My latest patent, Patent No. US 8718920 B2
, for a system and method for determining Earth-fixed trajectory launching from within a specified area, was granted by the director of the United States Patent and Trademark Office on May 6, 2014. The novel idea at the core of the technique was to recast the analysis in Earth-fixed frame and in mission elapsed time (MET) as opposed to other traditional methods that do the analysis in inertial frame and in civil time. In this view of the problem, for any specified moment in MET, the launch vehicle position in Earth-fixed frame is fixed. Shifting the launch time will cause changes to the encounter geometries between the launch vehicle and secondary orbiting objects in civil time due to the motion of the latter. Hence, for each location of the launch vehicle along its Earth-fixed trajectory that corresponds to some moment in MET, it is possible to determine blackout intervals in civil time when any of the secondaries appear too close to where the launch vehicle would be at this moment in MET. Collecting these results by judiciously sampling along the entire launch trajectory makes it possible to aggregate the overall blackout intervals and conversely the clear-to-launch intervals. The new patent describes how to solve a modified launch COLA problem in which the launch site can be located anywhere within a specified area. It still uses Earth-fixed frame and MET, but adds another spatial dimension to the problem. At a specified moment in MET, additional search is performed on a surface that at this moment represents current Earth fixed locations of all possible launches from the specified launch area. For each secondary, close approach is measured to that entire surface instead of to a single point as was the case in the previous analysis. A continuous two-dimensional search is performed on that surface to identify the point on the surface nearest to the passing secondary as the launch time is being varied within its window. Clearing the entire surface in this case means clearing its nearest point. The point is different for each secondary and changes from one moment in MET to another. Still, as was the case with a single launch, blackout intervals at any moment in MET can be collected after judiciously sampling in MET resulting in the overall blackout and clear-to-launch intervals for the entire selected surface, i.e., for all possible launch locations within specified area. You can download a presentation based on this patent here
or learn more about AGI's other patents here
Launch COLA for a specified launch area from Analytical Graphics, Inc. on Vimeo.