There is interesting new work from Cool Worlds. A quasite is a conceptual space-based satellite system proposed by the Cool Worlds Lab (led by astronomer David Kipping), representing a hybrid or modified version of a traditional statite. A statite is an earlier idea for a solar sail-based satellite that remains completely stationary relative to a star or the sun by perfectly balancing gravitational pull with outward radiation pressure from sunlight on a highly reflective, ultra-thin sail—essentially hoverin without orbiting. A quasite is not fully static like a statite but incorporates a blend of radiation pressure for partial stability and a modest tangential orbital velocity to prevent falling into the star. This results in a satellite that appears to orbit very slowly making it quasi-static. The concept allows for more practical designs, as it doesn’t require the sail to be unrealistically thin or perfectly balanced to achieve full statite hover. The quasite configuration is central to Cool Worlds’ proposed TARS (Torqued Accelerator Using Radiation from the Sun) system, a space-based satellite/propulsion platform designed for launching small interstellar probes.
The TARS system balances a system in space so that it is not pushed out by solar radiation and it builds up rotational speed.
Mirrored and dark sides convert solar radiation into rotating kinetic energy.
Using balanced electric charge it could resist releasing a catapulted payload at up to 1000 kilometer per second (0.3% of C).
I, Brian Wang, note that it could be used as a system for storing solar radiation as kinetic energy. The balanced system could keep spinning faster and faster and removing the kinetic energy is just like any other turbine converting to electricity.
Mass could be processed and used for large energy applications every few years.
It seems like 10 years can see systems spin up to store 10s of gigawatt hours. All of the pumped hydro in the world stores about 9 TWHs. 900 of the 1700 ton systems could just be deployed in space and build up large amounts of stored energy that could then be used for other applications.
Adapting TARS for power storage (spinning up with solar torque, storing kinetically, extracting via electromagnetic braking/dynamo induction to generate electricity) instead of payload launch avoids the “breakup” step, keeping the structure intact. This enables applications like space-based energy reserves for satellites, Mars bases, or beaming power via microwaves.
However, challenges include:
Deployment and Assembly: Launching large/massive versions requires multiple rockets (e.g., Starship for 100+ ton payloads) or in-space construction from asteroids/lunar resources. Unfurling the ribbon risks tears or instability; larger sizes amplify this.
Orbital and Stability Issues: Maintaining quasite orbit against solar wind, gravitational perturbations, or space debris is tricky. Rotation must be precisely controlled to avoid precession or tumbling.
Charging and Field Management: Sustaining high charge in space plasma (which can neutralize it) requires insulation or active recharging. Leakage or arcing could damage the structure.
Energy Extraction: To power applications, slow the rotation using induced currents (dynamo mode) in external coils, converting kinetic to electrical energy. Efficiency losses (~20–30%) and heat dissipation in vacuum are issues; no “snap” means reversible, but repeated cycles could fatigue materials.
Material and Durability:
Carbon nanotubes handle high stress, but cosmic rays/micrometeorites could degrade them. L
arger/heavier versions increase inertia, but as noted, if heavier/larger, spin-up is not inherently slower in proportional scaling (time constant due to torque scaling with area). However, fixed-torque scenarios would slow acceleration, enabling more storage at the cost of time.
Spin-up takes years, limiting rapid charging/discharging compared to batteries.
Scaling to TWh+ requires billions in investment, but it’s passive (solar-only) and long-lasting.
Brian Wang is a Futurist Thought Leader and a popular Science blogger with 1 million readers per month. His blog Nextbigfuture.com is ranked #1 Science News Blog. It covers many disruptive technology and trends including Space, Robotics, Artificial Intelligence, Medicine, Anti-aging Biotechnology, and Nanotechnology.
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Honestly, I looked at a concept like this when I was a teen, and first heard of solar sails. It’s not really practical.
As you know, in an elastic collision most of the energy ends up in the lighter object, and for solar sails, that’s always the sail. So you start out throwing away most of the energy of the incoming light. Solar sails only really shine as they get really light weight, and are traveling at very high speeds. At low speeds they’re horribly inefficient.
But you can’t reasonably expect a physical object to spin that fast, it would be torn apart.
Solar panels and using a motor of some sort to spin counter-rotating arms to zero out angular momentum would appear to be more efficient. Enormously so.
And you’re probably better off forgetting about storing the energy, and just having more generating capacity. The reason this proposal leans into storage is because it’s so wildly inefficient that the energy is produced at a really low rate, and you have to store it to occasionally get a worthwhile amount of power.
You want an amusing power source, that’s physically practical?
Place mass drivers on the Moon, and mine the Moon for useful minerals. At the same time build an orbital ring around Earth. Then use the mass drivers to launch material from the Moon to the orbital ring, only retrograde.
When the material reaches the orbital ring, it’s traveling much, much faster than it has to be launched from the Moon, and you can extract the kinetic energy, beaming some of it back to the Moon to power the mass drivers.
You do retrograde because it’s not hard to launch something into a retrograde orbit from the Moon, because the Moon isn’t orbiting very fast, and you get a much higher effective speed at the Earth end of the system. You can get away with it because the orbital ring has tethers to transmit the torque to the Earth, but you can balance the torque out by mixing retrograde and prograde launches appropriately, and skip the tethers.
This combines lunar mining, and usefully extracting the potential energy of the Moon. A twofer!
“and for solar sails, that’s always the sail. ”
Excuse me, “never” the sail.
You, Brian Wang are a genius.