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Charles, J.

Publications and source records attributed to Charles, J..

8 records
All sourcesNASA NTRSDOE OSTI
NASA NTRS2013

The "Programmatics" of the ISS Crewmembers' Twelve Month Mission

The mission duration for crewmembers' stay on the International Space Station (ISS) has historically been approximately six months, consistent with the service life of the Soyuz spacecraft that delivers and returns the crewmembers previous. Exploration missions beyond low Earth orbit are expected to require crew durations of a year or more. The ISS Partners have agreed to begin building an experience base of longer crew durations, and have selected two crewmembers to serve on ISS for approximately twelve months, beginning in the Spring of 2015. The preparations for the one NASA and one Roscosmos crewmember require many new considerations for the ISS Program and its Partnership - "programmatic" considerations that are separate from crew health concerns. Since the long-duration crew's Soyuz will need to be replaced halfway through their stay, crew rotation, handover and the Soyuz docking port plan are affected. There is also an opportunity for two short-duration crewmembers to fly during the Soyuz exchange. It is desirable to minimize additional training required of the prime and backup crewmembers; normal crew rotations have a Soyuz crew train as the backup crew, then train as the prime crew. Ground teams will adjust their traditional support to ISS crewmembers, including communication of long-term plans, onboard training, and logistics support. The lessons learned during the preparation and execution of the 12-month mission will support improvements in future ISS long-duration missions and exploration missions.

Hasbrook, Pete↗
NASA NTRS2012

Hybrid Ground Station Technology for RF and Optical Communication Links

To support future enhancements of NASA's deep space and planetary communications and tracking services, the Jet Propulsion Laboratory is developing a hybrid ground station that will be capable of simultaneously supporting RF and optical communications. The main reason for adding optical links to the existing RF links is to significantly increase the capacity of deep space communications in support of future solar system exploration. It is envisioned that a mission employing an optical link will also use an RF link for telemetry and emergency purposes, hence the need for a hybrid ground station. A hybrid station may also reduce operations cost by requiring fewer staff than would be required to operate two stations. A number of approaches and techniques have been examined. The most promising ones have been prototyped for field examination and validation.

Radio frequency (RF) communications↗
NASA NTRS2004

Mars Surface Analog Project: Preparing for Astronauts' First Hours on Mars

Astronaut missions to Mars may be decades in the future, but contemporary estimates of the physical capabilities of the crewmembers upon arrival after prolonged transit can guide development of operational requirements to be imposed on them. Requirements for functional capacities will differ depending on whether they land in a spartan ascent vehicle or in a well-equipped habitat, but each of those options brings with it certain operational risks. Rehabilitation will be an important factor for crew health, safety and efficiency after the multi-month transit from Earth. Specific recommendations will be stipulated for the time to be allotted for on-planet rehabilitation before the first planned surface excursion, such as the transfer from the ascent-lander to the habitat-lander. Three sequential workshops (the third including extramural experts in appropriate fields) examined the likely capabilities of crewmembers shortly after landing on Mars, the predicted operational requirements they will face, and the near-term steps to close the gap between the requirements and capabilities.

Charles, J.↗
NASA NTRS1994

Response to graded Lower Body Negative Pressure (LBNP) after space flight

The effects of space flight on orthostatic function were studied. LBNP tests (0 to -60 mmHg) were administered to 7 crew members preflight and 2 to 6 hrs after 6 to 9 day shuttle missions. Cardiac stroke volumes were obtained each minute by echo Doppler. Orthostatic responses are given. The data suggest a decline in postflight orthostatic function, as assessed by LBNP, due to reduced cardiac filling despite potentiated heart rate and vasoconstrictor reflex responses in most crew members.

Fortney, S.↗
NASA NTRS1994

Evaluation of a liquid cooling garment as a component of the Launch and Entry Suit (LES)

The LES is a partial pressure suit and a component of the shuttle life support system used during launch and reentry. The LES relies on gas ventilation with cabin air to provide cooling. There are conditions during nominal launch and reentry, landing, and post-landing phases when cabin temperature is elevated. Under these conditions, gas cooling may result in some discomfort and some decrement in orthostatic tolerance. There are emergency conditions involving loss of cabin ECS capability that would challenge crew thermal tolerance. The results of a series of tests are presented. These tests were conducted to assess the effectiveness of a liquid-cooled garment in alleviating thermal discomfort, orthostatic intolerance, and thermal intolerance during simulated mission phases.

Waligora, J.↗
NASA NTRS1992

Prediction of space sickness in astronauts from preflight fluid, electrolyte, and cardiovascular variables and Weightless Environmental Training Facility (WETF) training

Nine preflight variables related to fluid, electrolyte, and cardiovascular status from 64 first-time Shuttle crewmembers were differentially weighted by discrimination analysis to predict the incidence and severity of each crewmember's space sickness as rated by NASA flight surgeons. The nine variables are serum uric acid, red cell count, environmental temperature at the launch site, serum phosphate, urine osmolality, serum thyroxine, sitting systolic blood pressure, calculated blood volume, and serum chloride. Using two methods of cross-validation on the original samples (jackknife and a stratefied random subsample), these variables enable the prediction of space sickness incidence (NONE or SICK) with 80 percent sickness and space severity (NONE, MILD, MODERATE, of SEVERE) with 59 percent success by one method of cross-validation and 67 percent by another method. Addition of a tenth variable, hours spent in the Weightlessness Environment Training Facility (WETF) did not improve the prediction of space sickness incidences but did improve the prediction of space sickness severity to 66 percent success by the first method of cross-validation of original samples and to 71 percent by the second method. Results to date suggest the presence of predisposing physiologic factors to space sickness that implicate fluid shift etiology. The data also suggest that prior exposure to fluid shift during WETF training may produce some circulatory pre-adaption to fluid shifts in weightlessness that results in a reduction of space sickness severity.

Simanonok, K.↗
NASA NTRS1992

Countermeasure development to space adaptation

At the Johnson Space Center we are actively involved, with the collaboration of other NASA Centers and the scientific community at large, in the search for ways to counter the negative affects of spaceflight beginning with the improvement in our understanding of the adaptation. Heretofore this search will be broadly referred to as countermeasures development and includes not only the preservation of physiological well-being but also pyschological well-being. The psychological integrity of crews will, undoubtedly, become progressively more important as lengths, remoteness, and risks of missions increase. The character and priorities of our contermeasure development is very much dependent upon the character of the mission and requires a very close liaison between Medical Operations and the investigators. Because of the demands which countermeasure implementation imposes upon crew schedules and because of the potential weight, power, and budget impacts of the hardware and its development, a countermeasure can only become operational when it is either adequately validated or the human risk of not applying the existing technology exceeds the other negative impacts not directly related to crew health and safety.

Larochelle, F. T.↗