SELFRAG and the International Space Station

The SELFRAG Lab system has been used to support research on the international space station (ISS) into how chondrules (ancient minerals in meteorites thought to date back to the origin of the solar system) form.


A chondrule formation experiment aboard the ISS: Experimental set-up and test experiments

A research team led by the Goethe University in Frankfurt have designed an experiment performed aboard the ISS. EXCISS (Experimental Chondrule formation aboard the International Space Station) was undertaken to determine whether chondrules, component minerals of some meteorites thought to represent the chemistry of ancient earth, can be formed in microgravity conditions.

In order to prove that the chondrules could be successfully analysed once returned from the ISS after completion of EXCISS, terrestrial analogues were investigates. The Allende carbonaceous chondrite (a chondrite is a meteorite found to contain chondrules) was fragmented using the Lab system at the University of Frankfurt.

Electric pulse fragmentation (EPF) was used instead of traditional crushing due to the non-abrasive nature of the process. Delicate internal structures were to be investigated as par tof this research and thus a non-abrasive fragmentation technique was required to preserve these features for study. With such a small and valuable sample none can be wasted. Samples were treated according to the conditions in the table below:

Process conditions:

SampleCarbonaceous Chondrite Allende
Target ParticleChondrules
Electrode Gap15mm
Frequency 5Hz
Number of Pulses     50
Process time10 Seconds


Chondrule for ISS test
Figure 11 from the article: Virtual slice through a single porphyric chondrule obtained by synchrotron
microtomography. The chondrule was separated from the Allende meteorite by the selFrag


EPF allowed the easy removal of delicate minerals from the chondrite permitting investigation of internal annealing structures vital to the EXCISS project, and continues to support research into meterorites and the solar system worldwide. For more information see our article on apatite recovery from meteorite samples and the dating of the world’s oldest meteorite impact structure. The article is in Icarus volume 350 and available to download from Science Direct.