The History of Mars Exploration:
-A "Hit or Miss" Proposition

October, 2001 Observer's Notebook

by John Rummel

This month, NASA's latest attempt to explore the planet Mars will reach a moment of truth. On October 24th, the Mars Odyssey spacecraft is scheduled to arrive at and enter orbit around the red planet. Though it may seem like a sure thing, interplanetary space travel is no walk in the park, and NASA has been stung several times in the past few years by mission failures, and Mars missions have been particularly hard hit.

Since the space age began in 1957 with the USSR launch of Sputnik, there have been a total of 33 probes sent hurtling toward Mars. Eighteen of those missions were Soviet (one technically Russian; post-1991), fourteen American (including the Odyssey, currently en route), and one by Japan (currently en route). Defining success and failure can be a matter of perspective. I have counted as successes only those missions that successfully returned data according to the mission plan. There is some difficulty measuring the success of the Soviet missions at all since much information about those missions was completely unavailable until the 1990's, and even then there are differing opinions about what the mission objectives actually were. My source here is a NASA history web site.

Of the 18 Soviet/Russian probes, I count 4 successful missions. This is by giving partial credit to missions that arrived at Mars, but were only partially successful (e.g., Mars 3 in 1971, the lander failed shortly after landing, but the orbiter returned data for nearly a year). Four out of 18 doesn't sound very impressive, but in fairness to the Soviets, they were launching missions in the heady early days of the space program, when successes where much harder to come by. They launched five missions between 1960 and 1962 (all failures) before the Americans even got into the game with the launch of Mariner 3 in 1964 (also failed).

Of the fourteen American missions, I count 8 as successful with one (the Odyssey) still en route. The American program is conspicuous as of late due to some very high profile failures just in the last 10 years. The most painful (perhaps) was the Mars Observer, a billion dollar spacecraft that simply stopped transmitting a few days before reaching Mars in 1993. This was the USA's first mission back to Mars after the stunningly successful Viking I and II orbiter/lander missions of 1975-76. The USA followed up the Mars Observer mission with the successful Mars Global Surveyor and Pathfinder missions of 1996. Then failure struck again as two more missions were lost within the space of a few months, the Mars Climate Orbiter in 1998 and the Mars Polar Lander in 1999.

The remaining mission, the Japanese spacecraft Nozomi, was scheduled to arrive at Mars in early 1999, but due to a fuel shortage, was left in a solar orbit, where it will attempt another rendezvous with Mars in 2003. It is intended to study the Martian environment with an eye toward gathering atmospheric information to assist future mission planners.

Mars Odyssey's mission, once it arrives, is to conduct a detailed mineralogical analysis of the planet's surface from orbit and measure the radiation environment. Scientists hope to determine whether the environment on Mars was ever conducive to life, to characterize the climate and geology of Mars, and to study potential radiation hazards to possible future astronaut missions. Don't miss this chance to watch history in the making!

Back to Astronomy Main Page