NASA Turns Off 2 Voyager Science Instruments to Extend Mission | Hacker News Reader

NASA Turns Off 2 Voyager Science Instruments to Extend Mission

blogs.nasa.gov

74 pointssohkamyung28 comments

Was curious what the actual energy available for Voyager 1 & 2 actually is, so I went and looked. Ended up finding much greater amount than I actually planned to.

At 43.9151 years (September 5, 1977), Voyager 1 is now at 49.14% (last report) of what used to be a 471 watt power supply at start of mission.

At 43.5263 years (August 20, 1977), Voyager 2 is now at 49.09% (last report) of what used to be a 476 watt power supply at start of mission.

The data was found from a kind of humorous paper and dataset publication on the subject that actually covers every RTG that was ever launched and used to only be available on "The Graph."

The publication version of "The Graph": https://www.tandfonline.com/cms/asset/cdf5f3b7-d619-4b10-93b...

The full dataset has RTG data from: Transit 5BN-1, Transit 5BN-2, Nimbus III, Pioneer 10, Pioneer 11, Viking 1, Viking 2, Apollo 12, Apollo 14, Apollo 15, Apollo 16, Apollo 17, Triad-01-1X, LES 8, LES 9, Voyager 1, Voyager 2, Galileo, Ulysses (F-3), Cassini, New Horizons, Curiosity, and Perseverance

Paper: https://www.tandfonline.com/doi/full/10.1080/00295450.2024.2...

Dataset: https://datadryad.org/dataset/doi:10.5061/dryad.1zcrjdfw2

The authors request the following reference for the use: C.E. Whiting and D.F. Woerner, "Chapter 8: Lifetime Performance of Spaceborne RTGs," The Technology of Discovery: Radioisotope Thermoelectric Generators and Thermoelectric Technologies for Space Exploration, D.F. Woerner, Ed., John Wiley & Sons, 2023. ISBN: 9781119811367

For a second I thought it was a DOGE cut.

The Project 2025 Self Harm Trauma runs deep.

It it possible to send much faster voyagers these days that’d overtake them in a matter of years?

The original voyager was an experiment. The second one was to take advantage of a planetary alignment.

Fun story: The first voyager broke the imagination of mankind. The world was going to change immensely. The new incoming Republican administration was not happy by this rapid change. So they were not going to take a new voyager idea very well. The (political) scientists suggested that voyager 2 will "ONLY" investigate 2 planets instead of 4. Nixon went ahead with this reduced plan. A decade later the voyager 2 trajectory was updated to investigate 2 additional planets. YAY!

> The world was going to change immensely. The new incoming Republican administration was not happy by this rapid change.

Got any sources on this? It sounds crazy but these times have proven crazy is not as unlikely as we rthought.

Neil deGrasse Tyson - We Stopped Dreaming - https://youtu.be/CbIZU8cQWXc

Not so much "sources" but rather it was a "this was not the goal".

(Side bit - after watching "We Stopped Dreaming" I find it necessary to watch Wanderers to dream again. https://erikwernquist.com/wanderers )

I didn't hear a single mention of Nixon or of attempting to stifle "rapid change", just general stuff about government spending priorities. Got anything on the actual interesting part?

I'm not the one making the initial claim.

I do agree with Tyson in that the reasons for the space race were "we need to beat the Russians" and when the US won the space race, the political will to continue with the dreams / expectations that the wasn't there to continue with that level of spending.

I do not believe it was a "we are afraid of change, lets stop those things" but rather "we won, we don't need to spend on them despite the (opinion: positive) changes that they're bringing to the US (opinion: and the world)."

With the economic situations of the 70s and 80s, it was a pulling back of funding. Things that cost money without any tangible gain to tax payers.

https://en.wikipedia.org/wiki/Budget_of_NASA

In the 60s about 4% of the federal budget was NASA. That dropped in the 70s and continued to fall with the occasional bump.

https://www.macrotrends.net/global-metrics/countries/USA/uni... I believe had more casual relationship with NASA (and other 60s ideals) budget than the fear of "rapid change".

That part is a philosophical extraction. Dr. Roy Casagranda talks about it in detail. https://youtu.be/zjUKUCYtqxA?si=-

https://youtu.be/zjUKUCYtqxA

Try this video. From marker 7:40, the segment goes on for 7 minutes or so. The guy is a great story teller so it is pretty entertaining.

It is possible to catch up to them, but it's beyond our current political and economic abilities.

The Voyager probes took advantage of a rare planetary alignment to get up to speed. In order to catch up with them, we'd have to send a powered craft which would have to actively thrust for a long time.

Someone better than me will have to do the math, but I doubt that we currently have the ability to build or fuel such a craft.

It's definitely doable. The "'Momentum Limited' Orion" concept[0] has a delta-v of 10,000 km/s, which should be plenty enough to catch up to either of the Voyager probes. It can also carry ~25,000 tons of payload - that's a lot of spare parts!

[0] https://en.wikipedia.org/wiki/Project_Orion_(nuclear_propuls...

If you're okay with just a flyby of the Voyager probes though, then you can use a laser sail. Breakthrough Starshot[1] is aiming for 60,000 km/s of delta-v. Lightsails have already been demonstrated several times in practice[2].

[1] https://en.wikipedia.org/wiki/Breakthrough_Starshot [2] https://en.wikipedia.org/wiki/Solar_sail#Projects_operating_...

> Lightsails have already been demonstrated several times in practice

Solar sails, yes. Starshot needs a Death Star Laser that makes the NIF look like a cat toy.

It's tough but doable; Parker Space Probe will reach 192 km/s and it'd take about 47 km/s to overtake Voyager 2 in 2 decades. A lot of gravity assists would be needed.

Great free (PBS!) documentary on Voyager, also discusses the planetary alignment piece.

https://www.pbs.org/video/the-farthest-voyager-in-space-qpbu...

We should be working on our Gliese 710 intercept mission.

https://www.reddit.com/r/IsaacArthur/comments/z236b2/in_129_...

https://en.wikipedia.org/wiki/Gliese_710

> In 1.29 million years, Gliese 710 will pass by the sun at about 2 light months.

That is a long time to prep. If I did my math right, Voyager 1 can already reach a 2 light month distance in some 3000 years with its current speed. It sounds like we can reconvene to discuss this in a million years.

    lightmonth=lightyear/365.25×30
    = 777062051136000 meter

    voyager1=16.9 ×1000meter / second
    = 16900 meter⋅second⁻¹

    (2×lightmonth)/voyager1 in year_julian
    = 2914.03674714165947778331 year_julian

Depends on how much mass we want to get there. It could be our chance to be a two star species.

I can guarantee any humans we ship out in the near future won't survive a million-year wait for it to come close...

I was thinking of something more along the lines of a large set of Obelisks.

What calculator is that?

https://heldercorreia.bitbucket.io/speedcrunch/

> in a matter of years?

I you're thinking 4 years, then I doubt a $1T budget could do it.

If you're thinking 80 years, then sure. But still pretty expensive - so why not spend the $$$ on something else?

There's a whole lot of nothing out there. Why rush to get a closer look at nothing?

https://en.wikipedia.org/wiki/FOCAL_(spacecraft)

> FOCAL (an acronym for Fast Outgoing Cyclopean Astronomical Lens) is a proposed space telescope that would use the Sun as a gravity lens.

> ...

> In order to use the Sun as a gravity lens, it would be necessary to send the telescope to a minimum distance of 550 astronomical units away from the Sun, enabling very high signal amplifications: for example, at the 203 GHz wavelength, amplification of 1.3 x 10e15. Maccone suggests that this should be enough to obtain detailed images of the surfaces of extrasolar planets.

> ...

> FOCAL does not require any non-existing technology; however, it has various limitations. A space mission of this duration and distance has never been attempted; for comparison, the Voyager 1 and Voyager 2 probes are at distances of 147 AU and 122 AU in 2019.

While it's beyond our current engineering, its not impractically more. It's a program that would span generations between launch and data collection.

New Horizons is the ~~fastest moving outbound craft~~ launched space craft.. though this also gets to direction of travel. There are faster ones - the Parker Solar Probe did 690,000 km/h on closest approach to the sun - that's 0.064 c... but for outbound, you've got the Pioneer 10 and 11 (Voyager 2 overtook Pioneer 10 on July 18, 2023), Voyager 1 and 2, and New Horizons.

Voyager 1 is 16.9 kps.

Voyager 2 is 15.3 kps.

New Horizons is 13.6 kps

https://www.wolframalpha.com/input?i=%28Voyager+1%2C+Voyager...

Related https://what-if.xkcd.com/38/

> New Horizons, the spacecraft currently headed out of the Solar System by way of Pluto, is never going to catch up to Voyager—it’s not moving fast enough and it’s headed in the wrong direction. But it could have.

The other problem is that Voyagers were on the Grand Tour. https://en.wikipedia.org/wiki/Grand_Tour_program This allowed them to get multiple gravity assists.

Voyager 1 is 2.5e10 km away. Lets pretend that we can launch now and get an outbound velocity twice of New Horizons...

> On January 19, 2006, New Horizons was launched from Cape Canaveral Air Force Station by an Atlas V rocket directly into an Earth-and-solar escape trajectory with a speed of about 16.26 km/s (10.10 mi/s; 58,500 km/h; 36,400 mph). It was the fastest (average speed with respect to Earth) human-made object ever launched from Earth.

So let's do 32 kps. That's 24 years to get to where it is now. At that time, Voyager 1 will be another 13 billion km further away.

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Ultimately, the problem is that we can't send faster Voyagers because the voyager program used a once in 175 year planetary alignment to go fast.

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