Social support and depressed mood in isolated and confined environments

The influence of isolation and confinement on social support and depressed mood was examined in a study of 235 men and women who spent a year at McMurdo Station in Antarctica, and a study of 77 men and women who spent a year at the Amundson-Scott South Pole Station. Although availability of support remained unchanged, there was a significant decrease in reported satisfaction with support obtained, as well as a significant increase in depressed mood. Satisfaction with support was inversely associated with depressed mood at the beginning and end of isolation and confinement. At the end of winter, this association varied by source of support. High levels of tension-anxiety, depression and anger preceded an increase in advice seeking, but high levels of advice seeking also preceded an increase in tension-anxiety and depression. Results suggest a significant erosion of social support under conditions of prolonged isolation and confinement, leading to an increase in depressed mood.     

Balloon film strain measurement

In order to understand the state of stress in scientific balloons, a need exists for the measurement of film deformation in flight. The results of a flight test program are reported where material strain was measured for the first time during the inflation, launch, ascent and float of a typical natural shape, zero pressure scientific balloon.     

Results of studies on advanced winged space transportation systems

This paper reviews advanced space transportation studies that have been conducted at the NASA Langley Research Center over the past several years and presents the impact of technology on vehicle size and weight. The focus of this work has been on systems that could become operational in the late 1990s and beyond with the primary emphasis on winged vehicles, both single-stage-to-orbit and two-stage concepts.     

Venus, Mars, and the ices on Mercury and the moon: astrobiological implications and proposed mission designs

Venus and Mars likely had liquid water bodies on their surface early in the Solar System history. The surfaces of Venus and Mars are presently not a suitable habitat for life, but reservoirs of liquid water remain in the atmosphere of Venus and the subsurface of Mars, and with it also the possibility of microbial life. Microbial organisms may have adapted to live in these ecological niches by the evolutionary force of directional selection. Missions to our neighboring planets should therefore be planned to explore these potentially life-containing refuges and return samples for analysis. Sample return missions should also include ice samples from Mercury and the Moon, which may contain information about the biogenic material that catalyzed the early evolution of life on Earth (or elsewhere). To obtain such information, science-driven exploration is necessary through varying degrees of mission operation autonomy. A hierarchical mission design is envisioned that includes spaceborne (orbital), atmosphere (airborne), surface (mobile such as rover and stationary such as lander or sensor), and subsurface (e.g., ground-penetrating radar, drilling, etc.) agents working in concert to allow for sufficient mission safety and redundancy, to perform extensive and challenging reconnaissance, and to lead to a thorough search for evidence of life and habitability.     

An Improved Piezoelectric Balance for Aerodynamic Force

A method for measuring model forces in the shock tunnel by means of an acceleration-compensated balance has been reported by the authors.1 Since that time, a continuing program of research and development on advanced shock-tunnel instrumentation at Cornell Aeronautical Laboratory, Inc. has led to a promising new balance configuration. This balance is inherently more compact than previous designs, and allows testing of higher lift/drag (L/D) configurations than before. The increased high-pressure capability of the shock tunnel, and the growing recognition of the importance of the shock tunnel as a means of generating large Reynolds number flow, have thus added to the importance of this new higher load, more compact balance concept. An experimental balance has been built and calibrated. The performance of this balance is presented in this paper.     

Reentry Vehicle Radar Altimeter Antenna Patterns

An analytical technique is proposed for investigating the effect of antenna pattern shape on reentry vehicle radar altimeter performance. Initially, a method is presented that computes the average performance under all roll positions. This method is then extended to allow performance to be determined at each roll position. Some numerical results are included that show roll effects for a typical antenna pattern.     

Rapid impactor sample return (RISR) mission scenario

Due to the long lead time and great expense of traditional sample return mission plans to Mars or other astronomical bodies, there is a need for a new and innovative way to return materials, potentially at a lower cost. The Rapid Impactor Sample Return (RISR) mission is one such proposal. The general mission scenario involves a single pass of Mars, a Martian moon or an asteroid at high speeds (7 km/s), with the sample return vehicle skimming just 1 or 2 m above a high point (such as a top ridge on Olympus Mons on Mars) and releasing an impactor. The impactor strikes the ground, throwing up debris. The debris with roughly the same forward velocity will be captured by the sample return vehicle and returned to Earth. There is no delay or orbit in the vicinity of Mars or the asteroid: RISR is a one-pass mission. This paper discusses some of the details of the proposal. Calculations are presented that address the question of how much material can be recovered with this technique. There are concerns about the effect of Mars tenuous atmosphere. However, it will be noted that such issues do not occur for RISR style missions to Phobos, Deimos, or asteroids and Near Earth Objects (NEOs). Recent test results in the missile defense community (IFTs 6–8 in 2001, 2002) have scored direct hits at better than 1 m accuracy with closing velocities of 7.6 km/s, giving the belief that accuracy and sensing issues are developed to a point that the RISR mission scenario is feasible.     

MESSENGER Mission Design and Navigation

Nearly three decades after the Mariner 10 spacecraft’s third and final targeted Mercury flyby, the 3 August 2004 launch of the MESSENGER (MErcury Surface, Space ENvironment, GEochemistry, and Ranging) spacecraft began a new phase of exploration of the closest planet to our Sun. In order to ensure that the spacecraft had sufficient time for pre-launch testing, the NASA Discovery Program mission to orbit Mercury experienced launch delays that required utilization of the most complex of three possible mission profiles in 2004. During the 7.6-year mission, the spacecraft’s trajectory will include six planetary flybys (including three of Mercury between January 2008 and September 2009), dozens of trajectory-correction maneuvers (TCMs), and a year in orbit around Mercury. Members of the mission design and navigation teams optimize the spacecraft’s trajectory, specify TCM requirements, and predict and reconstruct the spacecraft’s orbit. These primary mission design and navigation responsibilities are closely coordinated with spacecraft design limitations, operational constraints, availability of ground-based tracking stations, and science objectives. A few days after the spacecraft enters Mercury orbit in mid-March 2011, the orbit will have an 80° inclination relative to Mercury’s equator, a 200-km minimum altitude over 60°N latitude, and a 12-hour period. In order to accommodate science goals that require long durations during Mercury orbit without trajectory adjustments, pairs of orbit-correction maneuvers are scheduled every 88 days (once per Mercury year).     

Experiment LEND of the NASA Lunar Reconnaissance Orbiter for high-resolution mapping of neutron emission of the Moon

The scientific objectives of neutron mapping of the Moon are presented as 3 investigation tasks of NASA's Lunar Reconnaissance Orbiter mission. Two tasks focus on mapping hydrogen content over the entire Moon and on testing the presence of water-ice deposits at the bottom of permanently shadowed craters at the lunar poles. The third task corresponds to the determination of neutron contribution to the total radiation dose at an altitude of 50 km above the Moon. We show that the Lunar Exploration Neutron Detector (LEND) will be capable of carrying out all 3 investigations. The design concept of LEND is presented together with results of numerical simulations of the instrument's sensitivity for hydrogen detection. The sensitivity of LEND is shown to be characterized by a hydrogen detection limit of about 100 ppm for a polar reference area with a radius of 5 km. If the presence of ice deposits in polar "cold traps" is confirmed, a unique record of many millions of years of lunar history would be obtained, by which the history of lunar impacts could be discerned from the layers of water ice and dust. Future applications of a LEND-type instrument for Mars orbital observations are also discussed.