The aerodynamic challenges of SRB recovery

Recovery and reuse of the Space Shuttle solid rocket boosters was baselined to support the primary goal to develop a low cost space transportation system. The recovery system required for the 170,000-lb boosters was for the largest and heaviest object yet to be retrieved from exoatmospheric conditions. State-of-the-art design procedures were ground-ruled and development testing minimized to produce both a reliable and cost effective system. The ability to utilize the inherent drag of the boosters during the initial phase of reentry was a key factor in minimizing the parachute loads, size and weight. A wind tunnel test program was devised to enable the accurate prediction of booster aerodynamic characteristics. Concurrently, wind tunnel, rocket sled and air drop tests were performed to develop and verify the performance of the parachute decelerator subsystem. Aerodynamic problems encountered during the overall recovery system development and the respective solutions are emphasized

Mars Lander Vehicle/Parachute Dynamics

Parachute decelerators used exclusively or in combination with retro rockets have been considered prime candidates for the terminal descent and landing system of a scientifically instrumented Mars lander. The objective of this study is to understand basic relationships between parameters affecting dynamic response of the parachute and capsule and to define those aspects of the system which have a sensitive effect on the design of the lander capsule. Of particular interest is the response of the capsule to wind gusts and to establish the sensitivity to gust onset rates in the VM series of Martian atmospheres. The model used in studying parachute/capsule relationships consists of two bodies, each with three degrees-of-freedom, connected by an elastic riser cable. The total elastic nature of the parachute and shroud lines is simulated by the equivalent elasticity of the riser cable. The parachute and its enclosed and apparent inertia effects are treated in a rigid body sense. Parachute opening phase dynamics are included in the analysis model. Motion of the system is examined in either the pitch or yaw plane with roll motion assumed to be controlled near zero by an attitude control system. Capsule attitude excursions and attitude rates are investigated in detail because of their impact on optical and radar sensors. The ability of a simple rate damping attitude control system to combat capsule oscillations is included in the study. Usually a planetary entry vehicle utilizes a blunt body aeroshell coated with ablative material for the high dynamic pressure, high Mach number portion of the entry trajectory. Once this region has been traversed and Mach number is reduced to approximately 1.6, the parachute decelerator may be deployed. From this point on, the aeroshell serves little usefulness and may complicate the touchdown mechanics. It may be desirable, therefore to jettison the aeroshell as soon as possible after parachute deployment. The ease of accomplishing aeroshell separation while descending on a parachute is evaluated

Video guidance, landing, and imaging systems

The adaptive potential of video guidance technology for earth orbital and interplanetary missions was explored. The application of video acquisition, pointing, tracking, and navigation technology was considered to three primary missions: planetary landing, earth resources satellite, and spacecraft rendezvous and docking. It was found that an imaging system can be mechanized to provide a spacecraft or satellite with a considerable amount of adaptability with respect to its environment. It also provides a level of autonomy essential to many future missions and enhances their data gathering ability. The feasibility of an autonomous video guidance system capable of observing a planetary surface during terminal descent and selecting the most acceptable landing site was successfully demonstrated in the laboratory. The techniques developed for acquisition, pointing, and tracking show promise for recognizing and tracking coastlines, rivers, and other constituents of interest. Routines were written and checked for rendezvous, docking, and station-keeping functions

Generalized controlled invariance for nonlinear systems

A general setting is developed which describes controlled invariance for nonlinear control systems and which incorporates the previous approaches dealing with controlled invariant (co-)distributions. A special class of controlled invariant subspaces, called controllability cospaces, is introduced. These geometric notions are shown to be useful for deriving a (geometric) solution to the dynamic disturbance decoupling problem and for characterizing the so-called fixed dynamics for the general input-output noninteracting cont.rol problem via dynamic compensation. These fixed dynamics are a major issue for studying noninteracting control with stability. The class of quasi-static state feedbacks is used

Preparing For and Living in a Brave New World

Today\u27s generation of autistic people at the precipice of transitioning into adulthood face great opportunity as well as great struggles ahead of them. This workshop will present grassroots personal and professional efforts to develop responsive educational/social programs that lead to quality transitions to college, work opportunities, entrepreneurship possibilities, and daily living/relationship success

Balloon launched Viking decelerator test program

Four BLDT flights were conducted during the summer of 1972. The purpose of these tests was to qualify the Viking parachute system behind the full-scale Viking entry vehicle over the maximum range of entry conditions anticipated in the Viking '75 soft landing on Mars. A summary of the test series is presented. Test conditions ranged from a Mach number of 2.0 to 0.5 and dynamic pressure from 11.7 to 4.4 psf. This range of conditions covers the uncertainty in entry conditions at Mars due to atmospheric and entry performance uncertainties. Emphasis is placed on parachute performance and simulated Mars entry vehicle motions as influenced by the parachute performance. Conclusions are presented regarding the ability of the parachute to perform within the operational parameters required for a successful soft Martian landing. A list of references which covers all reports in the qualification test program is included

Dinosaurs, ASD, and Social Skills

A collaboration between CNN Hero Dr. Wendy Ross’ Autism Inclusion Resources (AIR) and the Academy of Natural Sciences yielded an innovation social skills group for Foundations’ Lifeworks students, matching expert museum education staff such as paleontologist Jason Poole and staff at the Academy with Drs. Mitchell and Moog. The results were nothing short of inspirational. This workshop will highlight the outcomes of the group, and share poignant stories experienced along the way. Development of self-advocacy skills and future transitions will be showcased