Draft:Original research/Interstellar vehicles

As the name suggests, interstellar vehicles are spacecraft that are capable of travelling to other stars. As of 9 December 2018, there was apparently one and only one interstellar vehicle: Voyager 1 (at right). As of 10 December 2018, there are now two interstellar vehicles Voyager 1 and 2.

Interstellars
Def. "between the stars" or "among the stars" is called interstellar.

Vehicles
Def. a "conveyance; a device for carrying or transporting substances, objects or individuals" or an "entity to achieve an end" is called a vehicle.

Planetary sciences
"The Voyager mission was designed to take advantage of a rare geometric arrangement of the outer planets in the late 1970s and the 1980s which allowed for a four-planet tour for a minimum of propellant and trip time. This layout of Jupiter, Saturn, Uranus and Neptune, which occurs about every 175 years, allows a spacecraft on a particular flight path to swing from one planet to the next without the need for large on board propulsion systems. The flyby of each planet bends the spacecraft's flight path and increases its velocity enough to deliver it to the next destination. Using this "gravity assist" technique, first demonstrated with NASA's Mariner 10 Venus/Mercury mission in 1973-74, the flight time to Neptune was reduced from 30 years to 12."

Theoretical interstellar vehicle
"From the NASA Kennedy Space Center at Cape Canaveral, Florida, Voyager 2 was launched first, on August 20, 1977; Voyager 1 was launched on a faster, shorter trajectory on September 5, 1977. Both spacecraft were delivered to space aboard Titan-Centaur expendable rockets."

"This graphic [on the right] shows the relative positions of NASA's most distant spacecraft in early 2011, looking at the solar system from the side. Voyager 1 is the most distant spacecraft, about 17.5 billion kilometers (10.9 billion miles) away from the sun at a northward angle. Pioneer 10, the next most distant, is about 15.4 billion kilometers (9.6 billion miles) away from the sun on the opposite side of the solar system. Voyager 2 is about 14.2 billion kilometers (8.8 billion miles) away from the sun on a southward trajectory, on the same side of the solar system as Voyager 1. Pioneer 11 is about 12.4 billion kilometers (7.8 billion miles) away from the sun. New Horizons is about 3 billion kilometers (2 billion miles) away from the sun, on its way to Pluto."

Strong forces
"While the four-planet mission was known to be possible, it was deemed to be too expensive to build a spacecraft that could go the distance, carry the instruments needed and last long enough to accomplish such a long mission. Thus, the Voyagers were funded to conduct intensive flyby studies of Jupiter and Saturn only. More than 10,000 trajectories were studied before choosing the two that would allow close flybys of Jupiter and its large moon Io, and Saturn and its large moon Titan; the chosen flight path for Voyager 2 also preserved the option to continue on to Uranus and Neptune."

Emissions
"Voyager 1's trajectory, designed to send the spacecraft closely past the large moon Titan and behind Saturn's rings, bent the spacecraft's path inexorably northward out of the ecliptic plane -- the plane in which most of the planets orbit the Sun."

"Following Voyager 2's closest approach to Neptune on August 25, 1989, the spacecraft flew southward, below the ecliptic plane and onto a course that will take it, too, to interstellar space."

Interplanetary medium
"As the spacecraft flew across the solar system, remote-control reprogramming was used to endow the Voyagers with greater capabilities than they possessed when they left the Earth."

Interstellar medium
The image above gives an approximate location of Voyager 1 in September 2013.

"On 5 November 2018, Voyager 2 crossed the boundary between the heliosphere — the bubble of solar wind emanating from the Sun — and interstellar space. [By comparing] the spacecraft’s observations with those of its twin, Voyager 1, which made the same crossing six years before [the] long-awaited second data point reveals that the heliosphere is symmetric, at least at the two points where the Voyagers crossed. But Voyager 2 encountered a much sharper, thinner boundary than Voyager 1."

Exploratory rocketry
The first and so far only successful propulsion system for interstellar travel is shown in the image at the right. This is the Titan IIIE with the Voyager 1 aboard its booster rocket, the Centaur upper stage.

Pioneers
On January 1, 2019, Pioneer 10 is predicted to be 121.69 AU from the Earth (about 11.3 billion miles); and traveling at 12.04 km/s (relative to the Sun) and traveling outward at about 2.54 AU per year. The brightness of the Sun from the spacecraft is magnitude &minus;16.6. Pioneer 10 is heading in the direction of the constellation Taurus.

On January 30, 2019, Pioneer 11 was 100.84 AU from the Earth and 100 AU from the Sun; and traveling at 11.241 km/s (relative to the Sun) and traveling outward at about 2.37 AU per year. The spacecraft is heading in the direction of the constellation Scutum near the current position (August 2017) RA 18h 50m dec -8° 39.5' (J2000.0) close to Messier 26. In 928,000 years it will pass within 0.25 pc of the K dwarf TYC 992-192-1.

Hypotheses

 * 1) Even only using subluminal technology, an interstellar vehicle is feasible.