Voyager 2

As most of us here have an interest in technology, just reading the news - I find it fascinating that they can communicate with a space craft 19 billion kilometres away. Presumably the power outputs and antenna sizes are fairly minimal on the craft. I wonder what frequencies are used and how they manage it. I know at the earth stations the antenna are fairly vast but still, its an amazing achievement.


Well they can’t just now…

Will be fine in October.


NASA’s website handily provides an idea of where both the Voyager craft now are. As I type this, V1 is 14.9 billion and V2 is about 12.4 billion miles from earth. That both are 1960s technology, and still transmitting, is truly remarkable.


They were launched in 1977 but yes, remarkable. I gather they have received a ping from V2 although it’s antenna is misaligned until Oct as Jamie mentioned

Pioneer 10 (launched 1972) and now inert, is about 12.5 billion miles from earth. Pioneer 11 (1973, also non-functioning) is 10.2 billion miles from home.

And an interesting fact that as The Earth travels around The Sun, the distance between us and Voyagers actually decreases at certain times!

1 Like

They were indeed, but their technology is essntially 1960s, developed as part of NASA’s “Grand Tour” concept. Developing a mission like Voyager takes a very long time - especially five or six decades ago.


What’s difficult to understand is how on earth given all the years since launch such an error was allowed to occur. All those years to perfect a full check system of such important directional orders

According to NASA, this is roughly where the five interstellar probes are Pioneers 10 and 11 and Voyagers 1 and 2 have left the solar system. They are all flying off in different directions. The two Voyagers have passed the heliopause and are now in interstellar space (depending on your definition of where space begins). The two Pioneers are lagging but 11 should cross the heliopause in about 2027 and 10 in about 2057.

New Horizons (launched 2006), should break the heliopause in about 2039.


IIRC, S-band & X-band


Google agrees: V2 transmits on 2.3 or 8.4 GHz, we send to it at 2.1 GHz.

V2’s transmission power is about 20 Watts (the Plutonium power sources on board can currently produce about ten times this), but its parabolic dish focuses this to a beam less than one degree wide, which explains how easy it is to end up with it pointing in a direction where we can’t detect it.

As both Voyagers get further from earth, the reducing S/N ratio means it has to transmit data more slowly. Apparently, V1 is currently down to 160 bit/s which is as low as it’s designed to go.

It’s all really rather clever and special, and that’s before you start discussing the famous Gold Discs.



“My god, Jim…”

But seriously, absolutely fascinating endeavour.


In ye olden days, S-band was used for “housekeeping commands & telemetry (aka TM/TC)”. I suppose the X-band would be for “science data”. X-band is of course the cough “military” band………

Ah, so that’s how we’re keeping tabs on the Klingons!

…and others…

1 Like

Nobody is wearing a red shirt………they all survived the encounter.


Indeed, all the info is available on the nasa site link Kev included above, some fascinating info there

‘V’ger’ from memory?

Was just about to make a similar comment.

1 Like

…and Persis Khambatta is only wearing a shirt by the looks of it! What a stunningly attractive lady, former ‘Miss India’ - equally stunned to see she died at 49 of a heart attack.

1 Like

I love how Voyager evolved in isolation to wear a miniskirt and high heels.

It’s a great movie from back when things were somehow appallingly chauvinistic and yet more innocent at the same time.

1 Like