Launch Center Research Articles

Calibration and performance of the neutron detector onboard of the DAMPE mission

The DArk Matter Particle Explorer (DAMPE), one of the four space-based scientific missions within the framework of the Strategic Pioneer Program on Space Science of the Chinese Academy of Sciences, was successfully launched on 2015 Dec. 17 from Jiuquan launch center. One of the most important scientific goals of DAMPE is to search for evidence of dark matter indirectly by measuring the spectrum of high energy cosmic-ray electrons. The neutron detector, one of the four sub-payloads of DAMPE, is designed to distinguish high energy electrons from hadron background by measuring the secondary neutrons produced in the shower. In this paper, a comprehensive introduction of the neutron detector is presented, including the design, calibration and performance. The analysis with simulated data and flight data indicates a powerful proton rejection capability of the neutron detector, which plays an essential role for TeV electron identification of DAMPE.

Atmospheric Flow at Alcântara Launch Center

The atmospheric flow at Alcântara Launch Center (CLA) was studied using Computational Fluid Dynamics (CFD) techniques. To characterize the region were considered the coastal cliff and the Integration Mobile Tower, called TMI, both within the launching and preparation area (SPL). In this study, the cliff was represented by a step of 90° with 40 meters of height. The inlet velocity profile was elaborate according to the power law, with exponent of 0.11, freestream velocity of 20 m/s and Reynolds number of 4.3 x 105, adopting neutral atmosphere. Three wind directions were considered, 90º, 125º and 135°. The numerical model used was the Reynolds Stress Model (RSM), based on the Reynolds-Averaged Navier-Stokes (RANS) equations. The solution of the equations was obtained by ANSYS FLUENT 19, which uses the finite volume method. The results showed good agreement with the wind tunnel tests especially for wind direction perpendicular to the cliff. The incident wind direction strongly influences the flow dynamics in the SPL forming a helicoidal vortex over the coastal cliff the higher the wind slope.

Estimativa da altura da camada limite planetária no Centro de Lançamento de Alcântara

Sea and land breeze circulation and the internal boundary layer are some aspects that make it difficult to determine the coastal Planetary Boundary Layer (PBL) height (h). This paper evaluates the h estimation for the Alcantara Launch Center (CLA) in Maranhão state using 14 months of remote measurements obtained by a ceilometer and by the ERA5 reanalysis. This response depends on the concentration of aerosols and atmospheric humidity present. Mean results indicated that dry months (September to November, with = 637 488 m) tend to have less hourly and seasonal variability of h compared to wet months (March to May, with = 770 912 m). A higher mean error in the wet season was obtained with ERA5 PBL h (h = 708 53 m over the land; e h = 648 46 m over the ocean) than in the dry season (h = 18 89 m; e h = 46 77 m). The greater amount of atmospheric humidity during the rainy season increases the estimation uncertainty. This condition was more frequent at night due to typical rainfall in the place.

Cof-cof: descobrindo a tuberculose

Temas de grande importância, como a tuberculose, são plausíveis de abordagem dentro da comunidade escolar, visto que, é uma doença com grande ocorrência e relevância. O objetivo do projeto foi promover o conhecimento da comunidade escolar acerca da importância da tuberculose, assegurando a disseminação de informações ao público-alvo. O projeto foi realizado na Escola Caminho das Estrelas, situada dentro do Centro de Lançamento do Município de Alcântara – Maranhão. A unidade de ensino contempla o ensino fundamental para 132 crianças do 1º ao 9º ano. Todos os alunos foram pré-avaliados para que fossem mensurados seus conhecimentos acerca da tuberculose. Em seguida, a temática foi explorada através de uma peça teatral com a presença dos membros executores do projeto, onde foram contemplados conceitos, sintomatologia, diagnóstico e tratamento da doença. Posteriormente, os alunos foram novamente avaliados, para assim, medir-se o aprendizado e desempenho dos alunos frente à ação proposta. Foi possível concluir através da intervenção, os escolares (1º ao 9º ano) tem pouco conhecimento sobre microbiologia, além disso, 36 (60%) das crianças do grupo 1 nunca tinham ouvido falar sobre tuberculose e 48 (80%) não sabiam sobre a cicatriz vacinal da BCG. O grupo 2, 4,33% acreditam que o tratamento da tuberculose é realizado através de chás ou de cirurgia. Por isso, se faz necessárias intervenções para que as crianças e adolescentes saibam o máximo de informações sobre a tuberculose, assegurando a disseminação de informações por elas para a comunidade em geral a sua volta.

Beam test calibrations of the HEPD detector on board the China Seismo-Electromagnetic Satellite

CSES (China Seismo-Electromagnetic Satellite) is a Chinese-Italian space mission dedicated to monitoring of variations of the electromagnetic field and waves, plasma parameters, and particle fluxes induced by natural sources and artificial emitters in the near-Earth space. The satellite was launched from the Jiuquan Satellite Launch Center in the Gobi desert (Inner Mongolia, China) on 2, 2018. The expected mission lifetime amounts to 5 years.The Italian contribution to the mission includes the design and construction of the High-Energy Particle Detector (HEPD), aimed to detect electrons in the energy range between 3 and 100 MeV and protons between 30 and 200 MeV, as well as light nuclei in the MeV energy range.In this paper, we describe the calibration procedures applied to HEPD based on data acquired during two tests at accelerator laboratories, which were performed on HEPD Flight Model prior to the delivery to China for final integration. An additional acquisition of cosmic muons was performed in order to better characterize the detector response before launch.

Intraseasonal climate forecast of iba tropical cyclone in northeast Brazil using the regional climate model - a case study

This study aimed to analyze the operationally stored simulations of the RegCM4.7 model using simulations performed by the National Center for Environmental Prediction (NCEP) coupled forecast system model version 2 (CFSv2) in downscaling. The South American domain, however, seeks to observe prevailing weather systems that may affect the Alcântara Rocket Launch Center in Maranhão. One case is analyzed with three different global initializations of the CFSv2 model. On March 25, 2019, the occurrence of Cyclone Iba on the southern coast of Bahia. The RegCM4.7 Regional Model was able to simulate tropical cyclone three months in advance. This performance is very important because the influence of these anomalous systems affect wind intensity and rainfall behavior in the Alcântara region because it would affect the convective processes on the continent in northeastern Brazil.

Current Status and Main Scientific Results of In-flight CSES Mission

The CSES (China Seismo-Electromagnetic Satellite) is the electromagnetism satellite of China's Zhangheng mission which is planned to launch a series of microsatellites within next 10 years in order to monitor the electromagnetic environment, gravitational field. The CSES 01 probe (also called ZH-1) was launched successfully on 2 February 2018, from the Jiuquan Satellite Launch Centre (China) and is expected to operate for 5 years in orbit. The second probe CSES 02 is going to be launched in 2022. The scientific objectives of CSES are to detect the electromagnetic field and waves, plasma and particles, for studying the seismic-associated disturbances. To meet the requirements of scientific objective, the satellite is designed to be in a sun-synchronous orbit with a high inclination of 97.4° at an altitude around 507 km. CSES carries nine scientific payloads including Search-coil magnetometer, Electric Field Detector, High precision Magnetometer, GNSS occultation Receiver, Plasma Analyzer, Langmuir Probe, two Energetic Particle Detectors (including an Italian one), and Tri-Band Transmitter. Up to now, CSES has been operating in orbit for 2 years with stable and reliable performance. By using all kinds of data acquired by CSES, we have undertaken a series of scientific researches in the field of global geomagnetic field re-building, the ionospheric variation environment, waves, and particle precipitations under disturbed space weather and earthquake activities, the Lithosphere-Atmosphere-Ionosphere coupling mechanism research and so on.

A Brazilian Space Launch System for the Small Satellite Market

At present, most small satellites are delivered as hosted payloads on large launch vehicles. Considering the current technological development, constellations of small satellites can provide a broad range of services operating at designated orbits. To achieve that, small satellite customers are seeking cost-effective launch services for dedicated missions. This paper deals with performance and cost assessments of a set of launch vehicle concepts based on a solid propellant rocket engine (S-50) under development by the Institute of Aeronautics and Space (Brazil) with support from the Brazilian Space Agency. Cost estimation analysis, based on the TRANSCOST model, was carried out taking into account the costs of launch system development, vehicle fabrication, direct and indirect operation cost. A cost-competitive expendable launch system was identified by using three S-50 solid rocket motors for the first stage, one S-50 engine for the second stage and a flight-proven cluster of pressure-fed liquid engines for the third stage. This launch system, operating from the Alcantara Launch Center, located at 2 ∘ 20’ S, would deliver satellites from the 500 kg class in typical polar missions with a specific transportation cost of about US$39,000 per kilogram of payload at a rate of 12 launches per year, in dedicated missions. At a low inclined orbit, vehicle payload capacity increased, decreasing the specific transportation cost to about 32,000 US$/kg. Cost analysis also showed that vehicle development effort would claim 781 work year, or less than 80 million dollars. Vehicle fabrication accounted for 174 work year representing less than 23 million dollars per unit. The launch system based on the best concept would, therefore, deploy small satellite constellations in cost-effective dedicated launches, 224 work year per flight, from the Alcantara Launch Center in Brazil.

Performance Evaluation of Multi-UAV Network Applied to Scanning Rocket Impact Area.

This paper presents a communication network for a squadron of unmanned aerial vehicles (UAVs) to be used in the scanning rocket impact area for Barreira do Inferno Launch Center—CLBI (Rio Grande do Norte, Brazil), aiming at detecting intruder boats. The main features of communication networks associated with multi-UAV systems are presented. This system sends information through Wireless Sensor Networks (WSN). After comparing and analyzing area scanning strategies, it presents the specification of a data communication network architecture for a squadron of UAVs within a sensor network using XBee Pro 900HP S3B modules. A brief description is made about the initial information from the construction of the system. The embedded hardware and the design procedure of a dedicated communication antenna to the XBee modules are presented. In order to evaluate the performance of the proposed architecture in terms of robustness and reliability, a set of experimental tests in different communication scenarios is carried out. Network management software is employed to measure the throughput, packet loss and other performance indicators in the communication links between the different network nodes. Experimental results allow verifying the quality and performance of the network nodes, as well as the reliability of the communication links, assessing signal received quality, range and latency.

The HEPD detector on board CSES satellite: in-flight performance

In this paper we will present a description of the High Energy Particle Detector (HEPD) onboard the China Seismo Electromagnetic Satellite (CSES) and its (preliminary) performance in flight.CSES mission aims at monitoring electromagnetic field, plasma and particles perturbations of atmosphere and inner Van Allen belts caused by solar and terrestrial phenomena and to the study of the low energy component of the cosmic rays.The satellite was launched from the Jiuquan Satellite Launch Center located in west of inner Mongolia on February 2nd, 2018 and is now orbiting in nominal condition. It hosts several instruments onboard: two magnetometers, an electrical field detector, a plasma analyser, a Langmuir probe and two particle detectors.The high energy particle detector (HEPD), designed and built by the Italian Limadou collaboration, is able to separate electrons and protons and identify nuclei up to Iron. HEPD provides good energy resolution and high angular resolution for electrons (3-100 MeV) and proton (30-200 MeV). The instrument consists of: 2 planes of double-side silicon microstrip sensors placed on the top of the instrument (direction of particle); 2 two layers of plastic scintillators (trigger) and a calorimeter (constituted by other 16 scintillators and a layer of LYSO sensors). A scintillator veto system completes the instrument. The commissioning of the HEPD and the other instruments on board was successfully completed in July 2018.

Design and on-orbit status of the trigger system for the DAMPE mission

DArk Matter Particle Explorer (DAMPE), the first Chinese astronomical satellite, was successfully launched at the Jiuquan Satellite Launch Center on 2015 Dec. 17. DAMPE consists of four subdetectors: Plastic Scintillator array Detector (PSD), Silicon-Tungsten tracKer-converter (STK), Bismuth Germanium Oxide (BGO) imaging calorimeter and NeUtron Detector (NUD). The global hardware trigger signal, which is generated by hits from the BGO calorimeter and the trigger logic board in the data acquisition system (DAQ), is responsible for event selection and DAQ synchronization of DAMPE. On orbit, to improve the detection efficiency, different trigger logics are used for event selection in different regions of latitude. The DAMPE trigger system compresses the average on-orbit trigger rate to 60Hz and reduces science data mass to less than 13GB per day to meet the requirement for the satellite’s data link. The whole trigger system has run stably up to now, ensuring excellent on-orbit operation of DAMPE.

Wet Days in the Dry Quarter of the Alcântara Launch Center Region: Observational Features

Precipitation events are infrequent in the dry quarter (SON) of the Alcântara Launch Center (Centro de Lançamento de Alcântara, CLA), the main launch site of the Brazilian Space Program. However, their occurrence could be a risk for activities during launch missions. In this work, the observational features of wet days (daily precipitation total ≥ 1 mm/day) in the dry quarter of the CLA region were studied. Daily precipitation totals over the course of 37 years (1979-2016, except 2006), outgoing longwave radiation (OLR) data and ERA-Interim reanalysis data were used. On average, in the dry quarter, there were 9 wet days, which accumulated 32 mm. The number and quarterly precipitation total of wet days showed pronounced interannual variability. This variability was negatively and significantly correlated with the interhemispheric sea surface temperature anomalies gradient in the Atlantic Ocean and the wind speed at 925 hPa over the CLA region. Based on a theoretical distribution (log-normal), the probability of occurrence of heavy precipitation days (daily total ≥ 10 mm/day) was only 0.5%. For days with heavy precipitation and deep convection (OLR ≤ 230 W·m-2), over a large area along the northeastern coast of South America including the CLA region, negative OLR differences (from the mean) and the strengthening of favorable conditions for deep convection were found. The large-scale organization of the convective activity and atmospheric features for higher precipitation events obtained in this work could be helpful for nowcasting and short-range weather forecasting during launch missions at the CLA.

Análise do perfil vertical do vento no Centro de Lançamento de Alcântara com uso de Análise de Componentes Principais

O objetivo deste estudo é fazer uma análise do comportamento do perfil vertical do vento, utilizando dados de radiossondagem no Centro de Lançamento de Alcântara (CLA), por meio do uso da técnica estatística multivariada da Análise das Componentes Principais (ACP), verificar se há presença de fluxos no perfil vertical do vento. Estes fluxos podem caracterizar circulações locais e estar associados com circulações do tipo brisa marítima, e também pode estar associado a circulações ao nível de mesoescala sinótica, tais como os Jatos de Baixos Níveis (JBN). Os resultados mostraram que nas três primeiras componentes no período noturno há presença de JBN, com 85% da variância explicada. A ocorrência dos JBN apresentou alturas típicas nas componentes, sendo a primeira com altura de 800 metros (direção média 60 a 70 graus), a segunda com altura de 400 metros (direção média 40 a 50 graus) e a terceira com 200 metros (direção média 50 a 60 graus). Tais JBN encontrados podem estar associados a processos relacionados a Camada Limite Planetária (CLP) no período noturno, como por exemplo o vento máximo de inversão e brisas.

APOD mission status and preliminary results

On September 20th, 2015, twenty satellites were successfully deployed into a near-polar circular orbit at 520 km altitude by the Chinese CZ-6 test rocket, which was launched from the TaiYuan Satellite Launch Center. Among these satellites, a set of 4 CubeSats conform the atmospheric density detection and precise orbit determination (APOD) mission, which is projected for atmospheric density estimation from in-situ detection and precise orbit products. The APOD satellites are manufactured by China Spacesat Co. Ltd. and the payload instruments include an atmospheric density detector (ADD), a dual-frequency dual-mode global navigation satellite system (GNSS) receiver (GPS and Beidou), a satellite laser ranging (SLR) reflector, and an S/X-band very long baseline interferometry (VLBI) beacon. In this paper, we compare the GNSS precise orbit products with co-located SLR observations, and the 3D orbit accuracy shows better than 10 cm RMS. These results reveal the great potential of the onboard micro-electro-mechanical system (MEMS) GNSS receiver. After calibrating ADD density estimates with precise orbit products, the accuracy of our density products can reach about 10% with respect to the background density. Density estimates from APOD are of a great importance for scientific studies on upper atmosphere variations and useful for model data assimilation.

Simulation and Practice of Condensation Recovery of Nitrogen Tetroxide Based on HYSYS

The theoretical calculation results of the condensation recovery rate and the required cooling power of an engineering application unit shown that condensation recovery of N2O4 in the waste gas is feasible and valuable in engineering applications.A simulation model was performed by using HYSYS and according to condensate-recovery process flow. Thus two important engineering parameters were simulated which included the thermal load of condensation system and the flow of glycol-water solution. The test results of an engineering application device based on these parameters at Jiuquan Satellite Launch Center indicated that the recovery efficiency can be above 90.0%, the purity of N2O4 recovered can be up to 99.6%.

Fatores que influenciaram as condutas dos pregoeiros do Centro de Lançamento da Barreira do Inferno (CLBI)

Resumo Este artigo trata dos fatores que influenciaram as condutas dos pregoeiros do Centro de Lançamento da Barreira do Inferno (CLBI) na execução dos processos eletrônicos de compras. Seu objetivo principal é analisar os fatores preponderantes que influenciaram as condutas dos pregoeiros do CLBI na execução dos pregões eletrônicos. A pesquisa teve como referência os preceitos da teoria sobre compras, tendo como dimensões de análise os aspectos organizacionais, motivacionais e de conhecimento e habilidades. A principal ferramenta metodológica consistiu em entrevistas semiestruturadas com os pregoeiros. Como resultado, verificou-se que a falta de reconhecimento da importância estratégica da atuação dos pregoeiros, de dedicação exclusiva e de especialização dos compradores públicos foram os principais fatores que influenciaram o desempenho dos pregoeiros do CLBI.

Wind Tunnel Investigation of the Wind Patterns in the Launching Pad Area of the Brazilian Alcântara Launch Center

This paper presents a wind tunnel study of the flow patterns in the main Brazilian Space Port, the Alcântara Launch Center (ALC), located in the Northwest region, over an irregular coastal cliff of 40 m height. In the ALC region, constant winds of strong incidence are very common, which can change the characteristics of the atmospheric boundary layer and affect safety conditions during launching operations. This study was conducted using a scaled model of the Launching Pad Area (LPA) in ALC complex with the purpose of getting insights about the wind flow patterns, as zones of strong vorticity, in that region when the wind incidence angle and coastal cliff characteristics change. The experiments were carried out in an aerodynamic wind tunnel, and for this reason it was necessary to use some techniques described in the literature to simulate an atmospheric boundary layer in a short test section wind tunnel. Hot-wire anemometer measurements were carried out for turbulence level evaluation with empty wind tunnel test section, and a two-dimensional Particle Image Velocimetry (PIV) was used for flow field velocity measurements in different confi gurations of wind incidence angle (α), Reynolds number and coastal cliff slope angle (β).

Seasonal Climate Forecast For The Alcântara Launch Center - Brazil

This work analyzed the performance of three cumulus convection parameterization schemes (Kain-Fritsch, Emanuel and Grell/Emanuel) in forecasting the seasonal climate during the transition from rainy to dry period (June to July 2017) in Alcântara Launch Center (ALC) located in Maranhão State-Brazil. For this reason, the outputs from the global NCEP climate forecast system (CFSv2) were used as initial and boundary conditions in the Regional Climate Model (RegCM4.4). The results also focused on the vertical wind profile in the lower atmosphere in the ALC. The forecasts of this variable were validated with data from the wind profile registered by a micrometeorological tower in ALC. The forecasts had better skill in represent the intensity wind in June/July on average and the better convective scheme was Grell Convection Scheme (the Land)/Emanuel convection Scheme (the Ocean).

Helium flux and elemental composition of galactic Cosmic Rays with the DAMPE space mission

DAMPE (DArk Matter Particle Explorer) is a space mission project promoted by the Chinese Academy of Sciences (CAS), in collaboration with Universities and Institutes from China, Italy and Switzerland. The detector is collecting data in a stable sun-synchronous orbit lasting 95 minutes at an altitude of about 500 km. It has been launched in December 17th, 2015, from the Jiuquan Satellite Launch Center, in the Gobi Desert. The main goals of the mission are: indirect search for Dark Matter, looking for signatures in the electron and photon spectra with energies up to 10 TeV; analysis of the flux and composition of primary Cosmic Rays with energies up to hundreds of TeV; high energy gamma-ray astronomy. Preliminary results about the Helium flux and Cosmic Ray composition will be presented and discussed.

Rocket emissions representation in atmospheric air‐quality models: The short‐range atmospheric transport and reaction of gases released by solid propellant engines

One risk associated with rocket‐launching activities is the inhalation of exhaust gases, which can occur either in the vicinity of the launch pad or, depending on the way these gases are transported and dispersed through the atmosphere, at locations far from the launch pad. Immediately after the ignition of the rocket motors, a large, hot cloud is formed near the ground, composed of carbon monoxide (CO) and carbon dioxide (CO2), hydrogen chloride (HCl) and also particulate material composed of aluminium oxide (Al2O3) in the case of rockets driven by a solid propellant. The Weather Research and Forecasting Model (WRF), an atmospheric mesoscale model, was modified in the present study to simulate the transport, dispersion and chemistry mechanisms (with the addition of reactions involving HCl and other chlorinated compounds) of these gases released during a launch. Simulations of the dispersion of effluents were performed for different rainfall regimes (dry and rainy periods) as well as for atmospheric thermal stability (day‐ and night‐time conditions) for a specific rocket (the Veículo Lançador de Satélites, VLS) at Brazil's Alcântara Launch Center (Centro de Lançamento de Alcântara, CLA). The results show that the most critical levels of HCl and CO occurred on the launch pad (Setor de Preparação de Lançamento, SPL) from the time of the launch (t0) to 10 min. The village of Alcântara, which is 9 km from the launch pad, could be affected according to the wind direction. The concentration of HCl reached a level in the range of 2200–3800 ppmv for both dry and wet periods respectively, and these concentrations can be very hazardous to humans.