Space is our Final Frontier. NASA’s Voyager I and II missions were supposed to last just 5 years from 1972-1977 exploring the outer planets of our solar system and yet they are still powering over 30 years later, continuing to transmit data to Scientists on Earth as they pass through interstellar space, exploring and boldly going where no man has gone before.
NASA Voyager photo credit: NASA
In 1977, two unmanned spacecraft, designed and built by NASA’s Jet Propulsion Laboratory, were launched on reconnaissance missions to the outer planets. Separate Titan/Centaur rockets launched Voyagers 1 and 2 in September and August 1977 toward Jupiter.
The launch window during 1977-79 which the Voyager missions took advantage of to fly by all four planets in our outer solar system happens only once every 176 years. If this window had occurred in 1965-66-67, we wouldn’t have had the technology to fly such a mission. If it had happened in the 80’s, we couldn’t have launched the mission as necessary rockets had been discontinued.
Each Voyager spacecraft carries a message in the form of a 12-inch gold-plated phonograph record. The record, together with a cartridge and needle, is fastened to the side of the spacecraft in a gold-anodized aluminum case that also illustrates how the record is to be played. The records contain greetings in 55 languages, samples of music from different cultures and eras, natural sounds of surf, wind, thunder, birds, whales and other animals, and a message from then US President Jimmy Carter.
In September 1977, Voyager 1’s camera looked back toward the home planet for a first-ever glimpse of the Earth and its Moon in a single photo.
NASA Voyager view of earth and moon. photo credit: NASA
Voyager’s fuel efficiency is quite impressive. Even though most of the launch vehicle’s 700 ton weight is due to rocket fuel, Voyager 2’s great travel distance of 7.1 billion km from launch to Neptune resulted in a fuel economy of about 13,000 km per liter. As Voyager 2 streaked by Neptune and coasted out of the solar system, this economy got better and better!
NASA Voyager Saturn’s Rings. photo credit: NASA
The rings of Saturn appeared to the Voyagers as a dazzling necklace of 10,000 strands. Trillions of ice particles and car-sized bergs race along each of the million-kilometer-long tracks, with the traffic flow orchestrated by the combined gravitational tugs of Saturn, a retinue of moons and moonlets, and even nearby ring particles.
Through the ages, astronomers have argued without agreeing on where the solar system ends. One opinion is that the boundary is where the Sun’s gravity no longer dominates – a point beyond the planets and beyond the Oort Cloud.
This boundary is roughly about halfway to the nearest star, Proxima Centauri. Traveling at speeds of over 35,000 miles per hour, it will take the Voyagers nearly 40,000 years, and they will have traveled a distance of about two light years to reach this rather indistinct boundary.
Barring any serious spacecraft subsystem failures, the Voyagers may survive until the early twenty-first century (~ 2020), when diminishing power and hydrazine levels will prevent further operation. Were it not for these dwindling consumables and the possibility of losing lock on the faint Sun, tracking antennas on Earth could continue to “talk” with the Voyagers for another century or two!