Back to the Top!
Date Entered: April 1992
Date Last Revised: April 1993
An exploration site located to the East of Tharsis has been selected for the definition of a long range rover mission. The landing site is to be at 21.5 deg. N and 78 deg. W in Kasei Valles.
During its traverse, the rover will cross several geological and geomorphological units and deploy on e large permanent station, to be included in a global network, and two small stations which will contribute together, with the large one, to a local network. During its traverse, the rover will perform geophysical profiles and a geochemical and mineralogical analysis of soil samples at various selected points along the traverse.
Scientific Rationale
Three main preliminary objectives are proposed:
1) The rover will contribute to the deployment of permanent stations, either isolated or part of a local or regional network. The involvement of the rover will allow the control of the deployment procedures of the stations and their instruments. These autonomous stations will thus perform seismological, magnetic, and meteorological measurements as well as deep electromagnetic soundings of the planet's inner structure.
2) During its traverse, the rover will perform geophysical profiling of the main planetary fields and vertical soundings (electromagnetic and radar measurements) over distances on the order of a few hundred kilometers. It will thus provide, in addition to the gravimetric and magnetic profiles, vertical cross- sections of the superficial terrains, of the martian ground ice, and of the deeper internal structure at different depths (figure 1).
3) The rover will also be used as a mobile surface laboratory having the capabilities for selection, acquisition, and analysis of samples. These analyses will include geochemistry, mineralogy, and age dating with an accuracy on the order of 100 million years over a period running from 0.5 to 4 billion years ago, in view to establish the chronological scale of the geolgical history of Mars.
Objectives
Here in chronological order are the main scientifics of this mission:
1) Landing site. From the beginning, sampling is proposed on the site itself, as well as the deployment of a first fixed station. The in-situ analysis of samples should provide informations on the origin of martian valleys (fluvial or glacial) and the geology of the cratered upland by materials carried by the outflow. Absolute age dating of the materials would allow to calibrate the craterization curve for the upper Hesperian period.
2) Mineralogical analysis of the At4 unit. Crossing the geological unit At4 of the lower Amazonian age would specify certain characteristics of volcanism in the Tharsis region. The surface probably includes volcanic flows coming from Uranus Patera. These volcanic flows, which are probably basaltic, are relatively older than those coming from Olympus Mons, for example.
3) Study of wrinkle ridges. Crossing wrinkle ridges in 2 and 3 (figure 2) will provide data about the superficial structure by geophysical profilings, as well as information about the type of compressive tectonics linked to the Tharsis bulge.
4) Deployment of the second fixed station.
5) Ground-ice study (electromagnetic sounding and profiling).
6) Study of a rampart crater. Geophysical profilings and sampling in the immediate vicinity of fluidized ejecta should provide information about how the fluidized ejecta get here. Furthermore, studying the blocks expelled during impact will provide information about the nature of the substratum (up to 1 km deep).
7) Study of the contact between geological unit Ht2 and Hr. The contact by superposition between Ht2 and Hr is expressed by the passage of the lava flows to a plateau covered with faults and ridges. Studying the contact between these two units by geophysical soundings and on-site analysis will specify volcanism's characteristics in the Tharsis region during the Hesperian period.
Studying the mineralogical composition of the lava unit Ht2 by taking samples should provide some answers about the old volcanic phases in the Tharsis region. As for the Hr unit, its origin is probably linked to fissural volcanism.
Potential Problems
For obvious safety reasons, the rover's landing site must be an almost smooth surface, both on a metric and kilometric scale. The landing site is located in Kasei Valles whose geological unit Hehp is characterized by a low rate of cratering and a slightly rough topography.
Such a reference mission implies that the rover can travel on a surface covered with decimetric blocks. Local dunes and aeolian mantling are probably also present during the traverse. Dunes can reach lengths of about a hundred meters, a height of ten meters and ahave a slope of 10 to 30%. Furthermore, metric blocks can cover most wrinkle ridges. The rover will have to go around them and be able to cross the slopes of these ridges, which are supposed to be between 10 to 30%.
Sequence of Operations
20/12/1998: DEPARTURE FROM EARTH
05/10/1999: ARRIVAL AT MARS
04/3/2000: END OF DUST STORMS
EARLY 04/2000: END OF CERTIFICATION PHASE AND DEORBITATION & LANDING AT SITE N DEG. 1
MID 04/2000: END OF VEHICLE RECEIVING ON GROUND AND BEGINNING OF SCIENTIFIC MISSION
1. EXPLORATION ON SITE N DEG. 1: - panoramic images - spectral imaging (visible, IR spectrometry) - selection of a site with bedrocks - teleprogrammed moving of the rover (approx. 100 m) - panorama - profilings - deployment of the first permanent station - imaging of the station for verification - coring(*) in the bedrock - sampling (Hchp unit), conditiong and analysis - deployment of station's magnetometer - placing seismometer i coring in coring - imaging of permanent station for verification
EARLY 05/2000: END OF MISSION ON SITE N DEG. 1
Moving about 50 km - electromagnetic sounding and profiling
EARLY 06/2000: CONJUNCTION
(Provisional stopping of mission except for automatic measurements not requiring moving)
EARLY 08/2000: STARTING MISSION AGAIN
2. EXPLORATION OF SITE N DEG. 2 (several days): - panorama - spectral imaging - sampling (unit At4) - sorting, conditioning, and analysis
MOVING ABOUT 80 KM: - electromagnetic sounding and profiling
EARLY 10/2000
3. EXPLORATION OF SITE N DEG. 3 - panorama - spectral imaging - sampling (wrinkle ridges) - sorting, conditioning, and analysis
MOVING ABOUT 35 KM: - electromagnetic sounding and profiling
EARLY 11/2000
4. ARRIVAL AT SITE N DEG. 4 - deployment of the second fixed station - deployment of magnetotmeter and seismometer - imaging for verification
5. MOVING ABOUT 105 KM: - electromagnetic sounding and profiling
EARLY 01/2001
6. EXPLORATION OF SITE N DEG. 6 - panorama - spectral imaging - sampling (fluidized ejecta) - sorting, conditioning, and analysis
MOVING ABOUT 48 KM: - electromagnetic sounding and profiling
EARLY 02/2001
7. EXPLORATION OF SITE N DEG. 7 - panorama - spectral imaging - sampling (Ht2/Hr) - sorting, conditioning, and analysis
MOVING ABOUT 58 KM: - electromagnetic sounding and profiling
EARLY 03/2001
8. EXPLORATION OF SITE N DEG. 8 - panorama - spectral imaging - sampling (Hr unit) - sorting, conditioning, and analysis - deployment of the third fixed station - verification imaging
EARLY 06/2001: END OF NOMINAL SCIENTIFIC MISSION AND BEGINNING OF CONJUNCTION
MID 06/2001: MOVING TOWARD MORE RISKY ZONES
- panorama - spectral imaging - profilings - sampling, sorting, conditioning, and sample analyses
END OF OPERATIONAL MISSION
(*) the total time of caring, sampling, sorting, conditioning, and analysis is estimated to be about 6 hours.
Preliminary strawman payload:
On the basis of the analysis of these three elementary misions, a model payload is defined for the rover itself, as well as for the fixed stations it will carry and deploy. A baseline mission for the rover is defined. A middle latitude mission, in which a 500 kg rover, carrying a 125 kg payload will be used. The rover will execute a total traverse of approximately 300 km ("straight line").
Back to the Top!
Tally Ho! On to the next site!
Whoa there! Back to the previous site!
Return to The Mars Catalog Home Page
Return to CMEX's Home Page