The Central Research Institute of Machine Building (TSNIIMASH) in Russia is conducting a series of space plasma experiments in order to evaluate the shape of previously observed “dead” zone, or shadowing due to the firing of an onboard arcjet plasma source. Radio amateurs are invited to participate in the space plasma experiment “Shadow” onboard the International Space Station (ISS) on November 25-28 and December 2-5.

According to the AMSAT-UK website, integrating of Electric Thrust (ET) onboard a spacecraft poses a certain set of problems, including electromagnetic compatibility of ET. One matter of interest is that highly ionized exhaust plumes of ET may scatter RF signals, producing large “dead” zone for communications. This plasma screening effect should be thoroughly studied before electric thrusters become standard onboard equipment. This experiment will help designers of future electrically propelled spacecraft to minimize the hazard of communication disruption by ET plasma plumes.

The experiment will use the ISS Amateur Radio 145.825 MHz FM AX.25 1200 bps packet radio downlink. The amateur packet radio technology in the SpEx “Shadow” -- as proposed by astronaut Alexander Kaleri, U8MIR -- will use the AX25 packets transmitted by “master stations” and reported by receiving Amateur Radio ground stations to track the effect of the plasma shadow.

The SpEx experiment will be enabled on the following schedule:

If you would like to participate, you must register in advance. You can download any needed software here.