Mars glob: Creation of an international network of Mars surface landers

Program MARS GLOB provides step-by-step deployment of an international network of Mars surface stations by association the MESUR NETWORK (USA), INTERMARS-NET (ESA) programs with the network of small stations and penetrators now under developing in Russia jointly with international cooperation in frameworks of the MARS-96 Project. It is offering also delivery on Mars surface two penetrators and Mars Rover. Now penetrators and Rover are developing by Russia with participation of other countries in frameworks of the MARS-98 (or MARS TOUR) Project.     

Structure of the middle atmosphere of Venus from analysis of Fourier spectrometer measurements aboard Venera 15

Infrared spectra of Venus measured by means of the Fourier spectrometer aboard Venera 15 orbiter were used for retrievals of temperature profiles of the atmosphere in the altitude range from 60 to 95 km. Monotonous profiles are typical for latitudes lower than 60° latitude, but on the dayside near the equator some traces of the upper atmospheric inversion were found in the profiles. At latitudes greater than 60°N the profiles contain an isothermal or inversional part between 10 and 100 hPa pressure levels. Temperature profiles inside the “warm dipole” maxima are the same as outside of this region and consequently these optical properties should be explained only by peculiarities of cloud structure there.     

Models of the structure of the atmosphere of Venus from the surface to 100 kilometers altitude

From a critical comparison and synthesis of data from the four Pioneer Venus Probes, the Pioneer Venus Orbiter, and the Venera 10, 12, and 13 landers, models of the lower and middle atmosphere of Venus are derived. The models are consistent with the data sets within the measurement uncertainties and established variability of the atmosphere. The models represent the observed variations of state properties with latitude, and preserve the observed static stability. The rationale and the approach used to derive the models are discussed, and the remaining uncertainties are estimated.     

Infrared spectrometry of Venus from “Venera-15” and “Venera-16”

Fourier spectrometers for the investigation of infrared spectra of Venus were installed on the recent Soviet orbiters “Venera-15” and “Venera-16”. Many spectra with reliable absolute calibration were obtained in the 280–1500 cm^?1 region with a spectral resolution of 5 cm^?1 (ground based processing) and about 7 cm^?1 (preoprocessed on board) and a spatial resolution of about 100 km at the Venusian cloud top level. Bands of CO₂, H₂O, H₂SO₄ and SO₂ are identified. The 15 μm-CO₂- fundamental band was used for retrieval of altitude dependent temperature profiles. There are significant differences in the cloud structure above 60 km for distinct regions of Venus, demonstrated by differences in the spectra.     

Results of measurements with the Planetary Fourier Spectrometer onboard Mars Express: Clouds and dust at the end of southern summer. A comparison with OMEGA images

We discuss the results of measurements made with the Planetary Fourier Spectrometer (PFS) onboard the Mars Express spacecraft. The data were obtained in the beginning of the mission and correspond to the end of summer in the southern hemisphere of Mars (L _s ～ 340°). Three orbits are considered, two of which passed through volcanoes Olympus and Ascraeus Mons (the height above the surface is about +20 km), while the third orbit intersects lowland Hellas (?7 km). The influence of the relief on the properties of the aerosol observed is demonstrated: clouds of water ice with a visual optical thickness of 0.1–0.5 were observed above volcanoes, while only dust was found during the observations (close in time) along the orbit passing through Hellas in low and middle latitudes. This dust is homogeneously mixed with gas and has a reduced optical thickness of 0.25±0.05 (at v = 1100 cm^?1). In addition to orographic clouds, ice clouds were observed in this season in the northern polar region. The clouds seen in the images obtained simultaneously by the mapping spectrometer OMEGA confirm the PFS results. Temperature inversion is discovered in the north polar hood below the level 1 mbar with a temperature maximum at about 0.6 mbar. This inversion is associated with descending movements in the Hadley cell.     

Exploration of Venus with the Venera-15 IR Fourier spectrometer and the Venus Express planetary Fourier spectrometer

The infrared spectrometry of Venus in the range 6–45 μm allows one to sound the middle atmosphere of Venus in the altitude range 55–100 km and its cloud layer. This experiment was carried out onboard the Soviet automatic interplanetary Venera-15 station, where the Fourier spectrometer for this spectral range was installed. The measurements have shown that the main component of the cloud layer at all measured latitudes in the northern hemisphere is concentrated sulfuric acid (75–85%). The vertical profiles of temperature and aerosol were reconstructed in a self-consistent manner: the three-dimensional fields of temperature and zonal wind in the altitude range 55–100 km and aerosol at altitudes 55–70 km have been obtained, as well as vertical SO₂ profiles and H₂O concentration in the upper cloud layer. The solar-related waves at isobaric levels in the fields of temperature, zonal wind, and aerosol were investigated. This experiment has shown the efficiency of the method for investigation of the Venusian atmosphere. The Planetary Fourier Spectrometer has the spectral interval 0.9–45 μm and a spectral resolution of 1.8 cm^?1. It will allow one to sound the middle atmosphere (55–100 km) of Venus and its cloud layer on the dayside, as well as the lower atmosphere and the planetary surface on the night side.     

Lunar and Planetary Robotic Exploration Missions in the 20th Century

The prospect of traveling to the planets was science fiction at the beginning of the 20th Century and science fact at its end. The space age was born of the Cold War in the 1950s and throughout most of the remainder of the century it provided not just an adventure in the exploration of space but a suspenseful drama as the US and USSR competed to be first and best. It is a tale of patience to overcome obstacles, courage to try the previously impossible and persistence to overcome failure, a tale of both fantastic accomplishment and debilitating loss. We briefly describe the history of robotic lunar and planetary exploration in the 20th Century, the missions attempted, their goals and their fate. We describe how this enterprise developed and evolved step by step from a politically driven competition to intense scientific investigations and international cooperation. This revised version was published online in August 2006 with corrections to the Cover Date.