MISSION TO MARS

Astronomical specifications: Discovery   Orbital characteristics: Distance from Sun  227,936,640 km Perihelion  206.6 x (106 km) Aphelion  249.2 x (106 km) Orbital Inclination  1.85 deg Orbital Eccentricity  0.0934 Orbital periode round Sun  1.8808476 years Orbital Speed  24.13 km/s Number of moons  2 Rings  No Physical characteristics: Diameter  6794 km Surface area  140,000,000 km² Volume  1.6318 x 1011 km³ Mass  6.4191 x 1023kg Density  3940 kg/cm³ Equatorial gravity  3.71 m/s² Escape velocity  5.02 km/s Rotation period  24.6 hours Axial tilt  25.19 deg Surface temperature  -65 C (227 K) Surface Pressure  0.01 bars Atmospheric composition  CO2 N2 Ar

Mars Valles Marineris

• The exploration of Mars has been an important part of the space exploration programs of the Soviet Union (later Russia), the United States, Europe, and Japan. Dozens of robotic spacecraft, including orbiters, landers, and rovers, have been launched toward Mars since the 1960s. These missions were aimed at gathering data about current conditions and answering questions about the history of Mars. The questions raised by the scientific community are expected to not only give a better appreciation of the red planet but also yield further insight into the past, and possible future of Earth.
• The exploration of Mars has come at a considerable financial cost with roughly two-thirds of all spacecraft destined for Mars failing before completing their missions, with some failing before they even begin. Such a high failure rate can be attributed to the complexity and large number of variables involved in an interplanetary journey, and has led researchers to jokingly speak of The Great Galactic Ghoul which subsists on a diet of Mars probes. This phenomenon is also informally known as the Mars Curse. As of November 2008, there are two functioning pieces of equipment (both American) on the surface of Mars beaming signals back to Earth: the Spirit rover and the Opportunity rover.

The planet Mars:

• Mars has long been the subject of human fascination. Early telescopic observations revealed color changes on the surface which were originally attributed to seasonal vegetation as well as linear features which were ascribed to intelligent design. These early and erroneous interpretations led to widespread public interest in Mars. Further telescopic observations found Mars' two moons - Phobos and Deimos, dry channels and depressions, polar ice caps, Olympus Mons, the solar system's tallest mountain, and Valles Marineris, the solar system's largest canyon system. These discoveries have only piqued further interest in the study and exploration of the red planet. Mars is a rocky planet, like Earth, that formed around the same time, yet with only half the diameter of Earth, and a far thinner atmosphere, it has a cold and desert-like surface. It is notable, however, that although the planet has only one quarter of the surface area of the Earth, it has about the same land area, since only one quarter of the surface area of the Earth is land.

Launch windows:

• In order to understand the history of the robotic exploration of Mars it is important to note that minimum-energy launch windows occur at intervals of 2.135 years, i.e. 780 days (the planet's synodic period) with respect to Earth. This is a consequence of the Hohmann transfer orbit for minimum-energy interplanetary transfer.
• Launch windows were/will be in:
  • November to December 1996
  • December 1998 to January 1999
  • April 2001
  • June to July 2003
  • August 2005
  • October 2007
  • December 2009
  • February 2012
• Like the outbound launch windows, minimum energy inbound (Mars to Earth) launch windows also occur at intervals of 780 (Earth) days.
• In addition to these minimum-energy trajectories, which occur when the planets are aligned so that the Earth to Mars transfer trajectory goes halfway around the sun, an alternate trajectory which has been proposed goes first inward toward Venus orbit, and then outward, resulting in a longer trajectory which goes about 360 degrees around the sun ("opposition-class trajectory"). Although this transfer orbit takes longer, and also requires more energy, it is sometimes proposed as a mission trajectory for human missions.

Mission details:

• Mars Reconnaissance Orbiter has captured a breath-taking of a towering dust devil more than half-a-mile (800 meters) tall swirling on the red planet in an image from the High Resolution Imaging Science Experiment (HiRISE) camera.
  
  

  Credit: NASA/JPL-Caltech/Univ. of Arizona

  HiRISE captured the image on Feb. 16, 2012, while the orbiter passed over the Amazonis Planitia region of northern Mars. In the area observed, paths of many previous whirlwinds, or dust devils, are visible as streaks on the dusty surface. The scene is a late-spring afternoon and the view covers an area about four-tenths of a mile (644 meters) across. North is toward the top. The length of the dusty whirlwind's shadow indicates the dust plume height. The plume is about 30 yards or meters in diameter. The image was taken during the time of Martian year when that planet is farthest from the sun. Just as on Earth, winds on Mars are powered by solar heating.

  
  

Mars missions:

Impacts and landings on Mars:

Mars-2    	   1971 Nov 27  44S 313W  Hellespontus Montes, Noachis province
Mars-3    	   1971 Dec  2  45S 158W  Sirenum Terra, Phaethontis province
Mars-6    	   1974 Mar 12  24S  25W  Margaritifer Terra, Margaritifer Sinus province
Viking 1  	   1976 Jul 20  22N  48W  Chryse Planitia, Lunae Palus province
Viking 2  	   1976 Sep  3  48N 226W  Utopia Planitia, Cebrenia province
MPF       	   1997 Jul  4  19N  34W  Ares Vallis, Oxia Palus province 
Perseverance   2021 Feb	18	?	 ?	  Jezero Crater

Mars Artificial orbiting objects:

External links:

• Wikipedia List of mission to Mars
• Wikipedia Film: Mission to Mars