The Instrument Test Dewar (ITD): Testing satellite instruments at 1.5 K

The Instrument Test Dewar (ITD) is a cryogenic facility designed and built to test Cosmic Background Explorer (COBE) satellite instruments at 1.5 K. The facility provides a high vacuum and thermal environment with payload thermal, electrical and optical interfaces. There are two concentric vacuum spaces which are not hermitically sealed. The instrument vacuum space is 81.28 cm by 243.84 cm and is cooled by an LHe shroud. The guard vacuum space surrounds an LN2 shroud. There are two separate cryosorption pumping systems and a mechanical LHe pumping system. The data acquisition systems provide payload and housekeeping data. There have been various problems with the facility, and changes and improvements have been made to assure optimum test conditions. COBE instrument testing has been completed on structural, thermal model hardware and the protoflight units

The test facility requirements for the thermal vacuum thermal balance test of the Cosmic Background Explorer Observatory

The Cosmic Background Explorer Observatory (COBE) underwent a thermal vacuum thermal balance test in the Space Environment Simulator (SES). This was the largest and most complex test ever conducted at this facility. The 4 x 4 m (13 x 13 ft) spacecraft weighed approx. 2223 kg (4900 lbs) for the test. The test set up included simulator panels for the inboard solar array panels, simulator panels for the flight cowlings, Sun and Earth Sensor stimuli, Thermal Radio Frequency Shield heater stimuli and a cryopanel for thermal control in the Attitude Control System Shunt Dissipator area. The fixturing also included a unique 4.3 m (14 ft) diameter Gaseous Helium Cryopanel which provided a 20 K environment for the calibration of one of the spacecraft's instruments, the Differential Microwave Radiometer. This cryogenic panel caused extra contamination concerns and a special method was developed and written into the test procedure to prevent the high buildup of condensibles on the panel which could have led to backstreaming of the thermal vacuum chamber. The test was completed with a high quality simulated space environment provided to the spacecraft. The test requirements, test set up, and special fixturing are described

Results of investigations on a 0.010-scale model of the configuration 3 space shuttle orbiter and external tank in the NASA/Ames Research Center 3.5-foot hypersonic wind tunnel (IA15)

Experimental aerodynamic investigations were conducted in a 3.5-foot hypersonic wind tunnel. The model used for this test was a 0.010-scale of the Configuration 2 Space Shuttle Orbiter and the External Tank. Six-component aerodynamic force and moment data were recorded over an angle of attack range from -8 deg to +30 deg at 0 deg and 5 deg angles of sideslip. Data was also recorded during beta sweeps of -8 deg to +10 deg at angles of attack of -10 deg, 0 deg, and 30 deg. All testing was done at Mach 7.3. Various elevon, rudder and orbiter to external tank attaching structures and fairings were tested to determine longitudinal and lateral-directional stability characteristics. Non-metric exhaust plumes were installed during a portion of the testing to determine the effects of the main propulsion system rocket plumes

Results of investigations on an 0.015-scale 140A/B configuration of the Rockwell International space shuttle orbiter (model 49-O) in the NASA/Ames Research Center 3.5-foot hypersonic wind tunnel (OA36)

The results of wind tunnel tests of the 140A/B configuration components are reported for the fuselage, canopy, elevons, bodyflaps, pods, engine nozzles, rudder, vertical tail, and wing. The test facility, and data reduction procedures are described. Test results for each component are graphed, and tabulated source data are included

Results of tests of a 0.010- and 0.015-scale models of space shuttle orbiter configurations 3 and 3A in the Ames Research Center 3.5 foot hypersonic wind tunnel (OA23)

Longitudinal and lateral-directional stability and control characteristics were evaluated at Mach numbers of 5.3, 7.3 and 10.3 at angles of attack up to 50 degrees with Beta = 0 degrees and, for a few cases, Beta = 5 degrees. Component force data, fuselage base pressures and shadowgraph patterns were recorded

Computer tools for systems engineering at LaRC

The Systems Engineering Office (SEO) has been established to provide life cycle systems engineering support to Langley research Center projects. over the last two years, the computing market has been reviewed for tools which could enhance the effectiveness and efficiency of activities directed towards this mission. A group of interrelated applications have been procured, or are under development including a requirements management tool, a system design and simulation tool, and project and engineering data base. This paper will review the current configuration of these tools and provide information on future milestones and directions

Parental stress increases body mass index trajectory in pre-adolescents.

What is already known about this subjectRates of childhood obesity have increased since the mid-1970s. Research into behavioural determinants has focused on physical inactivity and unhealthy diets. Cross-sectional studies indicate an association between psychological stress experienced by parents and obesity in pre-adolescents.What this study addsWe provide evidence of a prospective association between parental psychological stress and increased weight gain in pre-adolescents. Family-level support for those experiencing chronic stress might help promote healthy diet and exercise behaviours in children.ObjectiveWe examined the impact of parental psychological stress on body mass index (BMI) in pre-adolescent children over 4 years of follow-up.MethodsWe included 4078 children aged 5-10 years (90% were between 5.5 and 7.5 years) at study entry (2002-2003) in the Children's Health Study, a prospective cohort study in southern California. A multi-level linear model simultaneously examined the effect of parental stress at study entry on the attained BMI at age 10 and the slope of change across annual measures of BMI during follow-up, controlled for the child's age and sex. BMI was calculated based on objective measurements of height and weight by trained technicians following a standardized procedure.ResultsA two standard deviation increase in parental stress at study entry was associated with an increase in predicted BMI attained by age 10 of 0.287 kg m(-2) (95% confidence interval 0.016-0.558; a 2% increase at this age for a participant of average attained BMI). The same increase in parental stress was also associated with an increased trajectory of weight gain over follow-up, with the slope of change in BMI increased by 0.054 kg m(-2) (95% confidence interval 0.007-0.100; a 7% increase in the slope of change for a participant of average BMI trajectory).ConclusionsWe prospectively demonstrated a small effect of parental stress on BMI at age 10 and weight gain earlier in life than reported previously. Interventions to address the burden of childhood obesity should address the role of parental stress in children