10 ms·

It's been operating for 47 years and it still has fuel left to make attitude corrections. I wonder how they managed that feat.

by litoE 2y ago

turblety 2y ago
I presume solar power?
- Tor3 2y ago
  No, way too little sun out here. The sun is just a dot far away. The Voyagers both use RTGs, radioisotope thermoelectric generators. Decaying plutonium, essentially. That's for the electrically powered systems. The thrusters use liquid hydrazine, which is common for those kind of thrusters. Edit: There's more about that in the NASA link in a sibling comment.
- krige 2y ago
  Solar has nothing to do with it. Voyager uses hydrazine, of which over 80% has been used up over the years. They simply use not that much of it as it's not for thrust, but for aiming at Earth more or less.
- meindnoch 2y ago
  Lol. How would that work exactly?
  - JumpCrisscross 2y ago
    > How would that work exactly? Light sails. Laser propulsion. Photon rockets. None of which apply to Voyager. But none of which are laughably dismissible.
- gpderetta 2y ago
  Even with something like an ion engine (which I'm not sure were available when Voyager was launched), you would need leftover reaction mass.
Dennip 2y ago
IIRC They have some type of nuclear power. Not like a reactor but something much simpler that generates heat from radioactive decay.
- robbiep 2y ago
  the flow of electrons to allow systems to work is not the same as the expulsion of gasses to provide thrust
- reacweb 2y ago
  https://xkcd.com/2115/ https://xkcd.com/2115/ The RTGs generated about 470 W of electric power at the time of launch. In 2023, it was 260W.
magicalhippo 2y ago
Not to downplay how impressive the Voyager probes are, but it seems they packed a fair bit of hydrazine. From "Engineering the Voyager Uranus mission": While it was not a design requirement, the option for an extended mission past Saturn was always protected, unless it meant compromising a major mission objective at Jupiter or Saturn. Even though the probability of Voyager 2 lasting another five years was calculated to be in the range of 60 to 70 percent -- well below NASA's usual acceptable probability-of-success threshold -- the decision was made to send Voyager on to Uranus. After its Uranus encounter, Voyager 2 still carried 48% of the hydrazine initially loaded into its tanks, eight-and-a-half years before. [1]: doi:10.1016/0094-5765(87)90096-8 (can be found on the hub of science)

It's been operating for 47 years and it still has fuel left to make attitude corrections. I wonder how they managed that feat.

by litoE 2y ago

It's been operating for 47 years and it still has fuel left to make attitude corrections. I wonder how they managed that feat.

turblety 2y ago

I presume solar power?

Tor3 2y ago
No, way too little sun out here. The sun is just a dot far away. The Voyagers both use RTGs, radioisotope thermoelectric generators. Decaying plutonium, essentially. That's for the electrically powered systems. The thrusters use liquid hydrazine, which is common for those kind of thrusters. Edit: There's more about that in the NASA link in a sibling comment.
krige 2y ago
Solar has nothing to do with it. Voyager uses hydrazine, of which over 80% has been used up over the years. They simply use not that much of it as it's not for thrust, but for aiming at Earth more or less.
meindnoch 2y ago
Lol. How would that work exactly?
- JumpCrisscross 2y ago
  > How would that work exactly? Light sails. Laser propulsion. Photon rockets. None of which apply to Voyager. But none of which are laughably dismissible.
gpderetta 2y ago
Even with something like an ion engine (which I'm not sure were available when Voyager was launched), you would need leftover reaction mass.

Dennip 2y ago

IIRC They have some type of nuclear power. Not like a reactor but something much simpler that generates heat from radioactive decay.

robbiep 2y ago
the flow of electrons to allow systems to work is not the same as the expulsion of gasses to provide thrust
reacweb 2y ago
https://xkcd.com/2115/ https://xkcd.com/2115/ The RTGs generated about 470 W of electric power at the time of launch. In 2023, it was 260W.

magicalhippo 2y ago

Not to downplay how impressive the Voyager probes are, but it seems they packed a fair bit of hydrazine. From "Engineering the Voyager Uranus mission": While it was not a design requirement, the option for an extended mission past Saturn was always protected, unless it meant compromising a major mission objective at Jupiter or Saturn. Even though the probability of Voyager 2 lasting another five years was calculated to be in the range of 60 to 70 percent -- well below NASA's usual acceptable probability-of-success threshold -- the decision was made to send Voyager on to Uranus. After its Uranus encounter, Voyager 2 still carried 48% of the hydrazine initially loaded into its tanks, eight-and-a-half years before. [1]: doi:10.1016/0094-5765(87)90096-8 (can be found on the hub of science)