Voyager 1

Jupiter seen from Voyager 1.

The Voyager 1 is a 722-kilogram robotic space probe, launched on September 5, 1977, from Cape Canaveral, Florida. It remains operational today, continuing its extended mission of locating and surveying the edges of the solar system, including the Kuiper belt and beyond, as well as exploring immediate interstellar space, until the end of the mission. On August 25, 2012, at just over 19 billion km from the Sun or 122 AU, the probe left the heliopause, the first to reach interstellar space. Its original mission was to visit Jupiter and Saturn. It was the first probe to provide detailed images of the satellites of Jupiter and Saturn. At a distance of 153.14 AU (22,909,417,919 km) from the Sun, in June 2021, it is the farthest spacecraft from Earth and next to Voyager 2 in interstellar space, but still not leaving the solar system, with approximately 17,702 years left to leave the Oort cloud, which it will enter in about 300 years.

Voyager 1 is the first space probe to carry an audible message (Voyager Golden Record) and is currently the farthest man-made object from Earth, It travels at the fourth fastest relative speed of the Earth and the Sun among space probes, after Rosetta (which traveled at about 108,000 km/h between November 2009 and August 2014), Helios B which reached about 252,900 km/h in April 1976 and, above all, that the Solar Parker probe, which has already reached 324,000 km/h in its first approach to our star (on November 1, 2018) and is expected to be more than close to the Sun will be around 700,000 km/h in 2025.

Although its sister Voyager 2 was launched sixteen days earlier, it is not expected to pass Voyager 1. Neither is the New Horizons mission to Pluto, even though it was launched from Earth at a speed greater than of the two Voyagers, as during the course of its journey, Voyager 1's speed was increased due to assisted gravitational tugs. New Horizons' current speed is greater than Voyager 1's, but when New Horizons reaches the same distance from the Sun that Voyager 1 is now, its speed is estimated to be 13 km/s, while that of Voyager 1 is 17 km/s.

Voyager 1 is on a hyperbolic trajectory, and has reached escape velocity, which means its orbit will not return to the inner solar system. Along with Pioneer 10, Pioneer 11, Voyager 2, and New Horizons, Voyager 1 is an interstellar probe.

Both Voyagers have exceeded their originally estimated lifetime. Each probe derives its electrical power from three RTGs, (Radioisotope Thermoelectric Generators), which are expected to generate enough power to keep the probes in communication with Earth until at least the year 2025.

Planning and launching

Voyager's book.

Launch of Voyager 1.

The probe was launched on September 5, 1977 from NASA's Kennedy Space Center at Cape Canaveral aboard a Titan IIIE rocket.

A fuel burn defect in the second stage of the rocket initially made technicians fear that the probe would not reach Jupiter. However, the Centauro upper phase made it possible to compensate for this defect.

Despite being launched after its twin, Voyager 2, Voyager 1 reached Jupiter two months before its companion, and, following a faster trajectory, arrived at Saturn nine months before.

Mission development

The atmosphere of Jupiter photographed from Voyager 1.

Jupiter

Image of the volcanic activity of Io.

Voyager 1 took its first pictures of Jupiter in January 1979 and came closest on March 5, 1979 at a distance of 278,000 km. On his mission to Jupiter he took 19,000 photographs, in a period that lasted until April.

Due to the maximum resolution allowed by such a close approach, most of the observations about Jupiter's satellites, rings, magnetic field, and radiation conditions were taken in a 48-hour period around the close approach.

To photograph the planet Jupiter, NASA opted for Mexican inventor Guillermo González Camarena's Simplified Bicolor System, which was simpler in electronics than the US NTSC system, for such a long-distance mission.

It came within 18,641.76 km of Jupiter's satellite Io and was able to observe volcanic activity outside of Earth for the first time, something that went unnoticed by Pioneer 10 and 11. The discovery was made by navigation engineer Linda A. Marabout during an examination of a photograph several hours after the flyby.

Saturn

Accelerated by Jupiter's gravitational field, it reached Saturn on November 12, 1980, coming within a distance of 124,200 km. On this occasion, he discovered complex structures in the planet's ring system and obtained data on the atmosphere of Saturn and its largest natural satellite, Titan, from which it passed within 6,500 km. Due to the discovery of the atmosphere on this satellite, the mission controllers decided that Voyager 1 would make a closer approach to this moon, thus sacrificing the next legs of its journey, Uranus and Neptune, which were visited by its twin Voyager 2.

This second approach to Titan increased the probe's gravitational momentum, pulling it away from the ecliptic plane and ending its planetary mission.

The Earth and the Moon photographed by Voyager 1 on September 18, 1977. The image was processed to balance the luminosity of both bodies.

At the edges of the solar system

On February 17, 1998 at 11:10 p.m. (European time), Voyager 1 was 10,400,000,000 km from Earth, a record set ten years earlier by the Pioneer 10 probe.

In September 2004, Voyager 1 reached a distance of 14 billion kilometers (93.2 AU, 8.7 billion miles or 13 light hours) from the Sun and is therefore the farthest object ever constructed by beings human. On August 15, 2006, the Voyager 1 probe reached a distance from the Sun of 100 AU, that is, almost 15 billion kilometers. In 2020 it reached the distance of 148 AU.

It is moving away at a speed of 3.6 astronomical units (29 light-minutes) per year from the Sun, which corresponds to 17 km/s. Exact measurements indicate that the speed decreases very slowly in an unexpected way. The causes of this braking are the subject of various controversies.

In a press statement on May 24, 2005, NASA stated that Voyager 1 had reached, as the first human-made object, the area called the termination shock front, and will continue to travel through the region known as heliofunda, the last frontier of the solar system, close to the heliopause.

A pale blue spot (Pale Blue Dot). The Earth can be seen as a point of light located in the central part of the image. The photograph was taken by Voyager 1 in February 1990 at a distance of six billion kilometers from Earth.

Traveling very distant from the Sun, Voyager 1 is powered by three radioisotope thermoelectric generators (RTGs), which convert heat from the radioactive decay of plutonium into electricity, instead of the solar panels used in many other probes for interplanetary travel. It was estimated that the energy generated by this nuclear pile would be enough to power the main systems until the year 2025. The RTG degradation data shows that it has been preserved in better condition than expected, so the duration should be longer.

Voyager 1 carries with it on its journey into space one of two Earth sounds discs Sound of Earth.

On March 31, 2006, amateur radio operators from AMSAT in Germany tracked and received radio waves from Voyager 1 using a 20 m (66 ft) satellite dish in the city of Bochum, with an integration technique long. The data was compared and verified against the data from the station in Madrid, Spain of the Deep Space Network. This is believed to be the first successful amateur location attempt for Voyager 1.

In May 2008, Voyager 1 was at 12.45° declination and 17,125 hours of right ascension, heading towards the constellation Ophiuchus.

Interstellar mission

Position of interstellar probes launched from Earth. Voyager I will not be advanced by any probe released until now.

Both Voyager probes will have enough power to operate until the year 2025.

* Data tape operations are subject to the ability to receive data at 1.4 kbps via the DSN (Deep Space Network), and may be longer in case of using a future network with more sensitivity.

** Not before this date.

On July 7, 2009, Voyager 1 was 109.71 AU (16.414 million km) from the Sun when it crossed the termination shock front, entering the sunsheath, the terminal zone between the solar system and the Earth. interstellar space, a vast area where the Sun's influence yields to radiation from other distant bodies in the galaxy. At this distance, signals from Voyager 1 took more than fourteen hours to reach the control center at the Jet Propulsion Laboratory in La Canada Flintridge, California.

Since April 8, 2011, 17.49 billion km from the Sun, it detected a change in the flow of particles near the end of the heliosphere, which turns out to be oval. Scientists know this is so because of the way the solar wind behaved as Voyager passed by.

This stream of charged particles forms a bubble around our solar system known as the heliosphere. The wind moves at "supersonic" until it intersects with a shock wave called a termination shock.

At this point, the wind slows dramatically and warms up in a region called the heliopause. Voyager has already determined that the wind speed at your present location has dropped to zero. This means that Voyager has already reached the region where the solar wind begins to turn on itself as it crashes into the particles of interstellar space.

On June 14, 2012, NASA announced that Voyager 1 has reported a marked increase in the detection of charged particles from interstellar space, which are normally deflected by solar winds into the heliosphere. This is considered to be the edge of the solar system at a distance of 120.07 AU (17.86 billion km) from Earth, as the probe begins to enter interstellar space.

On September 12, 2013, NASA scientists reached a consensus based on observations that showed a sharp decrease in electrons per cubic meter since August 25, 2012, when it dropped to 0.08 electrons, leaving within the estimates that current models predict for beyond the solar system, which would be between 0.05 and 0.22 electrons per cubic meter. In this way, Voyager 1 becomes the first human-made object to overcome the heliopause and enter interstellar space.

On November 28, 2017, NASA scientists were able to correct the attitude of the probe's trajectory thanks to TCM ("Trajectory Correction Maneuver") thrusters that are the same as the attitude thrusters in size and capacity and are at the rear of the probe. They had not been used since Voyager 1 passed by Saturn 37 years earlier. The reorientation could be done by 10-millisecond pulses; a precision maneuver especially considering that the control signals took 19 hours and 35 minutes to reach the probe.

On February 23, 2017 at 20.916 million kilometers (137.747 AU, or 19 h and 22 min Earth light-hours), the probe is heading towards the center of our galaxy, the Milky Way, leaving the space dominated by the influence of our Sun since August 25, 2012 and thus entering the space between the stars, interstellar space.

On December 4, 2017, NASA reported that the VOYAGER 1 technical team, working with the TCM (Trajectory Correction) thrusters, managed to reorient the high-gain antenna towards Earth. With this procedure, it is expected to increase the useful life of the probe until at least the year 2025. Since its launch in 1977, these corrections of the spacecraft's position with respect to Earth were made with the attitude control thrusters., but these have degraded over time and continuous use. The TCM thrusters, on the other hand, had been inactive for 37 years, when they were used to maneuver the spacecraft and precisely point the instruments towards the planets studied.

On October 30, 2022, the probe was at a distance of 23,733,708,715 km (158.650043 AU, that is, 21h, 59m, 27s Earth light).

Voyager Gold Record

The Voyager gold record (titled in English as "The Sounds of Earth", in Spanish as Sonidos de la Tierra) are two copper phonograph records bathed in gold and 30 cm in diameter that accompany the Voyager space probes, launched in 1977 and which will take 40,000 years to reach the vicinity of the closest star to our solar system.

Because the probes are very small compared to the vastness of interstellar space, the probability that a space-traveling civilization would encounter them is very small, especially since the probes will eventually stop emitting any kind of noise. electromagnetic radiation. If it ever encounters an extraterrestrial species, it will most likely be around the time it passes the nearest star in Voyager 1's path, which it will reach in 40,000 years.