We need so much more money for NASA.
this post was submitted on 16 May 2025
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Swap the NASA and the Pentagon budget!
This is how we get to Mars y'all xD
I'm of the opinion we can't safely travel to mars. Not in our lifetimes.
The earth has a nice magnetic field that protects us from background ionizing charged particles, and an atmosphere that catches most other radiation (X-ray, gamma).
The length of time it would take with modern rockets to get to mars exposes the crew to extreme radiation. They could survive it, but radiation over time kills you with cancer, if you survive any acute effects.
We could maybe make superconducting magnets strong enough to create a field to reduce the charged particles, but then you have to keep them powered, and still deal with the uncharged background radiation (mostly gamma/X-rays). You could create a giant cylinder of lead around the crew capsule, but that would take an extraordinary amount of time to build in orbit.
Not to mention once you are on mars, you have to maintain those protections too - the Mars atmosphere is too thin to be very helpful and it does not have a a magnetic core.
There has been a notable lack of progress in that realm, and it will likely remain the reason we don't see a human to mars program.
I think you may have missed the jibe. NASA's missions to the Moon were just as hazardous considering how little we knew at the time and we pulled it off. The pentagon's budget is more than a trillion dollars and with the know-how we have these days I don't think Mars is unattainable at all if those resources were at our disposal. They just won't be... I guess unless China decides to try and one up us to Mars first. All it takes is injured pride for some of these people.
No, going to the moon and back was a week long, and going just TO Mars is 9 months long at the closest point.
Your looking at least at a 10x-20x increase in radiation dose over the mission which would be around 1Sv to 2Sv. That's a very high lifetime dose in a short period of time.
And honestly, while it would be cool, there is little point of sending humans to Mars.
People really underestimate how unique and cool our planet is with all that's going on.
Now, sending robots, and bringing some stuff back for analysis... Why not? Way cheaper too.
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alas, public funding of actual technological wizardry steals eyeballs away from the social sideshow, so... *snip*
And science in general. Those NIH cuts are insane.
For anybody else curious;
Voyager 1 uses hydrazine (N₂H₄) as fuel for its small attitude control thrusters. Hydrazine is a hypergolic monopropellant, meaning it doesn't require an external oxidizer—it decomposes exothermically upon contact with a catalyst, producing gas to generate thrust.
The thrusters are not used for propulsion, but rather to rotate and stabilize the spacecraft so that its antenna remains pointed toward Earth and its instruments can be properly oriented. Fuel consumption is extremely low—only a few grams per year—and Voyager 1 still has some hydrazine left, although it's running low. Once the hydrazine is depleted, the spacecraft will no longer be able to control its orientation, which means communication with Earth will cease.
The Voyager spacecraft have no engines for linear acceleration; instead, they follow the trajectory and speed gained from gravity assists during planetary flybys in the solar system.
That's cool, but forget the thrusters, how is the battery pack on that thing still keeping it powered!?
Good news: I may have a solution to my heating problem. Bad news: it involves me digging up the radioisotope thermoelectric generator. Now, if I remember my training correctly, one of the lessons was titled: "Don't dig up the big box of plutonium, Mark." I get it; RTGs are good for spacecraft, but if they rupture around humans... no more humans, which is why we buried it when we arrived. And planted that flag so we would never be stupid enough to accidentally go near it again. But, as long as I don't break it... [trails off, then starts laughing] I almost just said "Everything will be fine," out loud. Look, the point is, I'm not cold anymore.
Fucking love this book. Funniest thing I've ever read, consistently, from cover to cover
If you haven't read it already, try the new book "Project Hail Mary" also by Andy Weir. I found it even more enthralling.
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Half life of the plutonium isotope they used is about 88 years.
The spacecraft uses radioisotope thermoelectric generators. It converts the heat generated by radioactive decay of plutonium into electricity. Engineers have been able to keep it working all this time by selectively powering down unused systems.
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It's in interstellar space now, right? Why does it need thrusters to reorient its antenna towards Earth instead of some combination of angular momentum matched to its velocity? Does it have to track Earth's exact position based off the day of the year or something?
I am not as educated on this as others but, my understanding is that earth is an unbelievably small target from that distance.
It needs thrusters, because there are still some small forces acting on the probe. For example, asymmetrical emission thermal radiation may rotate the probe slowly. This accelerated the Pioneer probes somewhat, see Pioneer anomaly. So without correction you can't keep the orientation for years. Every tiny force would accumulate over this timescale.
thank you!
Out of interest I did some estimates and it seems that an asymmetry of three billionth of the total thermal radiation would be enough to rotate the probe once over a timescale of 10 years. So if the radioisotope generator has even just a tiny bit of a different infrared brightness on one side, it would turn voyager in a few years.
notes on calculation
Voyager weight: 815 kg
Approximate Diameter: 1 m
Assume mass and thermal radiation emitted with a center distance of this diameter. Then we can calculate as it would need to move 2π 2 m. It should be enough as coarse estimate and underestimate the acceleration. Distance to move: d = 6.3 m
Assume constant acceleration due to thermal radiation
RTG power at start: 3 * 2.4 kW = 7.2kW
RTG power now: 7.2kW * 10^(48/88) = 4.9 kW
Total of thermal radiation: 4.9kW / c = 16 uN
distance moved: d = a t^2 / 2
assuming 10 years accelerated movement movement:
a = 63 mm/yr^2
F = 52 fN
3 * 10^-9 of thermal force
To piggy back off your thoughts, why don't we send another probe to act as a relay between voyager and earth?
The thing is, now we have one ~~1-2~~ 3.7 meter sized antenna on the voyager probes and a 100 meter sized antenna on earth with high transmission power. Signal decays with distance squared. To get the same signal power to the voyager probe assuming an relay in the middle, it would need an 25 meter antenna with the large transmitter/receiver currently on earth on space.
In short it's easier to build a 4 times better transmission system on earth than in an relay in space.
One point where relays are used are mars rovers. There the orbiter has an large antenna and is close to the rover, so you don't need to land the large antenna at the surface.
Edit: fixed antenna diameter
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i just did some napkin maths, and currently, it is approximately 1 light day away from us (23.148 hrs, no relativistic consideration). For perspective, our nearest star is 4.25 light years away, and that is roughly 302.319161 times further than voyager. with voyager speed, it will reach centauri (not actually heading towards it, but just for distance perspective) in about in roughly 14511.319728 years (actually less than this).
edit - messed up the calc a bit, 302... should have been 1608.346293 and 14511... shoul dhave been 77200.622084, explanation in replies - root of errors - typo
Umm akhchually the nearest star is just 8 light minutes away fixes glasses
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space is nuts.
Only a small portion of space is almonds, walnuts, and so on, less than half
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you may think it's a long way down the road to the chemist's
Space is an appropriate name. It's just a lot of space with some hydrogen and helium dispersed throughout.
The heavier elements we measure in stars are such a tiny % of matter they become negligible outside of stars.
And it's big. We have no human way to comprehend how big it is. I fucking love space.
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Explains why the universe is in a nutshell.
That doesn't make sense though. How'd you get to 302? 302 times farther should only be about 302 light days away. It should be 365x4.25=1,551.25 light days farther from us.
That bit of the napkin has a smudge.
sorry, i messed up calculation
= (25*(10^9)*1000/(3 * 10^8))/(3600)
23.148148
= (4.25*365)*24/123.148
302.319161
the 123.148 should have been 23.148, i somehow got a extra 1 in there, so that reduced final value by nearly 5 times, hence i got ~300 days instead of ~1500 days
sorry, then number of days should be 1608.346293 (24/23.... * 365*4.25), and total time to reach there is 77200.622084 years (it should be less than this)
I'm always amazed at the shit they do at NASA to keep Voyager 1 running.
Keep trucking little buddy!
I'm curious, do the same people who think that the moon landing was faked also believe that Voyager is fake? Because to me, Voyager is more impressive at this point.
Let's be honest, why would they believe it was real? Literally the only piece of evidence any of them might have even heard of from Voyager would be the Pale Blue Dot, and they would just say "wow, someone poked some holes in a blanket with some lens flare". All of the planet pictures can be explained away as artists' renditions.
ETA: Also, if you haven't seen it by now, I recommend watching the film "behind the curve" to understand the level of willful self-delusion in which this sort of person engages, all to feel like they belong and their perspicacity is recognized by their chosen in-group.
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We're so back.
This is about roll thrusters that permit orientation that allows communications/operation from earth. How many years of fuel does it have for roll thrusters, and does it share fuel with propulsion thrusters, and is there any thought of making it go faster instead of staying operationally controllable?
Voyager has no propulsion thrusters. It got its velocity from planetary fly-by's and that's it. It can only turn itself, it has no other thrusters.
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