July 4, 1997: Mars Pathfinder sends the first rover to land on Mars

July 4, 1997

July 4th is a date of fundamental importance for the history of the United States of America: on this day in 1776, 13 English colonies within the American territory declared their independence from Great Britain. Independence Day represents an event deeply felt by the citizens of the U.S.A., but since 1997 this day has also taken on another, very important historical significance. On July 4, 1997, Sojourner, the first ever rover to have touched the surface of Mars, landed on the Red Planet of our Solar System, as part of the NASA mission called Mars Pathfinder (recently, China also sent its first rover on the fourth planet from the Sun, as you can read in our article).

Logo and symbol of the Mars Pathfinder mission

Although we are still a long way from coming into contact with life forms intelligent extraterrestrials like the fascinating Xernomorphs of Alien, the beginning of the exploration of a planet other than our Earth is yet another "great step for humanity". And, who knows, maybe one day not too far away we will also be able to see the first shipment of human beings to the Red Planet, a bit like the movie The Martian, which you can buy here on Amazon.

"Space, the last frontier"

The discovery, through observation, of ever greater details concerning what exists beyond our tiny (in astronomical terms) Earth does not only concern the portions of the visible Universe more distant from us. In fact, we can only "look" at objects millions of light years away and discover their composition thanks to the remote study of their spectrum, but missions such as the Mars Pathfinder enable us to analyze the alien soil of another planet on site, a ' truly unique and precious opportunity; now, it is hoped to be able to push rovers to planets and other types of objects increasingly distant from our home planet.

For these reasons, the Mars Pathfinder space research mission played a major role in the exploration of Mars. This is a NASA project that took shape on December 4, 1996, the day the probe was sent to the Red Planet; bearing in mind that it managed to touch the Martian soil on July 4th of the following year, we can easily deduce that its journey into space lasted exactly 7 months.

Mars Pathfinder: the origins of name Sojourner

As mentioned above, Mars Pathfinder is the name of the mission, while the rover that landed on the surface of Mars was called Sojourner; it is a tribute to Isabella Baumfree (circa 1797 - 1883), better known by the pseudonym she coined Sojourner Truth, and the story of the choice of the name is also very interesting!

In March 1994 she was instituted a competition in which students under the age of 18 from all over the world could take part; in addition to proposing the name of a historically valuable female character, the boys should have written a text in which they highlighted the merits and the way in which these, in their opinion, are connected to Mars and its exploration. 3500 young people took part in this initiative, the youngest of whom were only 5 years old. To win a place in the history of space missions was a girl from Connecticut, the very young Valerie Ambroise, who was then only 12 years old. The name of the heroine she chose was that of Sojourner Truth, who throughout her life fought for the abolition of slavery in the United States and for women's rights.

Sojourner Truth in a photograph of era

The reason why Valerie thought of Sojourner Truth is that the woman traveled all over the country trying to sensitize as many people as possible about the battles for social justice so dear to her; the theme of the abolitionist's long journeys is therefore the trait that unites it with the long journeys that the Sojourner rover would have made in a few years.

The Mars Pathfinder mission: the principle ...

When the probe touched the Martian soil, on July 4, 1997, Sojourner's exploration began, but he was not there alone to carry out direct studies in the field: while in fact the rover was used to analyze rocks and minerals, the lander, also called the "landing vehicle", assumed the function of a meteorological station. The two beating hearts of Mars Pathfinde r could communicate with each other using radio waves.

The Sojourner rover in full swing on a Martian rock

The American electronic engineer Anthony Spear was the Mars Pathfinder Science Mission Director for the Jet Propulsion Laboratory (JPL); however, it should be specified that it was not the first mission to Mars ever, but the first after 1976, the year in which the Viking Program was born, in which the two probes Viking 1 and Viking 2 had the task of taking photographs high resolution of the surface of Mars, study its atmospheric and soil composition and also look for any traces of alien life forms.

The great merit of the Mars Pathfinder mission was, as previously mentioned, to have sent the first rover to the surface of Mars. In addition, the mission also managed to keep faith with the motto "cheaper, faster and better" ("cheaper, faster and better") of the Discovery Program, a NASA initiative aimed precisely at the realization of important space exploration projects at low costs. : the Mars Pathfinder mission was in fact carried out using only 280 million dollars, a sum of money in itself considerable, but which is not so in this context, when compared to the total costs of other previous missions to explore the Martian soil. br>
The Sojourner rover being tuned. The image also provides an idea of ​​its small size

Sojourner analyzed the composition of several large rocks present on Mars while the lander, in addition to carrying out investigations and research on the planet's climate, also took several photographs of the rover in action and of the surface of the Red Planet itself.

Panoramic image of the landing site made by combining several photographs taken by the lander

… and the end

Mars Pathfinder would have it had to have a very short duration, ranging from 7 to 30 days approximately; however, the same lasted until 27 September 1997, the day on which the last contact was made, thus bringing the overall duration of the mission to about 3 months. To date, the causes of the cessation of communication signals still remain unknown, although the most accredited hypothesis is that this was caused by some problems in the functioning of the battery. The rover was supposed to automatically return to its lander, but that never happened. NASA continued to try to get in touch with Sojourner for some time, but as each attempt resulted in nothing, the US aerospace agency put an end to the research on March 10, 1998.

Also, precisely due to the fact that contacts with the Sojourner have been lost, it is not possible to establish its location on Martian soil. Mars Pathfinder was a pioneering mission that paved the way for other similar ones, carried out not only by the United States, but also by several other nations, thanks to which we become aware of a number of very interesting information and that we receive in increasing numbers thanks to the rovers sent to Mars and the audacity and foresight of scientists always ready to push the limits.