In March, the Mars Reconnaissance Orbiter spacecraft achieved its 10th anniversary in orbit around the red planet. With six other active missions from three nations currently either on the planet's surface or orbiting it, I thought now would be a good time to review the current state of Mars exploration, and developing plans for future manned missions.

The main objectives of MRO is returning high resolution imagery to help answer scientific questions and to assist in the selection of landing sites for surface missions. There are currently five orbiters — including MRO — and two rovers operating at Mars.


NASA's Mars Odyssey has been functioning in Mars orbit since 2001 as it captures surface imagery in infrared wavelengths both day and night along with several other instruments. It also acts as a relay station for communications between the unmanned Opportunity and Curiosity rovers operating on the surface and their NASA handlers.

Mars Express is an orbiter operated by the European Space Agency. In Mars orbit since 2003, it was accompanied by a lander named Beagle 2. Although Beagle 2 failed in achieving its mission, ME has been returning 3-D and color images ever since.

NASA's Mars Atmosphere and Volatile Evolution, or MAVEN, spacecraft reached Mars orbit in 2014 on its mission of contributing to the understanding of processes occurring in the upper Martian atmosphere. In 2012, I had a unique opportunity to visit the facility located in the foothills of the Rockies outside of Denver to observe the spacecraft during its assembly.

India's first interplanetary spacecraft named Mars Orbiter Mission entered Mars orbit two days after MAVEN in 2014 where it has been operating ever since. Billed as a "technology demonstration" mission, MOM has five experiments onboard including the low resolution Mars Colour Camera.

Meanwhile, driving around on the surface of Mars is Opportunity, a roving vehicle transmitting data since landing in early 2004. It is currently exploring a crater named Endeavour. Its twin rover Spirit operated until 2010. After hobbling for years with a stuck wheel, Sprit became mired in deep sand and eventually lost electrical power due to discharged batteries.

The Mars Science Laboratory rover nicknamed Curiosity landed on Mars as planned inside a crater named Gale in 2012. It is currently navigating some very gnarly terrain on Mars' Naukluft Plateau. Progress is slow as scientists must review returned images to plot the next leg of the route, a few meters at a time.

NASA's manned exploration of Mars is still a ways off. The current administration killed the Constellation program proposed by the previous administration. Constellation's goals included replacing the space shuttle and developing new space vehicles in support of a manned return to the moon by 2020. It was envisioned that the required hardware would eventually be developed for a manned landing on Mars in the 2030s.

On the other hand, the current administration favors a plan to develop and send an unmanned spacecraft to capture either a small asteroid or a boulder from an asteroid and place the retrieved rock into lunar orbit where it would be visited and studied by astronauts. One of the major criticisms of this program is that an eventual manned mission to Mars is not one of the program's primary or secondary objectives.

One element of the canceled Constellation program that is also in the asteroid program is development of the Orion spacecraft Crew Module, designed as a space vehicle for supporting long duration human exploration. The first unmanned test was Exploration Flight Test 1 in 2014 which sent an Orion CM on a suborbital mission lasting several hours.

The next unmanned Orion flight, Exploration Mission 1, is currently scheduled for 2018 and will be the first test with a new rocket launch vehicle called the Space Launch System and a service module being developed by ESA. The SLS will be the most powerful rocket ever built, standing taller and with more thrust than the previous giant — the Saturn V rocket that lifted astronauts to the moon nine times. EM-2, the first manned Orion mission, is presently planned for the early 2020s and could send astronauts on a trip around the moon for the first time in 50 years.

Curtis Roelle is a member of the Astronomical Society. His website is, and he can be reached at