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."

Comments

No thanks

[Anonymous Coward]

I am waiting for Build your own space mission For Dummies to come to my local B&N.

JPL

[miketo]

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.

Re:JPL

[rk]

Erm, JPL is part of NASA. Caltech manages JPL, and therefore a part of Caltech, but it's also as much a part of NASA as KSC, JSC, or any of the other NASA facilities.

so close!

[fjordboy]

From the Primer:

The BSF is intended to be used online via the worldwide web (http://www.jpl.nasa.gov/basics). There are interactive quizzes to let you check your own progress; no records are kept. No academic credit is offered for completion.

Bummer...just when I thought I could get academic credit for cruising the web...

Tweaking, JPL Style

[lpangelrob2]

And in the animation section...

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...

Re:Tweaking, JPL Style

[enosys]

I haven't had to deal with this issue since Wing Commander. I would have thought JPL would be capable of making software that plays animations at the same speed on all computers that are fast enough for it.

Then again if they forget to handle filesystem full errors on Mars rovers who knows... ;)

Warning

[savagedome]

They forgot the statutory warning.

DO NOT attempt this at home

Nice to see.

[Anonymous Coward]

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.

Re:Its Mind Boggling

[morcheeba]

Would you really want them back?

The objective of these missions is to learn more about mars.. if we were just interplanetary joyriding, then, yes, I'd want the rover back -- but that's not the case here.

Besides, the rovers are only a small portion of the cost of the mission - even if we could magically get these back for free, it would be worth the effort to build new rovers that incorporate the things learned on previous missions and provide new and different capabilities.

How it should have started...

[el-spectre]

"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

Long-feedback cycles and good design

[G4from128k]

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.

Re:Long-feedback cycles and good design

[steveha]

You are absolutely right -- for the current way we do space.

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:Long-feedback cycles and good design

[iggymanz]

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. Since you used example of missile, there is NO WAY to model the turbulence, forces, torques, etc. involved with a real missile in flight, though we are getting better at approximating them. Any missile design will have many man-years of "twiddling, tweaking, and hacking" in the evolution of its design.

To use an even simpler exmple, what if one burns 2.00000 moles of hydrogn and 1.00000 moles of oxygen, how much water is produced? If you answer that question based on what you learned in freshman chemistry you'd be wrong. In the real world, reactions never go to 100%, reagents aren't pure, and other chemicals besides water (like hydrogen peroxide) would be produced. And the ONLY way to know how much water would be produced under given conditions would be to actually do it. And then, you'd find for repeated experiments the amount wouldn't quite be the same!

And finally, I'd point out that when systems fail aboard a Mars rover, they're very much back the realm of hacking, tweaking and fiddling.

Re:Its Mind Boggling

[Anonymous Coward]

If you think the cost is mind boggling, you haven't seen what it would cost to if they were designed to return to earth when they were done.

Misleading title...

[pla]

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.

Re:how the communications are handled

[red floyd]

Doesn't work. The vibrational impulse is passed through the medium in the tube. This impulse goes slower than light.

Deep Space?

[glrotate]

Is Mars Deep Space? Shouldn't that term at least be reserved for regions outside the solar system? Or is that "Outer Space"?

Re:Deep Space?

[Detritus]

Most NASA satellites are in low-Earth orbit. Some are in geosynchronous orbit, like TDRSS. Some, like satellites that study the solar wind, are in unusual orbits that take them far away from the Earth. JPL handles the satellites that leave the vicinity of the Earth and the Moon.

NASA's satellite tracking and communication systems are adequate for spacecraft in the vicinity of the Earth and the Moon. They are not good enough to handle spacecraft at larger distances. That is why JPL's DSN (Deep Space Network) has much larger antennas, super low-noise preamps, and higher performance receivers and transmitters. Their systems are designed and optimized to work with very weak signals.

The difference between near space and deep space is more a matter of operating conditions than of geography.

Re:how the communications are handled

[nathanliesch]

your ping pong ball example is essentially how a electrical wire works. The electrons don't actually travel the length of the wire, they just "push" the ones next to them. Yet this is still limited by the drift velocity of electrons which is slower than the speed of light.
I think the only way to do speed up the conversation would be quantum entaglement but that's not been done outside the laboratory.

Re: communications: Interplantary Internet

[G4from128k]

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.

Re:how the communications are handled

[Shut the fuck up!]

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

why that won't work

Re:how the communications are handled

[Shut the fuck up!]

Gravitational effects travel at the speed of light. Here is a decent explanation

The now defunct Breakthrough Propulsion Project

[Pausanias]

Some of us like solar system exploration just fine, but already have our imaginations fixed on what it would take to get to the other stars. Rocks from Mars may be exciting, but getting to Alpha Centauri would be even more exciting, to say the least.

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:

To travel to our neighboring stars as practically as envisioned by science fiction, breakthroughs in science are required. One of these breakthroughs is to discover a self-contained means of propulsion that requires no propellant. To chart a path toward such a discovery, seven hypothetical space drives are presented to illustrate the specific unsolved challenges and associated research objectives toward this ambition. One research objective is to discover a means to asymmetrically interact with the electromagnetic fluctuations of the vacuum. Another is to develop a physics that describes inertia, gravity, or the properties of spacetime as a function of electromagnetics that leads to using electromagnetic technology for inducing propulsive forces. Another is to determine if negative mass exists or if its properties can be synthesized. An alternative approach that covers the possibility that negative mass might not exist is to develop a formalism of Mach's Principle or reformulate ether concepts to lay a foundation for addressing reaction forces and conservation of momentum with space drives.