HTR makes available engineering models of full-metal elastic Lunar wheels

All metal Lunar wheels mounted on small HTR rover

All metal flexible wheels for Lunar rovers

(IN BRIEF) HTR, based in Central Greece, is now offering its patented, all‑metal flexible wheels—designed since 2016 to endure the Moon’s extreme temperatures (–180 °C to +130 °C) and radiation—for commercial purchase worldwide via www.htr.gr and resellers like Roboshop; available in two sizes for Earth test vehicles (50–150 kg, equating to 300–900 kg lunar mass), these fourth‑generation wheels have proven their durability over 1 000 km of fine‑sand trials—far beyond NASA’s 1960s tests—and provide researchers with realistic lunar‑rover behavior on Earth, backed by strong patent protection, ongoing technical support, spare parts, and customization options.

What are the characteristics of these wheels and how they support lunar use?

• HTR has been manufacturing, testing and optimising elastic metal wheels since 2016. We have a revolutionary design protected by worldwide patents. The lunar environment is extremely challenging for rubber wheels. Radiation and temperature variation (the wide lunar temperature range from -180oC to +130oC), exclude the use of rubber and other polymers. This fact leaves only available the use of special metal alloys. After years of research, we have come up with an elastic metal wheel design, combining durability with excellent performance. The wheels we make commercially available today are exactly the same as those that meet the requirements for lunar operation.

So, you are addressing a very limited “audience”, which is preparing a vehicle for the moon and needs wheels?

• The target group for our wheels is much larger than the teams that are preparing a mission for the immediate future. We address all those who work on planetary exploration vehicles (rovers), either designing mechanical parts, navigation algorithms, path planning, etc. Our wheels are the only ones available at this moment that can be used and faithfully reproduce the behaviour of these vehicles under lunar conditions. Using our wheels, researchers will be able to see exactly how their vehicles will move on the lunar surface, provided they take into account lunar gravity and scale effects. Using other wheels, e.g. rubber wheels or 3D printed plastic parts, they will not achieve the same behaviour for the vehicle. As a result, they will not be able to reproduce in the lab exactly what will happen to their rovers once on the surface of the Moon. This can have a significant impact in predicting the performance of both the engineered parts and the algorithms that these teams develop. In short, we offer to these researchers an opportunity to “run” rover experiments with a realistic rover lunar behaviour, while still on Earth. There are many such groups around the world that are currently engaged in related research activities. For instance, in Greece, there are at least ten.

How confident are you that these wheels will withstand the demanding operating conditions they will be subjected to?

• At HTR we have performed endurance experiments of our wheels, for total distances of over 1000Km (see photo below), under the worst possible environmental conditions, (e.g. operation in extremely fine basaltic sand). For comparison, the lunar wheels used by NASA in the sixties where tested (and failed) for less than 100 km. HTR disassembled the tested wheels and analysed all the wear and failures, with the ultimate goal of redesigning the parts that needed to be reinforced. We are now in the 4th generation of this iterative process, therefore we can guarantee long term operation for the wheels, as long as they remain within the intended load limits. This is something that other manufacturers cannot do, because their wheels have not reached a similar level of design maturity. Unfortunately, – or fortunately- , the design of a lunar wheel is something that is mainly judged on endurance. Testing takes time, so any new design or change also takes time to be verified.

What kind of vehicles can your wheels be used on?

• The available wheels are of two types, for terrestrial vehicles ranging from 50 to 150Kg. Taking into account lunar gravity, this would mean that they could fit lunar rovers in the range of 300 to 900Kg. More details and an extensive manual for the wheels can be found on our website, www.htr.gr , or on a reseller’s website, such as Roboshop.

How did HTR decide to market these wheels worldwide, despite the obvious risk of them being replicated?

• This question has been a big dilemma for us. We like to think that because of the extremely low price at which we offer our wheels, no one would bother to copy them; it would be more advantageous to just buy them. On the other hand, given the patent protection of the design, no serious company or country would take the risk of copying them and presenting their vehicles to the international community, at the risk of being exposed. For our part, we will support all efforts of those who will buy and use our wheels, either for ground testing or for mission preparation, as long as they remain in contact with us, of course.

How can someone acquire your wheels?

• Our wheels are available on reseller sites such as Roboshop, or on the company’s website www.htr.gr

About HTR

HTR is a company located in Central Greece, Europe.

We build all metal flexible wheels since several years and we decided to make them commercially available. These are the first Engineering Models of all-metal flexible flight wheels to be made available to the Research Community, world-wide.

Media contact:

A Katelouzos
HTR
Kifissias Ave 188
14562 Kifissia Greece
info@htr.gr

Website:

Photos and Videos:

Image: Wheel after experimental operation on 1000km.

HTR’s active suspension rover with flexible metal wheels

Frequently Asked Questions (FAQs)

1. Why did HTR choose an all‑metal, elastic design for its lunar wheels?
   Rubber and polymer-based tires cannot survive the Moon’s extreme temperature swings (–180 °C to +130 °C) or the high‑radiation environment. HTR’s patented elastic metal wheels combine special metal alloys with a spring‑like structure to deliver flexibility, durability, and consistent performance under lunar conditions.
2. What advantages do HTR’s wheels offer during Earth‑based rover testing?
   Because they faithfully mimic lunar traction and deformation (when coupled with appropriate gravity scaling), these wheels let researchers validate mechanical components, navigation algorithms, and path‑planning software on Earth in a way that rubber or plastic wheels simply can’t.
3. How has HTR proven the long‑term endurance of its lunar wheels?
   HTR has run 1 000 km of endurance tests in ultra‑fine basaltic sand—far exceeding the < 100 km NASA wheels reached in the 1960s—disassembling and analyzing wear after each iteration. Now in its 4th generation, the design guarantees reliable operation within specified load limits.
4. What payload ranges do HTR’s two wheel models support?
   Each wheel set is rated for terrestrial test vehicles weighing 50–150 kg. Under lunar gravity (≈ 1/6 g), that equates to actual rover masses of roughly 300–900 kg, covering most current and near‑term exploration platforms.
5. Beyond lunar mission teams, who else can use these wheels?
   Any group working on planetary‐exploration rovers—whether focused on mechanical design, controls, navigation, or simulation—can benefit. Academic labs and private R&D teams worldwide use them to run realistic lunar mobility experiments on Earth.
6. How does HTR protect its wheel design from unauthorized copying?
   HTR holds worldwide patents on its elastic‑metal architecture. Combined with aggressive pricing—making purchase far simpler than reverse‑engineering—this legal and economic barrier deters both companies and state actors from infringement.
7. What kind of customer support does HTR offer after purchase?
   HTR provides detailed manuals, engineering guidance, and iterative design consultation for both ground testing and mission‑prep applications. Ongoing technical assistance ensures wheels are integrated and tested under the right load and environmental parameters.
8. Where can I order HTR’s lunar wheels?
   You can purchase directly from HTR’s website at www.htr.gr or through authorized resellers such as Roboshop. Detailed product specifications and user manuals are available online.
9. Can these wheels be repurposed for non‑lunar or terrestrial off‑road applications?
   While optimized for lunar analog testing, their metal‑alloy construction and elastic design also excel in harsh terrestrial environments—fine abrasive soils, extreme temperatures, and radiation‑like conditions—making them useful in specialized Earth‑based R&D too.
10. What is HTR’s background in wheel development?
    Founded in Central Greece, HTR has pioneered elastic‑metal wheel technology since 2016. These are the first all‑metal flexible flight‑model wheels made commercially available for the global research community.

SOURCE: HTR