NASA developed tires with memory foam for the new Rover

During his five-year stay on the red planet and the Curiosity Rover has done a tremendous research work and made many interesting scientific discoveries. And during all this time, the Autonomous Mars science laboratory, of course, had to ride on the surface of our planetary neighbor. However, in 2013, during a routine check of the management team "Curiosity" has been very surprised by the fact that all six wheels of the Rover have various injuries, including such as in the image below.

Realizing that the next Mars Rover, which is going to send to the Red planet by the mid 2020-ies, can expect similar problems, a team of engineers from the research center Glenn (NASA) decided to develop a new type of wheels.

To Start with, the design of the new wheels based on an earlier prototype Spring Tire – airless tire developed by Goodyear in cooperation with NASA in the mid 2000-ies. Interestingly, the original version of these airless tires first appeared even earlier – in the bearded ' 70s and again in the result of cooperation between Goodyear and NASA. However, in the new tires instead of using the spring-wire design used in the original models, the team at NASA decided to use a more durable and flexible construction.

The Moon, Mars and other planets in the Solar system have a very unfriendly, harsh landscape. In the case of the moon the main problem posed by the regolith that covers virtually the entire surface of the satellite. This fine dust is a residual soil, being a product of space weathering of rocks and can easily damage the mechanical parts of the vehicle. On Mars the situation is hardly easier: there is a large part of the surface are covered with regolith, but also small sharp rocks that can easily cut through even iron.

In 2013, after just one year of activity on the surface of Mars, wheels "Curiosity" began to show signs of serious wear. This situation has worried scientists, who began to doubt that the Rover will be able to complete their planned mission. As a result, it has also led to the fact that the research center Glenn decided to revise the design of the tyres, whose development had been conducted for almost a decade. The tire was developed with the prospect of a return to the moon program.

Development of new space for the tire research center Glenn actually was one of the priorities of the last ten years. In this regard, the engineers and NASA scientists returned several times to thinking, which has remained since the era of space missions "Apollo". At that time in the development of American and Soviet space programs were developed several variants of tyres destined for use on the lunar surface. Center Glenn chose as the basis of three options.

First used in the Soviet "Lunokhod". In his vosmiklasnica database was used of metal tires, combined with the axis through a plurality of spokes. On the outside of the tire there was a metal protector, designed to provide tighter coupling with the lunar soil.

For consideration also were the tires used in special car Modularized Equipment Transporter (MET), which was used by the astronauts for transport of lunar soil samples in one of the missions "Apollo". The development of tires for it, too, was conducted in conjunction with the company Goodyear. The pimp was non-motorized, and the astronauts had to make considerable physical effort to transport. However, her bus had a smooth rubberized surface, which is somewhat simplified, it's moved over the ground and rocks.

The Third design of the tire to which it was decided to apply, was used in the so-called Lunar Rover that was used by astronauts mission "Apollo-15, Apollo-16 and Apollo-17". This manned vehicle is used four large wheels with durable inner frame and a protector in the form of a flexible wire mesh structure. In the mid 2000's, when NASA started preparing for a possible new lunar missions (with the prospect of future missions to Mars), the engineers decided to revise the design of the tyres of the Lunar vehicle, incorporating new technologies and using new and more durable materials. As a result, the light appeared the same tires Spring Tire. Tread airless tire is composed of many interconnected metal rings (in the mail), making it both durable and flexible. This design not only can reduce weight, but showed a high capacity even in conditions of movement on the harsh surface.

To verify the behavior of the tire Spring Tire on the surface of Mars, engineers from the Research center Glenn began conducting tests on a special testing ground, designed to simulate surface conditions. Despite the fact that, in General, the bus showed themselves worthy in driving on simulated Martian soil, they are faced with a serious problem – the jagged rocks, which moved the test sample, began not only to deform the tire, but in the literal sense to separate them.

In the end, the engineers again went to work. The solution was the use of hyperelastic tire, which is a continuation of "spring" tires Spring Tire. The new tire uses a special alloy of Nickel-titanium also known as nitinol. This material is the leader among the alloys with shape memory effect. He is able to fully recover after 10% deformation. In the same Spring tires Tire, this figure is only 0.3-0.5 percent.

In addition, an advantage of tires from nitinol is light weight (at the same experimental prototype, it is only nine kilograms), the possibility of adjusting the level of adhesion to any surface and high damping properties. The tires with memory effect also increased and the increased flexibility that, in General, should have a positive impact on their durability.

"first, these tires will allow you to conduct research on more diverse types of surfaces. Secondly, as they are easier and generally able to adapt to a particular type of surface, they allow you to dig into the ground hard and heavy wheels, and is able to cope with heavier loads. In addition, as well as a tire with shape memory effect are able to absorb energy from impact of the ground at different speeds, they can be used on managed vehicles whose anticipated rate is substantially higher than the current Rovers", — noted on the website of the Research center Glenn.

The Use of hyperelastic tire need not be limited only to the space program. Now among the potential areas are the subject of tyres for passenger cars and SUVs, military, agricultural and aircraft equipment. The developers have already installed the experimental tire on the SUV Jeep Wrangler and have experienced her work in real conditions.

As for the first actual use of such tires, such opportunity will be in the next years, when NASA sends to the red planet next Mars Rover. If all goes according to plan, it will be somewhere in 2020. The new Rover would be designed to replace the "Curiosity" in his mission to search for signs of life on Mars. In addition, the Rover will seek to collect samples of Martian soil that you plan to return to Earth in the framework of the manned mission, which is to take place somewhere in the 2030-ies.