LEMFEV
LONG ENDURANCE MARS EXPLORATION FLYING VEHICLE
WELCOME TO LEMFEV
The Earth is the cradle of the mind, but one cannot live in the cradle forever.
K.E. Tsiolkovsky
ABOUT THE LEMFEV
Inspired by the historic flight of the NASA Ingenuity helicopter in April 2021, we started the design of the Long Endurance Mars Exploration Flying Vehicle, or LEMFEV for short, in March 2022. Our work is supported by the Russian Science Foundation and is aimed at the development of a concept for a UAV for Mars exploration.
Here is our Mars Exploration Word Cloud!
And what are your associations with Mars exploration?
Mars research broadens our understanding of the Universe and enables a better simulation of the circumstances on the planet for future Martian expeditions. Mars, although formed at the same time as Earth, differs substantially in size, climate, terrain, and many other factors.
Today, this is an ice desert with a thin atmosphere, scarred by faults, volcanoes, and canyons, and little shielding from the ionizing space radiation.
Still, this is a fascinating spot in our Solar system!
LEMFEV: AIRCRAFT - BUT A SPECIAL ONE
Delivery to Mars
The airplane will be mounted in the descend module, which will be an axis-symmetric, ballistic design. To put the spacecraft with the descent module on the departure trajectory to Mars, a four-stage injection program will be used. After entering the departure trajectory for Mars, the spacecraft will separate from the orbital unit and start its 8.5-month journey to the Red planet.
The LEMFEV design process is guided by the specific Martain environmental conditions (low density, low speed of sound, low temperature, dust storms, electrical phenomena, carbon dioxide carving). Martian rugged terrain will exclude the conventional take-off and landing option for an airplane. The expected operating area, altitude, and season may significantly affect the design decisions in terms of aircraft configuration, geometry and total mass.
Finally, the flow field on a Mars airplane is expected to be highly complicated with a strong interaction of viscous and compressibility effects. This makes the numerical simulation of the aircraft operating in Martian atmosphere extremely challenging.
Martian Atmosphere and Climate
Scientific Mission
Aircraft can perform modes of observation that are not achievable by rovers, landers, or orbiters. For our project, such targets can be canyons and craters, which walls might unveil million years of the Mars history. Among them, Hellas Planitia, the lowest part at the Mars surface, can be highlighted.
An alternative target for a Martian UAV may be the planetary boundary layer. A clear and quantitative understanding of this part of the atmosphere, and the way in which it interacts with the surface and atmosphere is important to understanding the past, present, and future Martian environment. This will enable the scientists to make reliable predictions of environmental conditions encountered during spacecraft entries and operations for mission safety and efficient design.
Martian Airfoils
The LEMFEV is expected to operate at relatively low Reynolds numbers (on the order of 100,000). This means the aircraft will suffer an increased friction drag and the formation of laminar bubbles. On the one hand, the laminar bubbles may locally increase the lift slope; however, this renders the lift curve non-linear. In addition, laminar bubbles may cause extensive flow separation at moderate angles of attack, therefore, high pressure drag. If the laminar bubble bursts abruptly just beyond the critical angle of attack, special measures need to be taken to prevent the rapid UAV’s stall and spin entry.
In our design effort, where the actual operating Reynolds numbers depend strongly on the design configuration, we optimize the airfoil section for each version of the airplane to ensure better aerodynamic performance.
Why Do We Need a Stratospheric Balloon?
We are planning to test the LEMFEV flying model at the end of 2024. To bring the model to conditions closest to those the UAV will experience on Mars, we will elevate the model to an altitude of approximately 32 km and release it for the flight test. The parameters of the atmosphere at this altitude are not identical to those of the Martian atmosphere near the surface; nevertheless, the magnitude of pressure is somewhat similar.
The Magic of Liquid Crystals
One of our airfoils will be tested in T-1, the subsonic closed circuit open working section wind tunnel of the Moscow Aviation Institute. To get an insight into the state of the boundary layer, we will be using liquid crystals.
Liquid crystals are a large class of compounds (mainly organic) that, in a certain temperature range above the melting point, combine the properties of liquids (fluidity, ability to form drops) and crystalline bodies (anisotropy of physical properties).
In liquid crystals, their optical properties change when exposed to temperature and shear stress variations. The thin layer of liquid crystals does not alter the parameters of the boundary layer. As a consequence, liquid crystals allow detecting the laminar-turbulent transition, flow separation and reattachment, the effect of shock waves on the boundary layer, etc.
Modeling the Martian Atmosphere
In our study, the data on the Martian climatological system were retrieved from the Mars Climate Database (MCD). The MCD is a database of meteorological fields derived from General Circulation Model numerical simulations of the Martian atmosphere and validated using available observational data.
The accuracy of MCD simulation is reported to be high, based on comparison to available measurements. It is also observed that MCD predictions appear closer to observations in northern summer at low dust loading than in northern winter when the atmosphere is dustier.
MCD offers combinations of dust and solar scenarios. In our work, we focus on the planetary boundary layer properties and use the Climatology (standard) solar average scenario. For comparison, we also use the simulation data from the Dust storm scenario, which represents Mars during a global dust storm (dust opacity set to 5 at all times and over the whole planet).
According to the standard solar average MCD scenario, the highest solar flux to surface expected on Mars amounts to approximately 450 . In this case, the maximum power available for a day-night solar airplane with a wing area of 5 from sun is approximately 263 W. In the case of a planetary dust storm, the maximum solar flux reduces to 220 and the available power falls down to 82 W, and the wing area must be no smaller than 15 .
Figures show the example Matlab surface plots extracted from the Mars Climate Database.
ANNOUNCEMENTS
07.12.2024
The first crash of our autopilot training model. The model flipped over immediately after I applied throttle. Log analysis reveals that everything took just 15 milliseconds. One motor mount separated from the model. Everything else was fine and ready for investigation and new flights. One of the learnings of the crash - we must reinforce the wing at the motor mounts with fiber glass.
09.11.2024
Our autopilot training model (a small plastic version of the scaled flight model of our Martian UAV) made its maiden flight!!! This proved one of the most important and inspiring moments in our project so far!
28.07.2024
Finally, the structural design of the first version of our flying model has been completed! The remaining plastic parts have been sent for printing. Looking forward to finalizing manufacturing and assembly, to try and fly it as soon as possible!
19.07.2024
Friday 19th was so special day for us because we gave a talk at the ICASSE 2024 conference in Zhangzhou, China. The topic of the talk was 'Enhancing the Airfoil Performance for a Fixed-Wing Mar-tian Aircraft', where we reported the first part of our effort to optimize the airfoil for our Martian aircraft. In contrast to this first, analytical part, the second part is truly numerical optimization, and has been completed recently.
09.07.2024
Now, the range of our capabilities include airfoil and propeller numerical design and optimization, which is oh so useful in our current as well as future aircraft projects!
23.06.2024
On Sunday, June 16, we spoke at the round table "Air-orbital and aerostatic flying vehicles" at the fifth space festival in the city of Kaluga. The round table was held in the educational center of the K.E. Tsiolkovsky Museum of the History of Cosmonautics. This is the first space museum in the world and the largest in Russia, created with the direct participation of S.P. Korolev and Yu.A. Gagarin. The museum's exhibits reveal the history of aeronautics, aviation, rocket and space technology. In the museum, you can learn a lot about the scientific legacy of Konstantin Eduardovich Tsiolkovsky, the founder of theoretical cosmonautics, a major inventor, and the author of works on philosophy and sociology. In particular, the museum presents images of future technology (airplane, airship, rocket, ethereal settlements), substantiated by the scientist. It was a great pleasure for me to speak in this famous place, among like-minded people. At the round table we spoke about our project, and shared plans for the future. We were received very warmly, and I hope that next time we will come to Kaluga to show a video of our little Mars aircraft model successfully performing a flight mission.
In addition, we have submitted documents for the aerospace congress at Moscow State University, which will be held in August.
15.05.2024
We have applied to give a talk at the International Conference on Aerospace Science, Systems, and Engineering 2024. The talk will be devoted to the LEMFEV's airfoils.
In addition, the start of the flying model manufacturing and production process was set to May 20th.
30.01.2024
On Friday, January 26th, we gave a talk at the Korolev Academic Space Conference 2024, the key conference for our project. In this talk, we focused on the solar VTOL BW1 configuration.
05.01.2024
I have uploaded the fourth stand-alone MATLAB code to Educational Resources | Lemfev. This code plots the characteristics of an airfoil as a function of Reynolds number for a set of angles of attack. The code can help identify the "critical Reynolds number range", that is, the range of Reynolds numbers where the aerodynamic properties of an airfoil abruptly change.
04.01.2024
Today, the Aerospace Systems journal published our new paper: 'Rocket-based versus solar wing-tail Martian UAVs: design, analysis, and trade studies', https://doi.org/10.1007/s42401-023-00267-w. Here is our Abstract:
In this study, a rocket-based UAV and a solar wing-tail Martian UAV were designed and assessed against a set of criteria established using a house of quality chart. For the design, analysis, trade studies, and optimization, MATLAB and XFLR5 were used. The optimized versions of the two configurations feature the same wing and tail airfoils, the same wing and tail planforms, different dimensions, weight, and performance. Therefore, distinct types of scientific missions are suitable for these aircraft. The results of the study extend our understanding of the capabilities of a Martian fixed-wing airplane in terms of payload mass, hence its scientific value, as well as in terms of its planform geometry and airfoil shapes.
You will find the full text of the paper in the page Our Publications | Lemfev.
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11.12.2023
On Thursday, December 7th, 2023, we gave a talk at the conference "New Materials, Technologies, and Devices in Aircraft and Manned Space Exploration" organized by the "Research Testing Center for the Training of Cosmonauts named after Yu.A. Gagarin." At the conference, we talked about future Mars exploration using convertible airplanes like our BW1 configuration. Our presentation, which lasted for 45 minutes instead of 10 minutes, triggered a great and vivid interest in our audience. It was the start of an interesting and challenging discussion, which enriched our perspective and broadened our engineering background. And, as always, the most valuable asset we gained at the conference was the new connections with experts from various disciplines and even cosmonauts. By the way, we were awarded a certificate for the best conference talk!
10.12.2023
On Monday, December 4th, 2023, we gave a talk at the International Aeronautics Congress hosted by the Central Aerohydrodynamic Institute (Moscow) with the support of the Zhukovsky Institute. Our presentation was devoted to the selection, design, and optimization of an airfoil for our Martian airplane.
The end goal of this study was twofold:
- to identify the most effective airfoil or airfoil-boundary layer trip combination for the LEMFEV in cruise and unveil the underlying physical reasons for this effectiveness;
- to determine if the operating range of angles of attack for the selected airfoil could be expanded by placing the boundary layer trips in a relatively aft position such that they affected the boundary layer at a higher angle of attack.
For design and analysis, MATLAB and X-FOIL were used.
Currently, we are ready to submit the related paper for publication.
01.12.2023
Last week, we gave four talks about the LEMFEV to kids aged 10 to 15 in four cities in the Moscow region: Chekhov (22.11.2023), Lobnya (27.11.2023), Elektrostal (28.11.2023), Zaraysk (29.11.2023). This beautiful opportunity was given to us by the organization "Movement of the Firsts" РДДМ "Движение Первых" (xn--90acagbhgpca7c8c7f.xn--p1ai). There is a new blog post on this topic:
https://www.lemfev.com/post/hopefully-our-lemfev-helps-incentivize-kids-to-become-space-explorers.
16.11.2023
Here is our new article published by MDPI Aerospace: Aerospace | Free Full-Text | Long-Endurance Mars Exploration Flying Vehicle: A Project Brief (mdpi.com)!
The paper is entitled 'Long-Endurance Mars Exploration Flying Vehicle: A Project Brief'. The paper presents specifications for our Long-Endurance Mars Exploration Flying Vehicle (LEMFEV), which we use as the design input data. The specifications are based on the analysis of previous Mars missions and scientific data collected by the operating Martian probes. The design specifications include the requirements related to the airplane’s delivery to the Martian surface; the requirements related to the Martian conditions (atmosphere and climate); and the requirements related to the scientific payload parameters and the mission flight profile.
This paper would not be possible without collaboration with the scientists of the Space Research Institute of the Russian Academy of Sciences, Daria Evdokimova and Kirill Alexandrov. Daria and Kirill helped us formulate a scientific mission for our LEMFEV in terms of payload and flight profiles.
The paper was designed to be helpful and informative for those colleagues starting the design of a Martian fixed-wing UAV.
06.11.2023
There is a new Matlab code available on the page Educational Resources | Lemfev:
16.10.2023
On October 9th, we gave a talk at The Fourteenth Moscow Solar System Symposium | The Fourteenth Moscow Solar System Symposium (cosmos.ru). The Abstract can be found here, pages 50-51: 14ms3_ABSTRACT-BOOK-2023-10-06.pdf (cosmos.ru)
01.10.2023
We began working on the design of an electric boxwing Martian airplane, the BW1 configuration!
23.09.2023
Our second in-house MATLAB code, Constraint Diagram for a Conventional Aircraft, is now available on the page Educational Resources | Lemfev. Constraint analysis is used to assess the relative significance of performance constraints on the aircraft design. Our code plots three axes... you are invited to explore which ones!
22.09.2023
We have added the first in-house MATLAB code, Airfoil XFOIL-based analysis, to the page Educational Resources | Lemfev. The code uses XFOIL to predict and plot a variety of aerodynamic properties of the input airfoil. We extensively use this piece of code in our design and analysis work.
19.09.2023
Last week, we submitted the article "Rocket-Based Versus Solar Wing-Tail Martian UAVs: Design, Analysis, and Trade Studies" for consideration by the Aerospace Systems journal. In this paper, we compare the performance of two LEMFEV configurations and reflect on the matching scientific missions.
29.08.2023
The reports describing the WT1 (the wing-tail solar LEMFEV version) and WT3 (the wing-tail rocket engine LEMFEV version) are complete! Now, we start writing a paper unveiling the key findings from this design effort and offering some conclusions as to what direction our subsequent work should take.
28.07.2023
We submitted the manuscript entitled "Long-Endurance Mars Exploration Flying Vehicle: A Project Brief" for consideration by the Acta Astronautica journal. It is a stringent journal, but we worked hard to ensure a high academic level in our research and writing while preparing this article.
23.07.2023
The paper "A Solar Wing-Tail Martian Science UAV: Design Space Exploration" was published by the Russian Aeronautics journal and is available online: https://rdcu.be/dhg0x; DOI: 10.3103/S1068799823010014.
21.07.2023
On July 7, we were awarded a certificate for the best paper at the International Conference on Aerospace Systems and Engineering, held at Shanghai Jiao Tong University (Home - ICASSE 2023 (sjtu.edu.cn)). In the paper, we presented specifications for our Long-Endurance Mars Exploration Flying Vehicle, LEMFEV, which will be used as future design input data. The specifications are based on the analysis of the previous Mars missions and the scientific data collected by the operating Martian probes. The design specifications include the requirements related to the airplane’s delivery to the Martian surface; the requirements related to the Martian conditions (atmosphere and climate); and the requirements related to the scientific payload parameters and the mission flight profile. For us, it is an extremely powerful motivator to keep working hard on our project. And we feel so happy that our LEMFEV project has gained attention and interest from the international engineering community!
20.07.2023
The "[Not] Fiction" program talks about new developments and discoveries. The main idea of the project is to show how scientific discoveries change our reality. Discoveries that people cannot believe and have only seen in science fiction films are happening every day and bringing new technologies to humanity. We were so lucky to be invited to this program, where we talked about our project - the most interesting, exciting, and challenging aspects of our work! And... I even played ball with the host, which was so joyful!
So please enjoy the story about our Mars exploration aircraft!
This is the version with the English subtitles: https://clipchamp.com/watch/PVtzcm2IBFi
And here is the original version of the program: https://mirtv.ru/video/75494/
19.07.2023
We are giving a talk at the Fourteenth Moscow Solar System Symposium organized by the Space Research Institute on October 9–13, 2023, here is the website of the conference: The Fourteenth Moscow Solar System Symposium | The Fourteenth Moscow Solar System Symposium (cosmos.ru)! Our presentation will be devoted to the LEMFEV configurations, and the radiation load it experiences throughout its mission.
