Relativistic propulsion using directed energy

Bible, Johanna; Johansson, Isabella; Hughes, Gary B.; Lubin, P. M.

doi:10.1117/12.2035346

Cited by 33 publications

(29 citation statements)

References 8 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…We will use this later for a DE-STAR standoff "photon rail gun" propulsion system. 2 The thrust per watt, in this case, is F∕P ¼ 2∕c ∼ 6.6 nN∕W or more than 10 5 times lower than our plume thrust. Current state of the art ion engines (e.g., VASMIR VX-200) use 200 kW and produced 5.7 N with an exhaust speed of 50 km∕s (10× shuttle main engine H 2 − O 2 and 20× that of the SRB which is ∼2.6 km∕s) and 72% efficiency using argon and a plasma exhaust equivalent T ∼ 10 6 K with a thrust per watt of 2.85 × 10 −5 N∕W or about 3% of the SRB thrust/watt.…”

Section: -D Thermal Calculationmentioning

confidence: 99%

“…In a companion paper, Bible et al 2 discuss using this mode to propel spacecraft at mildly relativistic speeds. For example, a 100-, 1000-, 10,000-kg spacecraft with a 30-m diameter (9 kg, 10-μm-thick multilayer dielectric) reflector will reach 1 AU (∼Mars) in 3, 10, 30 days.…”

Section: Optical Engineering 025103-16mentioning

confidence: 99%

“…The flux on target (W∕m 2 ) at a fixed distance scales as the d 4 where d is the linear dimension of the array and thus it increases very rapidly with increased size. This system is useful for many other purposes, which are briefly mentioned in this article (and discussed in greater detail in other SPIE Optics & Photonics 2013 Proceedings papers, including Hughes et al 1 and Bible et al 2 ).…”

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Toward directed energy planetary defense

et al. 2014

Self Cite

View full text Add to dashboard Cite

Abstract. Asteroids and comets that cross Earth's orbit pose a credible risk of impact, with potentially severe disturbances to Earth and society. We propose an orbital planetary defense system capable of heating the surface of potentially hazardous objects to the vaporization point as a feasible approach to impact risk mitigation. We call the system DE-STAR, for Directed Energy System for Targeting of Asteroids and exploRation. The DE-STAR is a modular-phased array of kilowatt class lasers powered by photovoltaic's. Modular design allows for incremental development, minimizing risk, and allowing for technological codevelopment. An orbiting structure would be developed in stages. The main objective of the DE-STAR is to use focused directed energy to raise the surface spot temperature to ∼3000 K, sufficient to vaporize all known substances. Ejection of evaporated material creates a large reaction force that would alter an asteroid's orbit. The baseline system is a DE-STAR 3 or 4 (1-to 10-km array) depending on the degree of protection desired. A DE-STAR 4 allows initial engagement beyond 1 AU with a spot temperature sufficient to completely evaporate up to 500-m diameter asteroids in 1 year. Small objects can be diverted with a DE-STAR 2 (100 m) while space debris is vaporized with a DE-STAR 1 (10 m).

show abstract

Section: -D Thermal Calculationmentioning

confidence: 99%

Section: Optical Engineering 025103-16mentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Toward directed energy planetary defense

et al. 2014

Self Cite

View full text Add to dashboard Cite

show abstract

“…It was not discussed in this paper, but DE-STAR also has the ability to perform a variety of other functions besides detection including deflection, vaporization and compositional analysis of NEOs. 6,7,8,910,11…”

Section: Discussionmentioning

confidence: 99%

Directed energy active illumination for near-Earth object detection

Riley

Lubin

Hughes

et al. 2014

Nanophotonics and Macrophotonics for Space Environments VIII

Self Cite

View full text Add to dashboard Cite

On 15 February 2013, a previously unknown ~20 m asteroid struck Earth near Chelyabinsk, Russia, releasing kinetic energy equivalent to ~570 kt TNT. Detecting objects like the Chelyabinsk impactor that are orbiting near Earth is a difficult task, in part because such objects spend much of their own orbits in the direction of the Sun when viewed from Earth. Efforts aimed at protecting Earth from future impacts will rely heavily on continued discovery. Ground-based optical observatory networks and Earth-orbiting spacecraft with infrared sensors have dramatically increased the pace of discovery. Still, less than 5% of near-Earth objects (NEOs) 100 m/~100 Mt TNT have been identified, and the proportion of known objects decreases rapidly for smaller sizes. Low emissivity of some objects also makes detection by passive sensors difficult. A proposed orbiting laser phased array directed energy system could be used for active illumination of NEOs, enhancing discovery particularly for smaller and lower emissivity objects. Laser fiber amplifiers emit very narrow-band energy, simplifying detection. Results of simulated illumination scenarios are presented based on an orbiting emitter array with specified characteristics. Simulations indicate that return signals from small and low emissivity objects is strong enough to detect. The possibility for both directed and full sky blind surveys is discussed, and the resulting diameter and mass limits for objects in different observational scenarios. The ability to determine both position and speed of detected objects is also discussed.

show abstract

“…Therefore, the craft has an effectively unlimited Δ v budget, at least in theory. Such a setup was recently discussed in [1] and explored previously in [2] and [3].…”

Section: Introductionmentioning

confidence: 99%

Orbital simulations of laser-propelled spacecraft

et al. 2015

Self Cite

View full text Add to dashboard Cite

Spacecraft accelerate by directing propellant in the opposite direction. In the traditional approach, the propellant is carried onboard in the form of material fuel. This approach has the drawback of being limited in Delta v by the amount of fuel launched with the craft, a limit that does not scale well to high Delta v due to the massive nature of the fuel. Directed energy photon propulsion solves this problem by eliminating the storage of fuel onboard. A phased array of lasers may be used to propel the spacecraft, contributing no mass to the spacecraft beyond that of the reflector, enabling a prolonged acceleration and much higher final speeds. This paper compares the effectiveness of such a system for propelling spacecraft into interplanetary and interstellar space across various laser and sail configurations. Simulated parameters include laser power, optics size and orbit as well as payload mass, reflector size and the trajectory of the spacecraft. As one example, a large 70 GW laser with 10 km optics could propel a 1 kg payload past Neptune (~30 au) in 5 days at 4% the speed of light, or a 1 g payload past Mars (~0.5 au) in 20 minutes at 21% the speed of light. However, even lasers down to 2 kW power and 1 m optics show noticeable effect on gram-class payloads, boosting their altitude in low Earth orbits by several kilometers per day which is already sufficient to be of practical use.

show abstract

Relativistic propulsion using directed energy

Cited by 33 publications

References 8 publications

Toward directed energy planetary defense

Toward directed energy planetary defense

Directed energy active illumination for near-Earth object detection

Orbital simulations of laser-propelled spacecraft

Contact Info

Product

Resources

About