A small satellite named ARISSat-1 (and “Kedr” or “Radioskaf-B” by the Russians, as ARISSat-1 is officially a Russian experiment) has been providing me with a lot of fun and satisfactions since August 3rd, when it was released from the ISS, or International Space Station, by the Russian cosmonauts during a spacewalk from the Pirs airlock located in the Russian segment of the station.
As I think that trying to cover and explain all about ARISSat-1 in a single entry would be too long, I’ll divide it into some parts so that in each part I can cover and explain better a different aspect of this great sat. In this first entry, and as its title says, I’ll give a general introduction to ARISSat-1 and to my experience with it, so let’s start!
ARISSat-1 is a project of the following organizations and agencies: ARISS (ARISS stands for “Amateur Radio in the ISS” and it is the international organization in charge of everything which is related with ham, or amateur, radio, in the International Space Station, such as school contacts for example. Currently there are two ham radio stations onboard the ISS, one in the Zvezda module and another in the Columbus module), AMSAT (also known as “The Radio Amateur Satellite Corporation”, it is an organization which has developed many amateur radio repeater satellites, and which launched the first of such sats, OSCAR, on December 12, 1961, only four years after the launch of the Russian Sputnik, which was the first satellite ever), NASA and Roscosmos (the Russian space agency).
ARISSat-1 is an experimental amateur radio satellite (or better said a microsatellite, given its dimensions of only 55 x 55 x 40 cm) developed as a follow-on project to SuitSat-1 (which in its turn consisted of a discarded Orlan Russian space suit which was deployed from the ISS and which was fitted with electronics and a transmitter box connected to an antenna located on the helmet, outside the suit and near a control panel which provided the interface for the astronauts to activate Suitsat prior to its deployment. More about Suitsat-1 in this PDF and also in this blog compilating audio recordings from it here). The development of ARISSat-1 started with that of SuitSat-2, but when an Orlan suit became unavailable for housing all the electronics and other elements (it had to be removed from the ISS to make space), the teams which were developing the new satellite moved on to the building of an spaceframe for this new sat so as to replace the discarded suit. The components designed originally for the Orlan suit, this is, the electronics in general and the control panel, were moved then to this new spaceframe. Note that as ARISSat-1 would be released manually by a cosmonaut of the ISS (as it happened with SuitSat-1), four big handles were included so that, despite the space suit’s gloves, cosmonauts could grip and handle it well.
Something that makes ARISSat-1 different from SuitSat-1 is that it does not only take its energy from a battery, but it also takes it from six solar panels (donated by NASA from a cancelled project, they dictated the overall size of the spaceframe) which provide energy for the operation of the sat and for recharging its battery when it is in the sunlight part of each orbit. These panels have also made possible that, after the failure of this battery a few days after the release of the sat (an unmodified Orlan space suit battery, intended for use in an Orlan suit for SuitSat-2) the satellite continues active despite the fact that this battery does not hold a charge anymore. Now, although when ARISSat-1 enters the eclipse phase of each orbit (or the phase in which it flies over the part of the Earth in which it is night time) it simply turns off because the solar panels stop providing electricity and the battery is dead, it performs outstandingly when it’s on sunlight and the solar panels are providing the energy for this great sat to work.
But what really makes ARISSat-1 special and different from all the rest of the satellites (at least for me! 🙂 ) is that, similarly to Suitsat-1, since it was released from the ISS, it has been continuously transmitting a tremendously special audio transmission. In ARISSat-1, this audio consists of recorded greetings in different languages (including one in Spanish and another in Catalan! 🙂 ), including a “Secret Word” in each language; an extract from the communications during the flight of Yuri Gagarin (the first human to go out to space); SSTV (Slow Scan TeleVision) pictures (!) in the Robot 36 format from one of the four cameras included in the equipment of ARISSat-1 (which can be easily decoded and obtained by just plugging the radio to, or playing the recorded audio of the pass through, the mic or line in input of the PC and using the free MMSSTV software for Windows); and spoken telemetry, in which the satellite actually reads to you (!!) the following values: MET (“Mission Elapsed Time” or the time since the last time the sat was powered up. With the battery failed this counter goes to 0 every time the satellite goes away from sunlight in each orbit); temperatures of both the IHU (“Internal Housekeeping Unit”) and the control panel (which is located on the outside of the frame of the satellite and which, like in SuitSat-1, provides the interface for the astronauts/cosmonauts to power it up); and also the voltage and the current from the battery!!! Certificates are available on the reception of secret words, telemetry and SSTV picture. ARISSat-1’s website says the following:
- Email the secret word/password, your name or group, date/time received,city, state, country and your email address to firstname.lastname@example.org to receive a certificate.
- Email the voice telemetry data, your name or group, date/time received,city, state, country and your email address to email@example.com to receive a certificate.
- Email a description of SSTV image, your name or group, date/time received,city, state, country and your email address to firstname.lastname@example.org to receive a certificate.
ARISSat-1 also has a transponder, or radio repeater, which works in the SSB (Single SideBand) modulation and which is available for use by licensed ham radio operators (who can use ARISSat-1 as any other ham radio repeater satellite), a CW or Morse code beacon, and a BPSK format digital telemetry downlink, including that of the experiment developed in the Russian University of Kursk that measures the change in atmospheric pressure as the satellite descends as a result of the braking effect of the residual atmosphere existing in LEO, or Low Earth Orbit.
As it can be seen, ARISSat-1 is a very special satellite which I and other radio listeners and ham radio operators all over the world are enjoying a lot. The most special on ARISSat-1, the voice beacon can be heard on the frequency of 145.950 (FM modulation) as the satellite makes a pass over you and no expensive receiving material is required (I’ve been hearing it since it was deployed with just a tiny ICOM IC-R5 scanner and a recycled “rabbit ears” dipole TV antenna positioned in a “V” shape). For all of you who might want to try receiving it in one of its passes over your location, here are some links:
- www.heavens-above.com is a great website for predicting passes of ARISSat-1, the ISS, and a lot of satellites more. After registrating and introducing your location, it will calculate and the passes of the selected satellite over you in a very useful picture. Generally speaking the higher the elevation (angle between the path of the pass and the local horizon) of the pass is, the best the reception will be.
- www.stoff.pl is the website for downloading Orbitron, a satellite tracking application which even works offline! Needs updating the TLE files periodically as they lose precision with time. Although it also predicts passes, I don’t find it as precise as the Heavens-Above website for this purpose. But I find it great for knowing where ARISSat-1, the ISS or any other satellite is in real time and, in the case of ARISSat-1, for knowing if some passes will be with daylight or not because, as I’ve said above, its battery failed and ARISSat-1 is only powered up when it its on sunlight and the solar panels generate electricity.
- Download link for the SSTV decoder sofware, MMSSTV: http://www.qsl.net/kf6ypq/MMSSTV.exe. By using a male-to-male audio cable with 3.5mm jack connectors to connect your receiver to the mic or line in input of your PC, this program will translate the SSTV audio into a picture which can be saved as a normal .jpg or .bmp file, great! Another option, if the computer is not available during the pass to decode the SSTV in real time, is to use a digital audio recorder (I use as one of these my smartphone together with a homemade connector adaptor) to record the audio of the pass, then plugging the recorder to the mic or line in input of the PC, playing the recording and just letting MMSSTV decode the image from the recording. This works great too. Some advice would be to record in a .mp3 format instead of in .wav (or at least I’ve had better results recording in .mp3)
- And other webpages of great interest about this satellite are:
That’s all for now. In my next ARISSat-1 post I’ll detail its internal components to at least complement the Chips in Space blog which gives abundant information about it. So, stay tuned!!!