nations, Mars '96 is one of the most ambitious planetary missions ever mounted, said Esposito. The 7-ton orbiting spacecraft, which will carry 18 instruments and four astrophysical experiments, also will deploy two soft-landing vehicles and two penetrators on the planet's surface.
The 15-foot-long penetrators, shaped like giant ice-cream cones and originally developed for military use, each carry 10 tiny instruments. A meteorological package on the rear of one of the penetrators designed by a Russian-Finnish team will carry the CU-Boulder photometer to measure sky brightness.
"We are interested in the weather on Mars," said Esposito. "The amount of sunlight on the surface can tell us how much cloud cover there is and how much dust is in the atmosphere. We should be able to calculate the abundance, size and composition of these dust particles, and learn more about how the dust concentrations affect the Martian climate."
Past observations of Mars indicate massive dust storms periodically blanket the planet, blotting out the sun for months and raising atmospheric temperatures.
The two-ounce photometer on the Mars '96 penetrator resembles a thick computer disc and can easily fit into a shirt pocket, said Esposito.
Although the photometer will remain on the surface of Mars for years, it will gather data for only a few seconds each day, he said. Over time, the instrument should provide Esposito and his colleagues with seasonal and annual information on Martian dust and its impact on the planet's climate.
The second CU-Boulder photometer will be attached to a scanner located on a spectrometer developed by a team of scientists from seven nations. The orbiting CU photometer will be used to point at what scientists believe to be a faint, doughnut-shaped ring of dust associated with Phobos, the largest moon of Mars.
"There have been reports hinting at this dust, but it has not yet been seen," said Esposito. "We think we will be able to see light scattered by the dust and calculate the size and abundance of the dust particles."
The cylindrical CU-Boulder photometer riding on the orbiter is only about 3 1/2 inches long and can fit in the palm of one's hand, he said.
"We needed instruments that were small in size, low in cost and could be developed rapidly," said Esposito, who hand-carried the instruments to the Moscow Institute of Applied Mathematics in 1995. "This was an opportunity for us to make some important observations during the mission."
Esposito was one of six American scientists collaborating with the Russians on the failed 1988 Russian Phobos missions to Mars. Russian controllers lost contact with both spacecraft prior to their slated arrival at the planet and its moons in 1989.
The primary scientific focus of Mars '96 will be to study the processes responsible for the evolution of the Martian surface, atmosphere and climate. The 60-million mile journey will include two loops past Earth before arriving at the Red Planet in December 1997.
source: from a JPL/NASA press release:
All six science instruments comprising the scientific payload of NASA's new Mars Global Surveyor orbiter have been integrated on the nearly complete spacecraft, which is in development at Lockheed Martin Astronautics Corp.
The last of the instruments -- the thermal emission spectrometer -- arrived at Lockheed Martin on May 28, completing Surveyor's suite of equipment to study the surface, atmosphere and interior of Mars over a full Martian year, the equivalent of about 687 Earth days.
During this phase of testing, Surveyor is being subjected to simulations of the harsh conditions of launch. After completing those tests, the spacecraft will undergo two weeks of testing in simulations that will replicate the environment of space -- extremely cold temperatures and illumination on one side of the spacecraft by the Sun -- to assure that Surveyor's temperature control design is adequate for its 10-month journey to Mars and two years in orbit around the planet.
Mars Global Surveyor carries six of the eight instruments that were flown on the Mars Observer spacecraft, which was lost in August 1993. The instruments include: a thermal emission spectrometer, designed to analyze infrared radiation from the surface of Mars; a Mars orbiter laser altimeter, which will measure the height of Martian surface features; and a magnetometer and electron reflectometer, which will search for evidence of current and ancient magnetic fields.
Also onboard the spacecraft are a Mars orbiter camera, which will take high resolution photographs of the planet and provide daily global weather maps, and an ultra stable oscillator that will be used along with Surveyor's telecommunications system to map variations in the gravity field of Mars and study its atmosphere.
Mars Global Surveyor also will carry a Mars relay radio system that will be used to support the Russian Mars '96 mission, planned for launch in late 1996. The relay system will periodically receive and relay data from instrument packages deployed to the Martian surface by the Russian Space Agency.
Of the six science instruments onboard the spacecraft, four -- the camera, laser altimeter, electron reflectometer and thermal emission spectrometer -- will be carried on the spacecraft's nadir panel, along with the relay system. Mars Global Surveyor will orbit the planet in a low altitude, nearly circular orbit over the poles of the planet, keeping its nadir panel continuously pointed at the surface. The spacecraft will complete one orbit around Mars about every two hours. As the weeks pass, Surveyor will create a global portrait of Mars, capturing the planet's ancient cratered plains, huge canyon system, massive volcanoes, gigantic channels and frozen polar caps.
Surveyor's science instruments have been provided by the following institutions: Hughes Santa Barbara Remote Sensing Inc., Goleta, CA, and Arizona State University, Tempe, provided the thermal emission spectrometer; NASA's Goddard Space Flight Center, Greenbelt, MD, provided the laser altimeter and magnetometer; the University of California, Berkeley, and the Centre National d'Etudes Spatiales, the French space agency, provided the electron reflectometer; Malin Space Science Systems Inc., San Diego, CA, furnished the Mars orbiter camera; Johns Hopkins University's Applied Physics Lab, Laurel, MD, provided the ultra stable oscillator; and the Centre National d'Etudes Spatiales furnished the Mars relay radio system.
Mars Global Surveyor will be shipped to Cape Canaveral, FL, in mid-August, where it will be fueled, integrated with the third stage booster of a Delta II expendable launch vehicle and readied for launch on Nov. 6.
Surveyor will arrive at Mars in September 1997 and spend approximately five months aerobraking through the Martian atmosphere to lower itself into the final mapping orbit. Global mapping operations will begin in March 1998, allowing scientists to obtain the first extensive record of Mars' surface, atmosphere and interior.
Mars Global Surveyor is the first of a decade-long program of robotic missions to Mars, managed by the Jet Propulsion Laboratory for NASA's Office of Space Science, Washington, D.C.
Heading into the home stretch of spacecraft assembly, NASA's Mars Pathfinder lander -- a tetrahedral-shaped spacecraft weighing 351 kilograms (772 pounds) and standing about 1 meter (3.2 feet) tall -- was mated today with its companion rover, Sojourner, just as it will fly to Mars later this year.
The lander and rover, in development at NASA's Jet Propulsion Laboratory, crossed a major engineering milestone with full integration after a year of rigorous testing of components making up the spacecraft's landing gear, said Brian Muirhead, Pathfinder flight system manager. Subsystems included a parachute, measuring 12.7 meters (41 feet) in diameter, three small, rocket-assisted deceleration thrusters to help the spacecraft brake through the Martian atmosphere, and giant, multi-lobed air bags to cushion its landing.
Now with its rover mounted and secured by cables to an inside petal, Pathfinder will be folded up to undergo integration testing in the next several days, Muirhead said. In the weeks ahead, the spacecraft will next be attached to the inside of its backshell and then be encased in a Viking-derived heatshield.
"This is actually the first and last time that we will see Pathfinder and Sojourner completely assembled until just before launch," Muirhead said. "It's exciting to see the spacecraft in full flight configuration, and to know that we have set a new standard for JPL and the world in the development of interplanetary spacecraft."
Currently residing in JPL's spacecraft assembly clean room, Pathfinder will be delivered to JPL's 25-foot space simulator in March for spin-balance, acoustic and thermal vacuum testing, added Robert Manning, flight system chief engineer. Over the summer, the spacecraft will be taken apart again for final pyro and electrical testing before its components are prepared for shipping on Sept. 1 to Cape Canaveral, Fla.
Pathfinder is designed to place a low-cost delivery system on the surface of Mars, demonstrating a new and unconventional atmospheric entry and landing approach. The spacecraft will be launched on Dec. 2 from Cape Canaveral, Fla., and spend seven months cruising to Mars. Landing on an ancient flood basin known as Ares Vallis, Pathfinder will touch down on July 4, 1997.
Twenty-four hours before Mars arrival, the spacecraft will turn approximately 7 degrees to its entry attitude and continue to descend, Manning said. Hitting the thin upper atmosphere at more than 27,000 kilometers per hour (about 17,000 miles per hour), the lander's heat shield will slow the craft to about 1,450 kilometers per hour (900 miles per hour) in about two minutes. An onboard computer will sense the slow-down in speed and eject a large parachute.
Seconds later, the heat shield, still red hot from the heat of entry, will be released and the lander will be separated from the backshell on a bridle. Because the rarefied atmosphere of Mars is only 1/100th as dense as Earth's, the parachute will slow the lander to about 250 kilometers per hour (155 miles per hour). A few seconds before impact, a giant cocoon of air bags will be inflated and the rockets will fire to literally stop the lander in mid-air and slow it to less than 72 kilometers per hour (45 miles per hour).
Landing four hours before sunrise, Pathfinder will bounce along the Martian surface like a huge beach ball before coming to a halt. The craft will spend the next three hours deflating and retracting its air bags, standing itself upright and unfolding its petals to expose the 10-kilogram (22-pound) Sojourner rover. Daylight will give Sojourner the solar power it will need to power up, rise to its full height and drive off one of the two exit ramps onto the Martian surface.
Although Pathfinder is considered an engineering demonstration, it will accomplish a focused set of science investigations with a stereo, multi-colored lander imager, atmospheric instruments that will be used as a weather station after landing, and an autonomous rover capable of measuring the composition of rocks and surface materials near the landing site. Sojourner will also perform mobility tests and image its surroundings. One of its first jobs will be to image the lander, so that scientists and engineers can determine the lander's condition and study the local terrain.
The Pathfinder lander will carry out most of its engineering objectives within the first few hours after landing, then be used to take panoramic images of the Martian landscape and support rover activities. The lander, the first in NASA's Discovery program of low-cost planetary spacecraft with highly focused science goals, has a mission lifetime of at least 30 days. Sojourner is expected to rove the surface of Mars for a minimum of seven days.
The Mars Pathfinder mission is managed by the Jet Propulsion Laboratory for NASA's Office of Space Science, Washington, D.C.
Mars Global Surveyor (MGS) is scheduled to be launched by NASA in November 1996 for a 10-month journey to Mars. It carries seven instruments that duplicate those lost on Mars Observer plus four additional instruments. MGS will go into a near-circular polar orbit 367 kilometers high. In its two years of orbiting, it should provide excellent global maps of Mars.
The following month, NASA is scheduled to launch Mars Pathfinder, which is to land on Mars in July 1997. It contains a small rover.
Also in December 1996, a Russian spacecraft, postponed from two years ago, is scheduled. This Mars 96 mission contains an orbiter and four landers. Two of the landers are to be able to penetrate several meters into the surface.
An extremely lightweight camera and a variety of instruments designed to study daily weather patterns and the icy south pole on Mars have been selected to fly aboard an orbiting spacecraft and lander in late 1998.
Known as the Mars Surveyor '98 Orbiter and the Mars Surveyor '98 Lander, the robotic missions will be launched in December 1998 and January 1999, respectively. They should enable detailed scientific studies of the planet's atmosphere, climate, meteorology and surface volatiles such as water ice and frozen carbon dioxide. The lander will be the first mission ever sent to the poles of Mars, where it will settle on terrain that appears to consist of alternating layers of clean and dust-laden ice.