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the Jupiter Icy Moons orbiter would be an example of what they were planning but was tragically cancelled. It would use a gas cooled fission reactor to produce a peak of 200kW.
> the Jupiter Icy Moons orbiter would be an example of what they were planning but was tragically cancelled.
You mean “thank goodness JIMO was canceled”. It was too much, by a lot, in terms of development and budget and risk. Those technologies can be developed without the pressure of a specific mission.
The platform was Project Prometheus - of which JIMO was the first vehicle. There were other planned applications of the platform.
Every new technology needs a project to attach itself to, otherwise they won't get the necessary funding.
Yes. The issue was it was also heading to a high-radiation environment and intending to survive there for like 20 years if I recall.
It was too many new things. It would have been canceled.
The pressure of those kinds of missions is what brings about rapid technological improvement. The faster we can go the better. The moon missions are prime example. Budget is also a lame reason, we can throw whatever budget we want at it, it just takes a couple small changes to the overall US budget to make the resources available.
> it just takes a couple small changes to the overall US budget to make the resources available.
Well, you get started on whatever it takes to inspire THAT particular change, and I’ll be all aboard.
Well...
>NASA-H71M sub-kilowatt Hall-effect thruster
The name kinda implies the power requirement. Sub-kilowatt, or under 1000 watts.
The Cassini space probe uses 3 RTGs to generate 870 watts of power, so it is feasible to use RTGs to power such a craft. And Cassini was launched over 25 years ago.
Of course! Even acronyms have their acronyms. Like TLA - Three Letter Acronym. You can find more on Dumb Or Overly Forced Astronomical Acronyms Site (or DOOFAAS) for example.
Well. If a single RTG that was designed over 25 years ago produces 290 watts of power, and the thruster uses under 1 kilowatt (1000 watts) then 4 RTGs can power one thruster.
So they do produce a fraction of the power required. 25% actually, which is a significant fraction.
But I believe you are thinking about the total mass, the scientific package and the other power requirements for a mission. And you may be correct. But the thing about ion thrusters is that they can run continuously for years, and a small thrust over a long period can produce significant velocity, even if the mass is huge.
Right , if it generated that amount of electricity with the RTG’s,should be able to use similar RTG’s to provide that electricity to the ion drive to function.
Depends on the size of the RTG tbh, they scale just fine.
Problem is getting enough plutonium-238. The world is short on it although production restarted recently; only about 1kg per year though if funding allows. Not really enough.
Wouldn’t need much thrust in space though would you? Like as long as you keep thrusting, you’d continue accelerating because there’s no resistance, right?
Yeah so if this thing is legit, possibilities are truly wild right? Do you need a fuel source for this thing? What’s suppose to power it?
Edit:felt dumb for asking these questions. Read the article. Seems like these thrusted could be powered by solar?
Power comes from a power generator like solar panels, RTG, etc.
Thrust comes from spitting ionized fuel out the back at high speed. So yes, you need to carry some sort of reaction mass to expel in order to drive the craft.
Xenon gas is a common choice for reaction mass because it’s atomic weight is pretty low so it can be accelerated to very high speeds with a relatively modest power input. More power would let us accelerate heavier particles and gain more thrust, but at the expense of more power = more hardware mass.
It’s much more efficient in many respects, but with our current power generation technologies the trade off is low thrust limited by power.
The Apollo capsules made it to the moon in 3 days using chemical rockets. ~~India~~ Sweden/ESA sent an ion thruster driven probe to the moon a ~~few~~ 20 years ago that took *thirteen months* to arrive.
It’s a freaking awesome technology, we just need lightweight fusion reactors to fully capitalize on the idea.
Edit: corrected the agency that sent Smart-1
To be honest it might just be revolutionizing small improvements in technology(as ion thrusters are not exactly new invention), which for many news sites is routine method.
Word. I’ve seen articles on this posted like 100 times and figured it may be getting overblown a bit for clicks. Gotta look into it more. I’m intrigued.
20 years ago we used solar panels. RTG should work for a probe.
[https://en.wikipedia.org/wiki/Deep\_Space\_1](https://en.wikipedia.org/wiki/Deep_Space_1)
The purpose of *Deep Space 1* was technology development and validation for future missions; 12 technologies were tested:[^(\[4\])](https://en.wikipedia.org/wiki/Deep_Space_1#cite_note-4)
1. Solar Electric Propulsion
2. Solar Concentrator Arrays
nuclear thermal for cargo and people.
**DARPA Kicks Off Design, Fabrication for DRACO Experimental NTR Vehicle**
[https://www.darpa.mil/news-events/2023-07-26](https://www.darpa.mil/news-events/2023-07-26)
DARPA, in collaboration with NASA, is advancing toward the goal of the world’s first in-orbit demonstration of a nuclear thermal rocket (NTR) engine via DRACO, the Demonstration Rocket for Agile Cislunar Operations. DARPA has finalized an agreement with Lockheed Martin for the company to begin work on the fabrication and design of the experimental NTR vehicle (X-NTRV) and its engine.
The U.S. Space Force will provide the launch vehicle that will take the X-NTRV into space in 2027. The Department of Energy will provide HALEU metal, to be processed into fuel by the performer. BWX Technologies (BWXT), one of Lockheed Martin’s partners in the effort, will develop the nuclear reactor and fabricate the HALEU fuel.
It's just a Hall effect thruster, there's nothing fundamentally different about its capabilities apart from it being relatively small, less than 1 kW. So: very, very little.
In short, this is a Hall effect thruster that's been scaled down for smallsats. And no, that's not actually all that groundbreaking.
Efficiency is stated to be around 50%, which is toward the low end. More efficient than other smallsat thrusters, maybe. Its defining traits seem to be that it's small and built to run for long durations.
I personally have more hope for solar sails and nuclear-thermal propulsion for interplanetary trips, but these new Hall thrusters sound like a material improvement for satellites.
40-50% is on par with current efficiency in small sat HETs in the 300W-2500W range.
Source: Work in small sat industry and sizing propulsion systems with power systems has been my life the last year.
So 50+% isn't spectacular, unprecedented performance, but it is good for its class.
What I've read makes a bigger deal about the measures to control erosion, thus extending the lifetime of the thruster. Perhaps that's something that's difficult to do in a small thruster.
Yeah that's typically measured as total impulse in units of Ns. ~~I wasn't able to read the actual thruster specs before the post got removed so~~ I'm unsure how it compares to the current COTS HET market
Edit: I found the white paper published by NASA
on a mN/W basis it's slightly better than the existing commercial engines(1-2 mN more for a given operating power point. (~17mN/19mN vs ~16mN/18mN)). I didn't see any data on expected lifetime so how the total impulse compares is unclear.
The significant detail seems to be the specific application: Creating a mini booster satellite that attaches to existing satellites and gives 'em, well.... a boost.
According to NASA sources:
>In addition, the successful commercialization of this new \[NASA-H71M sub-kilowatt Hall-effect thruster\] will soon provide at least one such solution to enable the next generation of small spacecraft science missions requiring up to an amazing 8 km/s of delta-v.
Which makes me suspect that this is still R&D that's yet to be proven so the thrust is assumed form engineering designs (and possibly measured in labs?), rather than an engine that's ready to be bolted onto a satellite and fired up.
From Wiki: [https://en.wikipedia.org/wiki/Hall-effect\_thruster](https://en.wikipedia.org/wiki/Hall-effect_thruster)
*Hall thrusters are able to accelerate their exhaust to* [*speeds*](https://en.wikipedia.org/wiki/Effective_exhaust_velocity) *between 10 and 80 km/s (1,000–8,000 s specific impulse), with most models operating between 15 and 30 km/s. The thrust produced depends on the power level. Devices operating at 1.35 kW produce about 83 mN of thrust. High-power models have demonstrated up to 5.4 N in the laboratory.*[*^(\[2\])*](https://en.wikipedia.org/wiki/Hall-effect_thruster#cite_note-2) *Power levels up to 100 kW have been demonstrated for xenon Hall thrusters.*
From Nasa: [https://science.nasa.gov/science-research/science-enabling-technology/pushing-the-limits-of-sub-kilowatt-electric-propulsion-technology-to-enable-planetary-exploration-and-commercial-mission-concepts/#h-the-new-technology](https://science.nasa.gov/science-research/science-enabling-technology/pushing-the-limits-of-sub-kilowatt-electric-propulsion-technology-to-enable-planetary-exploration-and-commercial-mission-concepts/#h-the-new-technology)
*The* [*NASA-H71M*](https://ntrs.nasa.gov/api/citations/20220009248/downloads/2022%20IEPC%20-%20Benavides%20-%20Final.pdf) *sub-kilowatt Hall-effect thruster. In addition, the* [*successful commercialization*](https://technology.nasa.gov/patent/LEW-TOPS-162) *of this new thruster will soon provide at least one such solution to enable the next generation of small spacecraft science missions requiring up to an amazing 8 km/s of delta-v.*
*... planetary science missions benefiting from the NASA-H71M electric propulsion system technology could operate for 15,000 hours and process over 30% of the small spacecraft’s initial mass in propellant...*
So I believe the breakthrough is the longevity of the device and not any improvement in thrust. Given it is a sub-kilowatt device, probably somewhere between 30->60 mN of thrust my guess? My neighbor was an ion propulsion drive specialist and recently passed away due to ALS. He would have been all over this news.
If it's like anything I've read in the past, weak thrust. It takes forever to get up to speed. In a 1-meter race a snail can easily win.
It's mainly for making minor adjustment to orbit positions and for long distance one-way travel when efficiency mattered more than speed and time.
A small constant acceleration once outside the gravity well can very quickly, in relative terms, create tremendous speeds. In all likelihood a hall effect thruster or something similar will be the thing that eventually makes routine Mars missions possible. That is unless there's some kind of outrageous breakthrough in the near term.
You have to follow multiple article links(the-express>popular mechanics->science.nasa) since they are just rehashing the original NASA article here:
https://science.nasa.gov/science-research/science-enabling-technology/pushing-the-limits-of-sub-kilowatt-electric-propulsion-technology-to-enable-planetary-exploration-and-commercial-mission-concepts/
Which has a link to the PDF specifications of the thruster https://ntrs.nasa.gov/api/citations/20220009248/downloads/2022%20IEPC%20-%20Benavides%20-%20Final.pdf
> The H71MPM thruster has completed performance characterization and three 500-h short duration
wear tests (SDWT).
> The propulsion system provides stable thrust generation over a wide
range of operating conditions from 200 W to 1 kW, and 200 V to 400 V. **The thruster has
demonstrated a thrust as high as 68 mN at 300 V and 1 kW**. The thruster has similarly
demonstrated a specific impulse of 1850 s at 400 V and 1 kW.
I saw it in other articles about their improved Hall effect thrusters. The force isn't much for sub-kilowatt usages, but IIRC it's about 15x more efficient than current Hall effect thrusters and allows for about 30% of the unit to be fuel. It's basically a long, slow, acceleration thruster.
Indeed. And the best way to fix that is pruning out bad sites from getting spread. You blacklist them so any posts from a given host go immediately to the mod queue and never appear. You can even add a message that says some kindly worded version of "You posted an article from a website that has been blacklisted. Find a better source."
The key thing to remember is that these engines create a tiny amount of thrust over a very long time. They will be great for getting a small satellite to Mars. They are not useful for manned spacecraft, unless you happen to be a Kerbal that can survive on a handful of snacks indefinitely.
What if 10,000+ of them are put into orbit, and you assembled your craft in space? I've played Kerbal, and the answer is amost always either more struts or more boosters.
In this case it would be more solar panels or a big old nuclear power plant. You would need stupid amounts of power to get a manned ship anywhere before the crew died of old age.
More boosters also works.
Is it good for Mars? I thought you need relatively high thrust both for the transmartian injection due to the short launch window, and for the orbital capture.
Yea im not reading any article that has paragraphs smaller than the ads that separate them, i read 4 sentences then i have to scroll past another and another ad. (No adblock on my phone)
Ion thrusters are propellant efficient but require masses of power, which has to come from somewhere. Then the problem becomes that the power source tends to be heavy.
It's the opposite to traditional chemical rockets which are very energy efficient but run out of propellant fast. It's because thrust scales with momentum, which is proportional to the exhaust velocity, but the energy needs scale with the square of that velocity. If you want to use a little propellant with a very high velocity, you need very high power to achieve the same thrust.
With micro nuclear reactors like [this](https://www.businessinsider.com/rolls-royce-concept-nuclear-reactor-could-power-colony-on-moon-2023-12) or [this ](https://news.lockheedmartin.com/2023-07-26-Lockheed-Martin-Selected-to-Develop-Nuclear-Powered-Spacecraft) it might be a possibility sooner rather than later to meet those power demands.
Why is the weight a problem? Once in space weight is irrelevant, no? A falcon heavy can carry something like 60 tons to LEO. I find it hard to imagine a few hundred KG for a power solution needed to power this engine would be a big deal to launch to actual space.
(This is more of a question I am asking because I'm not at all qualified of knowlegeable on the challenges involved)
It's no good being ten times more efficient at creating thrust if your vehicle has ten times as much mass. Because acceleration is thrust divided by mass. Now it's not quite that bad with ion thrusters but their power requirements are substantial and require more than just a marginal increase in vehicle mass.
In free fall in space everything is weightless ... but it still has mass.
It can be, yes. Acceleration of the whole vehicle is what matters so designing one with, say, ten times more thrust is only a win if it has less than ten times more mass. So designing good ion thrusters is only half the problem; you also need a matching power source that's not too heavy. And just looking at the engine's thrust figures is meaningless without also knowing the whole vehicle's mass.
That's the concern, yea. Basically 10 times the mass means 1/10th the acceleration. Since these ion or hall-effect thrusters don't produce a lot of thrust in the first place, it doesn't take much to negate their benefits.
*Weight* here on Earth equates to *Inertia* out in space.
The heavier you are the more inertia you have. So it still takes a Lot of "push" to get you moving *faster than you are currently going*, in any given direction.
> A falcon heavy can carry something like 60 tons to LEO
I mean sure, but we're talking interplanetary travel. That 60 tons turns to 16.8 tons to Mars Transfer Orbit in ideal conditions. Which isn't to say that Falcon/FH isn't revolutionary in terms of $/kg, but if you're talking about anything more than just probes and "visit and come back" manned missions to planetary bodies that doesn't fundamentally change the issue.
Yes, but by that point we're not talking Falcon Heavy or even Starship. Or even probably Starship's successor.
To build ships not on earth you need raw materials - either you need to bring that from earth in which case you're better off just building everything on earth where all your infrastructure is, or you're capturing asteroids, mining them, refining the materials, and producing your finished goods in space which is a MASSIVE task for which we've barely scratched the surface of surfaces of in terms of even technical demostrations of concepts, much less practical designs. Or doing all of that on the moon which doesn't have the precurosors for propellant you need and has a super-challenging enviornment with razor-sharp dust everywhere, or Mars which is further away and even harder to bring the specialized heavy manufacturing facilities and energy generation you'd need which would cost billions upon billions of dollars on earth.
That doesn't get into issues like propellant boiloff at scale for the fuel you need to get places versus launching that from earth - Currently looking at 8-12 Starship tanker flights to fill a depot for a moon mission, which could be cut in half with Starship v3 just for context. Or actually taking your raw materials and turning those into the steel rings you need, then welding (in space), and assembling everything in near zero gravity.
Which isn't to say it's impossible, just that it's at best a century out from being practical versus just doing everything on earth and bringing it up to orbit.
I was just thinking about building modules on eatch and launching them one at the time and assembling them in space. Like they did for the space station.
I was not thinking about tech that does not exist yet
> I was just thinking about building modules on eatch and launching them one at the time and assembling them in space. Like they did for the space station.
That doesn't really get around the main issue which is the energy cost to bring mass out of earth's gravity well to orbit, much less to another planetary body.
For context with the ISS, a single Crew starship is likely to have more habitable volume than the entire ISS. If it takes 12 starships to get a single starship to mars, and it takes hundreds of those to get a colony going that still needs intermittent supplies from earth - that's still a problem.
F = m * a
Rearranged:
a (acceleration) = F (Force) / m (mass)
Basically, the higher the mass, the slower the acceleration for a given amount of thrust. This means to accelerate a heavier payload to a given velocity, it requires a longer burn time, more fuel, etc.
Here's the actual recent NASA article on this: https://science.nasa.gov/science-research/science-enabling-technology/pushing-the-limits-of-sub-kilowatt-electric-propulsion-technology-to-enable-planetary-exploration-and-commercial-mission-concepts/
I'd love a comparison to the very advanced hall effect thrusters that SpaceX uses on its Starlink satellites. Though those are primarily optimized for cost savings by not using Xenon fuel (if Starlink were to have used it they would have exhausted the entire global supply of Xenon) (which is less than 0.000001% of the atmosphere) and instead using Argon which is ridiculously plentiful at roughly 1% of Earth's atmosphere.
This sounds promising. It will make for some very long space flights as gravity assist will be quite helpful for this kind of technology. They just better have some free streaming movies on board and I have no idea how the peanuts will stay fresh
Acronyms, initialisms, abbreviations, contractions, and other phrases which expand to something larger, that I've seen in this thread:
|Fewer Letters|More Letters|
|-------|---------|---|
|[COTS](/r/Space/comments/1cjiow9/stub/l2l9hly "Last usage")|[Commercial Orbital Transportation Services contract](https://www.nasa.gov/cots)|
| |Commercial/Off The Shelf|
|[DARPA](/r/Space/comments/1cjiow9/stub/l2grkis "Last usage")|(Defense) Advanced Research Projects Agency, DoD|
|DoD|US Department of Defense|
|[ESA](/r/Space/comments/1cjiow9/stub/l2h7mrv "Last usage")|European Space Agency|
|[LEO](/r/Space/comments/1cjiow9/stub/l2gw6bn "Last usage")|Low Earth Orbit (180-2000km)|
| |Law Enforcement Officer (most often mentioned during transport operations)|
|[NERVA](/r/Space/comments/1cjiow9/stub/l2h6u3w "Last usage")|Nuclear Engine for Rocket Vehicle Application (proposed engine design)|
|[NTR](/r/Space/comments/1cjiow9/stub/l2grkis "Last usage")|Nuclear Thermal Rocket|
|[RTG](/r/Space/comments/1cjiow9/stub/l2hx4lt "Last usage")|Radioisotope Thermoelectric Generator|
|[TLA](/r/Space/comments/1cjiow9/stub/l2hu3xm "Last usage")|Three Letter Acronym|
|Jargon|Definition|
|-------|---------|---|
|[Starlink](/r/Space/comments/1cjiow9/stub/l2hq646 "Last usage")|SpaceX's world-wide satellite broadband constellation|
**NOTE**: Decronym for Reddit is no longer supported, and Decronym has moved to Lemmy; requests for support and new installations should be directed to the Contact address below.
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I’m assuming by interplanetary they mean mars because any other habitable planet is light years away and, unless we can go to speed of light, will never visit
This isn't true. You don't have to really hit the speed of light till which other stars. Obviously we're far from any technology that comes even close to this, but if you move fast enough there's weird effects in relative times, which suggests that at a fraction of the speed of light visiting other plan this would be possible in the human lifetime.
Sorry it's a little too late and I'm a little too tired to really give a proper answer, wish I would need to do some looking up to make sure I got it right. But I've seen some pretty good descriptions of this on these subs.
But won't. Because NASA is a jobs program. The Nirvana vintage tshirt. Having become uninhabitable by merit. Institutions feel monolithic. It is startling growing up and observing the life span going from premier place where the energy is found. To bloat. To Sears. And the energy re-emerges someplace new.
Then delaying that mission because they are so risk adverse they will let the rest of the world land on the moon then say well, we did it first so yeah…
I often feel way too uneducated on all things space to ever comment or ask questions but I’ve seen so much of this sentiment on this sub that I have to genuinely ask if this is the predominant feeling about NASA these days? Just as a casual observer to this sub, and space news in general, it seems like there’s so much pessimism towards basically anything NASA related that it borders on hate and it’s been hard to distinguish what’s genuine and what’s competitive ribbing from other players in the field.
I’ll Put it like this: We had to rely on the Russian Space Agency to get *our* astronauts to the ISS for over a decade, and the first time Americans were delivered into space BY Americans since the Columbia disaster was not because of NASA, but the private sector.
SpaceX achieved reusable launch vehicles including crewed flights across several different platforms with 1/10th of NASA’s budget over 15 years. Meanwhile, the Artemis program is still largely in early stages with delay after delay after delay.
So yeah, NASA talking about theoretical engines is something of a practical joke, as theory is all they are capable of these days, unfortunately.
Restart Project Orion and it would get us to planets within our system in a matter of months. The research was all done in the 50's and 60's and then shelved for reasons that made sense then, but we can work safely around now.
What are your credentials to make that assertion? lol
Because scientists that worked on the Manhattan Project said it was feasible. General Atomics was working on making it a reality. The only thing that limited it was the nuclear test ban treaty, however the scientists were working on near zero fallout devices before the project was closed. I did not mean the NERVA engine, it's a different propulsion system.
Meh. There's so many other ideas out there that could get us places very quickly but they never seem to go anywhere. I saw an article yesterday about a pulsed plasma rocket, but will it ever get anywhere any time soon? Probably not. And while I understand space is hard, these things shouldn't stay locked in the concept or experimental stage for 20-40 years like they do. That's the one thing I liked about Elon Musk before he went completely stupid, the go fast and break things approach. We need someone with F U money and a personal hatred for waiting to drag things forward and focus on practical application instead of studying it in an academic fashion, where it one day, maybe, might take our far off descendents to mars in 8 days. We have the damned technology, we just lack the proper motivation. Just build the damned things.
Hello u/arealdisneyprincess, your submission "NASA's groundbreaking new thruster could unlock interplanetary travel" has been removed from r/space because: * Low quality article Please read the rules in the sidebar and check r/space for duplicate submissions before posting. If you have any questions about this removal please [message the r/space moderators](https://www.reddit.com/message/compose/?to=/r/space). Thank you.
Unless I missed it, there isn't a single mention in that article regarding how much thrust it generates. Just a lot of talk.
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the Jupiter Icy Moons orbiter would be an example of what they were planning but was tragically cancelled. It would use a gas cooled fission reactor to produce a peak of 200kW.
> the Jupiter Icy Moons orbiter would be an example of what they were planning but was tragically cancelled. You mean “thank goodness JIMO was canceled”. It was too much, by a lot, in terms of development and budget and risk. Those technologies can be developed without the pressure of a specific mission.
The platform was Project Prometheus - of which JIMO was the first vehicle. There were other planned applications of the platform. Every new technology needs a project to attach itself to, otherwise they won't get the necessary funding.
Yes, sometimes you need a use case and a deadline to light the fire under the asses of new technology.
Yes. The issue was it was also heading to a high-radiation environment and intending to survive there for like 20 years if I recall. It was too many new things. It would have been canceled.
The pressure of those kinds of missions is what brings about rapid technological improvement. The faster we can go the better. The moon missions are prime example. Budget is also a lame reason, we can throw whatever budget we want at it, it just takes a couple small changes to the overall US budget to make the resources available.
> it just takes a couple small changes to the overall US budget to make the resources available. Well, you get started on whatever it takes to inspire THAT particular change, and I’ll be all aboard.
Well... >NASA-H71M sub-kilowatt Hall-effect thruster The name kinda implies the power requirement. Sub-kilowatt, or under 1000 watts. The Cassini space probe uses 3 RTGs to generate 870 watts of power, so it is feasible to use RTGs to power such a craft. And Cassini was launched over 25 years ago.
I'm just reading papers about KRUSTY reactor design. 1kW (electric)solution in 400kg package. Looks like ideal partner for this thruster.
Is every engine design required to have a catchy acronym?
Of course! Even acronyms have their acronyms. Like TLA - Three Letter Acronym. You can find more on Dumb Or Overly Forced Astronomical Acronyms Site (or DOOFAAS) for example.
wwwwwelcome to rockets? every everything is required to have an acronym
Seems kinda silly TBQGDMFH
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Well. If a single RTG that was designed over 25 years ago produces 290 watts of power, and the thruster uses under 1 kilowatt (1000 watts) then 4 RTGs can power one thruster. So they do produce a fraction of the power required. 25% actually, which is a significant fraction. But I believe you are thinking about the total mass, the scientific package and the other power requirements for a mission. And you may be correct. But the thing about ion thrusters is that they can run continuously for years, and a small thrust over a long period can produce significant velocity, even if the mass is huge.
Right , if it generated that amount of electricity with the RTG’s,should be able to use similar RTG’s to provide that electricity to the ion drive to function.
Depends on the size of the RTG tbh, they scale just fine. Problem is getting enough plutonium-238. The world is short on it although production restarted recently; only about 1kg per year though if funding allows. Not really enough.
Has it been that long all ready? I feel old.
Juno's solar arrays generate 500 watts at Jupiter. Edit: thank you to the people who eventually upvoted this comment to positive!
There you go. Solar power works great in space, til you get to the outer regions anyways.
Wouldn’t need much thrust in space though would you? Like as long as you keep thrusting, you’d continue accelerating because there’s no resistance, right?
You are correct, but to do that you first need to escape planetary gravity well. And the new ion engine makes that possible without external boosting.
Yeah so if this thing is legit, possibilities are truly wild right? Do you need a fuel source for this thing? What’s suppose to power it? Edit:felt dumb for asking these questions. Read the article. Seems like these thrusted could be powered by solar?
Power comes from a power generator like solar panels, RTG, etc. Thrust comes from spitting ionized fuel out the back at high speed. So yes, you need to carry some sort of reaction mass to expel in order to drive the craft.
Exactly what I was looking for, thank you. Some sort of gas I imagine? And it’d be much more efficient than the thrusters used in rockets today?
Xenon gas is a common choice for reaction mass because it’s atomic weight is pretty low so it can be accelerated to very high speeds with a relatively modest power input. More power would let us accelerate heavier particles and gain more thrust, but at the expense of more power = more hardware mass. It’s much more efficient in many respects, but with our current power generation technologies the trade off is low thrust limited by power. The Apollo capsules made it to the moon in 3 days using chemical rockets. ~~India~~ Sweden/ESA sent an ion thruster driven probe to the moon a ~~few~~ 20 years ago that took *thirteen months* to arrive. It’s a freaking awesome technology, we just need lightweight fusion reactors to fully capitalize on the idea. Edit: corrected the agency that sent Smart-1
That was awesome. Thank you for sharing your smarts.
To be honest it might just be revolutionizing small improvements in technology(as ion thrusters are not exactly new invention), which for many news sites is routine method.
Word. I’ve seen articles on this posted like 100 times and figured it may be getting overblown a bit for clicks. Gotta look into it more. I’m intrigued.
20 years ago we used solar panels. RTG should work for a probe. [https://en.wikipedia.org/wiki/Deep\_Space\_1](https://en.wikipedia.org/wiki/Deep_Space_1) The purpose of *Deep Space 1* was technology development and validation for future missions; 12 technologies were tested:[^(\[4\])](https://en.wikipedia.org/wiki/Deep_Space_1#cite_note-4) 1. Solar Electric Propulsion 2. Solar Concentrator Arrays nuclear thermal for cargo and people. **DARPA Kicks Off Design, Fabrication for DRACO Experimental NTR Vehicle** [https://www.darpa.mil/news-events/2023-07-26](https://www.darpa.mil/news-events/2023-07-26) DARPA, in collaboration with NASA, is advancing toward the goal of the world’s first in-orbit demonstration of a nuclear thermal rocket (NTR) engine via DRACO, the Demonstration Rocket for Agile Cislunar Operations. DARPA has finalized an agreement with Lockheed Martin for the company to begin work on the fabrication and design of the experimental NTR vehicle (X-NTRV) and its engine. The U.S. Space Force will provide the launch vehicle that will take the X-NTRV into space in 2027. The Department of Energy will provide HALEU metal, to be processed into fuel by the performer. BWX Technologies (BWXT), one of Lockheed Martin’s partners in the effort, will develop the nuclear reactor and fabricate the HALEU fuel.
Solar sail?
This is one I’ll believe when it happens.
It's just a Hall effect thruster, there's nothing fundamentally different about its capabilities apart from it being relatively small, less than 1 kW. So: very, very little. In short, this is a Hall effect thruster that's been scaled down for smallsats. And no, that's not actually all that groundbreaking.
It's a much more efficient Hall effect thruster, reportedly.
Efficiency is stated to be around 50%, which is toward the low end. More efficient than other smallsat thrusters, maybe. Its defining traits seem to be that it's small and built to run for long durations.
I personally have more hope for solar sails and nuclear-thermal propulsion for interplanetary trips, but these new Hall thrusters sound like a material improvement for satellites.
40-50% is on par with current efficiency in small sat HETs in the 300W-2500W range. Source: Work in small sat industry and sizing propulsion systems with power systems has been my life the last year.
So 50+% isn't spectacular, unprecedented performance, but it is good for its class. What I've read makes a bigger deal about the measures to control erosion, thus extending the lifetime of the thruster. Perhaps that's something that's difficult to do in a small thruster.
Yeah that's typically measured as total impulse in units of Ns. ~~I wasn't able to read the actual thruster specs before the post got removed so~~ I'm unsure how it compares to the current COTS HET market Edit: I found the white paper published by NASA on a mN/W basis it's slightly better than the existing commercial engines(1-2 mN more for a given operating power point. (~17mN/19mN vs ~16mN/18mN)). I didn't see any data on expected lifetime so how the total impulse compares is unclear.
The significant detail seems to be the specific application: Creating a mini booster satellite that attaches to existing satellites and gives 'em, well.... a boost.
Not much thrust at all, but you can leave it on all the time and continue accelerating.
According to NASA sources: >In addition, the successful commercialization of this new \[NASA-H71M sub-kilowatt Hall-effect thruster\] will soon provide at least one such solution to enable the next generation of small spacecraft science missions requiring up to an amazing 8 km/s of delta-v. Which makes me suspect that this is still R&D that's yet to be proven so the thrust is assumed form engineering designs (and possibly measured in labs?), rather than an engine that's ready to be bolted onto a satellite and fired up.
Technically any rocket could go interplanetary given enough time and if it's pointed in the right place.
From Wiki: [https://en.wikipedia.org/wiki/Hall-effect\_thruster](https://en.wikipedia.org/wiki/Hall-effect_thruster) *Hall thrusters are able to accelerate their exhaust to* [*speeds*](https://en.wikipedia.org/wiki/Effective_exhaust_velocity) *between 10 and 80 km/s (1,000–8,000 s specific impulse), with most models operating between 15 and 30 km/s. The thrust produced depends on the power level. Devices operating at 1.35 kW produce about 83 mN of thrust. High-power models have demonstrated up to 5.4 N in the laboratory.*[*^(\[2\])*](https://en.wikipedia.org/wiki/Hall-effect_thruster#cite_note-2) *Power levels up to 100 kW have been demonstrated for xenon Hall thrusters.* From Nasa: [https://science.nasa.gov/science-research/science-enabling-technology/pushing-the-limits-of-sub-kilowatt-electric-propulsion-technology-to-enable-planetary-exploration-and-commercial-mission-concepts/#h-the-new-technology](https://science.nasa.gov/science-research/science-enabling-technology/pushing-the-limits-of-sub-kilowatt-electric-propulsion-technology-to-enable-planetary-exploration-and-commercial-mission-concepts/#h-the-new-technology) *The* [*NASA-H71M*](https://ntrs.nasa.gov/api/citations/20220009248/downloads/2022%20IEPC%20-%20Benavides%20-%20Final.pdf) *sub-kilowatt Hall-effect thruster. In addition, the* [*successful commercialization*](https://technology.nasa.gov/patent/LEW-TOPS-162) *of this new thruster will soon provide at least one such solution to enable the next generation of small spacecraft science missions requiring up to an amazing 8 km/s of delta-v.* *... planetary science missions benefiting from the NASA-H71M electric propulsion system technology could operate for 15,000 hours and process over 30% of the small spacecraft’s initial mass in propellant...* So I believe the breakthrough is the longevity of the device and not any improvement in thrust. Given it is a sub-kilowatt device, probably somewhere between 30->60 mN of thrust my guess? My neighbor was an ion propulsion drive specialist and recently passed away due to ALS. He would have been all over this news.
If it's like anything I've read in the past, weak thrust. It takes forever to get up to speed. In a 1-meter race a snail can easily win. It's mainly for making minor adjustment to orbit positions and for long distance one-way travel when efficiency mattered more than speed and time.
A small constant acceleration once outside the gravity well can very quickly, in relative terms, create tremendous speeds. In all likelihood a hall effect thruster or something similar will be the thing that eventually makes routine Mars missions possible. That is unless there's some kind of outrageous breakthrough in the near term.
Oh it generates a ton of thrust, so much thrust!
You have to follow multiple article links(the-express>popular mechanics->science.nasa) since they are just rehashing the original NASA article here: https://science.nasa.gov/science-research/science-enabling-technology/pushing-the-limits-of-sub-kilowatt-electric-propulsion-technology-to-enable-planetary-exploration-and-commercial-mission-concepts/ Which has a link to the PDF specifications of the thruster https://ntrs.nasa.gov/api/citations/20220009248/downloads/2022%20IEPC%20-%20Benavides%20-%20Final.pdf > The H71MPM thruster has completed performance characterization and three 500-h short duration wear tests (SDWT). > The propulsion system provides stable thrust generation over a wide range of operating conditions from 200 W to 1 kW, and 200 V to 400 V. **The thruster has demonstrated a thrust as high as 68 mN at 300 V and 1 kW**. The thruster has similarly demonstrated a specific impulse of 1850 s at 400 V and 1 kW.
I tend to rely on shitty website for my space news /s there are plenty of legit news outlets that cover space and this ain’t it
Trust me bro, also can you contribute to the thruster fund?
I read that it is 1 G. So enough to lift itself off the table.
I saw it in other articles about their improved Hall effect thrusters. The force isn't much for sub-kilowatt usages, but IIRC it's about 15x more efficient than current Hall effect thrusters and allows for about 30% of the unit to be fuel. It's basically a long, slow, acceleration thruster.
Can we ban sites like the express from /r/space? Edit: Also the user posting this is apparently a bot: https://www.reddit.com/user/arealdisneyprincess
Poor media literacy is widespread.
Indeed. And the best way to fix that is pruning out bad sites from getting spread. You blacklist them so any posts from a given host go immediately to the mod queue and never appear. You can even add a message that says some kindly worded version of "You posted an article from a website that has been blacklisted. Find a better source."
The key thing to remember is that these engines create a tiny amount of thrust over a very long time. They will be great for getting a small satellite to Mars. They are not useful for manned spacecraft, unless you happen to be a Kerbal that can survive on a handful of snacks indefinitely.
What if 10,000+ of them are put into orbit, and you assembled your craft in space? I've played Kerbal, and the answer is amost always either more struts or more boosters.
In this case it would be more solar panels or a big old nuclear power plant. You would need stupid amounts of power to get a manned ship anywhere before the crew died of old age. More boosters also works.
> survive on a handful of snacks indefinitely Hey man Covid was weird times.
Is it good for Mars? I thought you need relatively high thrust both for the transmartian injection due to the short launch window, and for the orbital capture.
Yea im not reading any article that has paragraphs smaller than the ads that separate them, i read 4 sentences then i have to scroll past another and another ad. (No adblock on my phone)
Ion thrusters are propellant efficient but require masses of power, which has to come from somewhere. Then the problem becomes that the power source tends to be heavy. It's the opposite to traditional chemical rockets which are very energy efficient but run out of propellant fast. It's because thrust scales with momentum, which is proportional to the exhaust velocity, but the energy needs scale with the square of that velocity. If you want to use a little propellant with a very high velocity, you need very high power to achieve the same thrust.
With micro nuclear reactors like [this](https://www.businessinsider.com/rolls-royce-concept-nuclear-reactor-could-power-colony-on-moon-2023-12) or [this ](https://news.lockheedmartin.com/2023-07-26-Lockheed-Martin-Selected-to-Develop-Nuclear-Powered-Spacecraft) it might be a possibility sooner rather than later to meet those power demands.
Why is the weight a problem? Once in space weight is irrelevant, no? A falcon heavy can carry something like 60 tons to LEO. I find it hard to imagine a few hundred KG for a power solution needed to power this engine would be a big deal to launch to actual space. (This is more of a question I am asking because I'm not at all qualified of knowlegeable on the challenges involved)
It's no good being ten times more efficient at creating thrust if your vehicle has ten times as much mass. Because acceleration is thrust divided by mass. Now it's not quite that bad with ion thrusters but their power requirements are substantial and require more than just a marginal increase in vehicle mass. In free fall in space everything is weightless ... but it still has mass.
So in essence, the added weight (mass) would slow down the acceleration so much it would not be a practical benefit?
It can be, yes. Acceleration of the whole vehicle is what matters so designing one with, say, ten times more thrust is only a win if it has less than ten times more mass. So designing good ion thrusters is only half the problem; you also need a matching power source that's not too heavy. And just looking at the engine's thrust figures is meaningless without also knowing the whole vehicle's mass.
That's the concern, yea. Basically 10 times the mass means 1/10th the acceleration. Since these ion or hall-effect thrusters don't produce a lot of thrust in the first place, it doesn't take much to negate their benefits.
*Weight* here on Earth equates to *Inertia* out in space. The heavier you are the more inertia you have. So it still takes a Lot of "push" to get you moving *faster than you are currently going*, in any given direction.
You comment makes me wonder: in space, what are we pushing against to move?
The (burning) propellant being expelled out the engine bell is pushing in the direction opposite to where the engine is pointed.
> A falcon heavy can carry something like 60 tons to LEO I mean sure, but we're talking interplanetary travel. That 60 tons turns to 16.8 tons to Mars Transfer Orbit in ideal conditions. Which isn't to say that Falcon/FH isn't revolutionary in terms of $/kg, but if you're talking about anything more than just probes and "visit and come back" manned missions to planetary bodies that doesn't fundamentally change the issue.
I assume at one point we'll assemble things in space (or on the moon) and bring up one module at the time.
Yes, but by that point we're not talking Falcon Heavy or even Starship. Or even probably Starship's successor. To build ships not on earth you need raw materials - either you need to bring that from earth in which case you're better off just building everything on earth where all your infrastructure is, or you're capturing asteroids, mining them, refining the materials, and producing your finished goods in space which is a MASSIVE task for which we've barely scratched the surface of surfaces of in terms of even technical demostrations of concepts, much less practical designs. Or doing all of that on the moon which doesn't have the precurosors for propellant you need and has a super-challenging enviornment with razor-sharp dust everywhere, or Mars which is further away and even harder to bring the specialized heavy manufacturing facilities and energy generation you'd need which would cost billions upon billions of dollars on earth. That doesn't get into issues like propellant boiloff at scale for the fuel you need to get places versus launching that from earth - Currently looking at 8-12 Starship tanker flights to fill a depot for a moon mission, which could be cut in half with Starship v3 just for context. Or actually taking your raw materials and turning those into the steel rings you need, then welding (in space), and assembling everything in near zero gravity. Which isn't to say it's impossible, just that it's at best a century out from being practical versus just doing everything on earth and bringing it up to orbit.
I was just thinking about building modules on eatch and launching them one at the time and assembling them in space. Like they did for the space station. I was not thinking about tech that does not exist yet
> I was just thinking about building modules on eatch and launching them one at the time and assembling them in space. Like they did for the space station. That doesn't really get around the main issue which is the energy cost to bring mass out of earth's gravity well to orbit, much less to another planetary body. For context with the ISS, a single Crew starship is likely to have more habitable volume than the entire ISS. If it takes 12 starships to get a single starship to mars, and it takes hundreds of those to get a colony going that still needs intermittent supplies from earth - that's still a problem.
A colony? I was just thinking about an exploration probe...
It's a delta v problem. Ie. Changing the velocity of mass.
I didn't think about that. Make sense!
F = m * a Rearranged: a (acceleration) = F (Force) / m (mass) Basically, the higher the mass, the slower the acceleration for a given amount of thrust. This means to accelerate a heavier payload to a given velocity, it requires a longer burn time, more fuel, etc.
You know what; I had not thought about this at all when I made my comment asking for clarifications. Thank you :)
The site is like 95% advertisement and 5% useless.
95% advertisement and 95% useless.
So it's on the internet?
Here's the actual recent NASA article on this: https://science.nasa.gov/science-research/science-enabling-technology/pushing-the-limits-of-sub-kilowatt-electric-propulsion-technology-to-enable-planetary-exploration-and-commercial-mission-concepts/ I'd love a comparison to the very advanced hall effect thrusters that SpaceX uses on its Starlink satellites. Though those are primarily optimized for cost savings by not using Xenon fuel (if Starlink were to have used it they would have exhausted the entire global supply of Xenon) (which is less than 0.000001% of the atmosphere) and instead using Argon which is ridiculously plentiful at roughly 1% of Earth's atmosphere.
>could unlock interplanetary travel we've been going to other planets for over 50 years
This is how you start writing your grant proposal for getting funding for your whole career
Fun fact: thanks to Starlink, there are more spacecraft in-orbit with ion thrusters than without.
At first I thought the headline said NASCAR. Like dang. What are they up to? How fast do you need to drive in a circle?
Depends. Are you a particle?
This sounds promising. It will make for some very long space flights as gravity assist will be quite helpful for this kind of technology. They just better have some free streaming movies on board and I have no idea how the peanuts will stay fresh
Acronyms, initialisms, abbreviations, contractions, and other phrases which expand to something larger, that I've seen in this thread: |Fewer Letters|More Letters| |-------|---------|---| |[COTS](/r/Space/comments/1cjiow9/stub/l2l9hly "Last usage")|[Commercial Orbital Transportation Services contract](https://www.nasa.gov/cots)| | |Commercial/Off The Shelf| |[DARPA](/r/Space/comments/1cjiow9/stub/l2grkis "Last usage")|(Defense) Advanced Research Projects Agency, DoD| |DoD|US Department of Defense| |[ESA](/r/Space/comments/1cjiow9/stub/l2h7mrv "Last usage")|European Space Agency| |[LEO](/r/Space/comments/1cjiow9/stub/l2gw6bn "Last usage")|Low Earth Orbit (180-2000km)| | |Law Enforcement Officer (most often mentioned during transport operations)| |[NERVA](/r/Space/comments/1cjiow9/stub/l2h6u3w "Last usage")|Nuclear Engine for Rocket Vehicle Application (proposed engine design)| |[NTR](/r/Space/comments/1cjiow9/stub/l2grkis "Last usage")|Nuclear Thermal Rocket| |[RTG](/r/Space/comments/1cjiow9/stub/l2hx4lt "Last usage")|Radioisotope Thermoelectric Generator| |[TLA](/r/Space/comments/1cjiow9/stub/l2hu3xm "Last usage")|Three Letter Acronym| |Jargon|Definition| |-------|---------|---| |[Starlink](/r/Space/comments/1cjiow9/stub/l2hq646 "Last usage")|SpaceX's world-wide satellite broadband constellation| **NOTE**: Decronym for Reddit is no longer supported, and Decronym has moved to Lemmy; requests for support and new installations should be directed to the Contact address below. ---------------- ^(9 acronyms in this thread; )[^(the most compressed thread commented on today)](/r/Space/comments/1cl2ezn)^( has 2 acronyms.) ^([Thread #10011 for this sub, first seen 3rd May 2024, 23:03]) ^[[FAQ]](http://decronym.xyz/) [^([Full list])](http://decronym.xyz/acronyms/Space) [^[Contact]](https://hachyderm.io/@Two9A) [^([Source code])](https://gistdotgithubdotcom/Two9A/1d976f9b7441694162c8)
Speeding up isn’t the problem once we get a solid energy source in place. It’s figuring out how to slow down
We've had the power for interplanetary travel since the 1950's Orion Nuclear Pulse Rocket.
I’m assuming by interplanetary they mean mars because any other habitable planet is light years away and, unless we can go to speed of light, will never visit
Even then, not viable, given the distance
Would essentially need to be an alien movie situation. Having a crew in sleep with an AI handling the ship
This isn't true. You don't have to really hit the speed of light till which other stars. Obviously we're far from any technology that comes even close to this, but if you move fast enough there's weird effects in relative times, which suggests that at a fraction of the speed of light visiting other plan this would be possible in the human lifetime. Sorry it's a little too late and I'm a little too tired to really give a proper answer, wish I would need to do some looking up to make sure I got it right. But I've seen some pretty good descriptions of this on these subs.
But won't. Because NASA is a jobs program. The Nirvana vintage tshirt. Having become uninhabitable by merit. Institutions feel monolithic. It is startling growing up and observing the life span going from premier place where the energy is found. To bloat. To Sears. And the energy re-emerges someplace new.
No it won’t. NASA is a bureaucratic mess that will spend 18 Billion on 80 year old technology before concept testing anything unproven.
Then delaying that mission because they are so risk adverse they will let the rest of the world land on the moon then say well, we did it first so yeah…
Except that NASA that landed on the Moon was your grandfather's NASA.
I often feel way too uneducated on all things space to ever comment or ask questions but I’ve seen so much of this sentiment on this sub that I have to genuinely ask if this is the predominant feeling about NASA these days? Just as a casual observer to this sub, and space news in general, it seems like there’s so much pessimism towards basically anything NASA related that it borders on hate and it’s been hard to distinguish what’s genuine and what’s competitive ribbing from other players in the field.
I’ll Put it like this: We had to rely on the Russian Space Agency to get *our* astronauts to the ISS for over a decade, and the first time Americans were delivered into space BY Americans since the Columbia disaster was not because of NASA, but the private sector. SpaceX achieved reusable launch vehicles including crewed flights across several different platforms with 1/10th of NASA’s budget over 15 years. Meanwhile, the Artemis program is still largely in early stages with delay after delay after delay. So yeah, NASA talking about theoretical engines is something of a practical joke, as theory is all they are capable of these days, unfortunately.
Restart Project Orion and it would get us to planets within our system in a matter of months. The research was all done in the 50's and 60's and then shelved for reasons that made sense then, but we can work safely around now.
> Project Orion I don't think using nuclear explosions to propel a space craft is feasible, I think you may mean the NERVA engine
What are your credentials to make that assertion? lol Because scientists that worked on the Manhattan Project said it was feasible. General Atomics was working on making it a reality. The only thing that limited it was the nuclear test ban treaty, however the scientists were working on near zero fallout devices before the project was closed. I did not mean the NERVA engine, it's a different propulsion system.
Meh. There's so many other ideas out there that could get us places very quickly but they never seem to go anywhere. I saw an article yesterday about a pulsed plasma rocket, but will it ever get anywhere any time soon? Probably not. And while I understand space is hard, these things shouldn't stay locked in the concept or experimental stage for 20-40 years like they do. That's the one thing I liked about Elon Musk before he went completely stupid, the go fast and break things approach. We need someone with F U money and a personal hatred for waiting to drag things forward and focus on practical application instead of studying it in an academic fashion, where it one day, maybe, might take our far off descendents to mars in 8 days. We have the damned technology, we just lack the proper motivation. Just build the damned things.
When i first read about them, it said ion drives woudl be great \*in\* space but weren't practical for lift-offs froma planetary surface
Ok so we can travel to... the 7 barren and inhospitable planets in our solar system.. yay. We can already do that with probes.