Voyager 1

Voyager 1 spacecraft is a NASA exploration of the outer solar system and interstellar space as part of the Voyager program. She was launched on 5 September 1977 by the Launch Complex 41 on Cape Canaveral with a Titan IIIE - Centaur rocket. Your identically constructed sister probe Voyager 2 was launched 16 days earlier on a different trajectory. Voyager 1 flew first to the planets Jupiter and Saturn and occurred approximately in August 2012 as the first man-made object generated in the interstellar space a.

The mission of the Voyager 1 is generally regarded as one of the greatest achievements of NASA and the space, because the probe has already surpassed their planned life expectancy far and still regularly sends data back to Earth. She is also the farthest from the Earth -built man-made object ever and will remain in this state for the foreseeable future. The distance from the Sun of Voyager 1 (Stand: January 30, 2014) about 126.78 astronomical units ( AU), about 18.97 billion kilometers, a distance about 17 hours and 22 minutes required for the light. Every year it takes around 3.6 AU (about 540 million km ) to, this corresponds to a (radial ) velocity of about 61,000 km / h From Earth, considers himself Voyager 1 is in the constellation Ophiuchus.

• 4.1 Start
• 4.2 Exploration of Jupiter
• 4.3 Exploration of Saturn
• 4.4 Family Portrait and Pale Blue Dot
• 4.5 Interstellar Mission
• 4.6 future

• 5.1 Energy Supply
• 5.2 The data and the probe in August 2013
• 5.3 instruments

Prehistory

The roots of the Voyager program date back to the mid-1960s. There were calculations of trajectories for probes that should take advantage of the late 1970s, the favorable positions of the outer planets. It was decided the construction of Voyager 1 and 2 in the early 1970s. Since they were originally planned as an extension of the Mariner series, the probes were initially designated Mariner 11 and 12. This designation was later dropped due to the large structural differences between the probes. By March 1975, the design phase was completed, and the construction of the two probes began.

Mission Objectives

Original mission objectives

The Voyager probes had no particular research focus. Since there were only a few knowledge about the outer planets at this time, they should be expanded. Therefore, the original mission objectives were relatively broad:

• Investigation of the atmosphere of Jupiter and Saturn in terms of circulation, structure and composition
• Analysis of the geomorphology, geology and composition of the moons
• Accurate determination of the mass, size and shape of the planets, moons and rings of all
• Investigation of various magnetic fields with respect to their field structure
• Analysis of the composition and distribution of charged particles and plasma
• Particularly accurate studies of the moons Io (Jupiter) and Titan (Saturn ).

Current interstellar mission

During Voyager 2 flew on toward Uranus and Neptune, of Saturn from Voyager 1 is located on the way through the outer regions of the solar system and into interstellar space since the passage of Saturn. On January 1, 1990 began with the " Voyager Interstellar Mission " (VIM ) the final stage of finding mission.

Currently (as of 2009) analyzed Voyager 1, the following phenomena:

• The strength and orientation of the magnetic field of the sun
• The composition, the direction and the energy spectra of solar wind and cosmic radiation
• The strength of radio waves, which are probably from the heliopause
• The distribution of hydrogen in the outer heliopause.

The program came several times for budgetary reasons in distress because of the operation of the probe per year multi-million dollar costs (personnel, DSN - time, etc.). International protests and the special position of Voyager 1 and Voyager 2 always prevented the complete setup of the program, with some budget cuts had to be accepted.

The probe and its scientific instruments

Voyager 1 is a several -meter and 800 -kg spacecraft. It consists essentially of a central annular aluminum cell (diameter about 1.80 m), which is ten square in cross section and is home to much of the electronics, a satellite dish (diameter about 3.6 m) and a 2.5 m long a cantilever which carries the majority of the scientific instruments. The energy generated by three radionuclide. Voyager 1 and Voyager 2 are identical.

Functioning of the mission

Start

Voyager 1 was on September 5, 1977-16 days after its sister probe Voyager 2 - launched from Launch Complex 41 at Cape Canaveral with a Titan IIIE - Centaur rocket. 13 days after the launch began a 30 - day trial for on-board systems and scientific instruments, which was successful. Due to the slightly higher starting speed (15,0 km / s compared to 14.5 km / s ) overtook Voyager 1 probe her sister already on December 15 at a distance of 1.75 AU. While the bulk of the march flight the spacecraft was in standby mode. Only every two months, there was a 20-hour Science phase in which the starry was examined and the Teilchenmessgeräte were turned on.

Exploration of Jupiter

Due to their speed advantage Voyager 1 first came to the Jupiter system. The scientific observations began on December 14, 1978, 80 days before the flyby of the planet.

The main phase of the study began on March 4, 1979, when the probe was removed only one day away from Jupiter. In addition to the planet itself and its rings and the moon Io was investigated, where the probe on 5 March approached to up to 18,460 kilometers. On the same day Ganymede were examined at a distance of 112,030 km and Europe at a distance of 732,270 km. The next day, Voyager approached the last to be examined moon Callisto to up to 123,950 km 1. The probe passed through the four large moons of Jupiter in just 30 hours. A total of 17 477 images were transmitted at the maximum data rate of 115.2 kbit / s during the study of the Jovian system.

Voyager 1 was accelerated by Jupiter at about 16 km / s. This 5 kg hydrazine for course corrections had to be used. Shortly after Voyager had one the last pictures sent Voyager 2 arrived on April 25 in the system and continued the observations. Thus Jupiter was observed over a period of almost seven months, which led to many new scientific findings.

Voyager 1 discovered when flying through the system, two new moons, Metis, and Thebe, and the weak planetary ring around Jupiter, whose existence had been suspected after the Pioneer 11 mission. On Io Voyager 1 discovered nine active volcanoes. After the flyby of Jupiter was recognized on the night side nor from millions of miles away flashes, indicating extremely severe thunderstorms within the Jovian atmosphere.

Jupiter in its true colors

Jupiter's "red spot" in false color

Eruption of a volcano on Io

Close-up of an active volcano on Io (including lava flows )

Low Kallistos " Valhalla crater "

Low resolution shot of the moon Amalthea

The moon Ganymede

Exploration of Saturn

On November 10, 1980, Voyager 1 arrived in the core area of the Saturn system, nine months before her sister probe. The next day, one of the most interesting objects was equal investigated: the moon Titan. They had known before the mission of the methane atmosphere, and some scientists thought it conceivable that the greenhouse effect could possibly support life on the surface. But already at greater distances one recognized the homogeneous cloud of smog of the moon, which made a study of the surface impossible. Therefore, the IRIS and UVS instrument were aligned on the edge of the atmosphere, at least to be able to analyze them in detail. Despite the time not inspectable surface of titanium some new insights were gained through its atmosphere. In addition to the large amount of nitrogen and traces of methane, ethylene and other hydrocarbons were detected. The atmosphere itself was extended and recognized as very tight, but much too cold for life. These findings made ​​the moon for the primary purpose of the launched in 1997, Cassini- Huygens.

After passing through the Saturn one of the most challenging phases of the mission began. Since the others had to be examined moons orbit very close to Saturn, all three moons ( Mimas, Dione and Rhea ) and the pronounced planetary ring had to be examined within only ten hours, which brought the scan platform to its limits. The data rate, meanwhile, was due to the now attained a distance from the Earth to 44.8 kbit / s decreased, which was much earlier begun to transfer than Jupiter, because Saturn is significantly greater with the ring system. In the end, approximately the same number of images made ​​as in Jupiter.

Many new moons were found by small size at the edges of the rings. Even with the Lagrange points of the moons some other companions were discovered. This phenomenon was already known on the planet ( Saturn follow at ± 60 °, some asteroids ), but was at moons a novelty. Voyager 1 also showed that the planetary ring of Saturn is not homogeneous and consists of many individual rings. As Voyager 1 for a more detailed study of Saturn's rings described no favorable trajectory and the PPS instrument failed, the trajectory of the following Voyager 2 was reprogrammed in order to analyze the rings of a better track can.

At the flyby of Saturn's south pole, the probe swung on its final orbit, they also promoted since then at an angle of 35 ° to the ecliptic of the solar system.

Saturn in false color

Saturn's rings in detail

The moon Mimas with its characteristic Herschel impact crater

The moon Dione

Titans atmosphere

Trajectories of Voyager 1 and 2 in the Saturn system

Family Portrait and Pale Blue Dot

On 14 February 1990, the ISS instrument was activated one last time for the creation of a unique Photos: It's a mosaic that shows six planets of the solar system in color. Scientifically, it had no greater value, but it inspired many scientists and laymen: the so-called family portrait.

In particular, the image of the Earth, called the Pale Blue Dot, attracted much attention and was elected in 2001 one of the ten best pictures of the space sciences. It is to this day the photo that shows the Earth taken from the greatest distance ( 6.4 billion kilometers ).

Interstellar Mission

During Voyager 2 flew on toward Uranus and Neptune, of Saturn from Voyager 1 is located on the way through the outer regions of the solar system and then into the interstellar medium outside the solar system since the Saturn Passage. The " Voyager Interstellar Mission " (VIM ): On January 1, 1990, the last phase of the mission began. In February 1998, " overtook " Voyager 1 probe Pioneer 10 and has since become the most distant object that was created by man, as well as the one with the highest escape velocity from the solar system.

In the period between August 2002 and February 2003, the particle sensors measured continuously unusual values ​​, which is why it was assumed that the preliminary Voyager 1 approached their destination: the large, outer region of the heliosphere, called " Heliosheath ". In this region, the particles of the solar wind mix with interstellar matter and move with reduced flow velocity. In the run-up to the Heliosheath, called termination shock, the probe appeared on 16 December 2004 at a distance of 94 AU (about 14.1 billion kilometers ) a. This was recognized, among others, the massive slowing solar wind and the abruptly changing the direction of the magnetic field was stronger even by 150%. In addition, we registered an increase of heavy ions and detected previously registered radio emission.

On 24 May 2005, JPL announced finally that the probe had reached the Heliosheath. On 23 December 2009, NASA announced that the data from the Voyager magnetometer indicate a strong magnetic field outside the solar system. This discovery provided the long-sought explanation of why the Local Interstellar Cloud does not dissolve: The cloud is strongly magnetized and therefore is held together by the field.

In the spring of 2010, further evidence of the approach of the probe to the limits of our solar system, the heliopause, found. These are based on the data of the LECP instrument, which registered a strong deceleration of the solar wind: the speed of the wind relative to the probe was made ​​during the period close to zero ( relative to the Sun or about 17 km / s ), which is the reduction of the influence sun means.

Using the MAG instrument Voyager was able to analyze the structure of the solar magnetic field at the edge of the solar system by direct measurements. Since 2007, the probe is located in a region in which the field is no longer stable, but is divided into a plurality of magnetic bubbles with a diameter of about 160 million kilometers. In June 2011, NASA announced that the reason for this probably is the rotation of the Sun. This also moved and folded its magnetic field, which in the equatorial plane at the edge of the solar system structure of the field leads to a large number of Rekonnexionen and thus " foamy " to. Beginning on 25 August 2012 There has been a sharp decrease in the measured by the probe ( resulting in interaction with the solar wind) anomalous cosmic rays ( ACR engl. ) and a significant increase in galactic cosmic rays ( GCR engl. ). Some observers concluded from this that Voyager 1 could have left the heliosphere. On December 3, 2012, NASA reported that Voyager 1 had the magnet motorway (English magnetic highway ), the edge of the heliosphere is reached. On September 12, 2013 New data analyzes were published, showing that Voyager 1 has the heliosphere leave at the end of 2012 and is the first human-produced object in interstellar space.

Old (left) and new (right) idea of ​​the solar magnetic field

Position and course of Voyager 1 (red) and Voyager 2 15 February 2009 from three different perspectives

The heliosphere of the sun, the heliopause and interstellar space to Alpha Centauri - size ratios

Future

In about 40,000 years, Voyager 1 will be the star AC 79 3888 ( constellation giraffe) happen.

Current status

Energy supply

The hydrazine fuel for the position control is still sufficient for at least the next 40 years. Much more critical is the power supply: Due to the progressive core process in the radionuclide and the wear of the thermoelectric elements, the available electrical power decreases by about 1.4 % per year. Therefore, many tools and their heating elements have already been turned off. The Energy Saving Planning NASA sees (as of 2008) the following measures:

• 2010: disable scanning platform and UVS
• Off tape storage system ( DTR): 2015
• 2016: disable position control
• 2020: phased closure of the still active instruments
• 2025 at the earliest: Deactivation of the latest scientific instrument.

The data of the probe in August 2013

As of August 31, 2013

• Speed ​​relative to the Sun: 17.037 km / s
• Fuel remaining: < 20.5 kg
• Performance of the radionuclide: 260.2 watts ( about 43 % power loss )
• Data rate real time: 0,016 kbit / s ( 34 m antennas of DSN)
• Maximum data rate: 1.4 kbit / s ( with 70 - m antennas of the DSN, Booth 1999)

Instruments

Stand: 2011

Voyager Golden Record

Voyager 1 performs a data plate of copper with it, which is coated to protect against corrosion with gold, the so-called " Voyager Golden Record ". On her image and audio information about humanity are stored. On the front there are, among others, a kind of instructions and a map indicating the position of the sun relative to 14 pulsars.

Popular Cultural Reception

Voyager 1 and Voyager 2 probe her sister attracted particularly during their early mission phase much attention, even in the general public. This is mainly due to the extraordinary mission profile ( particularly with regard to the distances ) and the very high quality for that time color photographs diverse motives. The idea of sending a " message to Space" by the Voyager Golden Record - plate attracted great attention.