The 1977 launch of NASA’s Voyager is considered to be one of the greatest achievements in human history. But why is it so important – and what is that little spacecraft doing all the way out there, anyway?

The World’s Largest Hearing Aid

Before we start talking about Voyager, we need to set up some important context.

In 1958, NASA set up the Deep Space Network. The Deep Space Network – or DSN – is a global array of large radio antennas (like, really large) strategically placed so that they have a full, unbroken line of communication into space no matter what Earth’s rotation or position is. 

You see, one thing scientists realized early on was that communicating in outer space would be very difficult. On earth it’s not too bad, because we can wire cables to most places and have outer atmosphere satellites for the rest. But in space – where there’s an indescribably long void in every direction – it’s difficult enough to contact something on the moon, let alone in deep space. So before Apollo, or Voyager, or any other major space expedition, they had to set up the foundation.

But there’s another aspect to this, and it’s the signal. We have the hearing, but how do we do the talking?

I think when it comes to that, we should focus on Voyager itself. 

What is Voyager?

Voyager’s mission is very simple: it gathers different readings about space, and sends those readings back to Earth. Some readings it takes include:

Imaging (pictures of planets, moons, etc.)Magnetic field readingsPlasma measurementsCosmic ray measurementsUltraviolet light readingsLow-energy charged particle measurementsPlasma wave measurementsLight polarization

In other words, just about everything that NASA scientists thought would be important to know about our solar system back in the 70s. But even more impressively, all of these readings end up being converted into the same analog radio frequency that is then transmitted back (via a directional antenna that tries its best to point to Earth) and picked up very faintly by the DSN. The DSN is then able to clean up these radio waves and convert them via signal processing back to a digital version of the measurements. And they thought of all this back in 1977!

Why is Voyager…?

Given the massive amount of time (50+ years), money ($4 billion upfront, $30 million every year after), and manpower (thousands) required in the Voyager undertaking, you might ask yourself the same question I did: how did this even happen in the first place? 

I mean, this is the United States we’re talking about – a nation that is notorious for shutting down the government for weeks over one line in a bill. Why was it that we were all able to agree to fund – and finish – such an ambitious work?

Well, like all miracle projects, it was a combination of the right stakeholders being aligned in the right ways.

The first were the scientists. 1977 isn’t just any year – physicists in the 60s determined that 1977 would be the first time in 176 years that the planets of Jupiter, Saturn, Uranus, and Neptune would all be aligned with each other. This meant that not only could Voyager visit all four of these planets in one mission – a feat never before achieved – but it could also use the gravitational forces from these planets to help it build momentum and “slingshot” out of the solar system at a much faster and fuel-efficient rate..

Then there were the politicians. While it is true the “space craze” began to die down during the late 70s, the Cold War most certainly did not. And given the once in a lifetime chance to gather readings from far outside the solar system, senators were primarily concerned that the Soviets would do it first. It’s also worth noting that the Voyager launch was in the enviable position of being after the success of Apollo 11 and 14 but before the disastrous failure of the Challenger, which is seen by many as the falling point for NASA’s cultural and political reputation.

Lastly, of course, there were the rest of us: the citizens. Time capsules have always fascinated us humans, and while most people didn’t care about the readings which NASA would receive, they did care about another – and arguably more famous – purpose for the Voyager: the Golden Records.

Used mostly as a marketing tool to get funding for the project, the Golden Records were a time capsule project headed by famous US science teacher Carl Sagan with a unique premise: it would be the first time capsule designed specifically for intelligent species outside of our own solar system. This made people real excited, and cemented Voyager’s completion – as well as making it one of the most important space projects of all time. 

The post The Story (and Meaning) of Humanity’s Greatest Achievement appeared first on Jacob Robinson.