Voyagers - Fabulous machines?

The Voyagers use the slingshot technique (around the planets) to add energy and allow them to travel out farther. This means they are going farther than they could have using only the energy from their launch vehicles.

Of course, the outer planets have to all be in the right position at the right time relative to each other. This alignment started in the 1970's. It won't happen again for another ~400 years. I'm glad it didn't happen in the 1930's. It came about at the same time we had the technology to exploit it.

How's that for a nice coincidence?

 

Not just fabulous, but movie stars, too. 'V ger' featured in the first Star Trek movie.

 

The ultimate in pulse-and-glide.

 

Now, if we could only get that slingshot effect to work with a Prius on close approach to big trucks.

 

And here I thought I was clicking into a thread about the fabulous Plymouth Voyager..

 

That was the [ame="http://en.wikipedia.org/wiki/Planetary_Grand_Tour"]Grand Tour[/ame], which isn't quite that rare, and didn't happen as planned. Voyager 2 salvaged some of that with a four planet flyby.

Two planet flyby opportunities, such as Voyager 1, Pioneer 11, and New Horizons, are available very frequently.

The Messenger probe did one Earth flyby, two Venus flybys, and three Mercury flybys before settling into orbit around Mercury on its fourth approach this past March. The earlier Cassini mission to Saturn was almost as complex, with flybys of Earth, Venus twice, and Jupiter.

 

I'd rate these probes leaving the Solar System as NASA's greatest achievement with the possible exception of the Apollo Moon landings....on "bang per buck" the greatest.

The most interesting thing is Voyager 1 finding the absolute limit of the heliosphere - where the Sun's gravity ends and it's truly in interstellar space > Voyager 1 - Wikipedia, the free encyclopedia

 

And honorable mention to Spirit and Opportunity

Are we there yet? Mars rover nears crater – This Just In - CNN.com Blogs

Three years to go 11 miles....makes hypermilers seem like speed freaks.

 

Voyager 1 stops communicating with Earth

NASA's Voyager 1 probe in interstellar space can't phone home (again) due to glitch | Space

It is still alive enough to be sending back a fixed repeating bit pattern, but not any science or vessel engineering data. The story indicates that it is still receiving and carrying out commands transmitted from Earth, but doesn't say how they know.

This isn't its first hiccup of this sort. I sure hope that its end has not yet arrived.

 

Time for the next deep-space mission with current technology. Perhaps two or three aimed at the nearest star(s)?

Bob Wilson

 

Mind-boggling distances.

$100-Million Plan Will Send Probes to the Nearest Star | Scientific American

 

Well, that's not so different from at least a few Priuschatters, yet somehow we make do.

Jokes aside, I do hope they're able to get a little more out of that old probe. I honestly think the Mariner missions (including the Voyagers) are some of the very best investments we ever made in exploratory science.

 

Voyager got new life as a Star Trek plot. More than once I guess. But Sci Fi aside, Chemical rockets might not get used again to send devices beyond solar system. That's quite a legacy.

Ion drives and nuclear propulsion attain higher speeds. 'Exo' targets are millionsfold more distant so speed is very important. Chemical rockets are snails. Big noisy impressive snails from our perspective, sure. And yet ...

 

I'm not sure. I know the V ger in the movie was a bit reminiscent of the Nomad probe in The Changeling ... but that episode predated the Voyager launch by a decade.

 

The ideal is gravity assist by the maximum number of planets before heading out beyond our solar system. Fortunately, the largest planets, Jupiter, Saturn, and Uranus are 'on the way out.' Getting a Sun, gravity assist is possible.

As for nuclear, it could widen the window for a gravity assist tour. But there would not be any usable thrust after the ejected material runs out. The decay heat would be useful for fighting the cold of space and power but not much else. There would be a significant, long term, risk of transmuting the payload.

Bob Wilson

 

Not finding the link, but I did like that one idea of firing bricks of solid rocket fuel at the departing payload, and then using lasers to ignite the fuel just when it is in the optimum position behind.

That way we get the benefit of highly reactive stored energy chemical fueling but it doesn't have to be carried with the payload or even launched at the same time.

Eh, they said we'd never re-use first stage boosters.

 

"they said we'd never re-use first stage boosters." Who they?

1960s was (presented as) a battle between US and Soviet (ideologies) to put boots on moon. Reuseability was not high priority.

In 70's to 90's reuseability was the Shuttle. Mixed successes there; it did at least build ISS.

Reuseability dangled until Musk SpaceX made it a profit center for earth-orbiting things. Having broken that wall SpaceX asserts that bigger things will follow.

Those expecting SpaceX to fail may be conflating Musk as a perfidious a-hole. He is, but earlier large tech advances came from a-holes. This is not disqualifying.

As such.

 

Uh, How?

Gravity assist - Wikipedia

"Interplanetary slingshots using the Sun itself are not possible because the Sun is at rest relative to the Solar System as a whole."

There is something related, the Oberth effect, a powered flyby, in which rocket burns deep inside gravity wells are magnified. But this is an active rocket burn during closest approach, whereas the aforementioned gravity assists were primarily passive, using just minor course correction burns for fine tuning long before approach. And doing this around the sun requires enormous protection from the scorching solar heat.

Oberth effect - Wikipedia

 

We agree, I was inaccurate. A passive, gravity assist would not be possible but it can amplify powered flight.

A tricky flight path, gravity assist would be the key to reaching highest, system speeds in our life times.

Bob Wilson