Since long, Scientists have been trying to find a way to deploy large structures in space. However, transporting such large structures into space is not feasible given the limitations on payload size. The patented invention from DARPA solves this problem by taking an ingenious approach of building large structures in space itself. It takes advantage of the very special conditions that exist in space, in particular, microgravity, which is the name given to extremely low gravitational forces in space.
The Defense Advanced Research Projects Agency (DARPA) is an agency of the U.S. Department of Defense responsible for the development of emerging technologies for use by the military.
One of the remarkable effects of microgravity is the creation and sustenance of very large bubbles. For example, it is possible to create bubbles in space that are 100 times bigger than the bubbles possible under earth’s gravity. A 50cm diameter bubble formed on earth will be 50m in diameter when formed in space.
To start with, injector ports are activated. Then, a polymer film is laid over two injector ports. A gas is then ejected through apertures in the injector ports causing the polymer films to inflate and form two bubbles which then intersect each other along a surface. When two bubbles of equal size intersect each other, the surface of intersection is a flat plane. The polymer film includes a UV curing agent, which hardens the bubbles when exposed to UV radiation; for example the UV radiation from the sun.
After hardening the polymer bubbles, one side of the intersection surface is coated with metal in order to provide a reflective surface.
Only the intersection surface is of use here, so the remaining parts of the bubbles are separated.
Such a reflective surface may be as large as a kilometer in diameter. It can be used as a solar sail for propulsion. Solar sails will make space travel far more cheaper, and help us reach further distances into the cosmos.
Other applications of this technology include large aperture microwave reflectors and antennas onboard satellites, large aperture space optics, calibration sources for ground and space-based sensors, drag surfaces for deorbiting spacecraft, and defensive mechanisms such as decoys to protect spacecraft from enemy.
Patent Number: 9, 108, 370
Patent Title: Microgravity fabrication and metalization of large, lightweight polymeric bubbles and films for space system applications
Inventors: Joshi; Prakash B. (Andover, MA), Oakes; David B. (Reading, MA), Salley; Edward J. (Andover, MA), Dokhan; Allan (Belmont, MA), Chiang; Kophu (North Andover, MA), Gelb; Alan (Boston, MA), Hagge; John (Laporte, MN), Green; B. David (Methuen, MA)
Assignee: Physical Sciences, Inc. (Andover, MA)
Family ID: 48136198
Appl. No.: 13/655, 240
Filed: October 18, 2012
Abstract: A method of forming a metalized polymeric bubble in a space, microgravity environment is described. A liquid polymer bubble having a predetermined diameter is formed from a mixture comprising a liquid polymer and at least one of a UV curing material, a stabilizer, a UV absorber, or a surfactant. The liquid polymer bubble is cured with radiation to form a rigid polymer bubble. The rigid polymer bubble is then metalized with a metal to form the metalized polymeric bubble.
The invention was made with government support under National Reconnaissance Office contract number NRO000-02-C-0370. The invention was made with government support under Missile Defense Agency/Air Force contract number HQ0006-06-C-7457. The invention was made with government support under Defense Advanced Research Projects Agency contract number HR0011-07-P-0007. The invention was made with government support under the Air Force Research laboratory contract number FA9453-09-M-0161. The government has certain rights in the invention.