Secondary Payload Research Articles

The First Validation of Aerosol Optical Parameters Retrieved from the Terrestrial Ecosystem Carbon Inventory Satellite (TECIS) and Its Application

In August 2022, China successfully launched the Terrestrial Ecosystem Carbon Inventory Satellite (TECIS). The primary payload of this satellite is an onboard multi-beam lidar system, which is capable of observing aerosol optical parameters on a global scale. This pioneering study used the Fernald forward integration method to retrieve aerosol optical parameters based on the Level 2 data of the TECIS, including the aerosol depolarization ratio, aerosol backscatter coefficient, aerosol extinction coefficient, and aerosol optical depth (AOD). The validation of the TECIS-retrieved aerosol optical parameters was conducted using CALIPSO Level 1 and Level 2 data, with relative errors within 30%. A comparison of the AOD retrieved from the TECIS with the AERONET and MODIS AOD products yielded correlation coefficients greater than 0.7 and 0.6, respectively. The relative error of aerosol optical parameter profiles compared with ground-based measurements for CALIPSO was within 40%. Additionally, the correlation coefficients R2 with MODIS and AERONET AOD were approximately between 0.5 and 0.7, indicating the high accuracy of TECIS retrievals. Utilizing the TECIS retrieval results, combined with ground air quality monitoring data and HYSPLIT outcomes, a typical dust transport event was analyzed from 2 to 7 April 2023. The results indicate that dust was transported from the Taklamakan Desert in Xinjiang, China, to Henan and Anhui provinces, with a gradual decrease in the aerosol depolarization ratio and backscatter coefficient during the transport process, causing varying degrees of pollution in the downstream regions. This research verifies the accuracy of the retrieval algorithm through multi-source data comparison and demonstrates the potential application of the TECIS in the field of aerosol science for the first time. It enables the fine-scale regional monitoring of atmospheric aerosols and provides reliable data support for the three-dimensional distribution of global aerosols and related scientific applications.

Trajectory & maneuver design of the NEA Scout solar sail mission

The Near-Earth Asteroid Scout (NEA Scout) mission aimed to deliver a 6U CubeSat to a slow flyby of a Near Earth Asteroid using a solar sail as the primary propulsion system. NEA Scout was launched as a secondary payload aboard Artemis I, on November 16, 2022, but communication with the spacecraft was not achieved. This paper describes the target asteroid selection and the innovative trajectory and maneuver design for the NEA Scout mission, including cold gas maneuvers, multiple lunar flybys, solar sail thrusting, and design margins for solar sailing. The resulting trajectory design tools, solutions, and analyses are potentially applicable to future solar sail missions.

Instrument Overview and Radiometric Calibration Methodology of the Non-Scanning Radiometer for the Integrated Earth–Moon Radiation Observation System (IEMROS)

The non-scanning radiometer with short-wavelength (SW: 0.2–5.0 μm) and total-wavelength (TW: 0.2–50.0 μm) channels is the primary payload of the Integrated Earth–Moon Radiation Observation System (IEMROS), which is designed to provide comprehensive Earth radiation measurements and lunar calibrations at the L1 Lagrange point of the Earth–Moon system from a global perspective. This manuscript introduces a radiometer preflight calibration methodology, which involves background removal and is validated using accurate and traceable reference sources. Simulated Earth view tests are performed to evaluate repeatability, linearity, and gain coefficients over the operating range. Both channels demonstrate repeatability uncertainties better than 0.34%, indicating consistent and reliable measuring performance. Comparative polynomial regression analysis confirms significant linear response characteristics with two-channel nonlinearity less than 0.20%. Gain coefficients are efficiently determined using a two-point calibration approach. Uncertainty analysis reveals an absolute radiometric calibration accuracy of 0.97% for the SW channel and 0.92% for the TW channel, underscoring the non-scanning radiometer’s capability to provide dependable global Earth radiation budget data crucial to environmental and climate studies.

The VLF Transmitter, Narrowband Receiver, and Tuner Investigation on the DSX Spacecraft

AbstractArtificially enhancing the pitch angle diffusion of the relativistic electrons trapped in the radiation belts with transmission of very‐low frequency (VLF) electromagnetic waves is the primary science objective of the wave‐particle interaction experiments (WPIx) on the Demonstration Science Experiments (DSX) spacecraft. The pitch angle diffusion occurs due to the interaction of stimulated whistler‐mode waves with these extremely high energy electrons. The primary payload of the DSX spacecraft is a high‐power VLF transmitter paired with a matched tuner, a two‐channel narrowband receiver, and an 81.6 m tip‐to‐tip carbon fiber longeron dipole antenna, collectively known as Transmitter, Narrowband receiver, and Tuner (TNT) instrument. TNT can execute a wide variety of programmable WPIx experiments and provide supporting in situ and remote plasma characterizations. In its main high‐power mode, the whistler stimulation on selected frequencies between 2.5 and 34 kHz is done by applying a high‐voltage signal, up to nominally 5 kV, at each transmit antenna monopole feed. Maximum power is radiated when the antenna‐plasma circuit reactance is tuned out, leading to resonance conditions at the selected frequency. In the radiation belts, the unknown and varying contributions of the ambient plasma to the total reactance have to be determined automatically and tuned out adaptively, steering the overall VLF circuit within the resonance state as DSX orbits the Earth. Auxiliary to the main WPIx mode, the low‐power relaxation sounding, remote plasma sensing, and listen‐only VLF‐HF emission spectrographic operations are used to probe the surrounding and remote plasma density and the local magnetic field strength.

The CanSat Compendium: A Review of Scientific CanSats

In recent years, CubeSats have gained popularity as secondary payloads in space missions due to their uniquely small size and minimal weight. This allows for the quick and inexpensive development of high-risk, high-reward investigations. The success of cube-shaped CubeSats has led to the development of a new class of small-scale and low-cost scientific platforms known as CanSats, which maintain a unique cylindrical shape. CanSats offer an even more economical alternative for conducting high-risk investigations, although they are typically constrained by having to operate within Earth’s atmosphere, which contributes to their reduced costs. However, the ability to test and improve space-bound hardware makes the CanSat a potential intermediary technology for continued space exploration. This survey paper seeks to provide a technical definition of CanSats and summarize the current state of the art in CanSat-based research. This paper covers the history of CanSats, their current mainstream applications, and their potential impact on the technology pipeline for space exploration. CanSats have proven to be versatile in various applications, including Earth science, aeronautics, and educational purposes. The lower cost of CanSats provides a wider range of researchers and educational institutions access to near-space science. Therefore, this paper also aims to explore the potential future applications of CanSats, particularly as an intermediary technology for testing and improving space-bound hardware, with potential benefits for future space missions. The findings from this survey could help to guide the further research and development of CanSats, as well as help to shape future space exploration efforts.

Evaluation of the Accuracy of Spectral Calibration Light Source on Spectral Radiance Acquired by the Greenhouse-Gases Absorption Spectrometer-2 (GAS-2)

Monitoring global greenhouse gas concentration information via satellite remote sensing has become a critical area of research to support the further understanding of global carbon emissions. The Greenhouse-gases Absorption Spectrometer-2 (GAS-2) is being developed as the primary payload of the Fengyun-3H (FY-3H), which will be launched in 2024. Achieving high-precision mesurements of greenhouse gases requires precise spectral calibration. However, currently, there is no method for assessing the detection accuracy of GAS-2 using spectral calibration light sources, and quantitative studies are lacking. In this study, the influence model of calibration light sources on spectral calibration accuracy is established, and the spectral radiance acquired via GAS-2 is simulated using the line-by-line radiative transfer model (LBLRTM). We investigated the impact of different linewidths and wavelength stabilities of the calibration light source on its accuracy in four wavelength bands. This study is the first to examine the effects of the linewidth and wavelength stability of a calibration light source on the spectral radiance acquired via GAS-2. The initial results demonstrate that if the linewidth of the calibration light source is approximately 100 MHz and the wavelength stability is in the order of subpicometers, the radiance error obtained by GAS-2 is less than 10%. Among the four bands, the 2.06 μm (strong-CO2) band is more affected by the calibration light source than the other three bands. In addition, the wavelength stability of the light source has a greater influence on the error than the linewidth of the light source under the same error condition. The research findings can be used to guide and reference the selection of light sources in the laboratory spectral calibration of GAS-2, ultimately contributing to the instrument’s quantitative development level.

A Multi-Pixel Split-Window Approach to Sea Surface Temperature Retrieval from Thermal Imagers with Relatively High Radiometric Noise: Preliminary Studies

In the following decade(s), a set of satellite missions carrying thermal infrared (TIR) imagers with a relatively high noise equivalent differential temperature (NEdT) are expected, e.g., the high resolution TIR imagers flying on the future Thermal infraRed Imaging Satellite for High-resolution Natural resource Assessment (TRISHNA), Land Surface Temperature Monitoring (LSTM) and NASA-JPL/ASI Surface Biology and Geology Thermal (SBG) missions or the secondary payload on board the ESA Earth Explorer 10 Harmony. The instruments on board these missions are expected to be characterized by an NEdT of ⪆0.1 K. In order to reduce the impact of radiometric noise on the retrieved sea surface temperature (SST), this study investigates the possibility of applying a multi-pixel atmospheric correction based on the hypotheses that (i) the spatial variability scales of radiatively active atmospheric variables are, on average, larger than those of the SST and (ii) the effect of atmosphere is accounted for via the split window (SW) difference. Based on 32 Sentinel 3 SLSTR case studies selected in oceanic regions where SST features are mainly driven by meso to sub-mesoscale turbulence (e.g., corresponding to major western boundary currents), this study documents that the local spatial variability of the SW difference term on the scale of ≃3 × 3 km2 is comparable with the noise associated with the SW difference. Similarly, the power spectra of the SW term are shown to have, for small scales, the behavior of white noise spectra. On this basis, we suggest to average the SW term and to use it for the atmospheric correction procedure to reduce the impact of radiometric noise. In principle, this methodology can be applied on proper scales that can be dynamically defined for each pixel. The applicability of our findings to high-resolution TIR missions is discussed and an example of an application to ECOSTRESS data is reported.

A rockoon closed helium buoyancy system; a first assessment

It is believed that the use of rockoons will revolutionize the space industry by giving priority service to microsatellite developers that now are secondary payloads for large rocket companies. However, stratospheric balloons, including rockoons, are typically filled with helium, the price of which has been rising sharply in the last decade, and if the tendency continues the use of helium in this technology could be seriously compromised. Here, we present a first assessment of the possibility for a helium closed buoyancy system in which helium is stored in a pressurized tank attached to the stratospheric balloon and pumped into the balloon and back by means of a centrifugal pump. Preliminary reckoning shows that by using a carbon-fiber-reinforced polymers (CFRP) composite as material for the storage vessel, a vessel diameter around 4.5 m will be necessary to transport a small rocket with a total mass of 150 kg. A helium closed buoyancy system will allow not just saving helium but also controlled buoyancy during lifting and the landing. Keywords: Rockoon, Helium Stratospheric Balloons, Helium Market

The CHROMA cloud-top pressure retrieval algorithm for the Plankton, Aerosol, Cloud, ocean Ecosystem (PACE) satellite mission

Abstract. This paper provides the theoretical basis and simulated retrievals for the Cloud Height Retrieval from O2 Molecular Absorption (CHROMA) algorithm. Simulations are performed for the Ocean Color Instrument (OCI), which is the primary payload on the forthcoming NASA Plankton, Aerosol, Cloud, ocean Ecosystem (PACE) mission, and the Ocean Land Colour Instrument (OLCI) currently flying on the Sentinel 3 satellites. CHROMA is a Bayesian approach which simultaneously retrieves cloud optical thickness (COT), cloud-top pressure and height (CTP and CTH respectively), and (with a significant prior constraint) surface albedo. Simulated retrievals suggest that the sensor and algorithm should be able to meet the PACE mission goal for CTP error, which is ±60 mb for 65 % of opaque (COT ≥3) single-layer clouds on global average. CHROMA will provide pixel-level uncertainty estimates, which are demonstrated to have skill at telling low-error situations from high-error ones. CTP uncertainty estimates are well-calibrated in magnitude, although COT uncertainty is overestimated relative to observed errors. OLCI performance is found to be slightly better than OCI overall, demonstrating that it is a suitable proxy for the latter in advance of PACE's launch. CTP error is only weakly sensitive to correct cloud phase identification or assumed ice crystal habit/roughness. As with other similar algorithms, for simulated retrievals of multi-layer systems consisting of optically thin cirrus clouds above liquid clouds, retrieved height tends to be underestimated because the satellite signal is dominated by the optically thicker lower layer. Total (liquid plus ice) COT also becomes underestimated in these situations. However, retrieved CTP becomes closer to that of the upper ice layer for ice COT ≈3 or higher.

Ridesharing Options from Geosynchronous Transfer Orbits to the Sun–Earth Region

Ridesharing options for secondary payloads to be delivered to regions beyond geostationary altitude are increasingly available with propulsive evolved expendable launch vehicle secondary payload adapter rings. The preliminary mission design for secondary payloads must consider the variability of the dropoff orbit orientation: a factor that is a function of the primary mission. In this analysis, assume that the dropoff orbit is an Earth-centered geosynchronous transfer orbit (GTO). Then, propellant-efficient transfers to periodic and quasi-periodic orbits near the Sun–Earth Lagrange point are constructed from a range of GTO orientations. Dynamical structures (such as hyperbolic invariant manifolds) associated with orbits near Sun–Earth Lagrange point are leveraged to identify and summarize various types of transfer opportunities.

A Simple Band Ratio Library (BRL) Algorithm for Retrieval of Hourly Aerosol Optical Depth Using FY-4A AGRI Geostationary Satellite Data

The Advanced Geostationary Radiation Imager (AGRI) is one of the primary payloads aboard the FY-4A geostationary meteorological satellite, which can provide high-frequency, wide coverage, and multiple spectral channel observations for China and surrounding areas. There are currently few studies on aerosol optical depth (AOD) inversion from FY-4A AGRI data. Based on AGRI data, a new land AOD retrieval algorithm called the band ratio library (BRL) algorithm was proposed in this study. The monthly average surface reflectance band ratio library was established after obtaining the relationship of band surface reflectance ratio from the MODIS combined AOD dataset. In order to calculate the hourly AOD, look-up tables (LUT) for the various aerosol models were constructed using the 6SV model. We quantitatively compared AOD produced from AGRI data with AERONET ground observations to validate the BRL algorithm. AGRI-retrieved AOD is in good agreement with AOD measured by AERONET, which has a correlation coefficient of R is 0.84, the linear regression function is AODAGRI = 0.80 ∗ AODAERONET − 0.004, the root-mean-square error (RMSE) is 0.16, and approximately 60% of the AGRI AOD results fall within the uncertain range of AOD = ±(0.2 × AODAERONET + 0.05). A cross-comparison was made with the MODIS AOD product provided by NASA. The comparison and verification show the proposed algorithm has a good accuracy of land AOD estimation from AGRI data.

Feasibility studies for a dust observatory between earth and the asteroid belt

Cosmic dust transports information about the composition and evolution of distant realms over space and time. Dust sources may be in our local neighbourhood, such as the surfaces of moons and small bodies, or further away, in the galactic environment. The interior of moons like Io or Enceladus are well known dust sources in our solar system. Dust grains are therefore like probes, giving us the opportunity to investigate these objects at a distance. Thus, a new field of activity has been born: Dust Astronomy. The ultimate tool for Dust Astronomy is a dust observatory which was never been flown so far. Until today, all our knowledge is based on smaller individual dust detectors flown on various interplanetary spacecraft. Recently, a new generation of dust telescopes, which can be combined to a full dust observatory, became available. The scientific goal of such an observatory is to characterise our micrometeoroid environment with high precision and sensitivity and to record an inventory of various dust populations from asteroidal, cometary and interstellar dust sources.Two competitive studies on a Dust Astronomy mission were performed as part of a master’s course, including mission analysis and spacecraft design. The goal was to demonstrate the feasibility of an observatory reaching the main asteroid belt with a minimum spacecraft mass using electric propulsion. Additional secondary payloads supporting the primary objective were selected as well. The results prove that small probes with less than 700kg mass are capable of placing an array of dust telescopes deep in the asteroid belt, leading to a huge leap in Dust Astronomy and our knowledge about the local dust environment.

Terminator orbits around the triple asteroid 2001-SN263 in application to the deep space mission ASTER

We search for stable orbits in the vicinity of the triple asteroid system, 2001-SN263, which will be target of the deep space mission ASTER, currently under study by the Brazilian space agency (AEB). Our numerical simulations include gravitational forces caused by the three bodies of 2001-SN263, higher-order terms of the primary’s gravity field, planetary perturbations and solar radiation pressure. Due to the low gravity of the triple system, the spacecraft’s motion becomes complex and the faint gravity forces of the secondaries are exceeded by radiation pressure from the Sun. However, we show that the so-called ”terminator orbits” within the asteroid system at distances between 6–10 km to the primary body can be found. A spacecraft parked in such orbit will stay within the system for several months without the need to adjust its trajectory. Additionally, these stable orbits will allow investigating the entire primary body including its poles as well as the two secondary bodies. We also show that a laser altimeter, which is part of ASTER’s primary payload, will benefit significantly from these terminator orbits.

Test Results From the Prelaunch Characterization Campaign of the Engineering Test Unit of the Ocean Color Instrument of NASA’s Plankton, Aerosol, Cloud and Ocean Ecosystem (PACE) Mission

This paper summarizes the results from the system level test campaign of the Engineering Test Unit (ETU) of the ‘Ocean Color Instrument’ (OCI), the primary payload of NASA’s ‘Plankton, Aerosol, Cloud and ocean Ecosystem’ (PACE) mission. The main goals of the test campaign were to optimize characterization procedures and evaluate system level performance relative to model predictions. Critical performance parameters such as radiometric gain, signal-to-noise ratio, polarization, instantaneous field-of-view, temperature sensitivity, relative spectral response and stability were evaluated for wavelengths from 600 to 2,260 nm and are in line with expectations. We expect the OCI flight unit to meet the PACE mission performance requirements. Building and testing the ETU has been extremely important for the development of the OCI flight unit (e.g. improved SNR by increasing the aperture, optimized thermal design), and we strongly recommend the inclusion of an ETU in the development of future spaceborne sensors that rely on novel technological designs. ETU testing led to the discovery of a hysteresis issue with the SWIR bands, and a correction algorithm was developed. Also, the coregistration of the SWIR bands relative to each other is worse than expected, but this was discovered too late in the schedule to remediate.

Design, Analysis, Test, and Model Correlation of a Flight-Like Additively Manufactured ESPA-Class Satellite

This paper presents the design, finite element analysis, dynamic testing, and model correlation of AdditiveSat, an additively manufactured Evolved Expendable Launch Vehicle (EELV) Secondary Payload Adapter (ESPA)–class spacecraft fabricated using fused filament fabrication. The AdditiveSat octagonal prism design incorporates several known additive manufacturing benefits, such as secondary structure printed directly into the primary structure and thus reducing the number of parts required to assemble the vehicle. A Pathfinder structure was printed and sine burst tested to , as well as random vibration, to demonstrate the feasibility of an additively manufactured ESPA-class structure to survive flight launch environments. A detailed model correlation effort noted several best practices for finite element models in order to generate acceptable dynamic predictions for this type of architecture. The final correlated model accurately predicts the frequency of major structural modes of the Pathfinder structure within 3% and also provides accurate predictions for high-frequency responses up to 1000 Hz.

Mars Exploration Using Sailplanes

We present the preliminary design of sailplanes, used for Mars exploration. The sailplanes mitigate the weight and energy storage limitations traditionally associated with powered flight by instead exploiting atmospheric wind gradients for dynamic soaring, and slope/thermal updrafts for static soaring. Equations of motion for the sailplanes were combined with wind profiles from the Mars Regional Atmospheric Modeling System (MRAMS) for two representative sites: Jezero crater, Perseverance’s landing site, and over a section of the Valles Marineris canyon. Optimal flight trajectories were obtained from the constrained optimization problem, using the lift coefficient and the roll angle as control parameters. Numerical results for complete dynamic soaring cycles demonstrated that the total sailplane energy at the end of a soaring cycle increases by 6.8–11%. The absence of a propulsion system, allowing for a compact form factor, means the sailplanes can be packaged into CubeSats and deployed as secondary payloads at a relatively low cost; providing scientific data over locations inaccessible by current landers and rovers. Various sailplane deployment methods are considered, including rapid deployment during Entry, Descent, and Landing (EDL) of a Mars Science Laboratory-class (MSL) vehicle and slow deployment using a blimp.

First Assessment of GF3-02 SAR Ocean Wind Retrieval

On 23 November 2021, the Gaofen-3-02 (GF3-02) satellite was successfully launched in the Jiuquan Satellite Launch Center of China. The primary payload is C-band Synthetic Aperture Radar (SAR), with a maximum resolution of 1 m, and includes 12 imaging modes such as Spotlight, Strip, and TOPSAR, which will play an essential role in marine environment monitoring. As an important marine environmental parameter, the wind speed accuracy retrieved by GF3-02 SAR directly reflects its performance and effectiveness as an operational product. Therefore, based on the wind data of buoys of the National Data Buoy Center (NDBC), ECMWF reanalysis V5 (ERA5), and HY-2B Scatterometer (SCA), a preliminary accuracy assessment of the wind speed retrieved by GF3-02 SAR is carried out in this paper. The wind speed retrieval accuracy of GF3-02 SAR in the co-polarization (HH+VV) data under different Geophysical Model Functions (GMFs) is discussed by using 478 level-1A Single Look Complex (SLC) ocean products acquired in Quad-Polarization Strip I (QPSI) and produced by the National Satellite Ocean Application Service (NSOAS) from January to March 2022. The results show that the optimal root mean square errors (RMSE) are 1.40 m/s, 1.18 m/s, and 1.24 m/s for the VV polarization and 1.39 m/s, 1.19 m/s, and 1.52 m/s for the HH polarization compared to the NDBC wind speed, the ERA5 wind speed, and the HY-2B SCA wind speed, respectively. The preliminary results show that GF3-02 SAR has good wind speed retrieval ability and can meet the needs of operational products.

Fluidic-Based Instruments for Space Biology Research in CubeSats

For the last 15 years, small satellites known as CubeSats have been used to investigate the effects of the space environment on biological organisms. All biological CubeSat missions flown to date have performed studies in low Earth orbit (LEO), each one improving its biological support sub-systems from the last. An upcoming NASA biological CubeSat mission, BioSentinel, will launch as a secondary payload on Artemis 1 and eventually reach a heliocentric orbit beyond LEO, and the protection of Earth’s magnetosphere. The main objectives of BioSentinel are 1) to investigate the biological effects of the deep space radiation environment and 2) to develop our technological capacity to support biological research in deep space. The instruments and subsystems within BioSentinel have heritage from previous CubeSat missions (e.g., fluidics, optics, thermal control), but are extended on many levels. BioSentinel improves upon the materials and design (e.g., decreased card vapor permeability to maintain low humidity; the addition of a fluidic manifold with internal check-valves, desiccant chambers, and bubble traps for each individual fluidic card) and adds new tools for discovery (e.g., onboard LET spectrometer). The main objective of this Perspective is to emphasize the evolution of the fluidic systems used in past and ongoing NASA biological CubeSat missions and highlight aspects of these systems that can be optimized for future experimentation beyond LEO.

A compact instrument for gamma-ray burst detection on a CubeSat platform II

The Gamma-ray Module, GMOD, is a miniaturised novel gamma-ray detector which will be the primary scientific payload on the Educational Irish Research Satellite (EIRSAT-1) 2U CubeSat mission. GMOD comprises a compact (25 mm times 25 mm times 40 mm) cerium bromide scintillator coupled to a tiled array of 4 times 4 silicon photomultipliers, with front-end readout provided by the IDE3380 SIPHRA. This paper presents the detailed GMOD design and the accommodation of the instrument within the restrictive CubeSat form factor. The electronic and mechanical interfaces are compatible with many off-the-shelf CubeSat systems and structures. The energy response of the GMOD engineering qualification model has been determined using radioactive sources, and an energy resolution of 5.4% at 662 keV has been measured. EIRSAT-1 will perform on-board processing of GMOD data. Trigger results, including light-curves and spectra, will be incorporated into the spacecraft beacon and transmitted continuously. Inexpensive hardware can be used to decode the beacon signal, making the data accessible to a wide community. GMOD will have scientific capability for the detection of gamma-ray bursts, in addition to the educational and technology demonstration goals of the EIRSAT-1 mission. The detailed design and measurements to date demonstrate the capability of GMOD in low Earth orbit, the scalability of the design for larger CubeSats and as an element of future large gamma-ray missions.

Research on radiometric calibration of the SVOM Visible Telescope

The Visible Telescope (VT), which is the primary payload for the Chinese-French Space Multi-band Variable Object Monitor (SVOM) mission, is designed to observe the optical afterglow of gamma-ray bursts (GRBs). While calibration is one of the key factors to validate that VT achieves its scientific objectives in terms of detection limit, photometric accuracy and photometric system deviation. In the dissertation, based on the scientific objectives and optomechanical parameters of SVOM VT, the calibration techniques for space-based astronomical telescopes are studied. We have carried out comprehensive characterization and high-precision calibration of VT qualification model in three phases: detector, instrumentation and in-orbit laboratory verification, and all tests have reached the desired results and meet the requirements of calibration indicators.