Scientists and engineers made significant development in the exploration missions of planets and celestial bodies in last few decades and gained knowledge about their resources and their properties. However, besides reaching the planets, to land safely in the universe still proves to be a difficult task. To change this, geology resources, atmosphere and radiation data are gathered by landers and rovers, which are required to verify measurements by probes from orbit. Landers and rovers provided with excavator booms extract rocks and dust for material properties analysis . The aim is to gather data and prepare strategies to build landing sites and radiation shielding habitats, and to develop suitable constructions, such as infrastructure, factories, and laboratories, prior to the arrival of astronauts.
To extend and facilitate such exploration missions, two in situ concepts are needed [2, 3]. Firstly, it is in situ fabrication and repair (ISFR) equipment and infrastructures. Secondly, it is in situ resource utilization (ISRU). As a result, resources for in situ lunar fabrication have been studied intensely in the last decade and several technologies have been proposed [4, 5, 6, 7]. To simulate materials on other planets, ceramic-based products are used, such as lunar regolith , which is very fine sand . In terrestrial environment lunar regolith simulants with similar mechanical-physical properties  were developed, such as LHT-1M , NU-LHT  or JSC-1A . However, due to different physical environment, material properties and behaviour on other celestial bodies differ from Earth. Behaviour of real regoliths differs based on the linearized angle of internal friction (LAIF, ϕ), effective angle of internal friction (EAIF, δ), flow function (ffc), cohesion c, and compressibility, depending on environment which regoliths are measured in, place of regolith excavation, environment of regolith origin and environment of regolith transformation. The composition of regoliths varies from place to place because of the variability in asteroid collisions and the weathering by wind or water. Therefore, there will be a crucial need to be able to measure mechanical-physical properties of in situ regoliths and bulk material resources during the exploration missions .
Due to the fact that transportation of any equipment from Earth is very costly, currently it may take years to get spare parts to orbit. This problem has been partially overcome by fused deposit modelling (FDM, registered trademark by Stratatys) technology modified for microgravity . FDM is a type of additive manufacturing (AM), where a 3D geometry is built by superimposed layers of extruded thermoplastic filament . FDM technology modified by Made in Space projects [14, 15] explore the possibility to create tools  that astronauts currently need for repairs or work. FDM allows for the use of a broad range of thermoplastics  which are light but durable and can withstand a certain extent of mechanical load when designed properly. FDM printing is also highly precise and most of its advantages are due to the enclosed printing chamber which allows the internal temperature to be maintained (nozzle-air-heated bed). It leads to better mechanical properties, where the adhesion between layers is strengthened and warping and curling of the printed parts are prevented . However, the technology is very costly and is not widely available for research. Extending the ability and options to print parts on demand in orbit or during exploration missions will reduce the time it takes to get parts to orbit, reduce the mission costs, reduce the need of having every tool and part on board, while increasing the reliability and safety of space missions.
Despite the developments in the field of 3D printing, there is a lack in studies on the use of printed elements in measuring devices and/or devices intended to measure bulk materials. Traciak et.al.  developed a 3D printed device to measure the surface tension of nanofluids and showed that the result of measurement is comparable with commercial devices. Bernard and Mendez  presented a low-cost Polarimeter to be used by students during classes. The study  described the dynamic behaviour of 3D-printed strain sensors embedded in structures and supported the statement that 3D printed sensors could be used for dynamic measurement. The study  reported the design of a 3D printed compact interferometric system for cell phones to measure small angles. All these studies show a high potential of 3D printing devices and the lack of specific guidance for the manufacturing of measuring equipment.
In order to fill the gap in this area, the aim of this study was to investigate the possibility of using measuring instruments made by material extrusion 3D printing method for the measurement of selected mechanical-physical properties of bulk materials. Due to the unaffordability of FDM 3D printing technology and related problems such as testing the effects of high radiation environments on printed measurement tools, fused filament fabrication (FFF) 3D printing technology was used in this study. This article thus presents a feasibility study of measuring mechanical-physical properties of bulk materials using 3D printed instruments, should the reasons for doing so arise. These reasons for printing original or modified measuring instruments are also encountered on Earth, such as the need for a lower weight of the measuring instruments, the ability to pre-print a set of laboratory measuring instruments or to print the set on the spot, to replace a damaged part with a new 3D printed part on-demand, the logistical unavailability, customization of the standardized tests for better understanding of the behaviour of the particulate materials, and cheaper manufacturing cost.
Supposing the measuring instruments will be used for exploration mission, regolith simulant samples were also tested. The measurements of the mechanical-physical properties such as EAIF (δ), LAIF (ϕ), ffc, cohesion c, compressibility, basic flowability energy BFE, stability index SI, and flow rate index FRI for lunar regolith simulants: lunar mare simulant (LMS-1) and lunar highlands simulant (LHS-1) from the CLASS Exolith Lab in Orlando, USA, are presented. EAIF (δ), LAIF (ϕ), ffc, c, and compressibility are fundamental characteristics of bulk material flow, which is used to design storage, handling, and process equipment. Firstly, two lunar regolith powders were characterized by particle size distributions and their morphology. Secondly, comparison of results was carried out between standard measuring instruments and 3D printed instruments from polylactic acid and acrylic styrene acrylonitrile materials. Values of EAIF (δ), LAIF (ϕ), ffc, c, compressibility, SI, FRI, and BFE were compared. Results presented in this article showed repeatability and similar precision for the test methods of Schulze’s ring shear test, Freeman’s FT4 shear test, Freeman’s FT4 compressibility standard test, and Freeman’s FT4 flow rate and stability standard test. This showed applicability of 3D printed instruments for the test methods in hardly reachable, or extra-terrestrial environment.