[HN Gopher] NASA's plan to "swarm" Proxima Centauri with tiny pr...
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NASA's plan to "swarm" Proxima Centauri with tiny probes
Author : Brajeshwar
Score : 37 points
Date : 2024-01-10 16:32 UTC (6 hours ago)
(HTM) web link (www.sciencealert.com)
(TXT) w3m dump (www.sciencealert.com)
| sp332 wrote:
| Let's see, total surface area of 1 square km, 1,000 probes in the
| swarm, that's 1,000 square meters per probe... but it can only
| weigh a few grams? Also it can't be sparse because the point is
| to capture light energy instead of letting it pass through.
| robin_reala wrote:
| The 1km^2 figure in the article was for the receiving "antenna"
| on earth. It doesn't give a figure for the size of the sails,
| but Breakthrough Starshot's equivalent swarm members were going
| for 4m^2:
| https://en.wikipedia.org/wiki/Breakthrough_Starshot#Light_sa...
| snakeyjake wrote:
| Breakthrough Starshot is a scam and I can't believe that NASA is
| falling for it.
|
| 1. Extremely high duty cycle 100 gigawatt laser. (edit: now
| apparently it's an "array" because someone with a brain mentioned
| that a 100 gigawatt laser is ludicrous) That's right 7 peak
| summer output Grand Coulee Dams and 12 Palo Verde nuclear power
| plants with all reactors operating simultaneously COMBINED would
| be needed to power this laser.
|
| 2. "Swarm" (jfc buzzwords) craft that are currently impossible to
| create. The swarm behavior including networking, sensors, radio,
| and command and control do not exist and are impossible at a
| simple base level when considering RF energy requirements even
| with far-future theoretical energy harvesting technology.
|
| 3. Perfectly-spherical-frictionless-cow-ifying the EXTREMELY REAL
| effects of space weather. Forget the interstellar medium, these
| things will be blown out of the beamwidth by the time they reach
| jupiter's orbit from solar winds alone.
| chuckadams wrote:
| It's one of many competing research projects, the sum total of
| which add up to less than a single shuttle launch. I'm content
| with a dead end or two.
| hex4def6 wrote:
| I'm curious about whether it's even feasible based on
| dispersion issues. My understanding is that it's hard to beat
| dispersion over long distances, regardless of your optics on
| the laser (and we're talking _long_ distances here...)
|
| Any optics experts able to chime in?
| lxe wrote:
| Given 1.6 sq meter 500W solar panels, that's an area of 320
| square kilometers. That can be constructed at $1/w at $100
| billion.
|
| Also it's not necessary (or technically, it's actually
| impossible) to have 100% duly cycle laser for propulsion.
|
| It's definitely a megaproject, but it's not a "scam"
| numtel wrote:
| For comparison 320km2 is about 2.5 San Franciscos
| lxe wrote:
| I asked chatgpt to make a quick demo to demonstrate the
| size of the 18x18 km2 square:
|
| https://lxe.github.io/map/
| 6d6b73 wrote:
| Lasers are running at 30-40% efficiency so for a 100GW laser
| you need 400GW power plant. But the power plant and
| transmission has some losses so you probably would need 500GW
| dylan604 wrote:
| You announce this kind of project so Congress Critters can get
| all up in arms about wasteful spending and is something that
| can then later be sacrificed to make them feel like they've
| done their job. Meanwhile...you have other projects that have
| been protected from the axe because the sacrifices of this
| farcical project.
| PeterisP wrote:
| So you're saying it's like the Queen's duck?
| https://bwiggs.com/notebook/queens-duck/
| readyplayernull wrote:
| Thinking whether they could use one of the projects aiming to
| launch small payloads into space, sort of space trebuchets:
|
| SpinLaunch - Developing a system that spins a payload at ultra-
| high speeds inside a vacuum chamber, then launches it into the
| sky using stored rotational energy. They claim it could launch
| small satellites for a fraction of the cost of traditional
| rockets.
|
| Launchloop - Proposed concept of using a powerful electromagnetic
| accelerator called a Launchloop to fling payloads into space. It
| would use low-cost electricity rather than expensive rocket fuel.
| Still in early feasibility stage.
|
| TAES - Developing a space trebuchet mechanism that uses
| centrifugal force similar to how a trebuchet launches
| projectiles. They're aiming to launch 6U CubeSats (10x10x30cm) to
| Low Earth Orbit for a relatively low cost per launch.
|
| Rocket Lab - Makes small Electron rockets for launching 150kg
| payloads to LEO. Over 20 successful launches to date and helping
| enable more frequent smallsat launches.
|
| Virgin Orbit - Uses a modified Boeing 747 to carry a 2-stage
| LauncherOne rocket to altitude, then releases and ignites to
| place payloads in orbit. Aims for frequent, affordable smallsat
| launches.
| 14 wrote:
| None of those solutions are suitable for this mission. These
| satellites need to be traveling a hundreds of thousand of
| kilometres an hour or more. Think about voyager 1 traveling at
| 65,000km/hr. It is still over 18,000 years before it will reach
| a light years distance and this mission is talking about 4
| light years. So the launch really has zero importance as does
| getting these satellites up to massive massive speeds. Anything
| less then like 1million kilometres per hour is probably just
| too slow. Edit: even at 1 million kilometres per hour it would
| still take over 4000 years to reach the full distance so really
| we need to be going unimaginably fast to get there.
| temp0826 wrote:
| Do these launchers actually make sense? Maybe from the moon
| (obviously not for earth orbit-destined satellites, but deeper
| space)
| kolinko wrote:
| Launching from altitude gives you very little, so does
| spinlaunching.
|
| It is because it's about speed, not altitude. Witch Spinlaunch,
| they plan to laumch around 5000kmph, and you need a speed of
| around 25000kmph to reach orbit.
|
| In other words, they would need to use their setup to launch a
| rocket of a size of 1/2-3/4 of size of a falcon1 to get into
| orbit, and even then, unless they land the second stage, they
| will come out far more expensive than what SpaceX is doing.
|
| The tech may work on moon, but even on Moon a different
| solution - similar to maglev - may be better, bacause there
| would be no issues with crazy centrifugal forces.
|
| Anything launching from earth will require some sort of a
| rocket fuel (or some new laws of physics), because even if you
| managed to launch at the speed of 25000km/h from the ground,
| the payload would slow down before it left the atmosphere.
| pokstad wrote:
| Just put a frozen brain in space and use nukes to send it there.
| m3kw9 wrote:
| This is the one time they are forcing the issue when the tech
| isn't even close but instead throwing 100billion to make it
| happen. Maybe use half that to do research for better fuel,
| materials, miniaturization and the other 50 to launch with higher
| chance of success
| dtgriscom wrote:
| This idea has shown up multiple times. I've never understood how
| they plan to communicate back, especially with a) gram-scale
| devices b) moving a significant fraction of the speed of light
| away from us while being c) multiple light-years away.
| ta93754829 wrote:
| lets say we did this, and we got the tiny probes up to even
| ~speed of light... then what are they going to do when they get
| there? what sensors can they carry and report back. And we
| wouldn't be able to slow them down, so they're going to transit
| through the target solar system relatively quickly (days even).
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(page generated 2024-01-10 23:00 UTC)