The Dimorphos ejecta plume properties revealed by LICIACube

The Double Asteroid Redirection Test (DART) had an impact with Dimorphos (a satellite of the asteroid Didymos) on 26 September 20221. Ground-based observations showed that the Didymos system brightened by a factor of 8.3 after the impact because of ejecta, returning to the pre-impact brightness 23.7 days afterwards2. Hubble Space Telescope observations made from 15 minutes after impact to 18.5 days after, with a spatial resolution of 2.1 kilometres per pixel, showed a complex evolution of the ejecta3, consistent with other asteroid impact events. The momentum enhancement factor, determined using the measured binary period change4, ranges between 2.2 and 4.9, depending on the assumptions about the mass and density of Dimorphos5. Here we report observations from the LUKE and LEIA instruments on the LICIACube cube satellite, which was deployed 15 days in advance of the impact of DART. Data were taken from 71 seconds before the impact until 320 seconds afterwards. The ejecta plume was a cone with an aperture angle of 140 ± 4 degrees. The inner region of the plume was blue, becoming redder with increasing distance from Dimorphos. The ejecta plume exhibited a complex and inhomogeneous structure, characterized by filaments, dust grains and single or clustered boulders. The ejecta velocities ranged from a few tens of metres per second to about 500 metres per second.

The pre-launch on-ground characterization of Ma_MISS spectrometer for ExoMars-Rosalind Franklin Rover mission. II. Radiometric calibration

The Ma_MISS miniaturized spectrometer is integrated within the Drilling System of the ExoMars Rosalind Franklin Rover for Mars exploration. Here we focus on the on ground calibration campaign to obtain radiometric and linearity calibrations of the Ma_MISS instrument, while the first paper dealt with the spectral calibration [De Angelis et al., Rev. Sci. Instrum. 93, 123704 (2022)]. The experimental setup used to carry out radiometric calibration is described, as are the methods used for data processing and key parameter retrieval. In particular, the Spectrometer Transfer Function (Responsivity), Signal-to-Noise Ratio, and detector linearity are determined. In a third paper [De Sanctis et al., Planet. Sci. J. 3, 142 (2022)], validation of the Ma_MISS calibration results through spectral measurements performed on rock and synthetic targets during the radiometric calibration campaign is described.

AstroBio-CubeSat: A lab-in-space for chemiluminescence-based astrobiology experiments

Space exploration is facing a new era in view of the planned missions to the Moon and Mars. The development and the in-flight validation of new technologies, including analytical and diagnostic platforms, is pivotal for exploring and inhabiting these extreme environments. In this context, biosensors and lab-on-chip devices can play an important role in many situations, such as the analysis of biological samples for assessing the impact of deep space conditions on man and other biological systems, environmental and food safety monitoring, and the search of molecular indicators of past or present life in extra-terrestrial environments. Small satellites such as CubeSats are nowadays increasingly exploited as fast and low-cost platforms for conducting in-flight technology validation. Herein, we report the development of a fully autonomous lab-on-chip platform for performing chemiluminescence-based bioassays in space. The device was designed to be hosted onboard the AstroBio CubeSat nanosatellite, with the aim of conducting its in-flight validation and evaluating the stability of (bio)molecules required for bioassays in a challenging radiation environment. An origami-like microfluidic paper-based analytical format allowed preloading all the reagents in the dried form on the paper substrate, thus simplifying device design and analytical protocols, facilitating autonomous assay execution, and enhancing the stability of reagents. The chosen approach should constitute the first step to implement a mature technology with the aim to conduct life science research in space (e.g., for evaluation the effect of deep space conditions on living organisms or searching molecular evidence of life) more easily and at lower cost than previously possible.

Momentum transfer from the DART mission kinetic impact on asteroid Dimorphos

The NASA Double Asteroid Redirection Test (DART) mission performed a kinetic impact on asteroid Dimorphos, the satellite of the binary asteroid (65803) Didymos, at 23:14 UTC on 26 September 2022 as a planetary defence test1. DART was the first hypervelocity impact experiment on an asteroid at size and velocity scales relevant to planetary defence, intended to validate kinetic impact as a means of asteroid deflection. Here we report a determination of the momentum transferred to an asteroid by kinetic impact. On the basis of the change in the binary orbit period2, we find an instantaneous reduction in Dimorphos's along-track orbital velocity component of 2.70 ± 0.10 mm s-1, indicating enhanced momentum transfer due to recoil from ejecta streams produced by the impact3,4. For a Dimorphos bulk density range of 1,500 to 3,300 kg m-3, we find that the expected value of the momentum enhancement factor, β, ranges between 2.2 and 4.9, depending on the mass of Dimorphos. If Dimorphos and Didymos are assumed to have equal densities of 2,400 kg m-3, [Formula: see text]. These β values indicate that substantially more momentum was transferred to Dimorphos from the escaping impact ejecta than was incident with DART. Therefore, the DART kinetic impact was highly effective in deflecting the asteroid Dimorphos.

The pre-launch on-ground characterization of Mars Multispectral Imager for Subsurface Studies (Ma_MISS) spectrometer for ExoMars rover mission: Spectral calibration

The Ma_MISS spectrometer is integrated within the drilling system of the Rosalind Franklin ExoMars rover. This paper reports the on-ground calibration campaign performed on the spectrometer. Here, we focus on the spectral calibration of the instrument. The experimental setup used to carry out calibration is described, and the methods used for data processing and key parameters retrieval are explained. In particular, the spectral parameters such as (i) pixel central wavelengths, (ii) spectral response function, (iii) spectral resolution, (iv) sampling, and (v) range are determined. In a follow-up paper, the linearity and radiometric calibrations are described, while in De Sanctis et al. [Planet. Sci. J. 3, 142 (2022)], the validation of spectral measurements performed on synthetic and natural rock targets is presented.

Evaluation of the effect of preload force on resonance frequencies for a traveling wave ultrasonic motor

In this paper, a novel method of numerical computation of the natural frequencies, depending on the most important running parameters for an ultrasonic motor, is described. The analyzed configuration by the Space Division of Alenia Spazio, Rome, within an Italian Space Agency (ASI) development program, is the flexural traveling wave one. The dynamic equations for the stator and the rotors of the ultrasonic motor are assumed into a differential system, whose equations are coupled by terms that represent interface generalized forces. In order to calculate natural frequencies of the motor-coupled terms of the equations are worked out with respect to the variables of the degrees of freedom. Hence, the mass, damping, and stiffness matrix for the whole system are obtained, then resonance frequencies, depending on the most important running parameters such as axial preload of the motor, are calculated. The results are compared with numerical ones, obtained by a finite element modeling (FEM) model, showing a good agreement.

The annual meeting: regulatory obligation or lifeline to the future?

Usually dreaded, annual meetings can provide a crucial, powerful, but often neglected context for reviewing the "vital signs" of a group practice: mission, membership, marketplace strategy and infrastructure. We propose that regular and thoughtful attention to essential issues of cohesion and effectiveness significantly increases the likelihood of group vitality and group member satisfaction. We suggest a methodology for embedding these essential conversations into the ritual of the annual meeting.

Consulting--Part 2. The art and science of using consultants

Part I of this series described a research project--a survey of more than 300 physician executives. Asked to share their personal experiences of unsuccessful consultations, our correspondents painted a clear picture of what can go wrong when organizational consultants enter health care systems, and described the lasting destructive sequelae to failed consultations. The two issues responsible for most failed consultations were the intrusion of internal politics into the process and the failure to clearly establish and maintain consensual goals. In Part 2, the consultation process is explored from a very different perspective. What are the issues that often trigger requests for consultation services, as well as the dynamics that can foreshadow success or failure before consultants are even engaged? What are the pitfalls and pointers for the successful use of consultation services?

Consulting--Part 1. Why consultations fail

The first article in this series describes a research project--a survey of more than 300 physician executives. Asked to share their personal experiences of unsuccessful consultations, our correspondents painted a picture of what can go wrong when organizational consultants enter health care systems, and described the lasting destructive sequelae to failed consultations. The two issues responsible for most failed consultations were the intrusion of internal politics into the consultation process and the failure to clearly establish and maintain consensual goals. Part 2 of this series will explore the consultation process from a different perspective, examining the issues that often trigger requests for consultation services and the dynamics that can foreshadow success or failure before consultants are even engaged.