Pioneer 11 used four SNAP-19 radioisotope thermoelectric generators (RTGs) (see diagram). They were positioned on two three-rod trusses, each 3 meters (9 feet 10 inches) in length and 120 degrees apart. This was expected to be a safe distance from the sensitive scientific experiments carried on board. Combined, the RTGs provided 155 watts at launch, and decayed to 140 W in transit to Jupiter. The spacecraft required 100 W to power all systems.
Analysis of the radio tracking data from the Pioneer 10 and 11 spacecraft at distances between 2070 AU from the Sun has consistently indicated the presence of a small but anomalous Doppler frequency drift. The drift can be interpreted as due to a constant acceleration of (8.74 1.33) 1010 m/s2 directed towards the Sun. Although it is suspected that there is a systematic origin to the effect, none was found. As a result, there is sustained interest in the nature of this so-called "Pioneer anomaly". Extended analysis of mission data by Slava Turyshev and colleagues has determined the source of the anomaly to be asymmetric thermal radiation and the resulting thermal recoil force acting on the face of the Pioneers away from the Sun, and in July 2012 the group of researchers published their results in the Physical Review Letters scientific journal.
In cognitive theory, behavior is explained as guided by cognitions (e.g. expectations) about the world, especially those about other people. Cognitive theories are theories of personality that emphasize cognitive processes, such as thinking and judging.
Albert Bandura, a social learning theorist suggested the forces of memory and emotions worked in conjunction with environmental influences. Bandura was known mostly for his "Bobo doll experiment". During these experiments, Bandura video taped a college student kicking and verbally abusing a bobo doll. He then showed this video to a class of kindergarten children who were getting ready to go out to play. When they entered the play room, they saw bobo dolls, and some hammers. The people observing these children at play saw a group of children beating the doll. He called this study and his findings observational learning, or modeling.
Early examples of approaches to cognitive style are listed by Baron (1982). These include Witkin's (1965) work on field dependency, Gardner's (1953) discovering people had consistent preference for the number of categories they used to categorise heterogeneous objects, and Block and Petersen's (1955) work on confidence in line discrimination judgments. Baron relates early development of cognitive approaches of personality to ego psychology. More central to this field have been:
Attributional style theory dealing with different ways in which people explain events in their lives. This approach builds upon locus of control, but extends it by stating we also need to consider whether people attribute to stable causes or variable causes, and to global causes or specific causes.
Various scales have been developed to assess both attributional style and locus of control. Locus of control scales include those used by Rotter and later by Duttweiler, the Nowicki and Strickland (1973) Locus of Control Scale for Children and various locus of control scales specifically in the health domain, most famously that of Kenneth Wallston and his colleagues, The Multidimensional Health Locus of Control Scale. Attributional style has been assessed by the Attributional Style Questionnaire, the Expanded Attributional Style Questionnaire, the Attributions Questionnaire, the Real Events Attributional Style Questionnaire and the Attributional Style Assessment Test.
Achievement style theory focuses upon identification of an individual's Locus of Control tendency, such as by Rotter's evaluations, and was found by Cassandra Bolyard Whyte to provide valuable information for improving academic performance of students. Individuals with internal control tendencies are likely to persist to better academic performance levels, presenting an achievement personality, according to Cassandra B. Whyte.
Recognition that the tendency to believe that hard work and persistence often results in attainment of life and academic goals has influenced formal educational and counseling efforts with students of various ages and in various settings since the 1970s research about achievement. Counseling aimed toward encouraging individuals to design ambitious goals and work toward them, with recognition that there are external factors that may impact, often results in the incorporation of a more positive achievement style by students and employees, whatever the setting, to include higher education, workplace, or justice programming.
Walter Mischel (1999) has also defended a cognitive approach to personality. His work refers to "Cognitive Affective Units", and considers factors such as encoding of stimuli, affect, goal-setting, and self-regulatory beliefs. The term "Cognitive Affective Units" shows how his approach considers affect as well as cognition.
Cognitive-Experiential Self-Theory (CEST) is another cognitive personality theory. Developed by Seymour Epstein, CEST argues that humans operate by way of two independent information processing systems: experiential system and rational system. The experiential system is fast and emotion-driven. The rational system is slow and logic-driven. These two systems interact to determine our goals, thoughts, and behavior.
Personal construct psychology (PCP) is a theory of personality developed by the American psychologist George Kelly in the 1950s. Kelly's fundamental view of personality was that people are like naive scientists who see the world through a particular lens, based on their uniquely organized systems of construction, which they use to anticipate events. But because people are naive scientists, they sometimes employ systems for construing the world that are distorted by idiosyncratic experiences not applicable to their current social situation. A system of construction that chronically fails to characterize and/or predict events, and is not appropriately revised to comprehend and predict one's changing social world, is considered to underlie psychopathology (or mental illness.) From the theory, Kelly derived a psychotherapy approach and also a technique called The Repertory Grid Interview that helped his patients to uncover their own "constructs" with minimal intervention or interpretation by the therapist. The repertory grid was later adapted for various uses within organizations, including decision-making and interpretation of other people's world-views.