STS SPECS:
Crew Capacity: 8 (10 could be carried in an emergency)
Max Acceleration Load < 3Gs.
Orbital Altitude: 100 to 217 nautical miles.
Cargo bay dimensions: 15 feet diameter, 60 feet long.
Basic Mission Length: 7 days in space

ORBITERS:
Enterprise (OV-101): used for Approach and Landing Tests, the Enterprise now is property of the Smithsonian Institution and is at Dulles Airport, Virginia.
Columbia (OV-102): the first operational orbiter, STS-1 first launched on 12 April 1981. Columbia has completed 23 flights to date.
Challenger (OV-099): the second orbiter, flew 10 missions between 1983 and 1986 for a combined total of 69 days in space. On January 28, 1986, Challenger and her crew were lost in a launch accident.
Discovery (OV-103): the third orbiter, Discovery has flown 24 missions since its maiden voyage on August 30, 1984.
Atlantis: (OV-104): Atlantis has flown 19 missions since its first launch on October 3, 1985. Atlantis is currently being upgraded and is scheduled to return to KSC on August 24, 1998.
Endeavour: (OV-105): Replacing the Challenger and completing the 4-orbiter space shuttle fleet, Endeavor has flown 13 missions since its first launch on May 5, 1992.

The Space Shuttle Discovery lifted off Tuesday at 6:06pm EDT on mission STS-91. This will be the ninth and final Shuttle/Mir docking mission, the 1st flight of Discovery to Mir and the 6th flight for the SPACEHAB single module configuration. This mission will also carry the Alpha Magnetic Spectrometer Investigation (AMS) which will search for anti-matter and dark matter in space.

E12 Europa - 16 December 1997
E13 Europa - 10 February 1998
E14 Europa - 29 March 1998
E15 Europa - 31 May 1998
E16 Europa - 21 July 1998
E17 Europa - 26 September 1998
E18 Europa - 22 November 1998
E19 Europa - 1 February 1999

The Galileo spacecraft just completed a close flyby of Jupiter's moon Europa . Called the Europa 15 encounter , Galileo flew over Europa at an altitude of only 2516 kilometers (1564 miles) on May 31st.

Data processing and transmission from Galileo's previous flyby of Europa is continuing. The material had been stored on the spacecraft's onboard tape recorder.

Some of the data transmission was delayed last week so that the Deep Space Network's 70-meter (230-foot) antenna (which was being used to receive Galileo's signal) could be used to support radio frequency observations of a newly identified gamma ray burst.

The Galileo spacecraft's attitude control system has been behaving anomalously since the spacecraft's closest flyby to Europa last December 16. Engineers believe that the anomaly may be caused by the spacecraft's repeated exposure to Jupiter's strong radiation. Thus far the Galileo flight team has been able to operate the spacecraft so that the anomaly has had very little effect on the spacecraft's performance.

The spacecraft successfully completed its primary mission in December 1997. Now in its two-year extension, called the Galileo Europa Mission, Galileo will conduct five more Europa flybys (including the May 30, 1998 encounter, four Callisto flybys, and one or possibly two flyby's of Io, depending on the spacecraft health.

On May 21st, The Galileo team released four more images of Europa from the previous, Europa 14, encounter in late March. They are in NASA's Planetary Photojournal at:

The Mars Pathfinder team is currently incorporating images from the JPL Planetary Photojournal into the main Pathfinder site and within the Science Results Section.

See the Directory of Pathfinder Images for the newly organized images from the Mars Pathfinder mission.

Analysis of Mars Pathfinder data continues, science results are available on-line. See: The Overview of the Mars Pathfinder Mission and Assessment of Landing Site Predictions - Science Online, and a link list of additional articles recently made available is at: http://mpfwww.jpl.nasa.gov/mpf/papers.html

...Since its landing on July 4, 1997, Mars Pathfinder has returned 2.6 billion bits of information, including more than 16,000 images from the lander and 550 images from the rover, as well as more than 15 chemical analyses of rocks and extensive data on winds and other weather factors."
Reference: the November 4, 1997 Jet Propulsion Laboratory Press Release announcing the winding down of the highly successful Mars Pathfinder mission.

Mars Pathfinder is the first mission to land on Mars since two "Viking" spacecraft touched down there in 1976.

In late April, the Mars Global Surveyor team acquired the first images of the "Face on Mars" since the Viking orbiter imaged the formation in 1976. The formation and its shadows appeared to look like a face in the Viking images. With the higher resolution images from the Mars Global Surveyor and under different lighting conditions, the "face" disappears.

On May 27, 1998, Mars and the Mars orbiting Mars Global Surveyor (MGS) spacecraft emerged from behind the sun after a month long period known as a "solar conjunction." Near the sun, solar electromagnetic noise interfered with the radio signals sent to and from the spacecraft. During the middle of this conjunction, the Sun actually eclipsed Mars and blocked radio communications with the spacecraft. Science operations, temporarily suspended through the solar conjunction, resumed by the end of May and will continue through a "Science Phasing" period until November 1998, when another period of aerobraking will restart on September 11th and continue through March 1999.

Aerobraking will lower the Mars Global Surveyor's current highly elliptical, 11.6-hour orbit around Mars to a low, circular, two-hour mapping orbit by April 1999 with a high point of 450km.

Check out MGS CURRENT ORBIT page for a cool real-time display of the MGS spacecraft position in Mars orbit.

by Laura Zoller
Space Update Writer

"NEAR spacecraft state is nominal. All instruments are off" - NEAR Weekly Report - May 29, 1998

The NEAR team plans to image Eros on August 13, 1998; exactly 100 years after its discovery.

NEAR's study of Eros will be the first in-depth examination of a near-Earth asteroid and is expected to yield information that will help scientists better understand the evolution of our solar system. NEAR is the first mission of NASA's "Discovery" series.

"The Lunar Prospector spacecraft continues to perform very well and instruments are collecting good data." - May 7, 1998 Lunar Prospector Status Report

On March 5th, 1998 Lunar Prospector project scientist announced that the Lunar Prospector had returned data that indicates that there is a high probability of water ice existing at both the north and south poles of the Moon.

It is possible that the presence of a significant amount of water on the Moon will aid the establishment of human communities beyond Earth.

See the CNN SCI-TECH article on Lunar Prospector's ice discovery at: CNN SCI-TECH Space - 05 March 1998 - Scientist: There is ice on the moon

For more information about ice on the Moon, check out the "Planetary Science Research Discoveries" article "Ice on the Bone Dry Moon" by Dr. Paul D. Spudis.

The Cassini spacecraft, on its way to Saturn, successfully flew by Venus on April 26th; on time and on target at 284 kilometers (176 miles) above the Venusian surface. Venus' gravity gave the Cassini spacecraft a boost in speed of about 7 kilometers per second (about 4 miles per second) to help the spacecraft reach Saturn in July 2004. Science instruments on the spacecraft searched for lightning in Venus' atmosphere during the flyby, and the radar instrument onboard was activated to test bouncing a signal off Venus' surface.

The Venus flyby is the latest of dozens of similar "gravity-assist" flybys of planets and moons performed by JPL-controlled spacecraft over the past three decades. Cassini will perform three more similar gravity-assist flybys: Venus again in June of 1999, Earth in August of 1999, and Jupiter in December 2000. All the flybys use the gravitational pull of the target planets to impart more speed to the spacecraft to help it reach Saturn. The Venusian flyby was the lowest-altitude gravity-assist planetary pass Cassini will make - Reference: Cassini Mission Status Report, April 29, 1998

Arriving on orbit around Saturn in 2004, Cassini will study the great ringed planet, its moons and ring system for at least four years. It will also deliver a scientific probe called Huygens which will parachute to the surface of Saturn's largest moon, Titan.

Planet-B is the first Japanese space mission to Mars. A Mars orbiting aeronomy mission, Planet-B is designed to study the martian upper atmosphere and its interaction with the solar wind. Instruments on the spacecraft will measure the structure, composition and dynamics of the ionosphere, aeronomy effects of the solar wind, the escape of atmospheric constituents, the structure of the magnetosphere, and dust in the upper atmosphere and in orbit around Mars. The mission will also be returning images of Mars' surface and the martian moons Phobos and Deimos.

Planet-B will initially be put into an elliptical geocentric 7000 km x 400,000 km parking orbit with its apogee just beyond the orbit of the Moon. Assuming that launch occurs in the early August launch window as scheduled, the first lunar swingby will take place in September. swing by close to the Earth and slingshot into an escape trajectory towards Mars. It is scheduled to arrive at Mars on 11 October 1999.

Planet-B will be inserted into a highly eccentric Mars orbit 300 km x 47,500 km with an inclination of 138 degrees and a period of just over 38 hours.

The nominal mission is planned for one martian year (approximately two Earth years). An extended mission may allow operation of the mission well beyond the original two years.

The Deep Space 1 launch delay will require a change in targets and encounter dates. Previous plans included the following flyby/encounter schedule: Asteroid McAuliffe Flyby: January 1999, Mars Flyby: April 2000, Comet West-Kohoutek-Ikemura Encounter: June 2000.

Deep Space One is the first deep space mission of NASA's New Millennium Program. The New Millennium Program (NMP) is an agressive technology demonstration established to validate advanced technologies while returning science data.

"The goal is at least one flight each month" - Kane Casani, manager of the New Millennium Program. Reference: NMP press release - February 10, 1995 (One flight each month will make keeping SPACEUPDATE up-to-date a much more demanding job!)