Hackers In Space: Designing A Ground Station

An anonymous reader writes with some new information on the happenings of the Hacker Space Program. From the article: "At the Chaos Communication Camp 2011 Jens Ohlig, Lars Weiler, and Nick Farr proposed a daunting task: to land a hacker on the Moon by 2034. The plan calls for three separate phases: Establishing an open, free, and globally accessible satellite communication network, put a human into orbit, and land on the Moon. Interestingly enough, there is already considerable work being done on the second phase of this plan by the Copenhagen Suborbitals, and Google's own Lunar X Prize is trying to spur development of robotic missions to the Moon. But what about the first phase? Answering the call is the 'Shackspace,' a hackerspace from Stuttgart, Germany, who've begun work on an ambitious project they're calling the 'Hackerspace Global Grid.'"

these guys....

[Anonymous Coward]

disclaimer: I'm a satellite telecom engineer.

What these guys don't know about satellite telecom could fill a swimming pool. "A open, free and globally accessible satellite communications network"? Sure. Except for the free part, it already exists. With a properly designed VSAT terminal (either C or Ku band) anywhere that's not beyond 83 degree latitude can get broadband net access. Why is VSAT service not cheap? It costs $200 million to launch a 6000 kilogram satellite into geostationary orbit, and the satellites lasts on average 12 to 16 years. The $200m satellite has less aggregate data capacity than a fiber optic cable the diameter of a pencil. Installing a 1.2 meter Ku-band VSAT terminal with DVB-S2 compliant TDMA modem (iDirect Evolution series, for example) is not rocket science, but proper service starts at $400/month and up.

If they're trying to push a large amount of bandwidth through small, cheap low earth orbit satellites I believe they're going to run into some fundamental engineering constraints (satellite power budget, shannon limit, the fact that two axis tracking antennas are expensive).

Re:Work on the easy stuff first.

[drmpeg]

What you don't know about ham radio could fill a swimming pool (I love that phrase). Hams have access to all kinds of frequencies that penetrate the ionosphere and have built and launched many satellites. http://en.wikipedia.org/wiki/OSCAR [wikipedia.org] The most interesting amateur satellites were OSCAR 10, 13 and 40. These were in high altitude (40,000 km) Molniya orbits that provided many hours of coverage. Two-axis tracking was required, but was so slow that it could be done by hand. The big problem with amateur radio is that commercial traffic is not allowed. That is, no connection to the internet.

Re:these guys....

[schnell]

You're correct... satellite broadband can be had in the US for far less than $400/month. ViaSat and WildBlue's services (may or may not qualify as "broadband" depending on your definition) start at around $50/month [viasatresidential.com]. The GP's citation of $400/month for satellite broadband refers to "business class" VSAT data service. Residential satellite Internet is heavily oversubscribed, often north of 100:1. Also note the Fair Access Policy [montanasatellite.com] terms under which you will be throttled for excessive data usage.

For some use cases, the results will be indistinguishable at the lower price point; for others they will be very different. Think of the difference between the two as being T1 service from a business provider vs. home cable or DSL service.