Tests of gravity with future space-based experiments

This article discusses the dilemma of the defense intelligence. It discusses the interweaving yet complicated relationship of the Department of Defense (DOD) and the Office of Director of National Intelligence (ODNI). Immersed in a divided and a “stovepiped” culture, the member agencies of the intelligence community lacked coordination and collaboration. In this article, the nature of the three agencies of the DOD: the National Security Agency (NSA), the National Reconnaissance Office (NRO), and the National Geospatial-Intelligence Agency (NGA) are discussed. The evolution of coordination among the intelligence community agencies and the impact of 9/11 on the cooperation and collaboration between the agencies are also discussed including the era of the Director of National Intelligence (DNI) and the challenges posed by the future space surveillance.

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Using supraglottic airways by paramedics for airway management in analogue microgravity increases speed and success of ventilation

Scientific Reports ◽

10.1038/s41598-021-88008-x ◽

2021 ◽

Vol 11 (1) ◽

Author(s):

Jochen Hinkelbein ◽

Anton Ahlbäck ◽

Christine Antwerber ◽

Lisa Dauth ◽

James DuCanto ◽

...

Keyword(s):

Airway Management ◽

Success Rate ◽

Simulated Microgravity ◽

Laryngeal Tube ◽

Space Missions ◽

Airway Device ◽

Future Space ◽

Secondary Endpoints ◽

Present Trial

AbstractIn the next few years, the number of long-term space missions will significantly increase. Providing safe concepts for emergencies including airway management will be a highly challenging task. The aim of the present trial is to compare different airway management devices in simulated microgravity using a free-floating underwater scenario. Five different devices for airway management [laryngeal mask (LM), laryngeal tube (LT), I-GEL, direct laryngoscopy (DL), and video laryngoscopy (VL)] were compared by n = 20 paramedics holding a diving certificate in a randomized cross-over setting both under free-floating conditions in a submerged setting (pool, microgravity) and on ground (normogravity). The primary endpoint was the successful placement of the airway device. The secondary endpoints were the number of attempts and the time to ventilation. A total of 20 paramedics (3 female, 17 male) participated in this study. Success rate was highest for LM and LT and was 100% both during simulated microgravity and normogravity followed by the I-GEL (90% during microgravity and 95% during normogravity). However, the success rate was less for both DL (60% vs. 95%) and VL (20% vs. 60%). Fastest ventilation was performed with the LT both in normogravity (13.7 ± 5.3 s; n = 20) and microgravity (19.5 ± 6.1 s; n = 20). For the comparison of normogravity and microgravity, time to ventilation was shorter for all devices on the ground (normogravity) as compared underwater (microgravity). In the present study, airway management with supraglottic airways and laryngoscopy was shown to be feasible. Concerning the success rate and time to ventilation, the optimum were supraglottic airways (LT, LM, I-GEL) as their placement was faster and associated with a higher success rate. For future space missions, the use of supraglottic airways for airway management seems to be more promising as compared to tracheal intubation by DL or VL.

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Time-delay interferometry

Living Reviews in Relativity ◽

10.1007/s41114-020-00029-6 ◽

2020 ◽

Vol 24 (1) ◽

Author(s):

Massimo Tinto ◽

Sanjeev V. Dhurandhar

Keyword(s):

Time Delay ◽

Laser Interferometer ◽

Laser Light ◽

Space Antenna ◽

Phase Measurements ◽

Laser Noise ◽

Future Space ◽

Laser Interferometer Space Antenna ◽

Overall Performance ◽

Mathematical Foundations

AbstractEqual-arm detectors of gravitational radiation allow phase measurements many orders of magnitude below the intrinsic phase stability of the laser injecting light into their arms. This is because the noise in the laser light is common to both arms, experiencing exactly the same delay, and thus cancels when it is differenced at the photo detector. In this situation, much lower level secondary noises then set the overall performance. If, however, the two arms have different lengths (as will necessarily be the case with space-borne interferometers), the laser noise experiences different delays in the two arms and will hence not directly cancel at the photo detector. To solve this problem, a technique involving heterodyne interferometry with unequal arm lengths and independent phase-difference readouts has been proposed. It relies on properly time-shifting and linearly combining independent Doppler measurements, and for this reason it has been called time-delay interferometry (TDI). This article provides an overview of the theory, mathematical foundations, and experimental aspects associated with the implementation of TDI. Although emphasis on the application of TDI to the Laser Interferometer Space Antenna mission appears throughout this article, TDI can be incorporated into the design of any future space-based mission aiming to search for gravitational waves via interferometric measurements. We have purposely left out all theoretical aspects that data analysts will need to account for when analyzing the TDI data combinations.

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Agoraphilic navigation algorithm in dynamic environment with obstacles motion tracking and prediction

Robotica ◽

10.1017/s0263574721000588 ◽

2021 ◽

pp. 1-19

Author(s):

H. S. Hewawasam ◽

M. Yousef Ibrahim ◽

Gayan Kahandawa ◽

T. A. Choudhury

Keyword(s):

Free Space ◽

Motion Tracking ◽

Dynamic Environment ◽

Experimental Tests ◽

Cluttered Environments ◽

Navigation Algorithm ◽

Prediction Module ◽

Future Space ◽

Free Spaces ◽

Advanced Development

Abstract This paper presents a new algorithm to navigate robots in dynamically cluttered environments. The proposed algorithm uses basic concepts of space attraction (hence the term Agoraphilic) to navigate robots through dynamic obstacles. The new algorithm in this paper is an advanced development of the original Agoraphilic navigation algorithm that was only able to navigate robots in static environments. The Agoraphilic algorithm does not look for obstacles (problems) to avoid but rather for a free space (solutions) to follow. Therefore, it is also described as an optimistic navigation algorithm. This algorithm uses only one attractive force created by the available free space. The free-space concept allows the Agoraphilic algorithm to overcome inherited challenges of general navigation algorithms. However, the original Agoraphilic algorithm has the limitation in navigating robots only in static, not in dynamic environments. The presented algorithm was developed to address this limitation of the original Agoraphilic algorithm. The new algorithm uses a developed object tracking module to identify the time-varying free spaces by tracking moving obstacles. The capacity of the algorithm was further strengthened by the new prediction module. Future space prediction allowed the algorithm to make decisions considering future growing/diminishing free spaces. This paper also includes a bench-marking study of the new algorithm compared with a recently published APF-based algorithm under a similar operating environment. Furthermore, the algorithm was validated based on experimental tests and simulation tests.

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