As is known, the dream of many radio amateurs is to broadcast from a rare country, and preferably from a specific location as the very first. Many do not hesitate to spend all their strength and, of course, significant financial resources for this goal. Recently, there was a news in the media that a radio amateur is going to broadcast - from the International Space Station! Of course, this is nothing new, there have been several broadcasts from this space object in the past (see the links below), but so far these have been purely technical or educational activities. This time, however, it is supposed to be a typical expedition, which, in order to achieve its goal in full, assumes the recognition of this station as an independent country DXCC. This means that it must meet relatively strict criteria - the submitted application for inclusion in the list is based on point 2B - island areas (here is a debatable orbital height that does not meet the required 350 km at perigee) or 1C - political entity based on the international character of the object (does not belong to one state). If even this does not pass, Loby is ready to enforce inclusion under Article 3 – special areas, due to the specificity of the object.
Behind the whole event is a group of HAMs from the USA and Finland; for understandable reasons – it is not a small matter, a broad technical but above all financial security of the event is necessary. So-called space tourists occasionally visit the station (currently, a fifth person is about to visit), but the price for an individual's private stay is in the order of tens of millions of US dollars, which is too much for most amateurs (already exhausted by building their own QTH) an unreal dream. Even so, it is unrealistic for more people to participate in the event - there will be only one operator. According to the agreement, the participants of the event will each deposit a prescribed amount, and a lottery will determine who will be the lucky one - the operator of the expedition.
You will read in the article
Technical aspects
However, the event also brings other difficulties, primarily technical. Up to now, the activities have taken place mainly in bands VHF, however, the interest of opposing stations is mainly in short waves, and as much as possible in the bands. Today, it is not a problem to cover all the required frequencies with one transceiver (the main and back-up transceiver of a suitable small design has already been promised as a sponsor by the Yaesu company), the problem is antennas and final stages. For obvious reasons, it is not possible to place the antennas inside the station (poor efficiency, interference with reception, interference with the devices on board), it is necessary to place them outside. For this, it is necessary to ascend into free space (so-called EVA - Extra-vehicular activity), which is very dangerous and has not been allowed for space tourists until now. NASA refused to participate in the EVA (despite the offered financial amount), so there is no choice but for the amateur to stretch the antennas himself.
Antennas
The upper KV bands are relatively unproblematic, where verticals are expected to be installed (direction indicators have been abandoned; firstly due to weight and then due to the rotation of the station, which would constantly direct them elsewhere). Much more interesting are the lower KV bands, where only wire antennas come into consideration. Due to the dimensions of the station, it will be possible to install a dipole on 7 MHz, but there is nowhere to tie the ends on 160 and 80 m. The solution was found - to leave the ends free! Thanks to the state of weightlessness in space, the wire will not fall, it will stay where it is. Just "shoot" it correctly, it will unfold and stay in position. The rotation of the station will create a weak centrifugal force, which will ensure its permanent tension.
End stage
The appropriate final stage is another intensively debated point. There are two limiting factors - the possible power input, so as not to exceed the capacity of the on-board power grid, and the released heat, which could increase the temperature in the station. That is why the choice was made for a transistor variant with a small power of 500 W. So the signals will not be as strong as we are used to.
Effect of spread
The specifics of the expedition is also the operating style, especially the impact of propagation - the ionosphere. Previous expeditions were located on the surface of the Earth, where there was a reflection from the ionosphere. But what happens when the peer station is in the middle of layer F? The good fortune of the current period of low solar activity is that the upper bands will have optimal conditions when the band is completely closed, that is, at low ionization, when waves pass without significant absorption and reflection. It is assumed that it will not be necessary to use split operation - ground stations will not hear anything else anyway and will not be disturbed. However, it is assumed that all earth stations will not call on the same frequency so that the operator can dial undisturbed in the pileup. Lower bands can be problematic due to D and E layer absorption. Optimal times will be selected based on experiments (with expected scientific benefit). The log will be available online on the existing packet radio BBS (145.800 MHz, 1200Bd AFSK); an on-board web server variant is also being considered, but is unlikely to be implemented due to the risk of overloading and crashing. At the end of the expedition, the complete log will be uploaded to the Logbook of the World (helping to recognize the status of a separate "country").
The expedition is also preparing a technical innovation – the entire operation will be continuously recorded and stored together with the frequency as an MP3. After the end of the event, every amateur will receive a pri QSL also the part of the recording where its signal is.
Due to the expected enormous interest and previous delays, details are not being released until a launch date is set. Preparations are in full swing, we have a lot to look forward to!
References:
[1] [http://www.nasa.gov/missions/shuttle/f_hamradio.html](http://www.nasa.gov/missions/shuttle/f_hamradio.html)
[2] [http://spaceflight.nasa.gov/station/reference/radio/](http://spaceflight.nasa.gov/station/reference/radio/)
[3] [http://edmall.gsfc.nasa.gov/aacps/news/Ham_Radio.html](http://edmall.gsfc.nasa.gov/aacps/news/Ham_Radio.html)
73 on April 1, Pavel OK1DX