When it comes to the exploration of the solar system, no planet has spurred the scientific community to greater efforts, whipped up the general public into a greater frenzy of speculation, or resulted in pseudo-experts committing more bad science in quite the same way that the planet Mars has, and continues to do.
Nonetheless, since a flyby by Mariner 4 returned the first probe images of the Red Planet in 1965, the combined results of dozens of exploratory missions over the decades by all manner of spacecraft has resulted in more information being available about Mars than for any other planet outside of Earth. This makes selecting just ten interesting facts about the missions to Mars an exceedingly difficult task.
Nonetheless, the late, great Carl Sagan once wrote: “Mars has become a kind of mythic arena onto which we have projected our Earthly hopes and fears”, and it is in the spirit of hope that we present here a list of ten interesting facts about the various missions to Mars.
Getting to the surface of Mars is not easy
As of 2022, there have been 50 missions to Mars, starting with the Russian craft named Korabl 4 (1960) that failed to reach Earth’s orbit, and ending with the Perseverance mission which successfully landed on Mars’s surface on 18 February 2021.
In fact, getting to Mars is so difficult that only 18 missions can be seen as unqualified successes, with a further 3 missions being partially successful. However, the high failure rate is not a deterrent for would-be explorers, and in 2013, India launched its Mars-bound craft named MOM (Mars Orbiter Mission) which entered into a stable orbit around Mars on September 24, 2014, making India the first country whose efforts to explore Mars were successful on the first attempt.
You can’t go to Mars when you want
Missions to Mars are hugely expensive, which is why launches take place only when Mars and Earth are at their closest points of approach to each other, which in the case of Mars happens in intervals of 779.9 days, known as its synodic period with respect to Earth.
This results in saving to the mission’s traveling time, which in general takes about 7 months, as well as to its fuel costs. For example, the minimum amount of energy required to get to Mars varies over a roughly 16-year cycle, and during the 1969 and 1971 launch windows, much less energy was required to get to Mars than was required during the launch windows in the late 1970s.
Russia has the most mission failures
As stated elsewhere, getting to Mars is not easy, and Russia (or the erstwhile USSR), holds the unfortunate distinction of having suffered the highest number of total mission failures. Below are some details of these missions, when they were launched, and the reason for their failure:
- 1960: Korabl 4, Failed to reach Earth orbit
- 1960: Korabl 5, Failed to reach Earth orbit
- 1962: Korabl 11, Earth orbit only / spacecraft broke apart
- 1962: Mars 1, Communication failure
- 1962: Korabl 13, Earth orbit only / spacecraft broke apart
- 1964: Zond 2, Communication failure
- 1969: Mars 1969A, Launch vehicle failure
- 1969: Mars 1969B, Launch vehicle failure
- 1971: Kosmos 419, Achieved Earth orbit only
- 1971: Mars 2 Orbiter/Lander Orbiter, arrived, but no useful data / Lander destroyed
- 1973: Mars 4, Missed Mars altogether
- 1973: Mars 7 Lander, Missed Mars altogether
- 1988: Phobos 1 Orbiter, Lost en route to Mars
- 1988: Phobos 2 Orbiter/Lander, Lost near Phobos
- 1996: Mars 96 Launch, vehicle failure
However, Russia did manage some successful missions, including the Mars 3 mission, consisting of an orbiter and landing vehicle, that was launched in 1971, and during which the orbiter collected data for eight months. On the other hand, the lander only managed to transmit data for 14.5 seconds before failing. The only other noteworthy Russian success was the Mars 5 mission that returned 60 images over nine days before also failing, possibly due to impact with a micrometeoroid.
First close-up view of Mars
The image above shows the first close-up view of Mars taken from an altitude of about 6,100 miles by the Mariner 4 probe in July 1965. All told, Mariner 4 took 22 close-up images that showed the cratered surface; the image above spans an area of 300 km × 1,200 km. The craft also captured data confirming that Mars’ atmosphere consisted primarily of carbon dioxide at a pressure that ranged from 5 to 10 millibar, as well as detecting a small part of the planet’s intrinsic magnetic field. Currently, Mariner 4 is in an orbit around the Sun.
First picture of Mar’s surface
This image is the first ever picture taken of the surface of Mars. It was taken by the Viking 1 lander on July 20, 1976, as part of a program that was specifically designed to obtain high-resolution images of the Martian surface. Secondary mission objectives included obtaining data on the composition and structure of the Martian atmosphere, as well as looking for possible evidence of life in the Martian soil.
First color picture of water ice on Mars’ surface
Although the image above is not the first color picture of the Martian surface, it is the first color picture that shows evidence of water ice on Mars at the Utopia Planitia landing site of the Viking 2 lander. This image was taken on May 18, 1979, but was only transmitted to Earth by the Viking 2 Orbiter on June 7. The ice layer shown in this image is mixed with frozen carbon dioxide and is at most one-thousandth of an inch thick.
Eight American attempts to land on Mars have been successful
Since the discoveries made by NASA’s rovers Spirit and Opportunity dominated the media for many years longer than their design allowed, it is sometimes easy to forget about the other successful landings on Mars by American craft. In total, there have been eight successful landings, the first being Viking 1 & 2 (both in 1976), followed by the Pathfinder mission in 1979. Next in line were Spirit and Opportunity in 2004, followed by Phoenix in 2008, which was followed by the Curiosity mission in 2012, and Perseverance in 2021.
Spirit and Opportunity lasted 20-50 times longer than expected
Arriving on Mars in January of 2004, the rovers Spirit and Opportunity represent the most spectacularly successful exploration mission to date. Designed to last for only 90 Martian days, Spirit fell into a sand trap 5 years, 3 months, and 27 Earth days after landing, and transmitted its last communication with Earth on March 22, 2010 (Martian day #2 210) after engineers could not extract the rover from the sand trap.
However, Spirit’s twin, Opportunity, which stopped communicating in June 2018, had covered a distance of 44.97 kilometers (27.94 miles) by August 7, 2017, in a feat of endurance that has exceeded its original mission by 13 years, and 100-odd Earth days. That’s more than 50 times its planned duration of 90 Martian days.
While the discoveries made by Spirit and Opportunity will fill several large volumes, if not a small library, the most significant discoveries by far is the evidence both rovers found that liquid water once existed on Mars, closely followed by the discovery of an extra-Martian meteorite, the now-famous Meridiani Planum meteorite.
There has been some speculation by a variety of conspiracy theorists that aliens or other unknown entities had been cleaning the dust off the rover’s solar panels and camera lenses. However, the simple fact is that dust devils and strong winds in the Martian atmosphere had been keeping the panels and lenses clean, which no doubt made a huge contribution to the rovers’ longevity.
The Pale Blue Dot- as seen by Curiosity
This image shows another version of the famous Pale Blue Dot, an image of Earth taken by a Voyager spacecraft from the far edge of the solar system. In this image, Earth is visible as the brightest object in the Martian night sky, as seen through one camera in the Curiosity rover’s mast. The image was taken about 88 minutes after sunset on the 529th Martian day of Curiosity’s mission when the distance between Mars and Earth was roughly 160 million km (99 million miles).
Proof of alien life on Mars?
Despite the arguments of conspiracy theorists, the weird formations in this image taken by NASA’s Mars Reconnaissance Orbiter are nothing but wind-aligned sand dunes in a depression on Mars, most likely a degraded impact crater. There are many known examples of sand dunes on Mars aligning themselves with the prevailing wind conditions, but in this case, the formation is interspersed with small dot-like dunes, called “barchanoid dunes,” that UFO hunters contend are evidence of a Morse code-like communication by alien races.
However, to settle the dispute, planetary scientist Veronica Bray applied some advanced decryption methods to decipher the coded dunes, which revealed this startling message- “NEE NED ZB 6TNN DEIBEDH SIEFI EBEEE SSIEI ESEE SEEE!” In translation, I guess this probably means that there is not enough sand in the depression for winds from opposite directions to form the long, continuous linear dunes that occur elsewhere on Mars, as well as on Earth.