SJ-10 Satellite Research Articles

Microgravity Inhibits Cell Proliferation and Promotes Senescence and Apoptosis in Embryonic Stem Cells

With advancements in deep space exploration missions, long-term spaceflights pose potential hazards to the reproductive and developmental functions of astronauts. Embryonic stem cells (ESCs), which are crucial to the development and growth of individual organisms, are observably altered by a microgravity environment. However, the role and mechanisms of microgravity in other activities of ESCs are still unclear. Here, mouse embryonic stem cells (mESCs) were used to investigate and understand the effect of microgravity on their activities. Combined with the SJ-10 satellite and random position machine, which were utilized for spaceflight and microgravity simulation, respectively, the bioinformatic tools were also used to assess the effect that microgravity might have on mESC activities. Based on differentially expressed genes (DEGs) analysis, 114 DEGs were significantly up-regulated and 859 DEGs were significantly down-regulated in mESCs after being subjected to spaceflight. The activities, such as cell proliferation, senescence, and apoptosis, were selected and confirmed by Gene Ontology and Kyoto Encyclopedia of Genes and Genomes analyses. It demonstrated a reduced proliferation capability of mESCs but increased the number of senescent and apoptotic cells after being subjected to simulated microgravity. Real-time polymerase chain reaction analysis of the screened activity-related DEGs demonstrated approximately consistent trends of these gene expressions in both spaceflight and simulated microgravity, as was predicted by bioinformatics analysis. Overall, these findings suggest that microgravity inhibits the proliferation of mESCs and induces senescence and apoptosis, shedding light on the impact of microgravity on the fundamental functions of mESCs in reproductive and embryonic development.

Potential evidence for transgenerational epigenetic memory in Arabidopsis thaliana following spaceflight

Plants grown in spaceflight exhibited differential methylation responses and this is important because plants are sessile, they are constantly exposed to a variety of environmental pressures and respond to them in many ways. We previously showed that the Arabidopsis genome exhibited lower methylation level after spaceflight for 60 h in orbit. Here, using the offspring of the seedlings grown in microgravity environment in the SJ-10 satellite for 11 days and returned to Earth, we systematically studied the potential effects of spaceflight on DNA methylation, transcriptome, and phenotype in the offspring. Whole-genome methylation analysis in the first generation of offspring (F1) showed that, although there was no significant difference in methylation level as had previously been observed in the parent plants, some residual imprints of DNA methylation differences were detected. Combined DNA methylation and RNA-sequencing analysis indicated that expression of many pathways, such as the abscisic acid-activated pathway, protein phosphorylation, and nitrate signaling pathway, etc. were enriched in the F1 population. As some phenotypic differences still existed in the F2 generation, it was suggested that these epigenetic DNA methylation modifications were partially retained, resulting in phenotypic differences in the offspring. Furthermore, some of the spaceflight-induced heritable differentially methylated regions (DMRs) were retained. Changes in epigenetic modifications caused by spaceflight affected the growth of two future seed generations. Altogether, our research is helpful in better understanding the adaptation mechanism of plants to the spaceflight environment.

Exploration of Direct-Ink-Write 3D Printing in Space: Droplet Dynamics and Patterns Formation in Microgravity

As a simple, fast and effective 3D printing method, direct-ink-writing (DIW) has potential applications in repairing the circuit board in orbit, printing the wearable devices for the astronaut, and producing the solar cells for the energy supply in space. To expand the DIW technology to space, we designed the colloidal material box (CMB) as the prototype printer of DIW and verified its applicability in the Chinese SJ-10 satellite. The colloidal suspensions was adopted as a diluted ink model to investigate two key processes of DIW under microgravity environment: manipulation of the droplet and formation of the patterns. We have showed the dynamics of the droplet, which would determine the size of the features, could be controlled through tuning the wettability of the needles and the solid surface. Compared to the ground, the “coffee ring” effect was weakened for the drying patterns because of strong interfacial effect under weightless conditions. We have found that fast evaporation could assist for fabricating more uniform and ordered structures.

Starting life in space.

As far as we know, animal development is a process that is unique to our planet. That does not mean, however, that development beyond our realm is impossible. As it starts to become feasible for us to look to the sky for another place to call home, we may start to appreciate the gravity of this question. In this issue, Lei et al. investigate for the first time the repercussions of space travel on the first decisions made by mouse embryos. Developing a novel micro-incubator, capable of automatic micrography and fixation, harboring some 3400 two-cell embryos, they investigate the consequences of development after being projected into the stratosphere in the SJ-10 satellite [1].

The Trends in Global Gene Expression in Mouse Embryonic Stem Cells During Spaceflight.

The environment in space differs greatly from the environment on the ground. Spaceflight causes a number of physiological changes in astronauts, such as bone loss and immune system dysregulation. These effects threaten astronauts’ space missions, and understanding the underlying cellular and molecular mechanisms is important to manage the risks of space missions. The biological effects of spaceflight on mammalian cells, especially with regards to DNA damage, have attracted much attention. Rad9 −/− mouse embryonic stem cells (mESCs) are known to be extremely sensitive to DNA damage agents. In this study, a project of the SJ-10 satellite programme, we investigated the gene expression profiles of both Rad9 −/− mESCs and Rad9 +/+ (wild-type) mESCs in space with a focus on genes critical for inducing, preventing, or repairing genomic DNA lesions. We found that spaceflight downregulated more genes than it upregulated in both wild-type and Rad9 −/− mESCs, indicating a suppressive effect of spaceflight on global gene expression. In contrast, Rad9 deletion upregulated more genes than it downregulated. Of note, spaceflight mainly affected organ development and influenced a wide range of cellular functions in mESCs, while Rad9 deletion mainly affected the development and function of the hematological system, especially the development, differentiation and function of immune cells. The patterns of gene expression in mouse embryonic stem cells in space is distinct from those in other types of cells. In addition, both spaceflight and Rad9 deletion downregulated DNA repair genes, suggesting a possibility that spaceflight has negative effects on genome for embryonic stem cells and the effects are likely worsen when the genome maintenance mechanism is defective.

Marangoni-Convection-Driven Bubble Behavior and Microstructural Evolution of Sn-3.5Ag/Sn-17Bi-0.5Cu (Wt Pct) Alloy Solidified on Cu Substrate Under Space Microgravity Condition

Marangoni convection significantly affects the solidification structure as it controls the bubble behavior and mass transfer in the melt. Sn-3.5Ag/Sn-17Bi-0.5Cu (wt pct) alloy with different surface tension gradients was fabricated and solidified on a Cu ring substrate under space microgravity condition (SJ-10 satellite) to study the Marangoni convection formation mechanism. The pore and element distributions in the solidified alloy and surface tension gradient in the melt were analyzed. The differences between the microstructures of alloys solidified under microgravity and normal gravity conditions were also investigated. The surface tension gradient induced by Bi concentration difference resulted in the formation of Marangoni convection from the right to left of the melt under the microgravity condition. In the left (Bi-scarce) part of the melt, Marangoni convection induced by the Cu concentration difference flowed from outside to inside. Driven by bubble-agitation convection, Cu mainly migrated from the substrate to the right part of the melt. Therefore, dendrite-like CuxSny was distributed along a gradient. Under the normal gravity condition, significant gravity-induced convection resulted in an even distribution of Bi and Cu, which decreased the contact angle and reduced the surface tension, thus promoting nucleation of the alloy. Therefore, fine dendrite-like CuxSny with larger number density were uniformly distributed in the melt.

Opposed Flame Spread over Cylindrical PMMA Under Oxygen-Enriched Microgravity Environment

The enriched oxygen ambient may be applied to China’s next generation space station. To understand the fire behaviors under oxygen-enriched microgravity environment, flame-spread experiments on extruded poly(methyl)methacrylate (PMMA) rods with 10-mm diameter were conducted in the SJ-10 Satellite. The opposed flame-spread behaviors were studied at the oxygen-enriched ambient (33.5% and 49.4%) under low flow velocities in the range of 0 to 12 cm/s. After the ignition in the middle of the sample, an opposed flame spread was achieved, rather than the forward flame spread. The flame-spread rate increases with the opposed flow velocity, due to the decreased flame width and the enhanced flame heat flux. Moreover, a blue flame sheet with a frequent burst of bubbles is found throughout the opposed-flow spread process, showing a near extinction behavior. For the oxygen concentration above 25%, normal-gravity experiments suggest that whether PMMA is cast or extruded should have a negligible effect on the opposed flame spread in microgravity. Compared to normal gravity, the microgravity flame spread rate in the oxygen-enriched atmosphere is slower which is the order of 0.1 mm/s, only one-tenth to one-fifth of that in normal gravity at the same nominal opposed flow velocity, and the acceleration of flame spread in microgravity by increasing oxygen concentration is also much smaller. This result suggests that (1) if the environmental gas flow is small, the fire hazard increased by raising oxygen level in microgravity space cabin can be much smaller than that on Earth; and (2) the fire risk of oxygen-enriched microgravity environment might be overestimated when a ground-based test method is employed to evaluate the burning characteristics of solid material.

An integration design of gas exchange, bubble separation, and flow control in a space cell culture system on board the SJ-10 satellite.

Pathophysiological changes of astronauts under space microgravity involve complex factors and require an integrative perspective to fully understand the mechanisms. The readouts from space cell biology experiments strongly depend on the hardware and especially the cell bioreactor that is used in distinct spacecraft. Herein, a specialized cell culture bioreactor is designed for culturing mammalian cells on board the SJ-10 satellite. This hardware focuses mainly on satisfying the requirements of gas exchange, bubble separation, and flow control, as well as their functional and structural integration on cell culture within the technical and environmental constraints of the spacecraft platform under microgravity. A passive bubble separator is constructed and is connected in series to an individual cell culture chamber to remove the bubbles that were produced in orbit during cell growth. A moderate flow rate is preset to provide sufficient mass transfer and low shear stress in a well-designed flow circuit. Together with other modules of temperature control, in situ microscopic imaging, and online imaging acquisition, this novel space cell culture system is successfully used to culture human endothelial cells and rat bone marrow-derived mesenchymal stem cells in the SJ-10 mission. The advantages and shortcomings of the integration design are discussed for this type of the hardware.

The volume ratio effect on flow patterns and transition processes of thermocapillary convection

Thermocapillary convection has always been one of the most important research topics in microgravity fluid physics. A space experimental study on the thermocapillary convection in an open annular liquid pool – a typical thermocapillary flow system – has been conducted on the SJ-10 satellite of China. This space experiment has observed the spatial temperature distribution of the liquid free surface using an infrared thermal imager, obtained the flow pattern transition process, analysed the oscillation characteristics and revealed the instability mechanism of themocapillary convection. The shape effects on the flow instability are researched by changing the volume ratio, Vr, which denotes the ratio of the liquid volume to the volume of the cylindrical gap between the walls. The volume ratio effect has been focused on for the first time. For a certain volume ratio, the flow pattern would transform from the steady state to the oscillation state accompanied by directional propagating hydrothermal waves with increasing temperature difference. In addition, the significant influences of the volume ratio on the critical conditions and wavenumber selection have been analysed in detail.

Microgravity diffusion flame spread over a thick solid in step-changed low-velocity opposed flows

We report results from a microgravity combustion experiment conducted aboard the SJ-10 satellite of China, focusing on the structure and dynamics of diffusion flames spreading over a thick PMMA in low-velocity opposed flows. The width of the PMMA sample is chosen to be as large as possible in order to minimize the side diffusion effects of oxygen, and for each of the four oxygen concentration cases considered, four decrementally changing gas flow velocities are imposed such that a wide range of parameter values are spanned near the quenching limit. Two distinct flame spread modes are identified near the quenching limit, namely the continuous flame mode for gas flow velocities greater than an oxygen-concentration dependent critical value, and the flamelet mode for subcritical gas flow velocities. The transition process between these two spread modes due to a step change in the gas flow velocity is usually accompanied by flame oscillations, and diffusive-thermal instability of the leading flame front is identified as the mechanism controlling such transition. A correlation of the flame spread rate data among different oxygen concentrations indicates that, in the presently considered radiation-controlled regime the normalized flame spread rate deviates from the predictions of the thermal theory and decreases monotonically with the increase in the flame Damköhler number. Meanwhile, with the decrease in the flame spread rate, the standoff distance and the inclination angle at the flame leading edge show an increasing and decreasing trend, respectively. An energy balance analysis across the fuel surface beneath the flame leading edge indicates that the variation of the heat absorbed by the solid for vaporization is sub-linear with respect to the flame spread rate, thereby implying that the fuel regression depth has a tendency to increase with decreasing flame spread rate. Moreover, the energy balance analysis suggests that the quenching boundary and the marginal stability boundary identified on the flammability map are, respectively, intrinsically associated with a certain specific ratio of the overall heat losses to the total heat conducted from the flame, or equivalently, associated with a certain specific value of the flame spread rate.

Surface configurations and wave patterns of thermocapillary convection onboard the SJ10 satellite

A fluid experiment was conducted on China’s SJ10 satellite to assess the instability of thermocapillary convection under microgravity. Oscillations of thermocapillary convection in an annular pool were investigated when the difference in temperature exceeded a certain threshold. Dynamics and transitions of the wave pattern were observed using an infrared camera. This work is concerned with the effect of the surface configuration on the wave patterns. There are 3 types of surface configurations that depend on the volume ratio: Vr < 0.77 (zone 1), 0.77 < Vr < 1 (zone 2), and Vr > 1 (zone 3). An irregular local wave occurs at Vr < 0.65, and a regular azimuthal wave occurs at Vr > 0.65. We observed the regular wave with the wavenumber m = 3 in zone 1 and zone 3 and the competition between m = 3 and m = 4 in zone 2. The nonlinear dynamics of traveling waves, standing waves, and counterpropagating waves were studied. The standing wave appears near the onset and transitions to the traveling wave. With a similar mechanism, counterpropagating waves with m = 3 and m = 4 occur in some cases at the onset. Additionally, counterpropagating waves also act as a transitional mode when the traveling wave transitions from m = 4 to m = 3. The traveling wave is very stable, but it develops into standing waves or Benjamin-Feir instability under highly supercritical conditions.

The critical condition and oscillation – transition characteristics of thermocapillary convection in the space experiment on SJ-10 satellite

This paper is an investigation on oscillation characteristics and transition routes of thermocapillary convection in an annular liquid pool in the space experiment carried out on SJ-10 recoverable scientific experiment satellite. Thermocapillary convection caused by non-uniformity of surface tension and the instability problem of the convection are introduced, and the measurement by thermocouples has been analyzed in detail. Through the relationship between the critical condition of start-oscillation in thermocapillary convection and the volume ratio, and the relationship between the oscillation frequency and the volume ratio, transition processes from steady flow to oscillatory flow and then to bifurcation are investigated. In addition, the acting mechanism of thermocapillary force has been discussed comparing with buoyant-thermocapillary convection on the ground.

Smoke emission and temperature characteristics of the long-term overloaded wire in space

We developed an experimental payload to study the overloaded characteristics of wire insulations on board the China’s SJ-10 satellite. In 2-week microgravity experiments provided by the orbital flight, the smoke emissions of overloaded wire insulations were observed in space for the first time. Two smoke emission modes, namely the end smoke jet and the bubbling smoke jet, were identified with polyethylene insulations. The results showed that the geometry of the pyrolysis front dominated the direction and the range of the end smoke jet. The non-oxidative pyrolysis that occurred between the wire core and the insulation produced the high-temperature smoke and caused the bubbling smoke jet. The bubbling jet has a significant impact on the temperatures of adjacent wires, revealing an additional fire risk in microgravity. The effects of insulation thickness and excess current on the temperature rise were also discussed.

Microgravity-induced hepatogenic differentiation of rBMSCs on board the SJ-10 satellite.

Bone marrow-derived mesenchymal stem cells (BMSCs) are able to differentiate into functional hepatocytelike cells, which are expected to serve as a potential cell source in regenerative medicine, tissue engineering, and clinical treatment of liver injury. Little is known about whether and how space microgravity is able to direct the hepatogenic differentiation of BMSCs in the actual space microenvironment. In this study, we examined the effects of space microgravity on BMSC hepatogenic differentiation on board the SJ-10 Recoverable Scientific Satellite. Rat BMSCs were cultured and induced in hepatogenic induction medium for 3 and 10 d in custom-made space cell culture hardware. Cell growth was monitored periodically in orbit, and the fixed cells and collected supernatants were retrieved back to the Earth for further analyses. Data indicated that space microgravity improves the differentiating capability of the cells by up-regulating hepatocyte-specific albumin and cytokeratin 18. The resulting cells tended to be maturated, with an in-orbit period of up to 10 d. In space, mechanosensitive molecules of β1-integrin, β-actin, α-tubulin, and Ras homolog gene family member A presented enhanced expression, whereas those of cell-surface glycoprotein CD44, intercellular adhesion molecule 1, vascular cell adhesion molecule 1, vinculin, cell division control protein 42 homolog, and Rho-associated coiled-coil kinase yielded reduced expression. Also observed in space were the depolymerization of actin filaments and the accumulation of microtubules and vimentin through the altered expression and location of focal adhesion complexes, Rho guanosine 5'-triphosphatases, as well as the enhanced exosome-mediated mRNA transfer. This work furthers the understanding of the underlying mechanisms of space microgravity in directing hepatogenic differentiation of BMSCs.-Lü, D., Sun, S., Zhang, F., Luo, C., Zheng, L., Wu, Y., Li, N., Zhang, C., Wang, C., Chen, Q., Long, M. Microgravity-induced hepatogenic differentiation of rBMSCs on board the SJ-10 satellite.

A Comparative Study of Near-Limit Flame Spread Over a Thick Solid in Space- and Ground-Based Experiments

Microgravity experiments have been performed aboard the SJ-10 satellite of China to investigate flame spread behaviors over a thick PMMA in low-velocity opposed flow. Two variables are considered: opposed-flow velocity in a range of 0 to 9 cm/s, and ambient oxygen concentration in a range of 25% to 50%. It is found that, when the flow velocity is reduced, the initial extended flame may breaks into separate flamelets after a dynamic transition process. This is the first observation of the flamelets spreading over a thick solid fuel in microgravity. Flame and flamelet propagate with a steady spread rate, which increases with the increasing flow velocity and oxygen concentration. A flammability map using oxygen concentration and flow velocity as coordinates is established, which delineates the uniform regime, the flamelet regime, and extinguished regime. The flammability boundary was extended to lower oxygen concentrations and lower flow velocities by the flamelet regime. The microgravity results are compared with the counterparts in ground-based narrow channel apparatus (NCA) experiments. Results showed that although the NCA tests overestimate the flame spread rate and flammable area, also exhibit differences in detailed flamelet formation process, flame and flamelet behaviors agree well with that in microgravity in a qualitative manner.

Microgravity-Induced Alterations of Inflammation-Related Mechanotransduction in Endothelial Cells on Board SJ-10 Satellite.

Endothelial cells (ECs) are mechanosensitive cells undergoing morphological and functional changes in space. Ground-based study has provided a body of evidences about how ECs can respond to the effect of simulated microgravity, however, these results need to be confirmed by spaceflight experiments in real microgravity. In this work, we cultured EA.hy926 ECs on board the SJ-10 Recoverable Scientific Satellite for 3 and 10 days, and analyzed the effects of space microgravity on the ECs. Space microgravity suppressed the glucose metabolism, modulated the expression of cellular adhesive molecules such as ICAM-1, VCAM-1, and CD44, and depressed the pro-angiogenesis and pro-inflammation cytokine secretion. Meanwhile, it also induced the depolymerization of actin filaments and microtubules, promoted the vimentin accumulation, restrained the collagen I and fibronectin deposition, regulated the mechanotransduction through focal adhesion kinase and Rho GTPases, and enhanced the exosome-mediated mRNA transfer. Unlike the effect of simulated microgravity, neither three-dimensional growth nor enhanced nitric oxide production was observed in our experimental settings. This work furthers the understandings in the effects and mechanisms of space microgravity on ECs, and provides useful information for future spaceflight experimental design.

Energetic particles’ fluxes and dose in the Radiation Gene Box measured by space radiation detector onboard SJ-10 satellite

To evaluate the hazard of space radiation posing to the tissues, it is important to obtain exact fluxes of different radiation particles. The Radiation Gene Box (RGB) onboard SJ-10 spacecraft was an instrument designed to investigate the effects of space environment on the mESCs and drosophila. To derive the dose received by the tissues inside the RGB, the Space Radiation Detector (SRD) was installed inside it. The SRD was designed to derive the fluxes of electron, proton, hellion and gamma rays around it. If the type of the particles, the energies, the fluxes and the conversion coefficients are known, the dose received by the tissues could be evaluated. The SRD was designed as a ΔE-E solid-state telescope. By measuring the energy deposited in the three subdetectors, the particles’ type and their energies could be discriminated. The data of SRD were divided into 15 bins by the types of particles and their energy ranges. The gamma ray flux was higher than any other particle flux inside the RGB, and the electron was the most intense charge particle, while the helium ion was the most harmful radiation to the cells inside the RGB. The dose rate inside the Radiation Gene Box was much higher than in the ground, but the integral dose of 12 days inside the RGB was about 2.13 mSv. It seemed unlikely to have obvious biological effects on the tissues of mice and drosophila.

Space microgravity drives transdifferentiation of human bone marrow-derived mesenchymal stem cells from osteogenesis to adipogenesis.

Bone formation is linked with osteogenic differentiation of mesenchymal stem cells (MSCs) in the bone marrow. Microgravity in spaceflight is known to reduce bone formation. In this study, we used a real microgravity environment of the SJ-10 Recoverable Scientific Satellite to examine the effects of space microgravity on the osteogenic differentiation of human bone marrow-derived mesenchymal stem cells (hMSCs). hMSCs were induced toward osteogenic differentiation for 2 and 7 d in a cell culture device mounted on the SJ-10 satellite. The satellite returned to Earth after going through space experiments in orbit for 12 d, and cell samples were harvested and analyzed for differentiation potentials. The results showed that space microgravity inhibited osteogenic differentiation and resulted in adipogenic differentiation, even under osteogenic induction conditions. Under space microgravity, the expression of 10 genes specific for osteogenesis decreased, including collagen family members, alkaline phosphatase ( ALP), and runt-related transcription factor 2 ( RUNX2), whereas the expression of 4 genes specific for adipogenesis increased, including adipsin ( CFD), leptin ( LEP), CCAAT/enhancer binding protein β ( CEBPB), and peroxisome proliferator-activated receptor-γ ( PPARG). In the analysis of signaling pathways specific for osteogenesis, we found that the expression and activity of RUNX2 was inhibited, expression of bone morphogenetic protein-2 ( BMP2) and activity of SMAD1/5/9 were decreased, and activity of focal adhesion kinase (FAK) and ERK-1/2 declined significantly under space microgravity. These data indicate that space microgravity plays a dual role by decreasing RUNX2 expression and activity through the BMP2/SMAD and integrin/FAK/ERK pathways. In addition, we found that space microgravity increased p38 MAPK and protein kinase B (AKT) activities, which are important for the promotion of adipogenic differentiation of hMSCs. Space microgravity significantly decreased the expression of Tribbles homolog 3 ( TRIB3), a repressor of adipogenic differentiation. Y15, a specific inhibitor of FAK activity, was used to inhibit the activity of FAK under normal gravity; Y15 decreased protein expression of TRIB3. Therefore, it appears that space microgravity decreased FAK activity and thereby reduced TRIB3 expression and derepressed AKT activity. Under space microgravity, the increase in p38 MAPK activity and the derepression of AKT activity seem to synchronously lead to the activation of the signaling pathway specifically promoting adipogenesis.-Zhang, C., Li, L., Jiang, Y., Wang, C., Geng, B., Wang, Y., Chen, J., Liu, F., Qiu, P., Zhai, G., Chen, P., Quan, R., Wang, J. Space microgravity drives transdifferentiation of human bone marrow-derived mesenchymal stem cells from osteogenesis to adipogenesis.

DEM simulation of granular segregation in two-compartment system under zero gravity**Project supported by the National Natural Science Foundation of China (Grant Nos. 11474326 and 11274354), the “Strategic Priority Research Program-SJ-10” of the Chinese Academy of Sciences (Grant No. XDA04020200), and the Special Fund for Earthquake Research of China (Grant No. 201208011).

In this paper, granular segregation in a two-compartment cell in zero gravity is studied numerically by DEM simulation. In the simulation using a virtual window method we find a non-monotonic flux, a function which governs the segregation. A parameter is used to quantify the segregation. The effect of three parameters: the total number of particles N, the excitation strength , and the position of the window coupling the two compartments, on the segregation and the waiting time τ are investigated. It is found that the segregation observed in zero gravity exists and does not depend on the excitation strength . The waiting time τ, however, depends strongly on : the higher the , the lower the waiting time τ. The simulation results are important in guiding the SJ-10 satellite microgravity experiments.

Thermocapillary Convection Experiment Facility of an open Cylindrical Annuli for SJ-10 Satellite

Thermocapillary convection has always been a hot topic of great importance in either crystal growth or thin films science. A space experiment about thermocapillary convection in an open cylindrical annuli pool will be done on SJ-10 satellite. A payload for space experiment has been established, which includes a cylindrical annuli thermocapillary convection system, a thermocouple temperature controlling system and measurement system, a thermal infrared imager, a high-precision displacement sensor, and an experiment controlling system. Some experiments have been done on the ground in order to compare with the results of space experiment. Some results from the ground experiment are shown, such as temperature oscillation, surface oscillation, and flow pattern transfer.