As I've said on one of my other pages, as a curious person, I'm really interested in technology, where its going etc.
Because of this I've been following the Mars missions closely, watching out for new developments on the pages available on the web.
Launch vehicle: Delta II Rocket
Launch date: 07 November 1996
Estimated arrival date:
Actual arrival date: 01:17 UT 12 September 1997 (9:17 p.m. EDT September 11)
Craft Stats:
Weight:
Dimensions:About 10 meters from the tip of one solar array to the tip of the array on the opposite side. Not including the science instrumentation, the main body of the spacecraft is about 1.9 meters tall and 1.4 meters wide.
Material:Most of the structure is composed of a honeycombed aluminum mesh with thin graphite epoxy sheets attached to the inside and outside faces. This combination is light, but extremely durable. The power producing cells on the solar arrays are made out of silicon and gallium arsenide.
On orbit mass: 1030.5 kg
Load:
Power Supply: 4 Solar Array Panels, 667W
Mission cost:$154m approx
Upload the Project Plan
Look here to see The MGS components diagram The MGS will attempt to complete 6 primary missions:-
The Mars Orbital Camera (MOC)
- Michael Malin, Malin Space Science Systems
The Mars Orbital Camera will take high resolution images, on the order of a meter
or so, of surface features. It will also take lower resolution images of the
entire planet over time to enable research into the temporal changes in the
atmosphere and on the surface.
Thermal Emission Spectrometer (TES)
- Phil Christensen, Arizona State University
The Thermal Emission Spectrometer is a Michelson interferometer that will measure
the infrared spectrum of energy emitted by a target. This information
will be used to study the composition of rock, soil, ice, atmospheric dust, and
clouds.
Mars Orbital Laser Altimeter (MOLA)
- David Smith, Goddard Space Flight Center
This instrument will measure the time it takes for a transmitted laser beam to
reach the surface, reflect, and return. This time will give the distance, and
hence the height of the surface. Combining these measurements will result in
a topographic map of Mars.
Radio Science Investigations (RS)
- G. Leonard Tyler, Stanford University
Measurements of the Doppler shift of radio signals sent back to Earth will
allow precise determination of changes in the orbit, which will allow for a
model of the Mars gravity field. As the spacecraft passes over the poles on
each orbit, radio signals pass through the Martian atmosphere on their way to
Earth. The way in which the atmosphere affects these signals allows determination
of its physical properties.
Magnetic Fields Investigation (MAG/ER)
- Mario Acuna, Goddard Space Flight Center
A magnetometer will be used to determine whether Mars has a magnetic field, and
the strength and orientation of the field if one exists. An electron reflectometer
will measure remnant crustal magnetization.
Mars Relay
- Jacques Blamont, Centre National d'Etudes Spatiales
The Mars Relay experiment consists of an antenna which will route received signals
through the Mars Observer Camera for transmission to Earth. The relay will be
used to support surface landers and rovers from other Russian, European, and
U.S. missions.
Launch Date: 04 December 1996 UT 06:58
Arrival Date: 04 July 1997 UT 16:57
Launch Vehicle: Delta II
Mass: 264 kg (lander), 10.5 kg (rover)
Power System: Solar panels
ii)THE SOJOURNER ROVER
FACTS:-
Launch vehicle: Pathfinder
Launch date:
Estimated arrival date:
Actual arrival date:
Weight:
Dimensions: 21' long by 19' wide and 10' high.
The Pathfinder mission was designed to help find the best way to build, land and operate future spacecraft to advance our knowledge of Mars, and perhaps someday land humans there.
The Pathfinder's arrival on the Martian surface was a major test for the new technology and methods that had been carefully planned by NASA.
Rather than establishing an orbit to slow down the ship and gradually descend, as landing crafts have done in the past, Pathfinder was designed to go straight into the atmosphere as essentially crash-land.
Just before the point of impact, four balloons inflated, allowing the craft to bounce on the surface until it came to a stop. These balloons had been especially designed by the scientists at NASA to withstand high impacts and hard conditions.
The craft was travelling about 40 m/hr (72 km/hr) when it hit the surface and bounced about 15 meters (50 feet) into the air, bouncing another 15 times and rolling before coming to rest approximately 2.5 minutes after impact and about 1 km from the initial impact site.
The advantage to this approach is that Pathfinder was able to bounce to a stop in rocky or rough areas, and hence give the Sojourner access to alot more areas like Mars' mountainous regions and canyons, which are considered more interesting, and potentially more important, in gaining a better understanding of the planet.
The Viking craft, which went to Mars in 1975, didn't have this technology so were limited to landing in a flat plain likened to Mars' equivalent of the Sahara Desert. But the Pathfinder also conducted experiments designed to test the feasibility of turning Mars' atmosphere, which is 95 percent carbon dioxide, into rocket fuel by combining it with ceramic material at a temperature of about 1,500 degrees Fahrenheit (about 830 degrees Celsius)!!!
Because of the distance between Earth and Mars, fuel will have to be made there if spacecraft are to one day blast off of its surface to return to Earth. Pathfinder's assignment was to test various new solar power technologies that might create the requisite temperature on what is a freezing planet compared to Earth.
Pathfinder also gathered data on the effect of dust on space equipment, an important area of knowledge for Mars exploration, as the dry planet is subject to huge dust storms.
The NEAR Earth flyby occurred on Friday, January 23. Closest approach, at an altitude of 540 km, was at 2:23 a.m. EST (07:23 UT).
Launch Date: 17 February 1996 - 20:43 UT (3:43 PM EST)
Launch Vehicle: Delta II
Planned on-orbit mass: 805 kg (includes 318 kg propellant)
Power System: Solar panels of 1800 W
The Near Earth Asteroid Rendezvous (NEAR) mission is the first of NASA's Discovery missions, a series of small-scale spacecraft designed to proceed from development to flight in under three years for a cost of less than $150 million. The spacecraft is equipped with an X-ray/gamma ray spectrometer, a near infrared imaging spectrograph, a multispectral camera fitted with a CCD imaging detector, a laser altimeter, and a magnetometer. A radio science experiment will also be performed using the NEAR tracking system to estimate the gravity field of the asteroid. The ultimate goal of the mission is to rendezvous with and achieve orbit around the near Earth asteroid 433 Eros in February, 1999, and study the asteroid for approximately one year. Eros is an S-class asteroid about 14 x 14 x 40 km in size. Studies will be made of the asteroid's size, shape, mass, magnetic field, composition, and surface and internal structure. Periapsis of the orbit will be as low as 24 km above the surface of the asteroid. Prior to its encounter with Eros NEAR flew within 1200 km of the C-class asteroid 253 Mathilde on 27 June 1997. It will then fly by the Earth on 23 January 1998. The spacecraft has the shape of an octagonal prism, approximately 1.7 m on a side, with four solar panels and a fixed 1.5 m X-band high-gain radio antenna.
On Friday, 27 June 1997 at 8:56 AM EDT NEAR flew within 1200 km of the C-class main-belt asteroid 253 Mathilde. The fly-by took place at 9.93 km/sec and included high-resolution (180 m/pixel) and color (seven filter) imaging. The images will be used to study the size, shape, surface features, colors and to search for any small moons of Mathilde.
The Lunar Prospector is designed for a low polar orbit investigation of the Moon, including mapping of surface composition and possible polar ice deposits, measurements of magnetic and gravity fields, and study of lunar outgassing events. Data from the 1 to 3 year mission will allow construction of a detailed map of the surface composition of the Moon, and will improve our understanding of the origin, evolution, current state, and resources of the Moon. The spacecraft is a graphite-epoxy drum, 1.4 meters in diameter and 1.22 meters high with three radial instrument booms. It is spin-stabilized and controlled by 6 hydrazine monopropellant 22-Newton thrusters.
Communications are through two S-band transponders and a slotted, phased-array medium gain antenna and omnidirectional low-gain antenna.
There is no on-board computer, ground command is through a 3.6 kbps telemetry link.
After launch, the Lunar Prospector had a 105 hour cruise to the Moon, followed by insertion into a near-circular 100 km altitude lunar polar orbit with a period of 118 minutes. The nominal mission duration is one year. A two year extended mission following this is possible, during which the orbit will be lowered to 50 km and then 10 km altitude to obtain higher resolution measurements.
More Detailed Information on the Mission and Spacecraft
Scientific Investigations:-
Gamma Ray Spectrometer (GRS)
G. Scott Hubbard, NASA Ames
Neutron Spectrometer (NS)
William Feldman, Los Alamos The GRS and NS will return global data on elemental abundances, which will be used to help understand the evolution of the lunar highland crust and the duration and extent of basaltic volcanism, and to assess lunar resources. The NS will also locate any significant quantities of water ice which may exist in the permanently shadowed areas near the lunar poles.
Magnetometer (MAG)
Mario Acuna, NASA Goddard; Lon Hood, Univ. of Arizona LPL Electron Reflectometer (ER)
Robert Lin, UC Berkeley SSL The MAG/ER experiments will return data on the lunar crustal magnetic field and the lunar induced magnetic dipole. These data will help provide an understanding of the origin of lunar paleomagnetism and the degree to which impacts can produce paleomagnetism, and allow constraints on the size and composition of the (possible) lunar core.
Alpha Particle Spectrometer (APS)
Alan Binder, Lockheed The APS instrument will be used to find radon outgassing events on the lunar surface by detecting alpha particles from the radon gas itself and its decay product, polonium. Observations of the frequency and locations of the gas release events will help characterize one possible source of the tenuous lunar atmosphere. Determination of the relationship of outgassing sites with crater age and tectonic features may be possible. This may in turn be used to characterize the current level of lunar tectonic activity.
Doppler Gravity Experiment (DGE)
Alex Konopliv, NASA JPL This investigation will use Doppler tracking of S-Band radio signals to characterize the spacecraft orbit and determine the lunar gravity field. This data will provide information on the lunar interior and, combined with lunar topographic data, will allow modelling of the global crustal asymmetry, crustal structure, and subsurface basin structure. It can also used for planning future lunar missions.
