I have written before about the Archimedes project. Archimedes is a privately sponsored, designed, built and operated balloon probe to Mars. It is a creation of scientists at the Mars Society of Germany. In the past five years, they have gone from designing the mission, the components, and building them, to testing them on parabolic flights (in microgravity environment) and in space on a test vehicle. A 1:2.5 scaled, but complete version, called Miriam, is currently being prepared for a March 2008 flight test (when it will be launched by an Orion sounding rocket to an altitude of about 100 km, from the Esrange sounding rocket range in Sweden). If everything goes well, Archimedes will be able to catch the 2009 launch window to Mars.
Experiments on a zero-G flight. 28-30 June, 2005.
Amateurs to the rescue
So far, Archimedes appears to be on track. But how is a small, privately funded group going to get the spacecraft to Mars? Apparently aboard another private spacecraft. AMSAT-DL, the radio amateur satellite organization in Germany is building an amateur satellite, that will carry Archimedes (which itself has no propulsion system) to Mars. But let them introduce themselves first. (I tried to translate the video, the text is below).
Hartmut Päsler (DL1YDD): Hello and good morning, I welcome you to the stand of Amsat Deutschland (AMSAT-DL), which is a collaboration, an association of interested radio amateurs, engineers, technicians and scientists, to build communication satellites on a non-commercial base since 1974, we celebrated the thirtieth anniversary not long ago. As a short summary, I should say that we took part in several satellite projects, and right now the so-called Phase 3-E satellite is under construction; the progress of the construction is relatively good, we want to have the satellite in a flight ready state by the end of the year at the latest, and are looking for a launch opportunity in the next year.
Let's check the poster of the project and we can see that the satellite has a mass of approximately 170 kg, it's greatest extent is about 2 meters, solar cells, a lot of communication payload, from 144 MHz to 47 GHz, very small mirrors can be seen on it as well, which are for the high microwaves frequencies. The satellite is being built in Marburg, where right now integration is being finished.
Furthermore, we are planning a project, a satellite to Mars, which of course wouldn't be a communication satellite, as the signal takes 40 minutes to Mars, so you can't make instant communication with it. We are trying to take there a scientific payload: a balloon project, in which a balloon probe should be deployed in the Martian atmosphere, and we would provide the communication relay to Earth. To be able to do that, we have reactivated an old, 40 years old radio telescope in Bochum, a 20 m parabolic dish. Last year we received the signals of Voyager-1, which was launched in 1977, and which is still active - it is about 15 billion km from
Earth at the moment. To make it clear, the signal takes 13 hours to reach us, one receives what was sent 13 hours earlier. It's worth to note that Voyager is the farthest object man has ever created.
This is a prototype of an antenna that can be used for example to track the Mars mission, or for other things, it's built by Freddy de Guchteneire from Belgium, to whom I hand over the microphone, to explain some basic things about this antenna.
Freddy de Guchteneire (ON6UG): AMSAT-DL, P5 mission to Mars - we've just started to build hardware, newly developed, for our Mars mission. Here you can see this looks like a normal parabolic dish, but it really isn't a normal parabolic dish, it's a so-called ADE, axio-displaced ellipse antenna, which has higher efficiency than a normal dish. A radio amateur's parabolic dish has about 50% efficiency...
H.P: AMSAT-DL, and AMSAT worldwide in general finances itself only from donations, from your engagement - that we're honoured by -, in part from industrial sponsors, but for the most part we have to cover our financial needs from donations. So we created his donation initiative, it can be seen on our homepage, www.amsat-dl.org, where one can send us more or less arbitrary sums, and book such pixels, that everybody can see on the internet. We hope to amend our financial situation a little, because the negotiation of the launch of the satellite is going on, which can entail great financial expenditures. Thank you very much for visiting our stand, I hope it was interesting for the viewers, and stirred interest in perhaps amateurs in general or radio amateurs, there are an unbelievabe number of technical challenges, one can learn a lot, you're invited.
The P3 satellites
AMSAT Germany (like AMSAT-North America), is an alliance of engineers, technicians, scientists, students, radio amateurs and space travel enthusiasts. They carried out several succesful missions in the past 30 years. In 16 November, 2000 their Phase-3 D (Amsat-Oscar 40) amateur radio satellite was launched from Kourou, French Guyana on an Ariane-5G rocket. With its diameter of 2.3 meters, height of 70 cm, and its span of 6.5 meters with unfolded solar panels, AMSAT-Phase 3-D was the largest amateur radio satellite so far. It was also the heaviest with a launch mass of 650 kg.
A little table of the Amsat Phase naming scheme:
- Phase 1: a short life, technology testbed satellite, with only battery power, no solar cells.
- Phase 2: with solar cells, designed to last for 1 year. Low Earth Orbit.
- Phase 3: A highly elliptical, Molniya-type orbit. This allows a much wider coverage. They appear to stay over one spot for several hours at a time, which is much more comfortable for the radio amateurs who want to use it.
- Phase 4: An amateur satellite in geostationary orbit. None have been built yet.
- Phase 5: Capable of lunar or interplanetary missions.
P3-D - that was operating until its failure in 2004 - is going to be the base for the interplanetary mission, Phase 5-A. P5-A is going to be a relay between Earth and the Archimedes probe. But it can also carry other, smaller scientific experiments. Actually, even P3-D carried three small experiments, for example one that was studying the Van Allen radiation belt. It also had two different cameras: YACE, a small black and white CMOS camera; and SCOPE, which was built by the Japan AMSAT Association.
Separation of an Ariane-5 adapter, filmed by the YACE camera on P3D
Building the P3-E
However, AMSAT has to carry out more preparatory experiments before the Mars mission. Therefore, the successor of the now silent P3-D, the Phase 3-E amateur satellite, that is currently under construction, is going to serve as a testbed for these. Included are a star navigation camera, a new onboard computer and an ultra-stable reference oscillator, which can be used to improve communications. They will also have to simulate some procedures, like communication using very weak signals. P3-E is going to be finished by the end of 2007.
As it is explained in these documents, the P5-A spacecraft doesn't actually need to be more complicated than the P3-D. The main tricks are rather to get it to Mars, and to maintain communications. To get into space, they will use a cheap place on an Ariane launch to GTO (geostationary transfer orbit). However, being a secondary payload means they can't influence the launch date and time, and the launch may be in a bad time for a Mars departure. There appears to be a tricky solution to this. Moon flybys can be used to modify the orbit of the spacecraft, and this makes it possible to keep it in parking orbit for months, and then send towards Mars at the right departure window. The propulsion system of the P3-D is enough for these maneuvers, and for the subsequent insertion into orbit at Mars, 10 months later.
As for reliable communications, the refurbished telescope in Bochum already proved capable of receiving signals from Mars Odyssey, Mars Express, Rosetta, and Voyager-1.
Nevertheless, there are still many challenges to be overcome. There aren't many details about attitude control yet. Thermal balance is also going to be different from an Earth orbiting satellite. At the distance of Mars, the solar constant is less than half of that in Earth orbit, which can cause a drop in the spacecraft's temperature of several tens of degrees. Power production from the solar panels also drops to its half.
We have to patiently wait for more details to emerge. Until then, information and news on the project's website (in German): Go to Mars with Amsat-DL.
Donations are possible for the P3-E amateur satellite here.
Donations are possible for the P5-A satellite to Mars here.