Planned Products of the Mars Structure Service for the InSight Mission to Mars

Space Science Reviews - The InSight lander will deliver geophysical instruments to Mars in 2018, including seismometers installed directly on the surface (Seismic Experiment for Interior Structure,...     

Psychology and culture during long-duration space missions

The objective of this paper is twofold: (a) to review the current knowledge of cultural, psychological, psychiatric, cognitive, interpersonal, and organizational issues that are relevant to the behavior and performance of astronaut crews and ground support personnel and (b) to make recommendations for future human space missions, including both transit and planetary surface operations involving the Moon or Mars. The focus will be on long-duration missions lasting at least six weeks, when important psychological and interpersonal factors begin to take their toll on crewmembers. This information is designed to provide guidelines for astronaut selection and training, in-flight monitoring and support, and post-flight recovery and re-adaptation.     

Human interactions during Shuttle/Mir space missions

To improve the interpersonal climate of crewmembers involved with long-duration space missions, it is important to understand the factors affecting their interactions with each other and with members of mission control. This paper will present findings from a recently completed NASA-funded study during the Shuttle/Mir program which evaluated in-group/out-group displacement of negative emotions; changes in tension, cohesion, and leader support over time; and cultural differences. In-flight data were collected from 5 astronauts, 8 cosmonauts, and 42 American and 16 Russian mission control personnel who signed informed consent. Subjects completed a weekly questionnaire that assessed their mood and perception of their work group's interpersonal climate using questions from well-known, standardized measures (Profile of Mood States, Group and Work Environment Scales) and a critical incident log. There was strong evidence for the displacement of tension and dysphoric emotions from crewmembers to mission control personnel and from mission control personnel to management. There was a perceived decrease in commander support during the 2nd half of the missions, and for American crewmembers a novelty effect was found on several subscales during the first few months on-orbit. There were a number of differences between American and Russian responses which suggested that the former were less happy with their interpersonal environment than the latter. Mission control personnel reported more tension and dysphoria than crewmembers, although both groups scored better than other work groups on Earth. Nearly all reported critical incidents came from ground subjects, with Americans and Russians showing important differences in response frequencies.     

Active polar gullies on Mars and the role of carbon dioxide

The detection of geologically recent channels and gullies on Mars has been interpreted as evidence for recent water activity on this arid and cold planet. The presence of active water would have considerable implications for the history of Mars and for the potential for an active near-surface biota; however, water is not the only substance that can flow and may actually be one of the least likely candidates when the modern permafrost environment is considered. Here, a key site of recent gully and channel development on Mars is reported at 71 degrees S in Sisyphi Cavi, within the annual zone of polar CO2 ice and snow accumulation. Superposition of channel features over and/or through the defrosting CO2 snowpack shows that the channels are active at the present day and probably have fluid flows every spring during the annual defrosting. In itself, this is a significant observation as active fluid flows of any nature have not yet been proven on Mars. However, the ambient temperature at the time of gully activity appears to require a role for CO2 in the formation of the channels, rather than water. A model is proposed for gas-lubricated flow in the channels based on avalanching of CO2 snowpack and clastic debris. If similar mechanisms are responsible for all the recent gullies on Mars, then perhaps no near-surface astrobiological targets are available.     

Leisure time activities in space: a survey of astronauts and cosmonauts

Questionnaires were returned from 54 astronauts and cosmonauts which addressed preferences for media and media-generated subjects that could be used to occupy leisure time in space. Ninety-three percent of the respondents had access to records or audio cassettes, and cosmonauts had greater access than astronauts to multiple media. Cosmonauts and long-duration space travelers reported that they missed various media more than their astronaut and short-duration counterparts. Media subjects that related to international events, national events and historical topics were rated as most preferable by all respondents and by several of the respondent groups. The findings are discussed in terms of their relevance for occupying free time during future long-duration manned space missions.     

Psychosocial issues affecting crews during long-duration international space missions

Psychosocial issues can negatively impact on crew performance and morale during long-duration international space missions. Major psychosocial factors that have been described in anecdotal reports from space and in studies from analog situations on Earth include: 1) crew heterogeneity due to gender differences, cultural issues, and work experiences and motivations; 2) language and dialect variations; and 3) task versus supportive leadership roles. All of these factors can lead to negative sequelae, such as intra-crew tension and cohesion disruptions. Specific sequelae that can result from single factors include subgrouping and scapegoating due to crew heterogeneity; miscommunication due to major or subtle language differences; and role confusion, competition, and status leveling due to inappropriate leadership role definition. It is time to conduct research exploring the impact of these psychosocial factors and their sequelae on space crews during actual long-duration international space missions.     

Psychological, psychiatric, and interpersonal aspects of long-duration space missions

America's future in space calls for manned missions that are of long duration and increasing complexity. Under these conditions, psychological and interpersonal stressors will take on added importance in affecting the safely of the crew and the outcome of the mission. Through an analysis of reports from manned American and Soviet space missions and Earth-bound simulations, several psychological, psychiatric, and interpersonal issues can be identified that could affect the success of the space station and other long-duration space ventures. Psychological issues include sleep problems, alteration in time sense, demographic effects, career motivation, transcendent experiences, homesickness, and alteration in perceptual sensitivities. Psychiatric issues include anxiety, depression, and psychosis, psychosomatic symptoms, emotional problems related to the stage of the mission, and postflight personality changes. Interpersonal issues include interpersonal tension, decreased cohesiveness over time, need for privacy, and task vs emotional leadership. Steps can be taken to minimize the impact of these issues, both before and during the mission.     

DebrisWatch I: A survey of faint geosynchronous debris

Recent anomalies exhibited by satellites and rocket bodies have highlighted that a population of faint debris exists at geosynchronous (GEO) altitudes, where there are no natural removal mechanisms. Despite previous optical surveys probing to around 10–20 cm in size, regular monitoring of faint sources at GEO is challenging, thus our knowledge remains sparse. It is essential that we continue to explore the faint debris population using large telescopes to better understand the risk posed to active GEO satellites. To this end, we present photometric results from a survey of the GEO region carried out with the 2.54 m Isaac Newton Telescope in La Palma, Canary Islands. We probe to 21st visual magnitude (around 10 cm, assuming Lambertian spheres with an albedo of 0.1), uncovering 129 orbital tracks with GEO-like motion across the eight nights of dark-grey time comprising the survey. The faint end of our brightness distribution continues to rise until the sensitivity limit of the sensor is reached, suggesting that the modal brightness could be even fainter. We uncover a number of faint, uncatalogued objects that show photometric signatures of rapid tumbling, many of which straddle the limiting magnitude of our survey over the course of a single exposure, posing a complex issue when estimating object size. This work presents the first instalment of DebrisWatch, an ongoing collaboration between the University of Warwick and the Defence Science and Technology Laboratory (UK) investigating the faint population of GEO debris.     

Analysis of Regolith Properties Using Seismic Signals Generated by InSight’s HP<Superscript>3</Superscript> Penetrator

InSight’s Seismic Experiment for Interior Structure (SEIS) provides a unique and unprecedented opportunity to conduct the first geotechnical survey of the Martian soil by taking advantage of the repeated seismic signals that will be generated by the mole of the Heat Flow and Physical Properties Package (HP³). Knowledge of the elastic properties of the Martian regolith have implications to material strength and can constrain models of water content, and provide context to geological processes and history that have acted on the landing site in western Elysium Planitia. Moreover, it will help to reduce travel-time errors introduced into the analysis of seismic data due to poor knowledge of the shallow subsurface. The challenge faced by the InSight team is to overcome the limited temporal resolution of the sharp hammer signals, which have significantly higher frequency content than the SEIS 100 Hz sampling rate. Fortunately, since the mole propagates at a rate of \(\sim1~\mbox{mm}\) per stroke down to 5 m depth, we anticipate thousands of seismic signals, which will vary very gradually as the mole travels.Using a combination of field measurements and modeling we simulate a seismic data set that mimics the InSight HP3-SEIS scenario, and the resolution of the InSight seismometer data. We demonstrate that the direct signal, and more importantly an anticipated reflected signal from the interface between the bottom of the regolith layer and an underlying lava flow, are likely to be observed both by Insight’s Very Broad Band (VBB) seismometer and Short Period (SP) seismometer. We have outlined several strategies to increase the signal temporal resolution using the multitude of hammer stroke and internal timing information to stack and interpolate multiple signals, and demonstrated that in spite of the low resolution, the key parameters—seismic velocities and regolith depth—can be retrieved with a high degree of confidence.     

Implementation of an ESA delta-DOR capability

This paper describes the implementation of delta-DOR (delta-differential one-way ranging) receivers within the ESA Deep Space ground station network. Delta-DOR provides very accurate plane-of-sky measurements of spacecraft position which complement existing line-of-sight ranging and Doppler measurements. We discuss how this technique has been adapted and implemented at the two ESA deep-space ground stations using existing equipment and infrastructure. These new capabilities were added by writing new software modules for the standard ESA digital receiver (the intermediate frequency modem system—IFMS). With these upgrades the receiver has the ability to record accurately timetagged signals from up to eight IF sub-channels. These sub-channels can have bandwidths of 50 kHz–2 MHz with a sample quantization of 1–16 bits per component. The IF samples are stored locally for subsequent retrieval over a WAN by the correlator facility at ESOC.