Technology 01

How Artificial Meteors Are Generated

How Artificial Meteors Are Generated

If you are lucky, on a clear night sky you can see a meteor streaking across the sky. This streak of light is due space dust re-entering the atmosphere at high speeds, causing aerodynamic heating1 and emitting a glow of light that is observed on the ground at night.

What we do is to artificially generate meteors by releasing a "meteor particle" from a satellite into the atmosphere.

ALE's meteors, compared to natural ones, are more massive and travel through the atmosphere more slowly, which allows them to be observed for a longer time.

Note 1: Aerodynamic heating is the phenomenon that occurs when an object travelling through the atmosphere at supersonic speeds compresses the air in front of it, and the drag produced by the compressed air causes the object to heat up and generate light.

Technology 02

Meteor Particle Release Technology

Meteor Particle Release Technology

In order to generate a man made meteor at a desired location and time, the meteor particle release parameters must be fine-tuned to a very high degree of accuracy. ALE has succeeded in creating a system capable of releasing particles at a high level of precision over the operational lifetime of the satellite, which could have up to several thousand releases.

In addition to a release system capable of handling high-precision parameters, the satellite incorporates the latest Japanese technology for the calculation and execution of the required release direction, position and speed. Together as a unit, the highly precise release conditions are achieved.

Technology 03

Safety Measures

Safety Measures

Safety Check during Release Phase

Before and during a release of meteor particle, the ALE satellite performs multiple safety checks to avoid any unintended collisions between an ALE meteor particle and other space objects, such as satellites.


Conjunction check against other satellites

ALE will check the position and trajectories of all other satellites. Only if it is deemed that there is sufficient clearance between the particle's trajectory and other satellites will the particle be released.


Function check of the satellite position and release direction determination system

The satellite has 3 star tracking sensors, 2 position measurement systems, and 3 internal clocks on-board. 3 independent CPUs will calculate the satellite's position and attitude based on the measurements from these sensors. Only if all 3 CPUs obtain the same result, that the systems are deemed to be operating properly, will release occur.


Functional check of the release speed determination system

The meteor source is propelled by pressurized gas. There are 3 pressure gauges on-board the pressure system. 3 CPUs take the measurement data of these pressure gauges, and only if all 3 CPUs compute the same result for proper operation will the meteor particle be emitted.

Safety of the Released Meteor Particle

When the meteor particle, which is released at an altitude of 400km, reaches approximately 80km above the ground, it decelerates rapidly due to atmospheric drag. Because of this deceleration, there is no risk of the meteor particle reaching the ground at high speeds.
Furthermore, aerodynamic heating of the particle will cause it to burn up completely before an altitude of around 60km.

This phenomena has been predicted by mathematical simulations and experimentally verified in a facility which simulates the conditions of outer space and air pressure during re-entry.

Technology 04

Environmental Impacts

Environmental Impacts

It is estimated that several hundred tons of space dust rain down on Earth every day.
The particle that will be used in ALE's meteor is made of the same material as the space dust that rains onto Earth on a daily basis, and is a sphere of only 1cm. In total, the 400 meteor particles loaded onto our satellite will only have a mass of around 1kg. Therefore, impact on the environments expected to be minimal.