Jet Propulsion Laboratory (U.S.). Mars Observer and Mars Global Surveyor Projects.

In 1980, the NASA Advisory Council formed the Solar System Exploration Committee (SSEC) to formulate a long-range program for planetary exploration. This program would build on the scientific strategies developed by the Committee on Lunar and Planetary Exploration of the National Academy of Science's Space Science Board, and would also recognize the fiscal constraints likely to apply to NASA's science program in the foreseeable future.

As a result of extensive investigation of scientific priorities, mission opportunities, launch vehicle and technology capabilities, and overall program planning for affordability and basic supporting research, the SSEC's initial recommendation in 1983 was establishment of a Core program for planetary exploration through the year 2000.

This Core program consisted of two elements: first, the basic supporting activities of research mission operations, technology development and advance planning, and second, the Core planetary missions program. Two distinct series of missions were recommended: the Planetary Observers for exploration of the inner solar system, and missions utilizing the Mariner Mark II spacecraft for exploration of the outer solar system.

In 1985, the Announcement of Opportunity culminated a FY85 new start for the Mars Observer Project. Four years later, the FY89 NASA Budget established the estimate for the development costs (through launch plus 30 days) for Mars Observer at $419M in real year dollars excluding the upper stage or injection capability, Space Transportation System (STS) integration and STS launch costs, and the Jet Propulsion Laboratory (JPL) institutional costs of Tracking and Data Acquisition and of the Space Flight Operations Center. The Mission Operations and Data Analysis phase of the project was estimated at 79.9M in real year dollars.

The Mars Observer was the first of the Planetary Observer missions, a series of low cost, modest scope missions for exploration of the inner solar system. MO was programmed to be the first mission returning to Mars since 1976. Spacecraft development costs were by basing design on civilian and military Earth-orbiting spacecraft designs. General Electric's Astro-Space Division produced the Mars Observer spacecraft carrier vehicle, or bus. The Titan III launch vehicle was provided by Martin Marietta Commercial Titan, Inc.; the Transfer Orbit Stage was supplied by the Orbital Sciences Corporation and built by the Martin Marietta Astronautics.

Mars Observer was launched on September 25, 1992, aboard a Titan III launch vehicle from Cape Canaveral Air Force Station in Florida. The objective of the Mars Observer mission was to place a spacecraft in orbit about Mars for one Martian year, providing a nadir-oriented platform from which to carry out a series of cost-effective experiments and measurements designed to meet the scientific objectives of the mission.

The objectives were to perform an extended orbital study of the Martian surface, atmosphere, gravitational and magnetic fields using a spacecraft operating at an altitude of 361 km and an inclination of 93°.

Mars Observer had completed an 11-month, 711-million-kilometer (442-million-mile) journey to Mars and was within three days of entering orbit around the planet when it fell silent at about 1:00 Universal Time on August 22, 1993. (6 p.m. Pacific Daylight Time on August 21st).

The spacecraft was about to begin pressurizing its fuel tanks in preparation for the August 24th orbit-insertion maneuver when its transmitters were turned off and the spacecraft was never heard from again. It was believed that Mars Observer developed a major leak in its propulsion system sending it out of control. It was the first loss of an U.S. planetary mission in 27 years.

In conclusion of Mars Observer operations, JPL attempted the last realistic chance to validate that the spacecraft still existed and was properly operating-except for its telemetry transmitter. That occurred in late September, during a search for a beacon from a radio relay system onboard the spacecraft by radio astronomy antennas at Jodrell Bank in England, at Stanford University, and at the Goldstone tracking facility near Barstow.

"Had the spacecraft been in either of its predicted locations in orbit around Mars or in a flyby orbit around the Sun and had it been able to receive and process commands from the ground, we fully expected that a signal from its independent radio transmitter would have been detected," said Dr. Sam Dallas, Mars Observer mission manager.

While minimal support for ground-tracking of Mars Observer did continue through mid February, JPL had begun a Mars Recovery Study Team effort to explore the most cost-effective, low-risk ways of recovering the Mars Observer science during the next Mars launch opportunities in 1996, 1998 and 2000.

As a result of that effort, many of the personnel involved in the Mars Observer project went on to become part of the teams that were planning how the scientific data from the mission would improve our knowledge of Mars. Therefore, NASA and the U.S. Congress quickly authorized FY95 funding for the Mars Global Surveyor Program.

The Mars Global Surveyor mission was approved for a 1996 launch. MGS was a mission that was to recover as much as possible of the science that would have been done by the lost Mars Observer. All of the plans, designs and knowledge that went into creating all the instruments on board were used to build Mars Surveyor. In addition, Martin Marietta consequently refunded NASA $19 million in award fees from the Mars Observer failure due to a catastrophic failure clause in the contract, (provisional On-Orbit Performance Award payments) solely attributable to the Contractor.

The Mars Global Surveyor was the first mission of a new, decade long program of robotic exploration of Mars. This simulated an aggressive series of orbiters and landers scheduled for launch every 26 months as Mars moves into alignment with Earth.

Mars Global Surveyor (MGS) spacecraft was successfully launched on November 7, 1996, aboard a McDonnell Douglas Delta II 7925A launch vehicle from Cape Canaveral Air Station (CCAS) in Florida. After launch on the Delta II Lite 7925 vehicle with nine strap-on rocket boosters and a Star 48 (PAM-D) third stage, there was a 10 month cruise phase, at the end of which the MGS was inserted into an elliptical capture orbit at 01:17 UT September 12, 1997.

MGS was designed to orbit Mars over a two-year period and collect data on the surface morphology, topography, composition, gravity, atmospheric dynamics, and magnetic field. This was used to investigate the surface processes, geology, distribution of material, internal properties, evolution of the magnetic field, and the weather and climate of Mars. To establish the required mapping orbit, the MGS spacecraft had to supplement its propulsive capabilities by aerobraking. Aerobraking was accomplished by lowering the periapsis altitude of the orbit into the upper reaches of the Martian atmosphere and allowing drag forces to reduce the orbital energy.

The spacecraft itself was a rectangular box approximately 1.17 x 1.17 x 1.7 meters in size, made up of two parts, the equipment module and the propulsion module. All instruments except the magnetometer were stored on the nadir equipment deck, on one of the 1.17 x 1.17-meter surfaces.

This was the top of the equipment module, which was 0.735 m high. The main thruster and propulsion tanks were on the opposite side from the instruments, on the propulsion module, which was 1 meter high. Two solar panels, each 3.5 x 1.9 m in size, extended out from opposite sides of the craft. A 1.5-meter diameter parabolic high gain dish antenna was mounted on an adjacent side, and attached to a 2-meter boom, which was extended for mapping operations so the antenna could be held away from the body of the spacecraft. The spacecraft was three-axis stabilized with no scan platform.

The primary mission lasted one martian year (687 Earth days) through January 2001. An extended mission took place until April 2002. After that time, the orbiter acted as a relay until January 2003 in support of other missions of the Mars Surveyor Program.

The Mars Global Surveyor mission cost about $154 million to develop and build and $65 million to launch. Mission operations and data analysis cost approximately $20 million/year.

The Jet Propulsion Laboratory (JPL), California Institute of Technology, (CIT) managed Mars Global Surveyor and the Mars Program for NASA's Office of Space Science. JPL, NASA's lead center for automated space exploration, provided mission design and navigation, and managed mission operations.

From the description of Mars Observer and Mars Global Surveyor Operations Plans Collection, 1985-1998. (Jet Propulsion Laboratory Library and Archives). WorldCat record id: 733102112