The “Voyager 1” spacecraft is a 722 kilogram (kg; also known as kilo, the base unit of mass in the International System of Units and is defined as being equal to the mass of the “International Prototype Kilogram” (“IPK”), which is almost exactly equal to the mass of one liter of water)—1,592 lbs (pounds/pound-mass, a unit of mass used in the imperial, United States customary and other systems of measurement)—space probe, a scientific space exploration mission in which a spacecraft leaves Earth and explore space.
In September 5, 1977, the spacecraft was launched by the National Aeronautics and Space Administration (NASA), the agency of the United States government that is responsible for the nation’s civilian space program and for aeronautics and aerospace research, to study the outer Solar System, which consists of the Sun and the astronomical objects gravitationally bound in orbit around it, all of which formed from the collapse of a giant molecular cloud approximately 4.6 billion years ago, and interstellar medium (ISM), which in astronomy is the matter that exists n the space between the star systems in a galaxy. The spacecraft receives routine commands and transmits data back to the Deep Space Network, or DSN, a worldwide network of large antennas and communication facilities that supports interplanetary spacecraft missions.
At a distance of 120 astronomical units (AU, au, a.u., or ua; a unit of length equal to 149,597870.700 km or 92,955,807.273 mi, or approximately the mean Earth-Sun distance)—1.8x1010 km—as of February 2012, it is the farthest man-made object from Earth, the third planet from the Sun, and the densest and the fifth-largest of the eight planets in the Solar System. Voyager 1 is now in the heliosheath, which is the outermost layer of the heliosphere, beyond the termination shock; heliosphere is a bubble of charged particles in the space surrounding the Solar System, “blown: into the interstellar medium (the hydrogen and helium gas that permeates the galaxy) by the solar wind. On June 15, 2012, NASA scientists reported that Voyager 1 may be very close to entering interstellar space, the physical space within a galaxy not occupied by stars or their planetary systems, and becoming the first human-made object to leave the Solar system.
Being a part of the Voyager program, a US program that launched two unmanned space missions, scientific probes “Voyager 1” and “Voyager 2,” the spacecraft is in extended mission, tasked with locating and studying the boundaries of the Solar System. It includes the Kuiper belt, sometimes called the “Edgeworth-Kuiper belt—a region of the Solar System beyond the planets extending from the orbit of Neptune (at 30 AU) to approximately 50 AU from the Sun—heliosphere and interstellar space. The primary mission ended November 20, 1980, after encountering the Jovian system in 1979 and the Saturnian system in 1980; the exploration of Jupiter has to date been conducted via close observations by automated spacecraft while the exploration of Saturn has been solely done by robotic probes. It was the first probe to provide detailed images of the two largest planets and their moons, or natural satellites, celestial bodies that orbits a planet or smaller body, which is called its “primary.”