First Exotic Space Thruster Test Ends in Explosion

KentuckyFC writes "A NASA-funded test of an entirely new way to control orbiting satellites has ended with the prototype arcing dangerously and parts of the machine exploding. The new propulsion system is based on the Lorentz force: that a charged particle moving through a magnetic field experiences a force perpendicular to both its velocity and the field. So the plan is to ensure that a satellite passing though the Earth's magnetic field is electrically charged so as to generate a force that can be used to steer the spacecraft. The advantage of the idea is that it requires no propellant, which is a big deal since most satellites' lifespans are limited by the amount of fuel they can carry. But the first ground-based tests haven't gone entirely to plan."

I hope

parts of the machine exploding.

But the first ground-based tests haven't gone entirely to plan."

Good thing they told us that... I was beginning to lose faith in their work.

Explosions are an indicator of work

The best projects usually have a development report buried somewhere in their history that contains the phrase, "...and then it exploded."

Percy Spencer (microwave oven): "...and then the egg exploded."
James Watt (steam engine): "...and then the boiler exploded."
Alfred Nobel (dynamite): "...and then the nitroglycerin-soaked soil exploded."
Vladmir Titov (Russian cosmonaut): "...and then the Soyuz rocket exploded."
Werner von Braun (NASA engineer): "...and then the Jupiter rocket exploded."
Yang Liwei (Chinese Taikonaut): "...and then the Long March rocket exploded."
Sony test engineer: "...and then the battery exploded."
J. Robert Openheimer: "...and then the Trinity device exploded"...oh wait, that was supposed to happen.

A more personal anecdote:
Someone in the shop at work needed a simple room-temperature dryer for a special project, so he got some large diameter PVC pipe that was handy, filled it with a desiccant, put the material in that needed drying, and screwed the cap on. Then he left it alone for a few hours.

Apparently some sort of gas-producing chemical reaction took place, probably helped by the sun shining through the open door, (...wait for it...) and then the drying chamber exploded, blasting the plastic lid through the ceiling 25 feet overhead and covering the work bay with the tiny pellets of desiccant.

Engineering is fun.

Heh

From TFA: And as long as nobody gets hurt, a decent explosion livens up any experiment.

I'm pretty certain this is how Mythbusters got started.

Also from TFA: Obviously, a proplusion system that explodes while it is in operation needs some more work.

I dunno, kinda sounds like how rockets work.

Re:Heh

And not to mention the ill fated plan to detonate nuclear bombs behind a space craft as a method of propulsion...

(Orion programme if my memory isn't failing)

(On that point when will which ever god or other deity is responsible for our design fix the bloody faulty memory unit and start using error correcting cells?)

Re:Heh

It's a valid method...just not inside the atmosphere.

It's Rocket Science

Also from TFA: Obviously, a proplusion system that explodes while it is in operation needs some more work.

I dunno, kinda sounds like how rockets work.

Sure, you got the basic points all right. Now, let's see some advanced stuff:

It should go like this [youtube.com]

NOT like this [youtube.com].

Re:It's Rocket Science

You certainly get bonus points for irony using an Ariane 5 as an example of a rocket not blowing up...

Re:It's Rocket Science

From Wikipedia [wikipedia.org]:

As with many rockets, the initial flights of each new Ariane model have seen failures. However, overall, the Ariane 4 and 5 are the most reliable commercial rockets ever launched. As of January 2006, 169 Ariane flights have boosted 290 satellites, successfully placing 271 of them on orbit (223 main passengers and 48 auxiliary passengers) for a total mass of 575 000 kg successfully delivered on orbit. This success rate also makes Arianespace the foremost commercial launcher; in some years, more than two thirds of all commercial satellites have been launched with the company's vehicles.

Good for them

I'm actually glad to see NASA doing stuff that might not work. It seems that a lot of the space work thats been happening in the last decade or two has been stuff that we know we can do. There are still failures, but those tend to be metric vs imperial units issues, not because they're pushing forward in to new areas.

All new technology generates it's share of failures along the way. In the early days NASA blew up a lot of rockets in the process of learning to get them in to space. As long as we're using it on unmanned craft (or on the bench), a decent rate of failures is alright by me if they're learning something from them.

Re:Good for them

Goddard started out the same way...

Re:Good for them

As long as we're using it on unmanned craft (or on the bench), a decent rate of failures is alright by me if they're learning something from them.

I'd have to say that mindset is the #1 reason why I like science so much. Even in failure there's so much to learn from it.

So I'm glad I got burned think of all the things we learned
For the people who are still alive

Dirty

I'd be concerned if I tested my exotic thruster and it didn't end in an explosion.

Re:Dirty

"She" has an exotic thruster? o_O

Doesn't seem like a significant setback.

Here is the story, based on my admittedly non-expert reading: To use the (very exciting) Lorentz steering technology, the sattelite has to have an electric charge. The method they used to obtain the charge is to apply a voltage to a radioactive substance and then allow solar wind to carry away the positive charge, leaving the sattelite negatively charged. The problem seemed to be that this process caused sparks to arc across the sattelite, which in turn damaged electronics and dislodged soldering.

I'm not sure why this is a big deal. Couldn't they just use a different kind of solder, or at least insulate vulnerable electronics from the charge?

Re:Doesn't seem like a significant setback.

That's what I was working on figuring out, from the wording of the article ("explosion") it made it sound like a big deal, like when a rocket launch goes bad. (see various youtube links in this thread)

But when I got to reading, they use the word "explosion" for solder. Solder is not big. It's not like a fuel tank went up - this is a little bit of electronics. That sounds like a smaller explosion than you get with your average match when you strike it.

That's like talking about buildings and saying there was a "collapse", and if you RTFA close enough you find what they're actually referring to is the water glass on the table in the lounge tipped over.

Honest perhaps, but definitely deceptive.

Need more coffee

My brain initially processed the title as, "First Erotic Space Thruster Test Ends in Explosion". Needless to say I was very disappointed when I read the summary.

best to discover flaws early

You should watch videos of our first satellite attempts. I'm surprised we didnt have more fried astronauts.

Jazzing up the story a bit

As much as we all like a good explosion, that summary seems highly misleading. From the abstract:

Microscopic arcing was observed at voltages as low as -300 V. This arcing caused solder to explode off of the object. Insulating the object allowed the charge to remain on the object longer, while in the plasma, and also eliminated the arcing. However, this insulation does not allow a net charge to reside on the surface of the spacecraft.

"Caused solder to explode off the object" hardly sounds like much of an explosion.

Re:Jazzing up the story a bit

Oh sure, it doesn't sound that impressive until you realize the entire craft was covered in a 2-foot layer of solder.

Re:Jazzing up the story a bit

When you play back the high-speed camera footage taken through a microscope on a 100" screen...

Oh, nevermind... Even then it's probably not a very impressive explosion.

It bothers me that the editors here simultaneously push the "we don't invest enough in space research" platform, and fall into the "journalistic" trap of sensationalizing NASA's failures to make their readers feel "smarter than those rocket scientist guys".

I have every expectation that the readers and comment writers on Slashdot have vastly differing opinions on the subject, but you'd think that the clearly biased editorial staff here could get their story straight.

Redefining your way to success!

A NASA-funded test of an entirely new way to explode orbiting satellites has ended with promising success!

Another variant also had problems.

Another variant of this is to have two weights connected by a wire tether and tide-locked to the primary, so the wire is oriented at roughly right angles to the orbit. Then you put a current in the wire by ejecting electrons on one end and collecting them at the other - making it into a motor that can accelerate or decelerate along the orbit. No reaction mass, run it off the solar collectors, etc. This also ran into issues with arcing.

They tried an experiment on this with the shuttle and a tether to a satellite they were launching, and found a problem: The motion along the orbit also causes it to act like a generator, powered by the orbital momentum. (This was known - and also has possible uses.) This produces a voltage gradient along the wire tether. So the tether has to be insulated to prevent arcing to the very low-pressure plasma that constitutes the high atmosphere and solar wind.

What they discovered was that minute flaws in the insulation caused localized arcs to the surrounding plasma. These were powered by the orbital motion relative to the earth's field and were very intense. They quickly melted through the thin tether.

So such a motor is not an impossibility. But it will require some heavy engineering work to get around this problem.

(It also says that large-scale tethered orbital structures have an additional problem to be solved: Keeping the tethers intact despite kilovolts of induced voltage along the tether and the resulting arcing.)

It's easy to think of space as filled with a hard vacuum. Unfortunately it's actually filled with very low pressure conductive plasma and near the Earth that's dense enough to be a major engineering issue.

dependant on earth's magnetic field?

Will this screw up when the earths field begins fluctuating when poles being going into reversal again?

Mind you, when this begins, I suspect the last thing we would be worried about if/when this comes would be the odd satellite crashing back to earth.

They should have expected it.

This is how sputtering in a vacuum chamber is done, for manufacturing chips and coating surfaces. The company I work for builds power supplies for these vacuum chambers, and they generally require some arc handling circuitry. Here's [advanced-energy.com] a white paper on arcing.

If you have a negatively charged target in a plasma the target will attract positive ions which will knock bits off of the target if they arrive with sufficient velocity, otherwise they'll stick and neutralize the charge. In a sputtering chamber we want those bits knocked off. If we're sputtering something non-metallic we need to use RF to keep it charged.

The only failed test...

...is the one you don't learn anything from.

GO NASA!