A Deep Space Primer 118
phil reed writes "With the latest Mars missions still in the news, people might be curious about what it takes to actually run a deep space mission: how a spacecraft is designed, how the communications are handled, what kind of project management is in place to make it all work. The Jet Propulsion Laboratory has a primer online that gives broad general coverage of all aspects of putting a satellite into orbit and how to manage it once it's there. Fascinating reading, with lots of links to more detail."
how the communications are handled (Score:3, Interesting)
Deep Space? (Score:5, Interesting)
Re: communications: Interplantary Internet (Score:5, Interesting)
Its more than just the long delay. Interplanetary networking [keskus.hut.fi] is quite tricky due to the limited bandwidth, line-of-sight interruptions, the need to slew expensive high-gain antennas into precise scheduled pointing directions, as well as the massive levels of latency.
Re:Long-feedback cycles and good design (Score:5, Interesting)
But I look forward to the day when we can develop space hardware the same incremental way we develop other things. When flying into space is as cheap as flying to Australia, we won't have to have massive, incredibly careful engineering projects. We can just try stuff and go with what works.
P.S. Am I naive to think we can go to space as cheaply as going to Australia? No. We can't do it with the Space Shuttle, which requires many man-years of labor to rebuild after each flight. And we can't do it with expendable boosters, which are completely destroyed when you use them. We will need actually reusable spacecraft. I fear that NASA is no longer, as an organziation, able to build them, but someone else will. Go Xcor! Go Armadillo Aerospace! Go... anyone building these things.
steveha
Re:how the communications are handled (Score:3, Interesting)
not quite deep space (Score:4, Interesting)
The iridium network has only one location on the planet where communications actually uplinks and downlinks to land communications. Of course they have the ability to communicate to any one of the three or four sites if one were to fail, but it would only use one at any given time.
So if you made a call in antartica on a iridium sat phone to someone on a land line it would back haul the traffic using line of sight communications leap frogging each satalite before having the uplink/downlink to the ground. So I think it was a total of like 6 hops or something max unless there were of course other issues with the network, it could reroute through any visible satalites.
So the bandwidth of the entire network is limited to that one uplink/downlink which rotates satalites on an almost hourly basis. So it's not like they could make 1 satalite that could support more bandwidth communication to the ground than the others, they're all built the same. Any iridium sataliate can take the place of any other.
I know it's way off topic, but interesting to me none the less..
Re:how the communications are handled (Score:3, Interesting)
The now defunct Breakthrough Propulsion Project (Score:5, Interesting)
NASA used to have a project devoted to seriously studying what it would take to achieve interstellar travel. Unfortunately, funding for it got cut off in 2002. However, they did manage to publish several papers and still have their results online at the BPP site. [nasa.gov]
Here is a quote from the abstract of one of their papers:
Re:No thanks (Score:2, Interesting)
Seriously, it's easy to forget that just a century ago we were literally a horse-and-buggy civilization, and how amazing it is that we can make these things work at all. I was talking to a youngster at work the other day, and was suprised to learn that he didn't know what a slide rule was. Now our tools and toys are an order of magnitude better than when we went to the Moon, but we still have a lot of learning to do.
I can never get tired of watching those same rehashed rocket shows on the science channels, so thanks to the originator for the link!