Currently, the surface of Mars is being explored using special orbital stations, as well as stationary modules or slow-moving rovers. There is a fairly large gap between these research vehicles, which could be filled by various aircraft. It would seem, why artificial devices created by man still do not fly over the surface of the Red Planet? The answer to this question lies on the surface (in all senses), the density of the atmosphere of Mars is only 1.6% of the density of the earth's atmosphere above sea level, which in turn means that aircraft on Mars would have to fly at a very high speed in order to so as not to fall.
The atmosphere of Mars is very rarefied, for this reason, those aircraft that are used by humans when moving in the atmosphere of the Earth are practically in no way suitable for use in the atmosphere of the Red Planet. At the same time, surprisingly, the American paleontologist Michael Habib proposed a way out of the current situation with future Martian flying vehicles. According to the paleontologist, ordinary terrestrial butterflies or small birds can become an excellent prototype of devices capable of flying in the Martian atmosphere. Michael Habib believes that by recreating such creatures, increasing their size, provided that their proportions are preserved, mankind will be able to obtain devices suitable for flights in the atmosphere of the Red Planet.
Representatives of our planet such as butterflies or hummingbirds can fly in an atmosphere with a low viscosity, that is, in the same atmosphere as on the surface of Mars. That is why they can act as very good models for creating future models of aircraft suitable for conquering the Martian atmosphere. The maximum dimensions of such devices could be calculated using the equation of the English scientist Colin Pennisewick from Bristol. However, the main problems should still be recognized as issues related to the maintenance of such aircraft on Mars at a distance from people and in their absence on the surface.
The behavior of all floating and flying animals (as well as machines) can be expressed by the Reynolds number (Re): for this you need to multiply the speed of the flyer (or swimmer), the characteristic length (for example, the hydraulic diameter, if we are talking about the river) and the density liquid (gas), and the result obtained as a result of multiplication is divided by the dynamic viscosity. The result is the ratio of inertial forces to viscous forces. An ordinary aircraft is able to fly at a high Re number (very high inertia in relation to the viscosity of the air). However, there are animals on Earth that are "enough" for a relatively small number of Re. These are tiny birds or insects: some of them are so small that, in fact, they do not fly, but float in the air.
Paleontologist Michael Habib, considering this, suggested taking any of these animals or insects, increasing all proportions. So it would be possible to obtain an aircraft adapted to the Martian atmosphere, and not requiring a high flight speed. The whole question is, to what size could a butterfly or a bird be enlarged? This is where Colin Pennisewick's equation comes in. Back in 2008, this scientist proposed an estimate according to which the frequency of oscillations can vary in the range formed by the following numbers: body mass (body) - to the 3/8 degree, length - to the -23/24 degree, wing area - to the degree - 1/3, the acceleration due to gravity is 1/2, the density of the fluid is -3/8.
This is quite convenient for calculations, since corrections can be made that would correspond to the density of air and the force of gravity on Mars. In this case, it will also be necessary to know whether we correctly "form" vortices from the use of the wings. Fortunately, there is also a suitable formula here, which is expressed by the Strouhal number. This number is calculated in this case as the product of the frequency and amplitude of the vibration, divided by the speed. The value of this indicator will greatly limit the speed of the vehicle in cruise flight mode.
The value of this indicator for a Martian vehicle must be from 0.2 to 0.4, in order to correspond to the Pennisewick equation. In this case, at the end, it will be necessary to bring the Reynolds number (Re) into an interval that would correspond to a large flying insect. For example, among fairly well-studied hawk moths: Re is known for various flight speeds, depending on the speed, this value can vary from 3500 to 15000. Michael Habib suggests that the creators of the Martian plane also keep within this range.
The proposed system can be solved today in various ways. The most elegant of them is the construction of curves with finding the intersection points, but the fastest and much easier to enter all the data into the program for calculating the matrices and solve it iteratively. The American scientist does not give all possible solutions, focusing on the one that he considers the most appropriate. According to these calculations, the length of the "hypothetical animal" should be 1 meter, its mass is about 0.5 kg, and the relative wing elongation is 8.0.
For an apparatus or creature of this size, the Strouhal number would be 0.31 (very good result), Re - 13 900 (also good), lift coefficient - 0.5 (acceptable result for cruising flight). In order to really imagine this apparatus, Khabib compared its proportions with duck proportions. But at the same time, the use of non-rigid synthetic materials should make it even lighter than a hypothetical duck of the same size. In addition, this drone will have to flap its wings much more often, so here it would be appropriate to compare it with a midge. At the same time, the Re number, comparable to that of butterflies, makes it possible to judge that for a short time the apparatus will have a high coefficient of lift.
For fun, Michael Habib suggests that his hypothetical flying machine takes off like a bird or an insect. Everyone knows that animals do not scatter along the runway, for takeoff they push off the support. For this, birds, like insects, use their limbs, and bats (it is likely that pterosaurs did this earlier) also used their own wings as a pushing system. Due to the fact that the force of gravity on the Red Planet is very small, even a relatively small push is enough for takeoff - in the region of 4% of what the best earth jumpers can demonstrate. Moreover, if the pusher system of the apparatus manages to add power, it will be able to take off without any problems even from craters.
It should be noted that this is a very crude illustration and nothing more. Currently, there are many reasons why the space powers have not yet created such drones. Among them, one can single out the problem of deploying an aircraft on Mars (it can be done with the help of a rover), maintenance and power supply. The idea is quite difficult to implement, which in the end may make it ineffective or even completely impracticable.
Airplane to explore Mars
For 30 years, Mars and its surface have been surveyed by a wide variety of technical means, orbiting satellites, and more than 15 types of various devices, miraculous all-terrain vehicles and other cunning devices have studied it. It is assumed that soon a robot plane will also be sent to Mars. At least the NASA Science Center has already developed a new project for a special robotic aircraft designed to study the Red Planet. It is assumed that the aircraft will study the surface of Mars from a height comparable to that of the Martian exploration rovers.
With the help of such a rover, scientists will discover the solution of a large number of riddles of Mars, which have not yet been explained by science. The Mars spacecraft will be able to hover above the planet's surface at an altitude of about 1.6 meters and fly many hundreds of meters. At the same time, this unit will make photo and video recording in different ranges and scan the surface of Mars at a distance.
The rover should combine all the advantages of modern rovers, multiplied by the potential to explore vast distances and areas. The Mars spacecraft, which has already received the designation ARES, is currently being created by 250 specialists working in various fields. They have already created a prototype of the Martian plane, which has the following dimensions: a wingspan of 6.5 meters, a length of 5 meters. For the manufacture of this flying robot, it is planned to use the lightest polymer carbon material.
This device is supposed to be delivered to the Red Planet in exactly the same case as the device for landing on the planet's surface. The main purpose of this hull is to protect the spacecraft from the destructive effects of overheating when the capsule comes into contact with the atmosphere of Mars, as well as to protect the spacecraft during landing from possible breakdowns and mechanical damage.
Scientists plan to throw this aircraft to Mars with the help of already proven carriers, however, here they have new ideas too. 12 hours before landing on the surface of the Red Planet, the device will separate from the carrier and at an altitude of 32 km. Above the surface of Mars, it will release a Martian plane from the capsule, after which the Mars plane will immediately start its engines and, deploying its six-meter wings, will begin an autonomous flight over the surface of the planet.
It is assumed that the ARES aircraft will be able to fly over the Martian mountains, which are completely unexplored by earthlings and carry out the necessary research. Conventional rovers cannot climb mountains, and satellites have difficulty distinguishing details. At the same time, in the mountains of Mars, there are zones with a strong magnetic field, the nature of which is incomprehensible to scientists. In flight, ARES will take air samples from the atmosphere every 3 minutes. This is quite important, since methane gas was found on Mars, the nature and source of which is completely incomprehensible. On Earth, methane is produced by living things, while the source of methane on Mars is completely unclear and still unknown.
Also in the ARES Mars spacecraft they are going to install equipment to search for ordinary water. Scientists believe that with the help of ARES they will be able to obtain new information that will shed light on the past of the Red Planet. Researchers have already dubbed the ARES project the shortest space program. A Mars plane can only stay in the air for about 2 hours until it runs out of fuel. However, even in this short period of time, ARES will still be able to cover the distance of 1500 kilometers above the surface of Mars. After that, the device will land and will be able to continue studying the surface and atmosphere of Mars.
