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NASA Finds, Fixes Small Glitch in LADEE Moon Probe

timothy posted about a year ago | from the now-for-some-space-mining-action dept.

Moon 44

Friday's moon-bound NASA launch from Wallops Island went well, but, says NBC News, "[H]ours after the 11:27 p.m. EDT (0327 GMT) liftoff, NASA officials reported that the spacecraft's reaction wheels — which spin to position and stabilize LADEE in space without using precious thruster fuel — unexpectedly shut down. By Saturday afternoon, the glitch had been traced to safety limits programmed into LADEE before launch to protect the reaction wheel system, NASA officials said. Those fault protection limits caused LADEE to switch off its reaction wheels shortly after powering them up, according to a mission status update. Engineers have since disabled the safety limits causing the glitch and taking extra care in restoring the fault-protection protocols."

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All I can think of... (0, Funny)

Anonymous Coward | about a year ago | (#44786645)

is Jerry Lewis.
“hello nice LADEE!"

wheels... (3, Funny)

Longjmp (632577) | about a year ago | (#44786777)

Maybe NASA are rocket scientists, but it seems they still have trouble getting wheels going [wikipedia.org]
;-)

Re:wheels... (3, Interesting)

confused one (671304) | about a year ago | (#44786853)

ok, here's a challenge for you... design a flywheel based guidance system. make it redundant. make it work in the most inhospitable environment known to man -- space. hard vacuum. reactive ions (free ionic oxygen). radiation. operating temperature range -200 degF to 200 degF. The only cooling option for your motors and electronics is via a liquid loop and a large radiator. power is limited to a few tens of watts from a solar panel. You have to design it so it works for a decade without maintenance or repairs. good luck.

Hear that "WHOOOOSHING" sound? (1)

Anonymous Coward | about a year ago | (#44786913)

Hear that "WHOOOOSHING" sound? It's a joke flying right over your head.

In space ... (2)

PPH (736903) | about a year ago | (#44787647)

... no one can hear your jokes WHOOOOSH.

Re:Hear that "WHOOOOSHING" sound? (0)

Anonymous Coward | about a year ago | (#44789273)

He is "confused one", give him a break.

Re:wheels... (2)

jonfr (888673) | about a year ago | (#44786979)

We use kelvin in space. Not old and outdated Fahrenheit.

About Kelvin, http://en.wikipedia.org/wiki/Kelvin [wikipedia.org]

Based on the moon, the space temperature is around 120K (-153C) in our solar system this close to the sun on the dark side.

Temperature on the moon, http://www.space.com/18175-moon-temperature.html [space.com]

Re:wheels... (3, Insightful)

confused one (671304) | about a year ago | (#44787091)

I work for a sensor company. If you want Kelvin, then I'll use Kelvin. I don't really care if it's Celsius, Rankine, or frequency of cricket chirps. Our environmental chambers happen to be set up in Fahrenheit, because our production staff is comfortable with those units; and I used degF because it's what the U.S. centric audience would know. You might be surprised to know that in the real world, people might not use the scale you expect them to, even if it's a standard.

Re:wheels... (2)

Longjmp (632577) | about a year ago | (#44787141)

Our environmental chambers happen to be set up in Fahrenheit, because our production staff is comfortable with those units;

I assume some people involved in this [wikipedia.org] were also very comfortable with their units.

Re:wheels... (1)

confused one (671304) | about a year ago | (#44787209)

someone forgot to do the conversions before sending data to the customer.

Re:wheels... (0)

Anonymous Coward | about a year ago | (#44787799)

People on the internet would have had no where to turn if it crashed due to entering grams in a filed that expected kilograms, as I've seen happen in a lab environment before, instead of being an imperial versus metric issue.

Re:wheels... (1)

Anonymous Coward | about a year ago | (#44787155)

Good point. You do what you need to do to get the job done. Many people forget that we used Fortran to get Apollo 11 to the moon, rather than the government "standard" of Algol 60.

Re:wheels... (0)

Anonymous Coward | about a year ago | (#44787247)

brainfuck or nothing!!!

Re:wheels... (0)

Anonymous Coward | about a year ago | (#44787363)

Can I get it in fires of a thousand suns?

Re:wheels... (2)

confused one (671304) | about a year ago | (#44789095)

I don't have that conversion factor in my books; however, if you are willing to provide me with the information, then YES, I'd be happy to calibrate your sensors in units of "fires of a thousand suns".

Re:wheels... (0)

Anonymous Coward | about a year ago | (#44791045)

You could ask for the temperature in keV or MeV which get used plenty by astrophysicists and plasma physicists...

Re:wheels... (0)

Anonymous Coward | about a year ago | (#44787563)

and I used degF because it's what the U.S. centric audience would know.

You forgot us Europeans, you insensitive clod!

Re:wheels... (1, Interesting)

Nivag064 (904744) | about a year ago | (#44787913)

Most of the world uses Celsius (for science, Kelvin is okay) - isn't it about time the USA caught up?

I learnt MKSA (metric) units primarily from an American Physics textbook almost 50 years ago when I was at high school. I was brought up using the Imperial system - being in the England until I arrived in NZ when I was 12.

The metric system is so much easier to use, why are Americans so backward???

Re:wheels... (1)

confused one (671304) | about a year ago | (#44789121)

We're stubborn. We (as a country) started out as groups of outcasts, explorers and adventurers. When the King got carried away with taxation, we made ourselves into a country full of outcasts, fighting to separate ourselves from the British Empire, and then separated the western parts of the country from the Spain and Mexico. We tend to do things our own way and ignore the suggestions of others. Sometimes we even fight among ourselves... It's just the way we are.

Re: wheels... (0)

Anonymous Coward | about a year ago | (#44789311)

time for Americans to catch up? We're still waiting for ONE of you lamers to set foot on the moon, and voyagers have so much of a head start i submit we'll be using #-ft. for another hundred years. American engineers, (unlike the average slashdot trolls) are quite well versed in unit conversions. Unlike our European counterparts,, who whine like a bitch if they have to do anything more than move a decimal point. Go fuck you metric, or SI or whatever the dirty socialist french call it nowdays, we're trying to get some work done.
assholes.

Re: wheels... (0)

Anonymous Coward | about a year ago | (#44790803)

We used metric to get to the moon. Imperial units are based on some Queens foot size, and even the country that invented them (Britain) are starting to move towards using both, if not just metric.

Re:wheels... (1)

Anonymous Coward | about a year ago | (#44787121)

The question of the temperature in space is sort of silly. Maybe someone can pin a number down and maybe not. But the real question is heat transfer and the equilibrium point. There is no conduction or convection, so only radiative heat transfer works. If you are facing the Sun you are going to get a shitload of incoming radiative heat transfer and if you aren't then you are going to emit like a black body (unless you also get reflected light).

This is why a comparison with the Moon isn't valid. Conduction works on the Moon and it has cycles of hot and cold except in certain places like craters, which were found to be about 25-50 K. So is the temperature of space 25-50 K near the Moon? No again. It is more complex than that. Temperature isn't a particularly useful concept when describing space to laymen because the traditional analogues don't apply. Space can appear very hot or very cold, when it is simply the management of radiation that is causing the heat transfer.

Re:wheels... (1)

mcgrew (92797) | about a year ago | (#44790325)

We use kelvin in space. Not old and outdated Fahrenheit.

In space, Kelvin makes the most sense. Celsius logical, but a degree C is too broad a measurement and .1C is too fine for air temperature. Fahrenheit was obviously designed for air temperature measurement. Zero is damned cold, a hundred is damned hot, and a degree F is about the smallest temperature change skin can sense.

For cooking and chemistry Celsius makes the most sense. Different scales for different purposes.

Re:wheels... (0)

Anonymous Coward | about a year ago | (#44787181)

From what I hear, 3D printing solves all that with just a hand gesture over a holographic display.

Re:wheels... (0)

Anonymous Coward | about a year ago | (#44787233)

For flywheel-based systems, some of the aspects of space you offer as bad things are actually good. Hard vacuum - no frictional drag losses, no pesky rotor aerodynamics. Reactive ions - none inside the flywheel assembly, basically nothing that doesn't have a line of sight to the black sees the ionic environment because the ions collide/recombine/react with the intervening surfaces. Anyway, atomic oxygen isn't a problem beyond the near Earth environment. Power and associated thermal - could be problematic, but momentum wheels (the flywheels whereof you speak) don't dissipate much power, since high slew rates aren't needed in science vehicles. Military missions are a different story, but they use non-flywheel attitude control and divert actuators. And the biggest plus of the space environment is zero-G: no gravitational loads that have to be resolved at the flywheel bearings. Way lower bearing wear rates. No gravity-induced lubricant drift.

I don't think the space environment is a harder design problem, it's just different. When you learn the differences, it's about as hard as designing reliable, long-lived machines for use on Earth. I'll give you the weight issues, though. It's a bitch to lightweight everything.

Re:wheels... (1)

Tablizer (95088) | about a year ago | (#44787997)

"Dammit Jim! Imma rocket scientist, NOT a wheel scientist."

Well (0)

Anonymous Coward | about a year ago | (#44786823)

Better SAFE than sorry

Directed Crash? (1)

wrackspurt (3028771) | about a year ago | (#44787073)

LADEE [bbc.co.uk] will end its mission by crashing into the Moon.

Will the crash site be chosen in some hope of finding ice on the moon? Finding ice on the moon is crucial to a moon base isn't it? There's been no mention whether searching for signs of ice is part of LADEE's mission.

Re:Directed Crash? (1)

Longjmp (632577) | about a year ago | (#44787245)

LADEEs main missions are to examine the moon's atmosphere (or rather if there is any), along with gathering information about particle impacts (for further moon missions) and generally moon's surface
The final crash is collateral damage (okok, they'll watch dust rising from that impact closely too)

Re:Directed Crash? (0)

Anonymous Coward | about a year ago | (#44787613)

along with gathering information about particle impacts

So that's what ballistics tests are called now?

Last words... (2)

Gothmolly (148874) | about a year ago | (#44787149)

You arrogant ass, you've killed us!

Re:Last words... (1)

sumdumass (711423) | about a year ago | (#44787863)

I thought it was "what does this button do?"

Re:Last words... (1)

tocs (866673) | about a year ago | (#44790355)

No no ... it is "Watch this..."

SEE (1)

Revek (133289) | about a year ago | (#44787199)

Aren't they useful.

Switched them off because of a silly safety limit? (3, Funny)

osu-neko (2604) | about a year ago | (#44787223)

Jeb would never do that. Jeb has no limits.

Re:Switched them off because of a silly safety lim (1)

DerekLyons (302214) | about a year ago | (#44787811)

Hah! Another kerbalnaut - we're everywhere!

Re:Switched them off because of a silly safety lim (0)

Anonymous Coward | about a year ago | (#44788581)

Hah! Another kerbalnaut - we're everywhere!

Of course we are, you've seen the kind of impacts we go through...

sounds like torque-tach mismatch fault detector (1)

decsnake (6658) | about a year ago | (#44787249)

the ought to know better than to have that enabled at launch. You need to characterize the wheels on orbit and be sure that the limits are good before you turn that one on.

about the nice LADEE! (2)

Gravis Zero (934156) | about a year ago | (#44787299)

hello nice LADEE! http://www.space.com/22639-moon-dust-mystery-nasa-spacecraft.html [space.com]

The Lunar Atmosphere and Dust Environment Explorer (LADEE) spacecraft is expected to investigate lunar dust and the moon's extremely thin atmosphere once the craft makes it into orbit around Earth's closest celestial neighbor about 30 days after launch.

that's right, the moon has an atmosphere [space.com] kinda. it's technically an exosphere. [wikipedia.org]

In the moon's atmosphere, there are only 100 molecules per cubic centimeter. In comparison, Earth's atmosphere at sea level has about 100 billion billion molecules per cubic centimeter. The total mass of these gases is about 55,000 pounds (25,000 kilograms), about the same weight as a loaded dump truck.

before you ask, neither LADEE nor the internet is a big truck.

what they aren't telling you is that the NSA is coercing NASA to ***CARRIER LOST***

Just like Star Trek... (3, Funny)

prisoner-of-enigma (535770) | about a year ago | (#44787373)

Every time they had an insurmountable engineering problem, the Chief Engineer just says "override the safeties" and everything is fine. Good to know NASA is finally catching up to The Final Frontier!

Re:Just like Star Trek... (0)

Anonymous Coward | about a year ago | (#44788893)

Chief Engineer just says "override the safeties" and everything is fine.

Didn't theu usually reverse polarity of something?

Moon Aerosmith (0)

Anonymous Coward | about a year ago | (#44787721)

Moon, looks like a LADEE ...

More crappy Ball Aerospace reactions wheels? (1)

brillow (917507) | about a year ago | (#44790833)

I hope these aren't from the same company that built the crappy wheels on Kepler. Ball should stick with the mason jars.

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