Since Einstein, scientists have dreamed of Laser light powered rockets streaking through space at speeds approaching the speed of light. This vision came a step closer to reality on December 21, 2006, when Dr. Young Bae of the Bae Institute successfully demonstrated the world’s first Photonic Laser Thruster (PLT). Repeated experiments since then have reconfirmed results.
Dr. Franklin Mead, Senior Aerospace Engineer, and leading rocket scientist in laser and advanced propulsion at the Air Force Research Laboratory (AFRL) remarked, "I attended Dr. Bae's presentation about his PLT demonstration and measurement of photon thrust here at AFRL. It was pretty incredible stuff and to my knowledge, I don’t think anyone has done this before. It has generated a lot of interest around here."
Photon particles have been considered inefficient for producing thrust because they have zero mass, and no electric charge. The PLT system overcame the inherent photonic inefficiency by bouncing photons many times between two mirrors. Using a photonic laser and a sophisticated photon beam amplification system, Dr. Bae demonstrated that photonic energy could generate amplified thrust between two spacecraft by bouncing photons many thousands of times between them.
The patent-pending Bae Photonic Laser Thruster (PLT) was built and monitored with off-the-shelf laboratory components at the Southern California laboratory of the Bae Institute. With an amplification factor of 3,000, the photon thrust generated from the egg-sized laser head in the PLT prototype is equivalent to the thrust that can currently only be generated by orders-of-magnitudes larger and heavier industrial or weapons-grade lasers.
Although PLT can be used for a wide range of space applications, including accelerating spacecraft to near light speed, Dr. Bae has more immediate goals. He plans to include PLT in a Photon Tether Formation Flight (PTFF), another of his patent pending ideas for controlling spacecraft flying in formation with nanometer precision. By integrating PLT and space tethers, PTFF will enable the creation of large telescopes and synthetic apertures in space for high-resolution earth or space monitoring. PTFF promises precision 100,000 times greater than existing formation flying spacecraft missions, notably the Proba-3 currently planned by European Space Agency (ESA).
As a result of this successful PLT demonstration, thrust power requirements for a wide range of NASA spacecraft formation flight configurations, such as SPECS and MAXIM, are well within today's space power budgets. No other propellants are needed with PLT, resulting in mass energy savings, extended spacecraft missions, and contaminant-free operation for highly sensitive sensors.
Although built on a shoestring budget, the maximum photon thrust was demonstrated to be 35 µN, which is already close to, or sufficient power for many envisioned space missions. Encouraged by this breakthrough, the Bae Institute is actively seeking further funding for scaling up and constructing space flight ready PLT systems. “In addition to conventional formation flying, fractionated space architectures can benefit tremendously from the versatility and flexibility of a tightly controlled PLT system,” according to Dr. Bae.
The PLT project is currently funded by a Phase II NIAC grant (NASA Institute for Advanced Concepts), which funds only the most prestigious and revolutionary ideas for the next generation NASA space missions.