Advanced Guidance and Control for Hypersonics and Space Access
Advanced guidance and control (AGC application to hypersonic air-breathers is planned. We list the test cases used to demonstrate that the desired results are achieved, briefly describe an automated test scoring method, and display results of the tests. Some of the technology components have reached the maturity level where they are ready for application to a new vehicle concept, while others are not far along in development.
PERFORMANCE OF EVOLVED ACCELERATION GUIDANCE LOGIC FOR ENTRY (EAGLE)
This paper presents the design and performance of Evolved Acceleration Guidance Logic for Entry (EAGLE), an algorithm intended for future space transportation vehicles. The most distinguishing feature of EAGLE is its ability to plan a three-dimensional trajectory and thereby handle large crossrange entries. EAGLE consists of two integrated components: a trajectory planner and a tracking law. The planner generates reference drag acceleration and lateral acceleration profiles, along with the reference state and bank angle profiles. The tracking law, based on feedback linearization, commands the angles of bank and attack required to follow the reference drag and heading profiles. In this paper we discuss the planner and tracking law and present simulation results indicating the performance of EAGLE. Extensive simulations of a broad range of return-from-orbit entries show that EAGLE achieves the desired target with final position and heading errors within allowable tolerances.
Air scrubbing techniques for ammonia and odor reduction at livestock operations : review of on-farm research in the Netherlands
Acid scrubbers and biotrickling filters have been developed for ammonia (NH3) removal at pig and poultry houses 
in The Netherlands over the last 20 years to prevent acidification and eutrophication of soils. Because of growing 
suburbanization, odor removal is increasingly considered important as well. In this review, we report the results of the on-farm 
research on full-scale operated scrubbers for treatment of exhaust air from animal houses with regard to NH3 and odor 
removal in The Netherlands. The NH3 removal of acid scrubbers ranged from 40% to 100% with an overall average of 96%. 
The NH3 removal of biotrickling filters ranged from -8% to +100% with an overall average of 70%. Minimum empty bed air 
residence times (EBRTs) were 0.4 to 1.1 s. For acid scrubbers, process control with pH measurement and automatic water 
discharge is sufficient to guarantee sufficient NH3 removal. For biotrickling filters, however, improvement of process control 
is necessary to guarantee sufficient NH3 removal. The odor removal of acid scrubbers ranged from 3% to 51% with an overall 
average of 27%. The odor removal of biotrickling filters ranged from -29% to +87% with an overall average of 51%. 
Minimum EBRTs were 0.5 to 2.3 s. Further research is necessary to explain this variation and to improve the odor removal 
efficiency of both acid scrubbers and biotrickling filters.