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A Deep Space Primer
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."
I am waiting for Build your own space mission For Dummies to come to my local B&N.
It is so mind boggling when you think aabout the actual costs to make one of these mars rovers and how much it costs to send it up in space. After all these are basically disposable because they most likely will never get them bac unless we make a succesfull manned mission to mars.
MonkeysKickAss
There are a lot of smart, dedicated, and *unsung* heroes at JPL. NASA tends to get all the celebrity, but JPL deserves it just as much. Thanks to all who are working on our Mars missions and the various other missions that are increasing our knowledge of our universe and ourselves.
The anti-salmon
Too many windows on your screen may tax computer "power" causing animations to run too slowly, but if they're too fast, you might choose to run additional programs to use up computing power and slow the animations.
So it looks like JPL's also providing a newbie guide on "tweaking your system." :-)
I'd like to see how someone with a 3.0 GHz PC handles this...
-Rob
Marriage doesn't have to suck!
They forgot the statutory warning.
DO NOT attempt this at home
Free XBox, PS2
It's nice to see that space exploration has come so far in my lifetime. When I was a boy during WWII, travel to Mars, even by machines, was just science fiction, and the stuff of magazine covers. Most of the world's scientists and engineers were at work developing weapons of war, and for some of them, rockets, high altitude airplanes, etc. were allowed projects that laid the foundation for today's space miracles.
"In the beginning the Universe was created. This has made a lot of people very angry and been widely regarded as a bad move."
R.I.P. DNA
"Faith: Belief without evidence in what is told by one who speaks without knowledge, of things without parallel." - A.B.
This type of careful planning and careful execution is useful for any endeavour with long or expensive feedback cycles. That includes terrestrial tasks like creating nuclear powerplants. Too many engineers have a hands-on, tweak-and-see hacker mentality, where projects like Mars rovers, nukes (and many other projects)need to work as planned right out of the box.
A former boss and engineer had a great story about his early job experience designing circuits for a guided missile. He showed his first circuit design to the boss and the boss noted all the little adjustable pots in the circuit. The boss simply said, "Are you going to fly with that missile to tweak all the pots?"
Although simulations, testing, and prototyping are great, truely great engineering just works because it was designed correctly from the beginning to just work.
Two wrongs don't make a right, but three lefts do.
veerryy sloowwly. What is it? 20 minutes to mars and back? Light speed won't cut it when we talk about going anywhere farther than the moon. At our current level of comprehension, it's just not practical to go any father than Mars. We need to dream up something entirely different. Something that works like a very long tube filled with ping pong balls for example. Push one into one end and one pops out the other instantly, no matter how long the tube. I'm sure somebody has thought of this and has a name for it, but I sure don't know what it is.
What?
Humans have yet to perform any "Deep space" exploration.
The Voyager missions come the closest, but still remain fairly near home, on any meaningful interstellar scale.
The linked article discusses interplanetary exploration. Quite a bit of a difference.
Is Mars Deep Space? Shouldn't that term at least be reserved for regions outside the solar system? Or is that "Outer Space"?
20 minutes to mars and back? Light speed won't cut it when we talk about going anywhere farther than the moon.
Its more than just the long delay. Interplanetary networking 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.
Two wrongs don't make a right, but three lefts do.
But I look forward to the day when we can develop space hardware the same incremental way we develop other things.
Absolutely! I look forward to a range of advancements such as lower cost access to space (personal fav is a space elevator), truely routine manned space operations, and better adaptive/autonomous robotic systems.
Yet I fear that the foreseeable future (next 20 years at least) will be dominated by rare and expensive space projects in which every lauch counts and every EVA-hour is carefully scripted and rehearsed.
Its a vicious loop, really. Because space is expensive, space projects are very carefully planned and executed. And because space projects are so carefully planned and executed, they are expensive.
Two wrongs don't make a right, but three lefts do.
Maybe it's my browser but I got kinda disappointed with the first quiz - it keeps saying "Wrong, no selection made." on each of the checkbox responses - no matter which ones I check.
:)
I couldn't imagine JPL putting up a web quiz that didn't work - I mean, that'd be like having different modules in a probe using different units of measurement.... oh, yeah, oops...
I left my body to science, but I'm afraid they've turned it down...
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..
Not true. To design something very complicated like an aircraft or Mars rover there are *many* models and experimentation done, because almost all textbook equations are only approximations of reality.
Excellent point. My heat transfer prof warned us that the equations in the textbook would get answers that had as much as 30% error (if you were lucky). And, IIRC, some theories in material science only yield answers that are within an order of magnitude (factor of 10) of the true value.
But what I was alluding to was robustness -- designs that aren't affected by approximation errors (or the inevitable measurement errors when you build and test a prototype). Some of this is a matter of factors of safety (overdesign) but the truely great engineers create designs that are insensitive to encountered variations. At some level the ability of the Rover team to correct the recent faults represents this type of robustness. Yes, they are tweaking and hacking, but it was only because of a robust, remotely fixable design that let them do this.
Two wrongs don't make a right, but three lefts do.
Well, what do you expect? Making web-based quizzes is not rocket science. ;)
I cannot begin to comprehend an organism that can be so wrong in so many ways in such little space.
...American people need to vote this year, so their minds should not dwell on 500+ unnessacery deaths.
:
to take one sentence...
They should dwell on it, and their responsibilities as Citezens of the US. If the more than 200 million citezens, of the most powerful nation-state currently in existence, ever felt squeamish about the loss of 500 lives, there would be a LOT more wars, a lot more killing and a lot more misery. Or would you rather have Saddam still murdering and starving his people ?
There's so much trouble that could have easily been solved if that energy was put to more urgent matters
in short, my answer to your first sentence
The human condition is the need to explore.
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.
Here is a quote from the abstract of one of their papers:
Calling the almost insignificant distance between Earth and Mars "deep space" is like calling ankle-deep water at your local becah "deep ocean".
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