Brief history

It all started when our founder and astro enthusiast Anders Hjelset could not find any commercially available vehicles with the capabilities he was looking for, not anywhere.

He was about to acquire astro gear with larger aperture than what he already had, a 10” dobson, but only if he easily could take the much heavier gear to remote dark sky locations fully mounted. He wanted to avoid the heavy and somewhat risky hassle of assembling and dismantling the entire rig every time, out in the field, often in freezing darkness, and mostly alone.

A dark sky location is essential for high-quality observations and therefore often considered to be a Holy Grail for astronomers. Such a vehicle would easily take him anywhere from his urban home and thereby maximize the usability and benefits of the much heavier and more powerful gear. It was that simple.

He gathered a team of professional engineers and craftsmen and set out to develop and build the first trailer dome. This was back in 2018.
Three years later, our team around Trailer domes could offer vehicles with exactly the capability he was looking for. To fellow astro enthusiasts as well as to organizations and institutions within astronomy.

Product development

Trailer domes have been developed by using advanced CAD tools in combination with continuous real-life Trial & Error of every machined module. Thousands of engineering and machining hours have been required to build the prototype, which after three years stood fully featured and in perfect operational condition.

Specialized suppliers from different regions of the world have contributed with both development and deliveries of parts for the finished assembly. Even fellow astro enthusiasts have contributed with ideas and suggestions. One of them deserves to be extra high-lighted for giving valuable feedback and advice on various engineering challenges, Mr Yasuhiko Tsukuda from Japan.   

Critical modules

The pictures pinpoint very well the priorities for the product development process. The two most critical challenges to find solutions for were the damping module and the tripod. In fact, paramount for the whole concept. They were therefore the first ones to be developed.

Without solving these two there would simply be no sense in proceeding with anything else.


Another priority concerned technology. There is only one device which has its own dedicated motor and automation system, the actuator. All other power trains – it be the corner jacks, the tripod winch or the tilt-back roof – are operated by a commercially available handheld drill.  

This priority was driven by the urge to eliminate risk of software or electronic failures for the power trains out in the field. Therefore, even the actuator’s automation is limited to merely control Up and Down only. It can hardly be done less complicated. The same priority also had a decisive impact on the two most critical solutions, the damping module and the tripod. The capabilities of both solutions are based on pure Newtonian physics, gravity and mechanics. There are no sensors, guiding or automation systems that might fail or run into malfunctions, at some point, sooner or later. To push it a bit on its very edge, we humbly believe that gravity has been consistent and Newton’s laws valid for 14 billion years. And nothing can beat that reliability. Please download the Engineering PDF for more detailed information about components and features.
Field testing of damping with accelerometers and extra rigs for high-speed video cameras.

Trial & Error of tripod’s self-leveling and drop-locking.

Shock and vibration damping

Here are some key results derived from comprehensive Swiss MSR accelerometer analysis. They show to what extent shocks and vibrations on the trailer chassis are cancelled from hitting the astro gear mounted on the suspended platform:

Impact Forces never exceed 1,6 G in any direction
Shocks (Jolts) Most violent peaks reduced by factor 30
Vibrations Damaging impulse reduced by factor 250

This makes the astro platform by far the smoothest moving object on the whole equipage, i.e. including the towing car.

Gravel road used for vibration test runs.

Please look up the MSR Assessment PDF for further details and watch a Road Movie showing how both the equipage and the platform behave in various severe traffic situations.

Early stage of testing panic braking at 80 km/h on dry asphalt. Here with rig mock-ups, together with some blue hot smoke.. Note the stretched rear and compressed front dampers (max stretch 3 250 N, each damper). And, that the astro pier always stays upright, even here in this rather violent traffic situation.

During transport, it is recommended to loosen both clutches on the mount and secure the axles to stay around their centre positions with elastic silicone straps. This will spare the mount from undesired torques that otherwise will impact both the clutches and bearings.

The axles will always try to preserve their directions in space and thereby otherwise impose inertial forces onto the mount every time the trailer changes direction in curves or slopes.   

Rig stability

The rig is an all-steel construction of three sequential tripod solutions on top of each other. This in combination with a ground weight of 440 kg grant for an absolute rock-solid astro rig:

The wedge’s adapter plate on the platform rests on three tilting bolts
MiddleThe platform itself rests on three fixed telescopic tubes
BottomThe tubes rest in turn on the tripod anchored to the ground

There is even a forth tripod solution. The astro gear could be lifted higher up by inserting three distance blocks between the top plate and the heavy platform. Depending on the choice of mount and adapter cylinder, this might be needed in order to achieve a 100% free aperture down to the very horizon. However, the astro gear will then of course be more exposed under windy conditions.

Due to this, the trailer dome carries a set of four windshield nets as extra accessory. One or more nets could easily be strapped between corner poles inserted into the vertical pipes of the damping rigging structure.

US Patent 11,306,864

The most vital trailer dome solutions have IP protection granted by the U.S. Patent and Trademark Office. More details can be found in section ARCHIVE. The archive section also contains other technical documentation, short-movies, and newsletters.

The whole USPTO process took only 9 months and was managed by the highly competent and experienced patent agency OB Patents Inc.

Preferred suppliers

Great emphasis has been put into utilizing commercially available parts and components with already proven functionality. Carefully selected manufacturers play therefore a key role for the high quality of our finished assembly – it be the various rig modules or the fully featured turn-key trailer domes. Here a few of the most well-known ones (in alphabetical order):

  • Carr Lane, USA
  • Festo, Germany
  • Knott, Germany
  • Lesjöfors AB, Sweden
  • Miki Pulley, Japan
  • Misumi, Japan
  • STM, Italy
  • Variant, Denmark
  • Victron, The Netherlands


Ultimately, and most important, we have a very tight partnership with regional professionals for all stages of the manufacturing process:

Mechanical engineeringAFRY, Malmö office, Sweden
Machining and assemblyLomma Maskinteknik, Sweden
Automotive industryJPGS Kaross, Sweden
Electric power automationWiMix Automation, Sweden