A New Orbiting Deployable System for Small Satellite Observations for Ecology and Earth Observation

In this paper, we present several study cases focused on marine, oceanographic, and atmospheric environments, which would greatly benefit from the use of a deployable system for small satellite observations. As opposed to the large standard ones, small satellites have become an effective and affordable alternative access to space, owing to their lower costs, innovative design and technology, and higher revisiting times, when launched in a constellation configuration. One of the biggest challenges is created by the small satellite instrumentation working in the visible (VIS), infrared (IR), and microwave (MW) spectral ranges, for which the resolution of the acquired data depends on the physical dimension of the telescope and the antenna collecting the signal. In this respect, a deployable payload, fitting the limited size and mass imposed by the small satellite architecture, once unfolded in space, can reach performances similar to those of larger satellites. In this study, we show how ecology and Earth Observations can benefit from data acquired by small satellites, and how they can be further improved thanks to deployable payloads. We focus on DORA—Deployable Optics for Remote sensing Applications—in the VIS to TIR spectral range, and on a planned application in the MW spectral range, and we carry out a radiometric analysis to verify its performances for Earth Observation studies

The Comet Interceptor Mission

Here we describe the novel, multi-point Comet Interceptor mission. It is dedicated to the exploration of a little-processed long-period comet, possibly entering the inner Solar System for the first time, or to encounter an interstellar object originating at another star. The objectives of the mission are to address the following questions: What are the surface composition, shape, morphology, and structure of the target object? What is the composition of the gas and dust in the coma, its connection to the nucleus, and the nature of its interaction with the solar wind? The mission was proposed to the European Space Agency in 2018, and formally adopted by the agency in June 2022, for launch in 2029 together with the Ariel mission. Comet Interceptor will take advantage of the opportunity presented by ESA’s F-Class call for fast, flexible, low-cost missions to which it was proposed. The call required a launch to a halo orbit around the Sun-Earth L2 point. The mission can take advantage of this placement to wait for the discovery of a suitable comet reachable with its minimum ΔV capability of 600 ms−1. Comet Interceptor will be unique in encountering and studying, at a nominal closest approach distance of 1000 km, a comet that represents a near-pristine sample of material from the formation of the Solar System. It will also add a capability that no previous cometary mission has had, which is to deploy two sub-probes – B1, provided by the Japanese space agency, JAXA, and B2 – that will follow different trajectories through the coma. While the main probe passes at a nominal 1000 km distance, probes B1 and B2 will follow different chords through the coma at distances of 850 km and 400 km, respectively. The result will be unique, simultaneous, spatially resolved information of the 3-dimensional properties of the target comet and its interaction with the space environment. We present the mission’s science background leading to these objectives, as well as an overview of the scientific instruments, mission design, and schedule

DISC - the Dust Impact Sensor and Counter : dust in situ instrument for Comet Interceptor ESA mission

Comet Interceptor (CI) space mission, selected by ESA in June 2019 as the first F-Class mission, will study a dynamically new comet or an interstellar object passing through our Solar System for the first time by a unique multi-point 'snapshot' measurement, complementing single spacecraft observations made at other comets. CI is composed of a primary spacecraft, S/C A, which also acts as a communication hub, and two sub-spacecraft, S/C B1 (provided by JAXA) and S/C B2 (provided by ESA), that will allow multi-point observations of the DNC and the surrounding environment. The instrument suite Dust-Fields-Plasma (DFP) will be in charge of understanding: dust in the coma, magnetic field, plasma and energetic neutral atoms. We relate here on the Dust Impact Sensor and Counter (DISC) unit, part of the DFP suite, devoted to the coma dust characterization. DISC, part of the scientific payload on S/C A and S/C B2 of the mission, will detect and measure the momentum of individual dust impacting its sensitive surface during the DNC encounter.DISC architecture originates from the Impact Sensor Subsystem of the GIADA (Grain Impact Analyzer and Dust Accumulator) instrument that successfully flew on board the Rosetta/ESA spacecraft. DISC consists of a square aluminum plate whose sensitive area is 84 mm x 84 mm. Four lead zirconate titanate ceramic Piezoelectric, with resonant frequency 200kHz, are placed at the corners of the plate, one of which will act as an internal calibrator. DISC will characterize the coma dust environment at the spacecraft close encounter, in particular it will: 1) define the dust mass distribution for particles in the mass range 10‑15 - 10‑8 kg ejected from the nucleus; 2) count dust particles with mass >10‑15 kg; 3) constrain dust particles density/structure. We describe the DISC design, aims, methods, performances evaluation by real and simulated High Velocity Impacts and expected results

Analysis of dust shield and detection system response to hypervelocity impacts for Comet Interceptor Dust Impact Sensor and Counter

Introduction: The dust ejected by cometary nuclei encodes valuable information on the formation and evolution of the early Solar System. Several short-period comets have already been studied in situ[1], but their pristine condition was modified by multiple perihelion passages. Dynamically new comets (DNCs) remain pristine bodies since they never visited the inner Solar System, stationing more than 2000A.U. far away from the Sun in the Oort cloud.Comet Interceptor (CI) is the first F-class space mission selected by the European Space Agency to study a DNC or an interstellar object entering the inner Solar System for the first time[2]. The Dust Impact Sensor and Counter (DISC) is an instrument included in the Dust Field and Plasma (DFP) suite, part of the CI payload, dedicated to characterizing the dust encountered by the spacecraft (S/C) during its flyby in the coma of the target DNC. DISC will measure hypervelocity impacts (HVIs), in the range 10-70km/s, with cometary dust particles of 1-400μm diameter. It aims to characterize the mass distribution of dust particles in the range 10-15-10-8kg, and retrieve information on dust structural properties from impacts duration[3].DISC design: DISC is a 121×115.5×46mm3 aluminum box containing both the detection system and the electronics (Fig.1). The former consists in a 100×100×0.5mm3 aluminum plate with three piezoelectric traducers (PZTs) at its corners. HVIs induce shockwaves in the sensing plate. Far from the impacted area, such waves become acoustic Lamb waves that propagate up to the PZTs, which start to vibrate at their resonant frequency. A couple of electronic boards at the bottom of the unit allows to retrieve the particles momentum and kinetic energy from PZTs vibration signal.Fig.1: DISC sensing element and dust shield design.DISC detection system is derived from the GIADA Impact Sensor measurement subsystem, that was designed to measure impacts of slow particles[4]. During CI flyby, some hypervelocity dust particles might perforate DISC outer sensing diaphragm and represent a serious hazard for the instrumentation. A dedicated mechanical element preliminarily designed as made of four 1cm-thick aerogel blocks and a 1mm-thick aluminum frame was integrated into DISC design to shield the entire S/C from such dangerous impacts.Two key aspects need to be verified to ensure that the instrument is suitable for CI aims:DISC capability to survive the expected coma dust environment; DISC capability to measure the momentum/energy of impacting particles in the aforementioned size and mass ranges. Dust shield assessment: We verified DISC dust shield performance using a two-stage Light-Gas Gun (LGG) (Open University, Milton Keynes) to shoot mm-sized particles of various materials at speeds around 5km/s[5,6]. This facility allowed to test the instrument resistance to momenta in the range 10-2-10-1kg·m/s and to energies of the order of 102J. The dust shield showed good resistance up to energies of about 200J, released by a 3mm nylon bead at 5.5km/s. DISC resistance to higher-energy particles can be improved by increasing the aerogel thickness, without any further modifications to the general design.These experiments proved that DISC is compatible with the foreseen coma dust environment. Integrating a thicker aerogel layer in the design will reduce the risk of failure due to higher-energy particles to low enough values even for the S/C more exposed to the dust flux. The S/C beneath DISC unit is further protected by DISC lower layers.DISC performance: DISC will measure momenta in the range 10-11-10-3kg·m/s[7]. The LGG facility allows to reach high momentum values by shooting heavy particles, but their collision dynamics is very different from what expected for cometary dust. A different strategy to simulate the foreseen impact momentum range is needed.A Van der Graaf (VdG) gun can shoot μm-sized dust particles up to 20km/s, reproducing momenta of 10-9-10-7kg·m/s[8].The tested impact parameters range can be extended by simulating HVIs effects with a high-power pulsed laser beam. Laser intensity, beam dimension, and pulse duration can be regulated to respectively match impact pressure, section, and shock duration of the corresponding particle[9]. Laser intensities of 109-1010W/cm2 can generate surface pressures from kbar to Mbar, typical of cometary dust particles colliding at 3-6km/s. Using our Nd:YAG laser (λ=1064nm), which emits τ=6ns pulses with pulse energy of Epulse=1.2J, we can cover a momentum range of 10-10-10-5kg·m/s. Since laser simulated and VdG real impacts share part of the released momentum range, laser shots can be calibrated and their representativity verified with real collisions.The energy range expected for dust impacts measured during CI flyby is 10-7-102J. Laser simulated impacts cannot reach the higher energy values. However, the energy/pulse duration range is pretty vast and with some attenuators and pulse reducers the central/left part of the parameters space (around mJ energy and ns pulse time) could be reasonably covered.Fig.2. shows the optical setup: a polarizer attenuator splits the beam and allows to regulate its power; a couple of mirrors prevents backwards reflections to get to the laser output aperture; a beam expander enlarges the beam, which enters a vacuum chamber and is focused by a plano-convex lens on the DISC breadboard mounted on a 3-axis translational stage. The vacuum chamber is fundamental to prevent plasma generation in air around the focus.Fig.2: Optical setup for high-power pulsed laser simulated HVIs.By properly tuning the laser parameters, this strategy allows to achieve representative simulations of cometary dust HVIs. In addition to assess DISC performances, simulating the same impact many times provides large statistics to calibrate DISC detection system and momentum/kinetic energy retrieval methodology with great accuracy

A dedicated simulation chain for Hypervelocity Impacts effects on DISC sensor

Comet Interceptor is an ESA Fast-class space mission, which will be launched in 2029 towards an as-yet undiscovered Dynamically New Comet, i.e. never having approached the Sun before, or even an interstellar body. Comet Interceptor consists of three spacecrafts that will flyby the selected DNC. DISC sensors (part of Dust Field and Plasma suite) will be mounted on board two of the three foreseen S/C, aiming to determine cometary dust dynamical properties retrieving information from the particles impinging its sensitive surface. The DISC sensing plate will be exposed to the cometary dust environment thus subjected to Hypervelocity Impacts (HVI), due to the high speed of the flyby (10 - 70 km/s). Nowadays facilities don't let to test all the possible impact cases DISC will be subjected into the cometary environment (very high relative speed during flyby). To overcome this limitation, we set up a simulations system for the sensor with ANSYS TM software and AUTODYN TM hydrocode, capable of simulating a wide range of impacts characteristics (e.g. speeds, particles sizes) DISC will face during the operative phase. The simulation system involves a hybrid model discretized with both Smooth Particles Hydrodynamic (SPH) and Finite Element methods, and it is organized in two main steps: 1. The first step includes the region very close to the impact point, discretized with SPH. Here is reproduced the impact and the impacted surface evolvement from the generated shockwave, large material deformation and compression, till the formation of Lamb waves and the start of the elastic regime. 2. The second step is a transient structural analysis involving Finite Element discretization. The output of the previous step is used as input for this second one, which is applied to the entire DISC sensing plate to obtain the HVI effects till the plate edges, where PZT sensors are placed. This simulation considers the PZTs characteristics to get as output of the simulation the PZT signals. Impacts by different particles diameters and velocities have been simulated. Here we report the simulations system and some of the most relevant final outputs

Feasibility and outcome of interval debulking surgery (IDS) after carboplatin-paclitaxel-bevacizumab (CPB): A subgroup analysis of the MITO-16A-MaNGO OV2A phase 4 trial

Background Few data are available on the outcome of surgery after a bevacizumab-containing regimen. The MITO 16A- MaNGO OV2A phase 4 trial evaluates the outcomes of first-line CPB in a clinical-practice-like setting. Here we present the results of the subgroup of patients undergoing IDS after neoadjuvant treatment or suboptimal primary surgery. Methods 400 chemonaïve epithelial ovarian cancer patients, age â¥Â 18, ECOG PS 0â2 were eligible to receive C (AUC 5 d1, q21) plus P (175 mg/m2d1, q21) and B (15 mg/kg d1 q21) for 6 cycles followed by B maintenance until cycle 22nd. Results 79 patients (20%) underwent IDS. Overall, 74 patients received at least one administration of B before IDS. Median age was 61.2, 70% of the patients had FIGO IIIC disease. The median number of cycles before IDS was 3 both for chemotherapy and bevacizumab respectively. A residual disease â¤Â 1 cm was achieved in 64 patients (86.5%). Four percent of the patients experienced fever and 4% required blood transfusion after surgery. Surgical wound infection and/or dehiscence, pelvic abscess, intestinal sub-occlusion and fistula were experienced by one patient each. Conclusions In the MITO16A-MaNGO OV2A phase 4 trial, combined chemotherapy and bevacizumab did not hamper IDS and the rate of perioperative complications was similar to what expected without bevacizumab. These data support the hypothesis that adding bevacizumab to first line chemotherapy for ovarian cancer might not be denied to patients for whom IDS is planned

Randomized Controlled Trial Testing the Efficacy of Platinum-Free Interval Prolongation in Advanced Ovarian Cancer: The MITO-8, MaNGO, BGOG-Ov1, AGO-Ovar2.16, ENGOT-Ov1, GCIG Study

Purpose Platinum-based chemotherapy (PBC) for patients with progressing ovarian cancer (OC) is more effective with a longer time interval from previous platinum treatment (platinum-free interval [PFI]). In 1999, it was hypothesized that prolonging PFI with single-agent non-PBC (NPBC) may offer a strategy to improve overall outcome. MITO-8 aimed to verify this hypothesis commonly used in clinical practice although it has not been prospectively tested. Methods MITO-8 is an open-label, prospective, randomized, superiority trial. Patients with OC who experienced disease progression 6 to 12 months after their last platinum treatment were randomly assigned 1:1 to the experimental sequence of NPBC followed by PBC at subsequent relapse or the standard reverse treatment sequence. Overall survival (OS) was the primary end point. Results Two hundred fifteen patients were enrolled (standard arm [n = 108]; experimental arm [n = 107]). The trial ended before planned because of slow enrollment. PFI was prolonged in the experimental arm (median, 7.8 v 0.01 months). There was no OS benefit in the experimental arm (median, 21.8 v 24.5 months; hazard ratio, 1.38; 95% CI, 0.99 to 1.94; P = .06). Progression-free survival after the sequence was significantly shorter in the experimental arm (median, 12.8 v 16.4 months; hazard ratio, 1.41; 95% CI, 1.04 to 1.92; P = .025). Global quality-of-life change after three cycles was worse in the experimental arm. Slight differences were observed in the incidence of adverse effects. Conclusion MITO-8 supports the recommendation that PBC not be delayed in favor of an NPBC in patients with partially platinum-sensitive OC. PBC should be used as a control arm in future trials of new drugs in this setting.status: publishe

Living with Chronic Spontaneous Urticaria in Italy: A Narrative Medicine Project to Improve the Pathway of Patient Care

Chronic spontaneous urticaria (CSU) is perceived as a difficult to manage disease with negative impact on quality of life. The aim of this study was to highlight how to improve the care of people with CSU, using the methodology of narrative medicine. From June 2014 to March 2015, CSU-diagnosed patients and their physicians were asked to record their experiences of the condition in writing. Fourteen healthcare teams participated: 41% considered CSU as a challenge to overcome, while 22% experienced CSU as a big commitment. The number of professional involved was evaluated as insufficient in 11 hospitals. Seventy-five percent of the 190 Italian patients had visited 3 or more physicians before receiving a final diagnosis, with a perceived waste of time and resources. The therapeutic pathways were described as unsatisfactory in 83% of cases. As a result, anger and frustration were life-dominant emotions in 92% of patients. The critical points of the care pathway are related to organizational issues and lack of awareness

Adjuvant anastrozole versus exemestane versus letrozole, upfront or after 2 years of tamoxifen, in endocrine-sensitive breast cancer (FATA-GIM3): a randomised, phase 3 trial

Background: Uncertainty exists about the optimal schedule of adjuvant treatment of breast cancer with aromatase inhibitors and, to our knowledge, no trial has directly compared the three aromatase inhibitors anastrozole, exemestane, and letrozole. We investigated the schedule and type of aromatase inhibitors to be used as adjuvant treatment for hormone receptor-positive early breast cancer. Methods: FATA-GIM3 is a multicentre, open-label, randomised, phase 3 trial of six different treatments in postmenopausal women with hormone receptor-positive early breast cancer. Eligible patients had histologically confirmed invasive hormone receptor-positive breast cancer that had been completely removed by surgery, any pathological tumour size, and axillary nodal status. Key exclusion criteria were hormone replacement therapy, recurrent or metastatic disease, previous treatment with tamoxifen, and another malignancy in the previous 10 years. Patients were randomly assigned in an equal ratio to one of six treatment groups: oral anastrozole (1 mg per day), exemestane (25 mg per day), or letrozole (2·5 mg per day) tablets upfront for 5 years (upfront strategy) or oral tamoxifen (20 mg per day) for 2 years followed by oral administration of one of the three aromatase inhibitors for 3 years (switch strategy). Randomisation was done by a computerised minimisation procedure stratified for oestrogen receptor, progesterone receptor, and HER2 status; previous chemotherapy; and pathological nodal status. Neither the patients nor the physicians were masked to treatment allocation. The primary endpoint was disease-free survival. The minimum cutoff to declare superiority of the upfront strategy over the switch strategy was assumed to be a 2% difference in disease-free survival at 5 years. Primary efficacy analyses were done by intention to treat; safety analyses included all patients for whom at least one safety case report form had been completed. Follow-up is ongoing. This trial is registered with the European Clinical Trials Database, number 2006-004018-42, and ClinicalTrials.gov, number NCT00541086. Findings: Between March 9, 2007, and July 31, 2012, 3697 patients were enrolled into the study. After a median follow-up of 60 months (IQR 46–72), 401 disease-free survival events were reported, including 211 (11%) of 1850 patients allocated to the switch strategy and 190 (10%) of 1847 patients allocated to upfront treatment. 5-year disease-free survival was 88·5% (95% CI 86·7–90·0) with the switch strategy and 89·8% (88·2–91·2) with upfront treatment (hazard ratio 0·89, 95% CI 0·73–1·08; p=0·23). 5-year disease-free survival was 90·0% (95% CI 87·9–91·7) with anastrozole (124 events), 88·0% (85·8–89·9) with exemestane (148 events), and 89·4% (87·3 to 91·1) with letrozole (129 events; p=0·24). No unexpected serious adverse reactions or treatment-related deaths occurred. Musculoskeletal side-effects were the most frequent grade 3–4 events, reported in 130 (7%) of 1761 patients who received the switch strategy and 128 (7%) of 1766 patients who received upfront treatment. Grade 1 musculoskeletal events were more frequent with the upfront schedule than with the switch schedule (924 [52%] of 1766 patients vs 745 [42%] of 1761 patients). All other grade 3–4 adverse events occurred in less than 2% of patients in either group. Interpretation: 5 years of treatment with aromatase inhibitors was not superior to 2 years of tamoxifen followed by 3 years of aromatase inhibitors. None of the three aromatase inhibitors was superior to the others in terms of efficacy. Therefore, patient preference, tolerability, and financial constraints should be considered when deciding the optimal treatment approach in this setting. Funding: Italian Drug Agency