Slashdot Mirror
NASA's Voyager 2 Flew By Saturn 35 Years Ago Today (space.com)
An anonymous reader quotes a report from Space.com: Thirty-five years ago today, a NASA spacecraft got an up-close look at beautiful, enigmatic Saturn. On Aug. 25, 1981, the Voyager 2 probe zoomed within 26,000 miles (41,000 kilometers) of the ringed planet's cloud tops. The discoveries made by Voyager 2 -- and by its twin, Voyager 1, which had flown past Saturn nine months earlier -- reshaped scientists' understanding of the Saturn system and planted the seed for NASA's Cassini mission, which began orbiting the ringed planet in 2004, NASA officials said. Voyager 1 and Voyager 2 launched a few weeks apart in 1977, tasked with performing a "grand tour" of the solar system's big planets -- Jupiter, Saturn, Uranus and Neptune. The two spacecraft accomplished that goal, eyeing all four gaseous worlds up close, and also studying 48 of their moons. (Voyager 1 flew past Jupiter and Saturn, while Voyager 2 had close encounters with all four planets.) The Voyagers weren't the first spacecraft to fly by Saturn; that distinction belongs to NASA's Pioneer 11 probe, which did so in 1979. But the Voyagers broke a lot of new ground; they discovered four new Saturn moons, for example, and revealed an incredible diversity of landscapes on satellites such as Dione, Tethys and Iapetus, NASA officials said. August 25th appears to be a good day for nerds. You can view some out-of-this-world photos from NASA's Voyager 1 and 2 probes here.
After all these years, Voyager 2 is only 15 light-hours from Earth (Voyager 1 is 18 lh). Even if the newest probes may go somewhat faster, reaching the closest star (4.2 light-years) is a long way to go.
Slashdot, fix the reply notifications... You won't get away with it...
With modern tech, do the same missions, same planets, new info!
Voyager took advantage of an alignment of the planets that only occurs once every 175 years or so. A similar mission won't happen for a long time. Meanwhile, New Horizons just buzzed Pluto, and is now heading into the Kuiper Belt.
A flyby is acceptable for a first mission. The science data from Voyager answered some questions, but also raised lots of new questions. To answer these, we went for orbiting missions that would spend far longer at the planet, using better instruments, and new instruments inspired by the Voyager science return.
Flybys have big drawbacks: you only get a few hours of observation time, so you can't study patterns that occur over long periods (seasonal changes, for example). You can't even see the entire surface of the planet (unless you get lucky and the planet rotates really quickly).
For Jupiter and Saturn, we've had several orbiters now (e.g. Galileo, Ulysses, Cassini, Juno) and we've amassed far more knowledge than flybys could ever give us.
Uranus and Neptune haven't had dedicated missions yet, but that might change soon.
Voyager 3 and 4 were planned initially, by the way (identical to Voyager 1 and 2, with mission plans that included Pluto). They fell to budget cuts (early '70s, NASA was elbow-deep in expensive Apollo missions).