Scientific Payload Research Articles

Topographic Reconstruction of the “Tianwen-1” Landing Area on the Mars Using High Resolution Imaging Camera Images

High-resolution optical cameras have always been important scientific payloads in Mars exploration missions, and the Mars topographic data produced by their detection data can provide support for scientific research on Mars geomorphology and geological structure evolution. As of December 2021, there are still relatively few high-resolution image data at the sub-meter level on the Martian surface, with about 2.6% global coverage and even more limited stereo coverage (just about 0.4%). At the same time, there are still some difficulties in data acquisition and terrain reconstruction processing methods for high-resolution Mars images that need to be solved. This paper described how we designed the in-orbit stereo imaging strategy based on the characteristics of the High Resolution Imaging Camera (HiRIC) of China’s first Mars exploration mission (Tianwen-1), studied the technical solutions for HiRIC stereo image photogrammetry processing, and produced a topographic dataset for the “Tianwen-1” landing area, including digital orthophoto map (DOM) with a GSD (ground sample distance) of 0.7, 3.5m, and digital elevation model (DEM) with a GSD of 3.5m. Precision analysis results show that this topographic data has good consistency in planar position and elevation compared with the existing Mars terrain data, and has advantages in spatial resolution and terrain detail expression, which will be widely used in the geological background study of the “Tianwen-1” landing area, as well as landing site positioning, Martian surface remote operation planning and other Mars scientific research and engineering tasks.

Flight Experiment Validation of Altitude Measurement Performance of MOSIR on Tianwen-1 Orbiter

The MOSIR (Mars Orbiter Subsurface Investigation Radar) is one of the scientific payloads carried by the Tianwen-1 orbiter. MOSIR conducted a ground experiment in the desert near Dengkou County, northern China, before the launch of the Tianwen-1 satellite. The MOSIR prototype was suspended from a hot air balloon and flew over a flat region at an altitude of 2500–3300 m. This experiment aimed to verify the system performance and data processing. The data collected in subsurface sounding mode is performed range compression, and the altitude measurement data removes invalid data. After processing, the altitude measurement results of two operating modes are analyzed and compared with that of the Global Position System (GPS), which verifies the accuracy of the altitude measurement.

UV telescope TUS on board Lomonosov satellite: Selected results of the mission

The Tracking Ultraviolet Setup (TUS) was the first orbital detector aimed to check the possibility of recording ultra-high energy cosmic rays (UHECRs) at E≳100 EeV by measuring the fluorescence signal of extensive air showers in the atmosphere. TUS was an experiment funded by the Russian Space Agency ROSCOSMOS, and it operated as a part of the scientific payload of the Lomonosov satellite since April 2016 till late 2017. During its mission, TUS registered almost 80,000 events in its main operation mode, with a few of them being sufficiently interesting to be more deeply scrutinized as they showed light profile and duration similar to UHECR events, even though much brighter. At the same time, the data acquired by TUS in different acquisition modes have been used to search for more exotic matter such us strangelets and nuclearites, and to measure occurrence, time profile and signal amplitude of different classes of transient luminous events among other scientific objectives, showing the interdisciplinary capability of a space-based observatory for UHECRs. In this paper, we report a selection of studies and results obtained with the TUS telescope which will be presented and placed in the contest of the present and future missions dedicated to the observation of UHECRs from space such as Mini-EUSO, K-EUSO and POEMMA.

SuperCam calibration targets on board the perseverance rover: Fabrication and quantitative characterization

The Perseverance rover is exploring Jezero crater on Mars since February 2021. SuperCam instrument is part of the scientific payload, combining five different techniques in order to characterize the targets to sample: LIBS (Laser-Induced Breakdown Spectroscopy), Raman and Visible and Infrared (VISIR) spectroscopies, Sound Recording and a colored Imager. Thirty-six calibration targets have been developed for this instrument. Twenty-three of these calibration targets are dedicated to the LIBS technique, corresponding to rocks and/or minerals. Raman and VISIR spectroscopy have their own calibration targets but may also use the LIBS mineral targets as reference on Mars to test mineral detections. The choice and the fabrication of these calibration targets have been made in order to fulfill the science intents of the mission, as well as the technical and science intents of each of the SuperCam technique. These calibration targets have been spectrally characterized and they have shown to be chemically homogeneous at the SuperCam LIBS scale. Their elementary compositions are given, using two different quantitative methods. The composition of the calibration targets will be used as reference for future assessment of the quantitative capability of the SuperCam LIBS technique.

Onboard dynamic image exposure control for the Star–Planet Activity Research CubeSat (SPARCS)

ABSTRACT The Star–Planet Activity Research CubeSat (SPARCS) is a 6U CubeSat under development to monitor the flaring and chromospheric activity of M dwarfs at near-ultraviolet (NUV) and far-ultraviolet (FUV) wavelengths. The spacecraft hosts two UV-optimized delta-doped charge-coupled devices fed by a 9-cm telescope and a dichroic beam splitter. A dedicated science payload processor performs near-real-time onboard science image processing to dynamically change detector integration times and gains to reduce the occurrence of pixel saturation during strong M dwarf flaring events and provide adequate flare light-curve structure resolution while enabling the detection of low-amplitude rotational modulation. The processor independently controls the NUV and FUV detectors. For each detector, it derives control updates from the most recent completed exposure and applies them to the next exposure. The detection of a flare event in the NUV channel resets the exposure in the FUV channel with new exposure parameters. Implementation testing of the control algorithm using simulated light curves and full-frame images demonstrates a robust response to the quiescent and flaring levels expected for the stars to be monitored by the mission. The SPARCS onboard autonomous exposure control algorithm is adaptable for operation in future point source-targeting space-based and ground-based observatories geared towards the monitoring of extreme transient astrophysics phenomena.

Estimate of the background and sensitivity of the follow-up X-ray telescope onboard Einstein Probe

As a space X-ray imaging mission dedicated to time-domain astrophysics, the Einstein Probe (EP) carries two kinds of scientific payloads, the wide-field X-ray telescope (WXT) and the follow-up X-ray telescope (FXT). FXT utilizes Wolter-I type mirrors and the pn-CCD detectors. In this work, we investigate the in-orbit background of FXT based on Geant4 simulation. The impact of various space components present in the EP orbital environment are considered, such as the cosmic photon background, cosmic ray primary and secondary particles (e.g. protons, electrons and positrons), albedo gamma rays, and the low-energy protons near the geomagnetic equator. The obtained instrumental background at 0.5–10keV, which is mainly induced by cosmic ray protons and cosmic photon background, corresponds to a level of ∼3.1×10−2 countss−1keV−1 in the imaging area of the focal plane detector (FPD), i.e. 3.7 × 10−3 countss−1keV−1cm−2 after normalization. Compared with the instrumental background, the field of view (FOV) background, which is induced by cosmic photons reflected by the optical mirror, dominates below 2keV. Based on the simulated background level within the focal spot (a 30′′-radius circle), the sensitivity of FXT is calculated, which could theoretically achieve several μcrab (in the order of 10−14ergcm−2s−1) in 0.5–2keV and several tens of μcrab (in the order of 10−13ergcm−2s−1) in 2–10keV for a pointed observation with an exposure of 25 min. This sensitivity becomes worse by a factor of ∼2 if additional 10% systematic uncertainty of the background subtraction is included.

MiniCarb: a passive, occultation-viewing, 6U CubeSat for observations of CO2, CH4, and H2O

We present the final design, environmental testing, and launch history of MiniCarb, a 6U CubeSat developed through a partnership between NASA Goddard Space Flight Center and Lawrence Livermore National Laboratory. MiniCarb’s science payload, developed at Goddard, was an occultation-viewing, passive laser heterodyne radiometer for observing methane, carbon dioxide, and water vapor in Earth’s atmosphere at ∼1.6 µm s−1. MiniCarb’s satellite, developed at Livermore, implemented their CubeSat Next Generation Bus plug-and-play architecture to produce a modular platform that could be tailored to a range of science payloads. Following the launch on 5 December 2019, MiniCarb traveled to the International Space Station and was set into orbit on 1 February 2020 via Northrop Grumman’s Cygnus capsule which deployed MiniCarb with tipoff rotation of about 20° s−1 (significantly higher than the typical rate of 3° s−1 from prior CubeSats), from which the attitude control system was unable to recover resulting in a loss of power. In spite of this early failure, MiniCarb had many successes including rigorous environmental testing, successful deployment of its solar panels, and a successful test of the radio and communication through the Iridium network. This prior work and enticing cost (approximately $2 M for the satellite and $250 K for the payload) makes MiniCarb an ideal candidate for a low-cost and rapid rebuild as a single orbiter or constellation to globally observe key greenhouse gases.

Research on Aluminum Honeycomb Buffer Device for Soft Landing on the Lunar Surface

To obtain the resources of the moon, humans have launched a series of exploration activities on the moon, and the landing buffer device is an indispensable device on the lander required to perform lunar surface exploration missions. It can effectively protect the lander during landing scientific payloads such as instruments on the lander. Based on the mechanical properties and deformation mechanism of the aluminum honeycomb as buffer material, this paper compares and analyzes different simulation schemes and finally establishes the bonding model of the honeycomb by using the discrete element method; the parameters of the honeycomb material are matched through compression experiments to verify the discrete element honeycomb simulation and the feasibility of the scheme and its parameters. To meet the buffering requirements of large landers, a spider web honeycomb structure is proposed, its modeling method is studied by using the discrete element secondary development program, and the model is compressed as a whole to verify the energy consumption characteristics of the spider web honeycomb structure. Aiming at the honeycomb buffer device during the landing process, the cobweb honeycomb buffer structure and its corresponding landing coupling model were established using the discrete element method, the landing process was simulated and analyzed, and the landing results were predicted to verify the feasibility of the device, providing a reference for the design of the lander and its buffer device.

Tensegrity Robotics.

Numerous recent advances in robotics have been inspired by the biological principle of tensile integrity-or "tensegrity"-to achieve remarkable feats of dexterity and resilience. Tensegrity robots contain compliant networks of rigid struts and soft cables, allowing them to change their shape by adjusting their internal tension. Local rigidity along the struts provides support to carry electronics and scientific payloads, while global compliance enabled by the flexible interconnections of struts and cables allows a tensegrity to distribute impacts and prevent damage. Numerous techniques have been proposed for designing and simulating tensegrity robots, giving rise to a wide range of locomotion modes, including rolling, vibrating, hopping, and crawling. In this study, we review progress in the burgeoning field of tensegrity robotics, highlighting several emerging challenges, including automated design, state sensing, and kinodynamic motion planning.

Fungal Biomarkers Stability in Mars Regolith Analogues after Simulated Space and Mars-like Conditions.

The discovery of life on other planets and moons in our solar system is one of the most important challenges of this era. The second ExoMars mission will look for traces of extant or extinct life on Mars. The instruments on board the rover will be able to reach samples with eventual biomarkers until 2 m of depth under the planet’s surface. This exploration capacity offers the best chance to detect biomarkers which would be mainly preserved compared to samples on the surface which are directly exposed to harmful environmental conditions. Starting with the studies of the endolithic meristematic black fungus Cryomyces antarcticus, which has proved its high resistance under extreme conditions, we analyzed the stability and the resistance of fungal biomarkers after exposure to simulated space and Mars-like conditions, with Raman and Gas Chromatography–Mass Spectrometry, two of the scientific payload instruments on board the rover.

Contamination Control for Ultra-Sensitive Life-Detection Missions

A key science priority for planetary exploration is to search for signs of life in our Solar System. Life-detection mission concepts aim to assess whether or not biomolecular signatures of life are present, which requires highly sensitive instrumentation. This introduces greater risk of false positives, and perhaps false negatives. Stringent science-derived contamination requirements for achieving science measurements on life-detection missions necessitate mitigation approaches that minimize, protect from, and prevent science-relevant contamination of critical surfaces of the science payload and provide high confidence to life-detection determinations. To this end, we report on technology advances that focus on understanding contamination transfer from pre-launch processing to end of mission using high-fidelity physics in the form of computational fluid dynamics and sorption physics for monolayer adsorption/desorption, and on developing a new full-spacecraft bio-molecular barrier design that restricts contamination of the spacecraft and instruments by the launch vehicle hardware. The bio-molecular barrier isolates the spacecraft from biological, molecular, and particulate contamination from the external environment. Models were used to evaluate contamination transport for a designs reference mission that utilizes the barrier. Results of the modeling verify the efficacy of the barrier and an in-cruise decontamination activity. Overall mission contamination tracking from launch to science operations demonstrated exceptionally low probability on contamination impacting science measurements, meeting the stringent contamination requirements of femtomolar levels of compounds. These advances will enable planetary missions that aim to detect and identify signatures of life in our Solar System.

Science Missions of the Korean Lunar Exploration Program

The Korea Pathfinder Lunar Orbiter (KPLO), which is the Korean first lunar and space exploration spacecraft, will be launched in August 2022 and arrive in a lunar orbit in December 2022. The KPLO will carry out nominal missions while in a lunar polar orbit an ~100-km altitude for one year. The KPLO has five lunar science mission payloads and one technology demonstration payload in order to achieve their own science and technology goals. The science payloads consist of four Korean domestic instruments and one internationally collaborated science instrument for scientific investigations on the lunar surface and in a space environment. The Korean dometstic science instruments are the gamma-ray spectrometer named KGRS, the wide-angle polarimetric camera named PolCam, the fluxgate magnetometer named KMAG, and the high resolution camera named LUTI. The name of the internationally collaborated science instrument is ShandowCam, which was developed by Arizona State University, U.S., and funded and managed by NASA. The science data acquired by the science payloads will be released to the public in order to enhance scientific and educational achievements. The science data acquired by each science instrument will be archived and released through the web sites of the KPDS (KARI Planetary Data System) for the Korean science instruments and the NASA PDS (Planetary Data System) for the internationally collaborated science instrument.

Applications and Potentials of Intelligent Swarms for magnetospheric studies

Earth’s magnetosphere is vital for today’s technologically dependent society. To date, numerous design studies have been conducted and over a dozen science missions have flown to study the magnetosphere. However, a majority of these solutions relied on large monolithic satellites, which limited the spatial resolution of these investigations, as did the technological limitations of the past. To counter these limitations, we propose the use of a satellite swarm carrying numerous and distributed payloads for magnetospheric measurements. Our mission is named APIS — Applications and Potentials of Intelligent Swarms.The APIS mission aims to characterize fundamental plasma processes in the Earth’s magnetosphere and measure the effect of the solar wind on our magnetosphere. We propose a swarm of 40 CubeSats in two highly-elliptical orbits around the Earth, which perform radio tomography in the magnetotail at 8–12 Earth Radii (RE) downstream, and the subsolar magnetosphere at 8–12 RE upstream. These maps will be made at both low-resolutions (at 0.5 RE, 5 s cadence) and high-resolutions (at 0.025 RE, 2 s cadence). In addition, in-situ measurements of the magnetic and electric fields, plasma density will be performed by on-board instruments.In this article, we present an outline of previous missions and designs for magnetospheric studies, along with the science drivers and motivation for the APIS mission. Furthermore, preliminary design results are included to show the feasibility of such a mission. The science requirements drive the APIS mission design, the mission operation and the system requirements. In addition to the various science payloads, critical subsystems of the satellites are investigated e.g., navigation, communication, processing and power systems. Our preliminary investigation on the mass, power and link budgets indicate that the mission could be realized using Commercial Off-the-Shelf (COTS) technologies and with homogeneous CubeSats, each with a 12U form factor. We summarize our findings, along with the potential next steps to strengthen our design study.

Design and experimental research on buffer protection of high-g penetrator for deep space exploration

Deep space exploration technology is an important development direction for scientific exploration. The penetrator method has been proposed as an inexpensive method of studying planetary bodies. The basic principle of this method is that the detection equipment carried by the high-speed penetrator hits a planetary body at a high speed and is buried up to several meters below the surface to carry out detection work. During the frictional collision process with the planets crust, the instantaneous acceleration peaks of the scientific payload (electronic instrumentation) are large. Shock protection of these payloads is necessary to improve their survival and mission success. In this paper, with the goal of improving the survival rate of scientific loads inside a penetrator, a penetrator with a multilayer energy-absorbing structure is developed, in which cushioning protection measures, such as an aluminum foam-filled corrugated tube(AFFT) structure, polyurethane rubber, and epoxy resin potting, are applied to the penetrator. Since the analysis of this process is a highly nonlinear problem, a numerical modeling method is the main approach in this paper. The LS-DYNA software platform was used to simulate the penetrators penetration process on a moon soil medium. The results obtained using empirical formulas and theoretical derivations were compared with the results of numerical analysis to ensure the accuracy of the penetration simulation model. The finite element model of the penetrator was then verified and modified by conducting shock response spectral experiments and shock simulations. The results showed that the spacer scheme had a positive effect on the impact isolation and energy absorption. In addition, this scheme provides an important reference for the design of the penetrator prototype to guarantee the success of subsequent ground rocket sled experiments.

Conceptual Design of an Unmanned Aerial Vehicle for Mars Exploration

Significant technology advances have enabled planetary exploration aircraft to be considered as a viable science platform. These systems fill in a unique planetary science measurement gap, that of the regional scale, near-surface observation while providing a new perspective for planetary discovery. Exploration of Mars using UAV (Unmanned Aerial Vehicle) has been planned for over 25 years by leading space organizations such as NASA. Recent efforts have been able to produce some mature mission and flight system concepts, ready for flight project implementation. There are however si0gnificant numbers of challenges associated with getting an airplane to fly through the thin, carbon dioxide-rich Martian atmosphere. Traditional aircraft design expertise does not always apply to this sort of vehicle, and geometric, aerodynamic, and mission restrictions result in a restricted viable design space. This paper presents the conceptual approach that was taken to design a UAV capable of performing a VTOL (Vertical Take-Off and Landing) in the atmosphere of Mars. The UAV was designed to participate in the International Planetary Aerial Systems Challenge 2021. The UAV could carry a science payload of up to 5 kg (weight on mars).

Conceptual Design of an Unmanned Aerial Vehicle for Mars Exploration

Significant technology advances have enabled planetary exploration aircraft to be considered as a viable science platform. These systems fill in a unique planetary science measurement gap, that of the regional scale, near-surface observation while providing a new perspective for planetary discovery. Exploration of Mars using UAV (Unmanned Aerial Vehicle) has been planned for over 25 years by leading space organizations such as NASA. Recent efforts have been able to produce some mature mission and flight system concepts, ready for flight project implementation. There are however si0gnificant numbers of challenges associated with getting an airplane to fly through the thin, carbon dioxide-rich Martian atmosphere. Traditional aircraft design expertise does not always apply to this sort of vehicle, and geometric, aerodynamic, and mission restrictions result in a restricted viable design space. This paper presents the conceptual approach that was taken to design a UAV capable of performing a VTOL (Vertical Take-Off and Landing) in the atmosphere of Mars. The UAV was designed to participate in the International Planetary Aerial Systems Challenge 2021. The UAV could carry a science payload of up to 5 kg (weight on mars).

The Louisiana Space Consortium Student Sounding Balloon Program

Since the fall of 2003 the Louisiana Aerospace Catalyst Experiences for Students (LaACES) program has been providing university students a two semester project that culminates with the flight of a scientific balloon experiment. During the first semester students complete the Student Ballooning Course (SBC) which teaches basic skills necessary to develop a working scientific payload. The SBC consists of a series of lectures and activities providing instruction in electronics, programming, project management, balloon payload design, and introductory circuit assembly. The SBC introduces the BalloonSat, a sub-assembly designed at LSU for LaACES which contains a microcontroller, real-time clock and a four channel analog-to-digital converter. The second semester is spent on the design, development, testing and calibration of the payloads. Upon completion of the Flight Readiness Review, students travel to the NASA Columbia Scientific Balloon Facility (CSBF) in Palestine, Texas for integration, launch, recovery and science presentations. A flight capable Automatic Packet Reporting System (APRS) radio beacon armed with GPS and command capable cut down was developed to track the balloon during flight and to cut-down the payloads. Tracking vehicles are outfitted with radios tuned to APRS frequency and laptops displaying maps of the payload location. Here we describe LaACES; program development, tools and technologies, implementation, program, management issues and flight experiences.

Mineralogical and chemical properties inversed from 21-lunar-day VNIS observations taken during the Chang\u2019E-4 mission

We report on the mineralogical and chemical properties of materials investigated by the lunar rover Yutu-2, which landed on the Von Kármán crater in the pre-Nectarian South Pole–Aitken (SPA) basin. Yutu-2 carried several scientific payloads, including the Visible and Near-infrared Imaging Spectrometer (VNIS), which is used for mineral identification, offering insights into lunar evolution. We used 86 valid VNIS data for 21 lunar days, with mineral abundance obtained using the Hapke radiative transfer model and sparse unmixing algorithm and chemical compositions empirically estimated. The mineralogical properties of the materials at the Chang’E-4 (CE-4) site referred to as norite/gabbro, based on findings of mineral abundance, indicate that they may be SPA impact melt components excavated by a surrounding impact crater. We find that CE-4 materials are dominated by plagioclase and pyroxene and feature little olivine, with 50 of 86 observations showing higher LCP than HCP in pyroxene. In view of the effects of space weathering, olivine content may be underestimated, with FeO and TiO2 content estimated using the maturity-corrected method. Estimates of chemical content are 7.42–18.82 wt% FeO and 1.48–2.1 wt% TiO2, with a low-medium Mg number (Mg # ~ 55). Olivine-rich materials are not present at the CE-4 landing site, based on the low-medium Mg #. Multi-origin materials at the CE-4 landing site were analyzed with regard to concentrations of FeO and TiO2 content, supporting our conclusion that the materials at CE-4 do not have a single source but rather are likely a mixture of SPA impact melt components excavated by surrounding impact crater and volcanic product ejecta.

A comprehensive approach to predict a rocket's impact with stochastic estimators and artificial neural networks

One of the current ways to continue space research is to launch ballistic rockets that carry scientific payloads. To improve the accuracy of the instantaneous evolution of the payload impact on the Earths surface, it is necessary to estimate indirect measures more efficiently. This study proposes a comprehensive approach to determine the impact point prediction of ballistic rocket payloads. This approach combines tracking algorithms that are based on stochastic estimators with artificial neural network (ANN) models. Four existing stochastic estimators, namely a recursive Kalman filter (RKF), an extended Kalman filter (EKF), an unscented Kalman filter (UKF), and a particle filter (PF) are compared with four proposed stochastic estimators. These include a recursive Kalman filter aided by an ANN (RKFN), an extended Kalman filter aided by an ANN (EKFN), an unscented Kalman filter aided by an ANN (UKFN), and a particle filter aided by an ANN (PFN). This study shows that the results that are obtained through the proposed tracking algorithms RKFN, EKFN, UKFN, and PFN are better than those of the existing tracking algorithms RKF, EKF, UKF, and PF. The proposed estimators can be efficient low-cost tools to mitigate inaccuracies during tracking up to the payload's impact.

Project AstroSat: Five Years of Operations and Continuing

India’s first dedicated multi-wavelength satellite, AstroSat, was launched by PSLV C30 from the Satish Dhawan Space Centre, Sriharikota, Andhra Pradesh on 28 September 2015. It is India’s first multiwavelength observatory. AstroSat carries five scientific payloads and is capable of simultaneous observations from ultraviolet to very hard X-rays. It has completed five years of on-board operations in September 2020 as a proposal-based observatory. Currently, it has close to 1500 global users and has resulted in more than 150 articles in peer-reviewed journals. This article is an overview providing a brief description of the AstroSat mission and some recent results using data from this unique Indian space observatory.