Spacecraft Trajectories
Spacecraft Trajectories
| Group Name | probes |
| Reference | Jet Propulsion Lab's HORIZONS |
| Prepared by | Brian Abbott (AMNH/Hayden) |
| Labels | Yes |
| Files | pioneer10.speck, pioneer11.speck, voyager1.speck, voyager2.speck |
| Dependencies | none |
| Census | Pioneer 10 & 11, Voyager 1 & 2 trajectories |
This data group consists of the trajectories of the Pioneer 10 and 11 (green) and the Voyager 1 and 2 (yellow) spacecraft. These are the four farthest objects man has sent into space. To view them, follow the instructions on altering your clipping planes in “Planetary Orbits.”
The Pioneer program was the first large-scale planetary exploration mission undertaken by NASA. We highlight Pioneer 10 and Pioneer 11 here because they are traveling into interstellar space. However, these are but two probes in the program. Pioneers 6-9 were launched between 1965 and 1968 and were sent into orbit around the Sun. Pioneer 6 is the oldest NASA spacecraft in working order. The last successful communication with the craft occurred on December 8, 2000, to commemorate its 35th anniversary.
On March 2, 1972, Pioneer 10 was launched to fly by Jupiter. It was the first spacecraft to fly through the asteroid belt and made its closest approach to Jupiter on December 3, 1973. Pioneer imaged the planet and its moons and sent back measurements of Jupiter's magnetic field and atmosphere. The last signal was received from Pioneer 10 on January 23, 2003, before its radioisotope power source decayed to levels too low to send signals strong enough to detect.
Pioneer 11 was launched on April 5, 1973, and followed Pioneer 10 to Jupiter, then went on to image Saturn. Its last transmission was received on September 30, 1995. The spacecraft's antenna is now out of Earth's view, and with no communication possible, the craft cannot be moved to point its antenna back toward Earth. The probe may continue to transmit a signal today, but we have no way to detect it.
After the Pioneer 10 and 11 probes, the Voyager program began its “grand tour” of the Solar System. Voyager 2 was launched on August 20, 1977, with Voyager 1 following 15 days later. Midyear 1979, the spacecraft made their closest approach to Jupiter. In November 1980, Voyager 1 flew by Saturn and then, with a boost from Saturn, was ejected from the Solar System, beginning its interstellar mission phase.
Voyager 2 visited Saturn in summer 1981 and was the first spacecraft to visit Uranus, in January 1986, and Neptune, in summer 1989. Neptune then boosted Voyager 2 out of the Solar System.
The interstellar mission involves the investigation of the outer reaches of the Sun's influence. As the Sun moves through space, it is plowing into the gas that surrounds it. This sets up a shock whereby the particles streaming from the Sun ram into the particles of the interstellar gas. The Voyager spacecraft will one day encounter that shock and return data on the nature of this interstellar gas unaffected by the Sun. The spacecraft should begin entering this region in the next five years and cross it entirely 10 to 20 years after reaching the shock. Beyond this, Voyager will continue to sail into the Milky Way. In about 296,000 years, Voyager 2 will pass within 5 light-years of the bright star Sirius in Canis Major.
Scientists continue to communicate with the Voyager craft. Both are traveling at about 3.5 AU per year. On February 17, 1998, Voyager 1 surpassed Pioneer 10 to be the farthest man-made object.
The Trajectories
Each of the four trajectories begins from Earth's orbit, and their point of departure marks the location of Earth when the probes were launched. The trajectories extend to the year 2050. Labels appear either at planetary encounters or every 10 years once the spacecraft leave the Solar System. Alongside each year, we include the light-travel time in light-minutes (lm) or light-hours (lh).
If you turn on the 1-light-month grid, you will see that the probes will be about 1 light-day from Earth in 2050. One light-day is about 26 billion kilometers, or 16 billion miles, the distance light travels in one day.
© 2002-2005 American Museum of Natural History
Last Modified: 2007-12-19 by Brian Abbott