Lunar surface temperature variations provide key information about the thermophysical properties of the regolith. To date, temperatures have been measured using telescopes and orbiter instruments, ...providing information from mid‐infrared to long infrared (IR) wavelengths. Here, we report on temperature measurements in the short‐wavelength IR at centimeter scales observed in situ by the Chang’E‐4 rover. These local observations are an important complement to the existing large‐scale data. We show that even at 2.39 µm, where reflected radiation dominates the spectrum, thermal information can be retrieved from the data. The observed thermal radiances and derived temperatures depend on the observation geometry, specifically the relative azimuth angle between Sun and detector. This indicates that surface roughness on subresolution (millimeter) scales causes a non‐Lambertian radiation pattern of the emitted flux that is per definition independent of the observation angle. This behavior must be considered when deriving temperatures and thermal properties of lunar regolith.
Plain Language Summary
The Chang’E‐4 spacecraft landed in the Von Kármán Crater in the Moon’s South Pole‐Aitken Basin. A Visible and Near Infrared Spectrometer (VNIS) was carried on the “Yutu‐2” rover. The VNIS measured thermal emission on the surface of the Moon at short wavelengths and temperature variations at centimeter scales were retrieved during the first, second, and tenth day of rover operations on the lunar surface. These in situ observations are an important complement to the existing large‐scale measurements taken from orbit and reveal that the millimeter scale roughness plays an important role when deriving temperatures and physical properties of the lunar surface regolith.
Key Points
The Chang’E‐4 VNIS observed the lunar surface in situ in the 0.45–2.4 μm wavelength range
Emitted flux at centimeter scales is non‐Lambertian and depends on surface roughness and observation geometry
Surface roughness as described by the bidirectional RMS slope was found to be 22°–24°
Science objectives of the MMX rover Ulamec, Stephan; Michel, Patrick; Grott, Matthias ...
Acta astronautica,
September 2023, 2023-09-00, 2023-09, Letnik:
210
Journal Article
Recenzirano
Odprti dostop
The Martian Moons eXploration (MMX) mission by the Japan Aerospace Exploration Agency, JAXA, will explore the Martian moons Phobos and Deimos. In addition to investigating the moons remotely and ...returning samples from Phobos, MMX will also deliver a small (about 25 kg) Rover to the surface of Phobos. The payload of the Rover consists of four scientific instruments: RAX, a Raman spectrometer to measure signatures of the mineralogical composition of the surface material, NavCam, a stereo pair of cameras to investigate the terrain and allow for navigation, miniRAD a radiometer to measure the surface brightness temperature of both, regolith and rocks, and two WheelCams which will observe the wheel-surface interface, and thus investigate the properties and dynamics of the regolith. The cameras, will serve both, technological and scientific needs.
The rover will be deployed during the rehearsal phase of the landing operations for the main spacecraft and will thus land in proximity to the first sampling area. During its operational lifetime on Phobos (about 100 days), the in-situ measurements performed with the rover payload will provide scientific context for the returned samples, provide ground truth, study the surface heterogeneity and obtain information on the physical properties of undisturbed surface material. The MMX launch is planned for September 2024 and the Rover delivery is scheduled for 2027.
The Rover is a contribution by the Centre National d’Etudes Spatiales (CNES) and the German erospace Center (DLR) with additional contributions from INTA (Spain) and JAXA.
•In this paper we give an overview of the rover, which will be part of the MMX mission to Phobos.•The MMX rover will explore the surface of Phobos with cameras, a Raman spectrometer and a radiometer.•Scientific objectives and the mission outline are discussed.
The HP³ Mole system is part of the HP³ payload on the InSight discovery class mission, which will place a geophysical lander onto the surface of Mars in 2018. DLR's HP³ - instrument (Heat Flow and ...Physical Properties Package) will measure Mars' interior heat flux and thermal gradient down to a depth of 5 m and thus penetrates deeper below the Martian surface than any other instrument before. Being the locomotion system of the instrument, the HP³ Mole acts as a self-impelling nail in order to accomplish this goal. The inner hammering mechanism is spring driven and periodically loaded by a cylindrical cam mechanism. The innovative impact driven locomotion principle enables a minimum in required energy and mass, but leads to complex system behaviour and dependence of the inner mechanism dynamics on the outer force conditions exerted by the soil.
The scope of this paper is to provide an overview of the Mole, its role in the mission and payload, as well as to give a brief overview about its subsystems, its interfaces and working principle.
•Detailed presentation of a flight design subsurface access device (“mole”).•This mole is a contribution to the recently landed InSight mission on Mars.•Presentation of the design process, i.e. testing alongside with simulation.
The 2018 InSight (Interior Exploration using Seismic Investigations, Geodesy and Heat Transport) Mission has the mission goal of providing insitu data for the first measurement of the geothermal heat ...flow of Mars. The Heat Flow and Physical Properties Package (HP
3
) will take thermal conductivity and thermal gradient measurements to approximately 5 m depth. By necessity, this measurement will be made within a few meters of the lander. This means that thermal perturbations from the lander will modify local surface and subsurface temperature measurements. For HP
3
’s sensitive thermal gradient measurements, this spacecraft influence will be important to model and parameterize. Here we present a basic 3D model of thermal effects of the lander on its surroundings. Though lander perturbations significantly alter subsurface temperatures, a successful thermal gradient measurement will be possible in all thermal conditions by proper (
>
3
m
depth) placement of the heat flow probe.
Surgical lung biopsy (SLB) is recommended for patients with nonclassified interstitial lung disease (nILD) if high resolution computed tomography and/or transbronchial lung biopsy did not achieve a ...definitive diagnosis. Current literature suggests better patient tolerability and less postoperative complications if surgery is performed under spontaneous ventilation.
We conducted a propensity score matching (PSM) analysis of our nILD patients undergoing SLB under spontaneous ventilation or general anesthesia to investigate postprocedural AE-ILD, 30-/90-day mortality and perioperative variables in two academic high-volume centers (Hannover, Heidelberg).
All patients undergoing SLB for nILD under general anesthesia (GAVATS) and spontaneous ventilation (NIVATS) at both centers from February 2013 until April 2021 were analyzed retrospectively. Data of 132 patients were used for PSM resulting in 40 pairs.
There was one death in the NIVATS group 60 days after SLB and one AE-ILD in each cohort. Chest tube indwelling time, chest tube total effusion, length of hospital stay, and operative time were all in favor of NIVATS.
In our PSM analysis, NIVATS is associated with faster postprocedural recovery. However, a reduction in postoperative AE-ILD or 30-/90-day mortality was not observed.
The InSight lander rests on a regolith‐covered, Hesperian to Early Amazonian lava plain in Elysium Planitia within a ∼27‐m‐diameter, degraded impact crater called Homestead hollow. The km to cm‐scale ...stratigraphy beneath the lander is relevant to the mission's geophysical investigations. Geologic mapping and crater statistics indicate that ∼170 m of mostly Hesperian to Early Amazonian basaltic lavas are underlain by Noachian to Early Hesperian (∼3.6 Ga) materials of possible sedimentary origin. Up to ∼140 m of this volcanic resurfacing occurred in the Early Amazonian at 1.7 Ga, accounting for removal of craters ≤700 m in diameter. Seismic data however, suggest a clastic horizon that interrupts the volcanic sequence between depths of ∼30 and ∼75 m. Meter‐scale stratigraphy beneath the lander is constrained by local and regional regolith thickness estimates that indicate up to 10–30 m of coarse‐grained, brecciated regolith that fines upwards to a ∼3 m thick loosely‐consolidated, sand‐dominated unit. The maximum depth of Homestead hollow, at ∼3 m, indicates that the crater is entirely embedded in regolith. The hollow is filled by sand‐size eolian sediments, with contributions from sand to cobble‐size slope debris, and sand to cobble‐size ejecta. Lander‐based observations indicate that the fill at Homestead hollow contains a cohesive layer down to ∼10–20 cm depth that is visible in lander rocket‐excavated pits and the HP3 mole hole. The surface of the landing site is capped by a ∼1 to 2 cm‐thick loosely granular, sand‐sized layer with a microns‐thick surficial dust horizon.
Plain Language Summary
The InSight lander has geophysical instruments that are designed to determine the interior structure of Mars. Understanding the results from these instruments requires a geological analysis of materials beneath the landing site at Elysium Planitia. This study presents data that describe the vertical sequence of rocks and soils beneath the lander, as well as the geologic history. The results indicate that InSight rests on a 1.7‐billion‐year‐old lava plain that is covered in a 10–30 m thick regolith that was produced by impact cratering and modified by wind. The uppermost portion of the regolith is a ∼3 m thick horizon of sand. InSight rests on sand within a degraded impact crater. The sandy material contains a slightly cohesive horizon that is only ∼1–2 cm beneath the lander and is up to 10–20 cm thick. The sandy horizon overlies rock fragments that get progressively larger with depth. Bedrock of basaltic lava exists beneath the regolith down to a depth of ∼170 m. The bedrock is interrupted by weaker materials between depths of ∼30 and 75 m. Beneath ∼170 m, the sequence is dominated by ancient (3.7–4.1 billion years old), possibly sedimentary materials.
Key Points
InSight rests on Early Amazonian basaltic lava with an up to 10–30 m thick regolith. The upper 3 m of the regolith is sand dominated
The regolith contains a 10–20 cm thick cohesive horizon or duricrust. This horizon rests 1–2 cm beneath the lander
The upper 1–2 cm of the regolith comprises loosely‐consolidated sand to pebbles. Sand is rarely mobilized under current wind conditions
The Martian Moons eXploration (MMX) mission will study the Martian moons Phobos and Deimos, Mars, and their environments. The mission scenario includes both landing on the surface of Phobos to ...collect samples and deploying a small rover for in situ observations. Engineering safeties and scientific planning for these operations require appropriate evaluations of the surface environment of Phobos. Thus, the mission team organized the Landing Operation Working Team (LOWT) and Surface Science and Geology Sub-Science Team (SSG-SST), whose view of the Phobos environment is summarized in this paper. While orbital and large-scale characteristics of Phobos are relatively well known, characteristics of the surface regolith, including the particle size-distributions, the packing density, and the mechanical properties, are difficult to constrain. Therefore, we developed several types of simulated soil materials (simulant), such as UTPS-TB (University of Tokyo Phobos Simulant, Tagish Lake based), UTPS-IB (Impact-hypothesis based), and UTPS-S (Simpler version) for engineering and scientific evaluation experiments.
The NASA
InSight
mission will provide an opportunity for soil investigations using the penetration data of the heat flow probe built by the German Aerospace Center DLR. The Heat flow and Physical ...Properties Probe (HP
3
) will penetrate 3 to 5 meter into the Martian subsurface to investigate the planetary heat flow. The measurement of the penetration rate during the insertion of the HP
3
will be used to determine the physical properties of the soil at the landing site. For this purpose, numerical simulations of the penetration process were performed to get a better understanding of the soil properties influencing the penetration performance of HP
3
. A pile driving model has been developed considering all masses of the hammering mechanism of HP
3
. By cumulative application of individual stroke cycles it is now able to describe the penetration of the Mole into the Martian soil as a function of time, assuming that the soil parameters of the material through which it penetrates are known. We are using calibrated materials similar to those expected to be encountered by the
InSight
/HP
3
Mole when it will be operated on the surface of Mars after the landing of the
InSight
spacecraft. We consider various possible scenarios, among them a more or less homogeneous material down to a depth of 3–5 m as well as a layered ground, consisting of layers with different soil parameters. Finally we describe some experimental tests performed with the latest prototype of the InSight Mole at DLR Bremen and compare the measured penetration performance in sand with our modeling results. Furthermore, results from a 3D DEM simulation are presented to get a better understanding of the soil response.
Metastatic non-small cell lung cancer (NSCLC) remains the most common cause of tumor mortality despite the introduction of novel agents. Female sex hormones play a role in NSCLC pathogenesis and ...negatively influence the course of this disease. Herein, we present data on possible underlying mechanisms. Both estrogen and progesterone pre-treatment led to chemoresistance of A549 NSCLC cells in vitro by attenuating cisplatin-induced apoptosis. These effects were not antagonized by the estrogen or progesterone receptor antagonists ICI 182,780 and RU486 (mifepristone). Cisplatin induced apoptosis via activation of caspases -3/7, -8 and -9. Estrogen and progesterone attenuated levels of caspase activation. Interestingly, copper-transporter-1, which is responsible for the intracellular accumulation of cisplatin, was not modulated by sex hormones and the effects of estrogen and progesterone were neither additive nor synergistic. Our results suggest that estrogen and progesterone contribute to the development of chemotherapy resistance in NSCLC via non-classical sex hormone signaling pathways.
Measurements from the InSight lander radiometer acquired after landing are used to characterize the thermophysical properties of the Martian soil in Homestead hollow. This data set is unique as it ...stems from a high measurement cadence fixed platform studying a simple well‐characterized surface, and it benefits from the environmental characterization provided by other instruments. We focus on observations acquired before the arrival of a regional dust storm (near Sol 50), on the furthest observed patch of soil (i.e., ∼3.5 m away from the edge of the lander deck) where temperatures are least impacted by the presence of the lander and where the soil has been least disrupted during landing. Diurnal temperature cycles are fit using a homogenous soil configuration with a thermal inertia of 183 ± 25 J m−2 K−1 s−1/2 and an albedo of 0.16, corresponding to very fine to fine sand with the vast majority of particles smaller than 140 μm. A pre‐landing assessment leveraging orbital thermal infrared data is consistent with these results, but our analysis of the full diurnal temperature cycle acquired from the ground further indicates that near surface layers with different thermophysical properties must be thin (i.e., typically within the top few mm) and deep layering with different thermophysical properties must be at least below ∼4 cm. The low thermal inertia value indicates limited soil cementation within the upper one or two skin depths (i.e., ∼4–8 cm and more), with cement volumes <<1%, which is challenging to reconcile with visible images of overhangs in pits.
Plain Language Summary
InSight carried a six‐channel radiometer used to measure diurnal surface temperatures over the duration of the mission. Surface temperatures are controlled by insolation and the microscopic physical properties of the soil (typical grain size, density, degree of soil cementation, or internal layering) that could not be resolved without a microscope or other instruments. Because the InSight lander does not have any systematic way to interrogate the soil, we have instead analyzed these temperature data and characterized the near‐surface soil properties. We found that the soil structure near the lander is homogeneous within the top few cm, and is made of loose sandy material with very little to no cementation. These properties are consistent with those derived from orbit before landing using remote sensing techniques, but difficult to reconcile with visible imagery showing evidence for induration farther from the hollow margin.
Key Points
The InSight radiometers measured surface temperatures multiple times per sol over a flat and homogeneous patch of Martian soil
The thermal inertia of the soil in Homestead hollow is ∼183 ± 25 J m−2 K−1 s−1/2, consistent with aeolian fine sand infilling
The presence of a duricrust suggested by imagery is difficult to reconcile with this thermal inertia value
PDF