New Lithium-Plasma Engine Passes Key Mars Propulsion Test (universetoday.com) 38
NASA engineers have tested a next-generation lithium-plasma electric propulsion system that reached 120 kilowatts, a new U.S. record and about 25 times the power of the electric thrusters on NASA's Psyche spacecraft. "Designing and building these thrusters over the last couple of years has been a long lead-up to this first test," said James Polk, who is a senior research scientist at NASA Jet Propulsion Laboratory. "It's a huge moment for us because we not only showed the thruster works, but we also hit the power levels we were targeting. And we know we have a good testbed to begin addressing the challenges to scaling up." Universe Today reports: While 120 kilowatts is a new record, NASA estimates it a future human mission to Mars will require 2 to 4 megawatts of power consisting of several thrusters and requiring more than 23,000 hours (958 days/2.6 years) of operation. To accomplish this, the thrusters would have to withstand more than 2,800 degrees Celsius (5,000 degrees Fahrenheit), which the thrusters achieved during testing.
The reason for the extended operation is due to the estimated time of an entire human mission to Mars, which is estimated to be approximately 2.6 years. This is because the launch window to Mars only opens once every two years due to the orbital behaviors of both planets. While no mission has ever returned from the Red Planet, this same launch window works from Mars to Earth, too. When launched within this window, robotic spacecraft have traditionally taken approximately 6-7 months to reach Mars.
However, a human mission would require a much larger spacecraft to accommodate the astronauts, food, fuel, water, and other mission-essential items. For the approximate 2.6-year mission, this would entail approximately 6-9 months traveling to Mars, followed by approximately 18 months on the surface of Mars until the next launch window opens, then another approximate 6-9 months back to Earth. However, having much less fuel due to the electric propulsion system could potentially alter this timeframe.
The reason for the extended operation is due to the estimated time of an entire human mission to Mars, which is estimated to be approximately 2.6 years. This is because the launch window to Mars only opens once every two years due to the orbital behaviors of both planets. While no mission has ever returned from the Red Planet, this same launch window works from Mars to Earth, too. When launched within this window, robotic spacecraft have traditionally taken approximately 6-7 months to reach Mars.
However, a human mission would require a much larger spacecraft to accommodate the astronauts, food, fuel, water, and other mission-essential items. For the approximate 2.6-year mission, this would entail approximately 6-9 months traveling to Mars, followed by approximately 18 months on the surface of Mars until the next launch window opens, then another approximate 6-9 months back to Earth. However, having much less fuel due to the electric propulsion system could potentially alter this timeframe.
Mars is waste of resources. (Score:5, Insightful)
We should build industry on the Moon first and do cheaper robotic exploration.
And save the Earth - the only livable planet we will have in the near future...
Re: Mars is waste of resources. (Score:2)
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Re: Mars is waste of resources. (Score:4, Interesting)
Much to master before human travel to Mars. A nifty engine though could be useful for other space exploration. Robots probably better priority for initial explorations.
Yup, to make it even feasible, it is going to be a many generation effort. many hundreds of years, if we're doing anything other than a dash to Mars, then a two year exploration/survival effort, followed by a two year dash back.
Even the dash concept is no where near ready.
So let us take the Starship concept. First we have to get Starship working here. Then we have to set up some infrastructure on Mars. Landing facilities like the grabber need built and delivered to Mars, and fuel generation/storage facilities must be constructed and shown to work. Then a place to house the settlers must be found or constructed. The futuristic 3-D renderings are a pipe dream for the far future - initial settlers will most likely live in caves. Earthmoving (Marsmoving?) equipment must be designed and developed that will operate on Mars.
So right off, we see an issue. A sort of chicken and egg problem exists. Getting the starships safely down to Mars requires lot of infrastructure already built onsite. The nuts and bolts issues are all pretty daunting.
Frankly, if we are at all serious about colonizing Mars, we should start off with the small but critical (and doable) step of providing Mars with a synthetic magnetosphere, because if our eventual plan is to create an atmosphere, we have to stop the solar wind from stripping the atmosphere away.
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Starship is intended to land with feet or legs on Mars and the Moon. It would be silly to require a launch tower to land there because it would need to land there to deliver parts for a launch tower.
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Starship is intended to land with feet or legs on Mars and the Moon. It would be silly to require a launch tower to land there because it would need to land there to deliver parts for a launch tower.
Exactly that's my point, - and if that long candle wobbles and falls, what then, Saint Peter? What degree of slope can Starship land on and remain vertical. The Starship needs a flat and raised surface to launch from when taking off again. The poor launch platform they used at first did damage to the engines. A whole lot of flame impingement throwing debris all over. And with no launch tower, and taking off from an indeterminate surface, damaged engines could be a life ending disaster.
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CHNOPS can be recycled (Score:1)
The moon may be good for industry but it has very little else going for it. Mars has CHNOPS so it can sustain life. People on the moon would require constant imports from Earth. Mars also has a higher gravity which makes it likely to be a healthier environment.
Elements can be recovered and recycled given enough power. In theory we only need CHNOPS in an amount proportional to the population.
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that doesn't mean it can sustain *our* life and not at all in the way humanity evolved
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And save the Earth - the only livable planet we will have in the near future...
This would be wise but, looking at our success in that and extrapolating from it our caring, I think the New Martians, once established, will tell us to f*** right off.
All right! (Score:2)
We're that much closer to Mars-grown potatoes!
Don't forget tomatoes and sugar beets (Score:1)
We're that much closer to Mars-grown potatoes!
Yawn. Let me know when we have Mars-grown tomatoes and sugar beets so we can have some ketchup to go with the potatoes. :-)
120 kW (Score:3)
Is that 120kW of thrust, or are they reporting it in the same way we hear about datacentres - in terms of input power consumption rather than useful work?
Genuine question, because it doesn't say in the linked article and I can't be arsed to watch a damned youtube video
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The video is only 50 seconds long and doesn't answer your question exactly.
Re:120 kW (Score:4, Informative)
The 120kW figure is indeed input power. Thrust is typically quoted in Newtons, not Watts. The input power is useful because it's a proxy for thrust and vastly easier to measure. Ultimately, none of that really matters, however: the real figure of merit for ion engines (all rockets, really) is Specific Impulse. When NASA claims these use 90% less mass for the same total impulse, they're saying it's about one order of magnitude more propellant-efficient than a chemical rocket.
Re: 120 kW (Score:2)
What he said.
Pretty weird that they quote required thrust in watts. Also that they need continuous operation. Presumably during mars transfer you don't need the power aside from occasional corrections
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they're saying it's about one order of magnitude more propellant-efficient than a chemical rocket.
It is not one order of magnitude, it is 5 or 6.
Not 2.6 years of operation (Score:3)
requiring more than 23,000 hours (958 days/2.6 years) of operation
For the approximate 2.6-year mission, this would entail approximately 6-9 months traveling to Mars, followed by approximately 18 months on the surface of Mars until the next launch window opens, then another approximate 6-9 months back to Earth.
Why are the thrusters running during the 18 months at Mars? Mars has a much thinner atmosphere, so at any reasonable altitude any spacecraft in orbit will encounter much less drag than on the ISS around Earth. The ISS does not run its thrusters continuously; it gets an occasional boost from a Soyuz. And there isn't much space debris around Mars compared with LEO, so not much to dodge. If the entire spacecraft lands, it's definitely not running its thrusters the entire time.
So that's 12-18 months (1 - 1.5 years) of operation, only when it's headed to Mars or back. Half the quoted amount.
Re:Not 2.6 years of operation (Score:4, Funny)
Why are the thrusters running during the 18 months at Mars?
It's needed for the Purnell Maneuver.
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But they might want to idle the thrusters for 18 months, to prevent the thrusters going cold.
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Thees thrusters are ion/plasma engines.
Obviously you are not landing with them in an atmosphere.
Has nothing to do with a full flight under thrust ...
It would be very tough to return to Earth (Score:3)
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It would be much less expensive to put some mice in a rotating orbital habitat to see what low g does to a mammal than to send humans on long term missions to the Moon or Mars, but other than one limited Japanese experiment nobody seems interested in doing so.
That tells me that nobody is yet serious about such missions.
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It would be much less expensive to put some mice in a rotating orbital habitat to see what low g does to a mammal than to send humans on long term missions to the Moon or Mars, but other than one limited Japanese experiment nobody seems interested in doing so.
That tells me that nobody is yet serious about such missions.
Yup, While many are looking forward to being one of the million people living on Mars in 2050, the truth remains we are nowhere near ready.
What must be answered first is why do we want to establish a permanent presence on Mars.
Then if we answer that with a reason, we need to determine what and where.
We need to demonstrate the effects on mammals as you have noted - Is this a possible livable and survivable situation for the passengers?
We need to determine if this is a one way trip or availability to
Re: It would be very tough to return to Earth (Score:2)
Not only we are not ready, there is no point pursuing that goal. Mars is utterly unlivable.
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Not only we are not ready, there is no point pursuing that goal. Mars is utterly unlivable.
Exactly. An exploratory mission might be good, but living there is pointless.
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" why do we want to establish a permanent presence on Mars"
because Elon said so.
but now it seems he's all about going to the Moon which for more than a decade he said was pointless
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" why do we want to establish a permanent presence on Mars" because Elon said so. but now it seems he's all about going to the Moon which for more than a decade he said was pointless
True Dat. I wonder how he is planning on doing it. If you aer going to land and takeoff from the moon, you have to have both impressive engines to land safely with enough fuel that will allow you to escape from the moon's gravity well, make it back to earth, survive reentry than enough leftover fuel to land.
That is going to play hell with the max payload, and little room for error.
There is a reason that Apollo and now Artemis are using the concept of throwing away the parts that are no longer used. I f
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"Over 2.5 years you would have 1 year of almost no gravity and 1.5 years of 38% gravity. I can't imagine going back to Earth and walking around in 1G after all that time losing muscle"
if you're over 35 it's unlikely you'll ever fully recover
How much actual thrust is produced? (Score:1)
Re: How much actual thrust is produced? (Score:2)
You don't say! (Score:2)
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Why is that weird?
It is a lucky coincident that in our solar system this two planets have the same launch window in both directions.
Oh good (Score:2)
Another use for lithium.