Man's interest to explore Mars has never waned. When the Mariner 4 successfully made a fly-by on the red planet in July 14, 1965, NASA's enthusiasm for more probes has never been quenched. Although Mars is a familiar sight in earth's night skies considering that it is its closest neighbor, the process to know about the fourth planet from the sun is very difficult. Favorable planetary alignment for the Mars missions happens only every two years. In line with this, Martian explorations have been reinforced by sophisticated machines which tend to make the process a bit easier if not helpful for scientific investigators and observers.
First on the list is the Curiosity Rover which has been designed to determine the planet's habitability by assessing Mars's capability to sustain life. Also known as the Mars Science Laboratory, the rover is considered as NASA's most ambitious interplanetary mission. It has landed on the Gale Crater back in 2012. What is supposed to be a two-year mission has been extended indefinitely by the aeronautics and space agency.
Part of Curiosity's accomplishments is finding evidence that the red planet once held liquid water. It has also discovered organic chemical methane in Mars's atmosphere which can be linked to microbial existence.
Next is NASA's Mars Atmosphere and Volatile Evolution (MAVEN) which has been designed to study the planet's atmosphere, ionosphere and interactions with the sun and solar wind. The spacecraft, which landed in Mars last 2014, has also been tasked to investigate how the red planet's atmosphere and water were lost.
The Odyssey space shuttle comes in as the longest Mars mission since its launching in 2001. It has been programmed to map the amount and distribution of many chemical elements and minerals that make up the planet's surface. Since it is armed with high-powered cameras, the Odyssey has been able to determine mission risks by studying Mars's weather conditions.
In searching for the existence of liquid water, the Mars Reconnaissance Orbiter (MRO) has been equipped with six instruments to investigate underground deposits of the red planet. In addition, it also monitors the daily weather in Mars.
As part of the Mars Exploration Rover (MER) program, the Opportunity rover is another machine used in Mars exploration in 2003. It has been tasked in finding and classifying a wide range of rocks and soils on the planet.
While NASA has many successful missions on Mars, a dozen of its space crafts have died on the planet's surface. Among the notable machines are the Phoenix Mars Lander, which spent more than five months of digging to find signs of water, and Opportunity's twin rover Spirit which got stuck in a sand dune back in 2010 while exploring the Martian environment.
