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The simplest way to understand TARS is to think about something like this, two thin paddles joined by a tether. One side is painted silver & the other dark, with opposite phases. The silver side feels 2x the radiation pressure as the dark side, and thus TARS feels a torque.
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However, there's also an outward force trying to push TARS away from the Sun, which is bad since radiation pressure drops off as distance^2. So, we combat this by placing TARS in a "quasite" orbit, an idea I came up with in a previous paper: doi.org/10.3847/2515-5
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The whole thing is scalable but our paper considers the example of a 63m x 7m x 2.6um design weighing 1.6 kg made of CNT sheets. The strange dimensions are required for stability against tumbling (T-handle effect). One could imagine TARS being folded up at launch then unfurling
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After ~3 years @ 1AU, TARS would spin up to 12.1 km/s which is the critical velocity when the centrifugal force exceeds the tensile strength of the CNT sheets. Adding on the quasite orbital velocity, the ends are moving at 40.4 km/s - exceeding the Sun's escape velocity.
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A chipsat, similar to that proposed by Breakthrough Starshot, is released just before breakup, flying off in a tangential trajectory out of the Solar System. In principle we could boost the speeds by using eccentric orbits + Oberth effect, graphene sheets and gravity assists.
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We speculated that even faster speeds could be obtained by electrically charging the tips, providing a restoring force. This creates a rotating dipole that radiates and the new terminal speed is set by energy balance, and is ~1000 km/s (0.3% c!) - again just using the Sun!
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The magnetic field produces in this configuration could actually be useful in its own right, such as providing protection to a Mars base for example. And given these things weigh just ~kg, made of existing materials and powered solely by the Sun, we could make a lot of them.
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The paper is at arxiv.org/abs/2507.17615
I don't know if TARS would work or not, but interstellar flight is a personal dream & so I felt compelled to try. This isn't as fast as Starshot but should be far easier to make. Mostly, I hope this inspires others to work on this problem!
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This is super odd!! I just watched your video on YT - great job, very inspiring! 
- and 2hrs later you pop up in my X feed for the very first time 
. The YT algo and X algo appear to be synchronized 
. Pretty implausible that they're working together. So reckon that we're
- and 2hrs later you pop up in my X feed for the very first time . The YT algo and X algo appear to be synchronized . Pretty implausible that they're working together. So reckon that we're
Very cool! Amazing work here. A very interesting approach to interstellar transit. wrt the magnetic field generation should have a look if he hasn't already for Mars work. Thank you for sharing.
Thank you so much for sharing this. The way you play with patterns in nature is truly inspiring.
Released at such spin, isn't precision of the instant of release an issue if there's an actual target?
So basically.. Oumuamua? The length, the rotation, changes in brightness... It all checks out.
Are you coming to thr Interstellar Symposium in Austin in October? I think the plenary sessions are filled, but we could probably squeeze TARS in as a poster paperโฆ
this thing basically converts solar energy into magnetic fields. Imagine a bunch of very low cost TARS providing a localized magnetic field for Mars.
Interesting episode that leads down many rabbit holes.
Thousands of these ultra fast micro-satellites could in theory map our solar systemโs heliosphere rather quickly.
Couldnt we use this at controlled speeds on terrafirma to create turbines thus creating essentially free electricity ?
Another great idea! I wonder if this design can be altered to spin slightly slower and launch larger probes at slower speeds. I imagine something like this just waiting around for an interstellar object to pass by and then throwing a probe in its direction.
what's the orbital radius (time to spinup)/%escape velocity tradeoff look like?
"TARS" (Torqued Accelerator using Radiation from the Sun) is a novel concept for interstellar propulsion that leverages solar radiation to spin up a light sail in order to achieve speeds sufficient for interstellar travel without the need for extremely low areal densities
But, the tiniest of imprecisions in release time would result in the chipsat missing the target. The error compounds over distance, so even a fraction of a millisecond could result in millions of miles of deviation over time.
You can tell which aliens travel this way. The ones that land, and come out very dizzy.
yeah that's cool and all but back on earth in reality we'd simply use a laser, not this overcomplicated whateverthefuck
A+ invention. C+ name. How about โTorque-Accumulating Radial Sailโ? Avoids the awkward โusing,โ harkens to other solar wind sail proposals, and future-proofs for launching in other solar systems.
Can you use this to spin arbitrarily large objects (eg colony ship drum) by adding an axle? Could it also be used to create flywheel launcher? Also did not know about this company which is the ground based version
Amazing idea . Why donโt we combine Breakthrough Starshot and TARS. Basically increasing the size of TARS sails and use lasers from earth to speed up the TARS. Of course we would need to find the right balance between TARS sail size and increased weight
. Why donโt we combine Breakthrough Starshot and TARS. Basically increasing the size of TARS sails and use lasers from earth to speed up the TARS. Of course we would need to find the right balance between TARS sail size and increased weight
This is a very elegant idea. My professor would have loved this for his spacecraft instrumentation course. So they are single use launchers right? They could be an interesting way to intercept/perform flybyโs of interstellar visitors perhaps
"I've made a new interstellar drone system concept"
"Something new or solar sail?"
"Solar sail."
Cool concept.
Do we have the technology to be able to communicate with chip sats in interstellar space?
Seems to me a chip sat's transmitter would be very low powered.
Iโd assume itโs disposable, as you would have to find a way to flip the craft to de-spin, but at those velocities it seems challenging.
Using only the Sun's radiation is not strictly accurate; the concept also draws on some of Earth's orbital kinetic energy.
Cool concept though!
One of the most interesting and original space travel ideas Iโve seen in a long time
A fairly "basic" idea with good execution, it makes sense.
Also, wouldnยดt it be possible to "nudge" comets to a new trajectory with the silver paint provided we detect them in time?
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What a wonderful and great idea. And it will be useful even to send probes to the far Solar System, Kuiper belt, the oort cloud or even reach up an interstellar object passing by. I believe it very worths to try it! 
Interesting - I presume it is tapered to even out tensile stress in the sail?
I think this is the goofiest interstellar propulsion proposal I've ever seen. 10/10
How many deg/s it is rotating at release? The accuracy of the release mechanism will need to be SUPER accurate, or it will end up in some different quadrant altogether.
Carbon Nanotube Sheet is still a fantasy material. Coating it to have a different emmisivity will be difficult
Ive been toying with the idea that after starship enables cheap tons to orbit, wont the ability to build ships in space lead to the conclusion that nuclear pulse propulsion must be exempted from treaties
I think its neat, since it can send very small pay loads, incredibly fast so DEEP and cheap. Like just sending a bunch of clocks out tasked with powering up, checking the time, and beaming that data back to earth, to map out relative time and space.
