NASA NIAC -Robert Hoyt Spiderfab and Yong Bae Photonic Laser Thrusters

Robert Hoyt, Tethers, Unlimited, Inc., 2013 Phase II Fellow
SpiderFab: Architecture for On-Orbit Construction of Kilometer-Scale Apertures

Spiderfab – build in space and make structures 10 times bigger
A starshade twice the diameter to enable 16 times the earth sized planet finding capability for the same price

On orbit constructed solar array using a tension structure would be five times lighter

Young K. Bae, Y.K. Bae Corporation, 2013 Phase II Fellow
Propellant-less Spacecraft Formation-Flying and Maneuvering with Photonic Laser Thrusters

Watch live streaming video from niac2014 at

6.5 kw amplified 650 kilowatt thin disk laser. 4.3 millinewton thrust

Boeing has a 30 Kilowatt laser. With amplifiction can get to 20 millinewtons.

Photonic Laser Thrusters for Spacecraft Maneuvering NASA tech briefing, Jan 1, 2014

One of the most crucial technologies for developing and implementing the proposed PLT formation flying and spacecraft maneuvering is Directed Energy (DE) technology that has evolved and matured the long-range delivery of high-power laser beams. State-of-the-art DE technology is capable of delivering powers of multi-megawatts over distances of hundreds of kilometers, with matured precision pointing and focusing capability. Various solid state lasers, which are considered to be most ideal for PLT, are capable of delivering powers over 150 kW and according to the DE community, multimega- watt powers will be achievable by solid state lasers in a decade. Recently, Dr. Latham at AFRL demonstrated ~650 kW (with a 99% output coupler) of intracavity laser power with the use of a 6.5 kW ceramic Thin Disk Laser, which now is considered to be an ideal laser system for PLT. Although, the AFRL TDL is not optimized for PLT, its intracavity power translates into ~4.3 mN photon thrust in an active cavity for PLT. That’s more than 100 times more than our previous NIAC demonstration of 35 μN. In principle, photon thrusts in the range of 1 mN – 1 N from an operational power source of 100 W – 100 kW can be powered by currently available space-based solar panels.

Propellantless Spacecraft

Maneuvering with PLT In addition to propellant-free thrusting capability, PLT can provide “out-of-plane” maneuvering capability that enables unprecedented persistent formation flying that is needed for nextgeneration space endeavors. An example of such unprecedented formation flying configurations is shown below.

In this structure, pushing-out photon thrust is counter balanced by gravity gradient. In addition, PLT can enable propellantless “perpetual” station-keeping by beaming thrust from a resource vehicle to a mission vehicle.

They will scale the intracavity amplification from 100 to 1000 times instead of scaling the laser power (initially)

Currently, Yong Bae are developing a mNclass PLT capable of delivering photon thrust up to 5 mN by adapting an off-the shelf 1 kW class Thin Disk Laser. We are also developing space-qualified PLTs for a flight demonstration that will involve a small satellite and a CubeSat under the auspices of NIAC. In this scenario, the small satellite will be a resource vehicle that carries a PLT engine and a power source and the CubeSat will be a mission vehicle that carries with it an HR mirror with diagnostic and attitude control hardware. Such flight demonstration is predicted to be achievable in 3 – 5 years after completion of the present NIAC Phase II program.


If successfully implemented, PLT can Enable virtually unlimited mission lifetimes and expand operational capabilities, since advanced spacecraft maneuverings are no longer limited by onboard fuel;

• Enable unprecedented “out-of-plane” maneuvers that include persistent precision formation flying;

• Lower construction/operation costs by reducing the hardware required for higher orbit applications;

• Eliminate environmental contamination or damage to mission crucial elements during proximate operations from cross firing of traditional thrusters;

• End risks to personnel health, safety and environmental impact compared to current toxic propellants.

PLT, therefore, promises to enable innovative CONOPS to change how some current spacecraft endeavors are conceived, making the PLT spacecraft system a revolutionary departure from the “all-in-one” single-spacecraft app – roach, where a primary factor that dominates spacecraft design is a heavy and risk-intolerant science payload. Instead, PLT spacecraft maneuvering has evolved from a different path based on inter-body dynamics via thrust exchange. PLT spacecraft maneuvering really represents a technology push rather than a mission pull, and will enable an entirely new generation of planetary, heliospheric, and Earth-centric space endeavors.

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