Directed Energy Planetary Defense and Relativistic Probes
DE-STAR or Directed Energy System for Targeting of Asteroids and exploRation is a proposed system to deflect asteroids, comets, and other near Earth objects (NEOS) that pose a credible risk of impact. The objects that cross Earth’s orbit ,even relatively small ones, can still have a devastating effect. We propose an orbital planetary defense system capable of heating the surface of potentially hazardous objects to the point of vaporization. DE-STAR is a modular phased array of kilowatt class lasers powered by photovoltaics (PV). In our papers we distinguish between the large futuristic complete “stand-off” system which does NOT travel to the target we refer to as DE-STAR and the much smaller and more practical single launcher “stand-on” system which travels to the target we refer to as DE-STARLITE. There are a large number of technical papers, talks, orbital simulations and laboratory measurements below.
The modular design allows for incremental development and test, lowering cost, minimizing risk, and allowing for technological co-development. While DE-STAR is designed as a stand-off system (able to accomplish a task from afar), DE-STARLITE is a much smaller version which is deployable on a single launcher but still capable of mitigating large asteroids given sufficient warning.
The main objectives of DE-STAR and DE-STARLITE:
- To use the highly focused energy to raise the surface spot temperature to ~3,000 K, allowing direct vaporization and ejection of surface material altering the asteroid’s or comet’s orbit.
- The ideal system can simultaneously engage multiple targets.
Additional mission tasks include: space debris mitigation, powering or recharging of distant probes, standoff power to remote facilities, standoff photon drive propulsion of small spacecraft that can achieve relativistic speeds (DEEP-IN), composition analysis of remote objects including asteroids, and many others. The implications for SETI and ultra long range beacons extending even beyond our galaxy are also discussed.
The papers and videos below describe the various applications of this technology:
SPIE Optics and Photonics – San Diego – August 2015
Hughes et al. “Stand-off molecular composition analysis” (Invited): Paper
Brashears et al. “Directed Energy Deflection Laboratory Measurements” (Invited): Paper
Griswold, Madajian et al. “Simulations of directed energy thrust on rotating asteroids”: Paper
Steffanic et al. “Local phase control for a planar array of fiber laser amplifiers”: Paper
Research Mentorship Program – UCSB – Summer 2015
Vacuum Chamber Laser De-Spinning and Spinning Up of “Asteroid-like” Sample – July 2015
Cosmic Hazards and Planetary Defense – Springer – May 2015
Chapter on “Direct Energy Planetary Defense” – Pages 941-991
Book available from Springer here (We receive no funds from this.)
Hypervelocity Impact Symposium – HVIS – Boulder, CO April 2015
Conference Paper: Orbital Simulations for Directed Energy Deflection of Near-Earth Asteroids by Zhang et al.
Planetary Defense Conference – PDC – Frascati, Italy April 2015
Conference Paper: Effective Planetary Defense using Directed Energy by Lubin et al.
Vacuum chamber laser targeting of “asteroid like” sample at flux level >10 MW/m^2
See Brashears et al PDC 2015 above for details.
PDC April 2015 Simulated Threat
Below is a response to a hypothetical threat from a large asteroid as presented at the Planetary Defense Conference in Frascati, Italy in April 2015. The orbital simulation are done with a 3 body numerical solver and the results are compared to analytic approximations that are sometimes used (the 3 delta approximation). The numerical simulations are the proper way to look at a detailed mission while the analytic approximations are used for quick rough misision designs. See our papers for more details.
Suppose we send a DE-STARLITE mission to an asteroid and it arrives at the asteroid 4 years before impact (when the asteroid is ~2.9 au from the Earth). How far will the asteroid be deflected? Here’s a comparison of a 100 m, 200 m and a 300 m diameter asteroid with a 12N thrust (~ 100-200 kW laser). As can be seen even large asteroids can be effectively deflected even with modest DE-STARLITE missions. If we begin the interdiction process even earlier the laser power requirements are reduced or if larger power is used even short interdiction times are feasible. See our papers for more detailed mission discussions.
SPIE Optics + Photonics August 2014
Contributed Paper: DE-STARLITE – A Directed Energy Planetary Defense Mission by Kosmo et al.
Contributed Paper: Effects of asteroid rotation on directed energy deflection by Johansson and Hummelgard et al.
Contributed Paper: Directed energy active illumination for near-Earth object detection by Riley et al.
Invited Paper: Optical modeling for a laser phased-array directed energy system by Hughes et al.
SPIE Optical Engineering Article 2014
Journal Article: Toward directed energy planetary defense by Lubin et al.
SPIE Optics + Photonics August 2013
Plenary Paper: Directed Energy Planetary Defense by Lubin et al.
Keynote Paper: DE-STAR: Phased-Array Laser Technology for Planetary Defense and Other Scientific Purposes by Hughes et al.
Student Paper: Relativistic Propulsion Using Directed Energy by Bible et al.
Plenary Talk Description and Video: DE-STAR: A Planetary Defense and Exploration System by Lubin
News Article Asteroid-zapping lasers step out of science fiction by Burkhart
Video Interview Philip Lubin: A space-based array for planetary defense by Donnelly and Probasco
SETI Big Picture Science Radio Show – February 2014
Interview Space For Everyone: Philip Lubin by Niederhoff
SETI Talk – February 2014
Laboratory tests of high efficiency 19 element laser at 808 nm focused onto a Basalt target at a flux of about 20 MW/m^2. Max spot temperature is mass ejection limited at about 2600-3000K.
Physics based simulation of laser interaction with asteroid Apophis (325 m diameter) at 1 AU. Click on image to start and stop video. Caio Motta made this video with Cinema 4D Studio donated by MAXON Computer.
Plume ejecta speeds are approximately 1 km/s. Asteroid composition is typical high temperature rocky material (Si, Al, Fe, Mg oxides etc) with a spot temperature that is mass ejection limited at about 3000K for this example compound.
We gratefully acknowledge support from the NASA California Space Grant Consortium.