Picture of DNA strand

Pioneering chemical biology & medicinal chemistry through Open Access research...

Strathprints makes available scholarly Open Access content by researchers in the Department of Pure & Applied Chemistry, based within the Faculty of Science.

Research here spans a wide range of topics from analytical chemistry to materials science, and from biological chemistry to theoretical chemistry. The specific work in chemical biology and medicinal chemistry, as an example, encompasses pioneering techniques in synthesis, bioinformatics, nucleic acid chemistry, amino acid chemistry, heterocyclic chemistry, biophysical chemistry and NMR spectroscopy.

Explore the Open Access research of the Department of Pure & Applied Chemistry. Or explore all of Strathclyde's Open Access research...

A space-based laser system for the deflection and manipulation of near Earth asteroids

Gibbings, Alison and Vasile, Massimiliano and Hopkins, John-Mark and Wayman, Alastair and Eckersley, Steven and Watson, Ian A. (2014) A space-based laser system for the deflection and manipulation of near Earth asteroids. In: International High Power Laser Ablation and Beamed Energy Propulsion Symposium, HPLA/BEP, 2014-04-21 - 2014-06-25.

[img] PDF (Gibbings A et al - Pure - A space-based laser system for the deflection and manipulation of near Earth asteroids Apr 2014 - HPLA Conference Proceedings)
Gibbings_A_et_al_Pure_A_space_based_laser_system_for_the_deflection_and_manipulation_of_near_Earth_asteroids_Apr_2014_HPLA_Conference_Proceedings.pdf
Preprint

Download (566kB)

Abstract

Abstract Analysis gained from a series of experiments has demonstrated the effectiveness of laser ablation for the low thrust, contactless deflection and manipulation of Near Earth Asteroids. In vacuum, a 90 W continuous wave laser beam has been used to ablate a magnesium-iron silicate sample (olivine). The laser operated at a wavelength of 808 nm and provided intensities that were below the threshold of plasma formation. Olivine was use to represent a rocky and solid asteroidal body. Assessed parameters included the average mass flow rate, divergence, temperature and velocity of the ejecta plume, and the height, density and absorptivity of the deposited ejecta. Experimental data was used to verify an improved ablation model. The improved model combined the energy balance of sublimation with the energy absorption within the Knudsen layer, the variation of flow with local pressure, the temperature of the target material and the partial re-condensation of the ablated material. It also enabled the performance of a space-based laser system to be reassessed. The capability of a moderately sized, conventional solar powered spacecraft was evaluated by its ability to deflect a small and irregular 4 m diameter asteroid by at least 1 m/s. Deflection had to be achieved with a total mission lifetime of three years. It was found to be an achievable and measurable objective. The laser (and its associated optical control) was designed using a simple combined beam expansion and focusing telescope. The mission study therefore verified the laser’s proof-of-concept, technology readiness and feasibility of its mission and subsystem design. It also explored the additional opportunistic potential of the ablation process. The same technique can be used for the removal of space debris.