Slashdot Mirror
Spacecraft Crashes Into Satellite
Juha-Matti Laurio writes "A robotic NASA spacecraft designed to rendezvous with an orbiting satellite instead crashed into its target. Unbeknownst to engineers at the time, DART's main sensor mistakenly believed it was flying away from the satellite when it was actually moving 5 feet per second toward it, investigators found."
So that's where the minus sign should have gone, I knew I dropped it somewhere!
..., these figures can't be right!`
and an Obligatory Pratchett Quote:
Hex's pen was scratching across the paper.
Ponder glanced at the figures.
`
Ridcully grinned again. `You mean either the whole world has gone wrong or your machine is wrong?`
`Yes!`
`Then I'd imagine the answer is pretty easy, wouldn't you?` said Ridcully.
`Yes, it certainly is. Hex gets thoroughly tested every day` said Ponder Stibbons
`Good point, that man,` Said Ridcully.
B.
Every experiment which ends in a big bang is a good experiment.
Well, we answered that question. Mission accomplished!
Legalize recreational marijuana. Seriously.
it's a successfull hit, now let's build that missile defense system.
Well... Maybe they shouldn't have painted a giant bullseye on the side of the satellite.
DART: 50 points
NASA: -110 million dollars
"To surrender to ignorance and call it God has always been premature, and it remains premature today." -Isaac Asimov
No, but seriously, this is sad. It takes us farther away from what I'd like to see in a car, namely a self-steering one. I'd prefer one that detects an oncoming truck as oncoming and tries to get out of the way.
You are not entitled to your opinion. You are entitled to your informed opinion. -- Harlan Ellison
From Challenger:
"Engineers at Morton Thiokol (manufacturer of the solid rocket boosters) knew that the temperatures were outside of the design range of the O-rings. They strongly objected to the launch, but were overruled by senior Thiokol management."
From Columbia:
"In a risk-management scenario similar to the Challenger disaster, NASA management failed to recognize the relevance of engineering concerns for safety. Two examples of this were failure to honor engineer requests for imaging to inspect possible damage, and failure to respond to engineer requests about status of astronaut inspection of the left wing."
From DART:
"Investigators also raised issues with the mission's management style, saying that lack of training and experience caused the DART design team to shun expert advice. They also found that internal checks and balances were inadequate in uncovering the mission's shortcomings."
Not hampered by engineering degree, can tell difference between "toward" and "away from" - will work for same 6 figure salary previous position holder was receiving...
Take the 90-Day Challenge! http://rwmurker.bodybyvi.com/
Offical NASA writeup available here: http://patriot.net/~cary/slashdot/dart_mishap.html
e rview.pdf
Made from original PDF available here: http://www.nasa.gov/pdf/148072main_DART_mishap_ov
(I hate PDF's for simple text things like this)
--
NoFluffNews.com - Currently in development but seeking journalists and editors
In a subsequent news conference, DART claimed it did not remember hitting on the target after being spaced out on AMBIEN, a method it used to help it sleep(500s) before its launch from Kennedy Space Center. DART claimed that it got several bytes to eat before drinking a cup of Java and collecting its garbage. Upon introspection DART agreed that, despite its name, hitting on the target showed little Class despite the size of its Package.
...NASA has finally set aside a portion of its budget for the hiring of a trombone player to lighten the mood after each disasterous miscalculation with a well-timed "waaah WAAAAAAAAH."
I know it is fashionable to highlight the usual NASA-related budget cuts but a quote from TFA This to me sounds like an underfunded team rushing to meet deadlines. Or were they just simply unlucky/inept?
If this were really happening, what would you think?
Are you sure? Is that 5 feet per second or 5 metres per second?
Don't be apathetic. Procrastinate!
Same thing happened to me and the garage door when I was 14 years old backing my dad's Buick out of the driveway.
He didn't let me drive it again until I was 18.
As long as scientists and engineers are cogs in an organizational structure in which management tells them what to do, they will often produce crap, no matter how many PhDs there are in their midst. This is the case even when those managers were once brilliant technical engineers and scientists, because perceptions and priorities change when you switch into a management role.
This little episode was just another in a long line of screwups, and it won't be the last under current organizational models. Doing technical things can't be done properly unless insightful scientists and engineers are free of constraints on their insight, allowed to bypass the directional controls that management so loves, uninhibited from pointing our core problems in fear of their careers, and totally unshackled from the demands of time management.
Yes, I know that most managers would call this "anarchy", but therein lies the problem: by eliminating that alleged anarchy, you are also sacrificing the best that people can offer, just to make your life easier. Well, perhaps it's stating the blindingly obvious, but making management's life easy is not central to exploring the stars.
NASA's problem is the same one that permeates all technical industries, but in NASA's case the mishaps are just very public. I don't expect anything to change, but there is no doubting what the general problem is.
"The question of whether machines can think is no more interesting than [] whether submarines can swim" - Dijkstra
From the Feynman report:
It's not offtopic, dumbass. It's orthogonal.
Have *you* got $110 million in spare cash to throw at space research?
"Never attribute to malice that which can be attributed to stupidity." - Anonymous
This all happened on April 15 2005. A better write-up here: http://www.space.com/news/060516_dart_mishap_updat e.html. And here's the Wikipedia entry: http://en.wikipedia.org/wiki/DART_(spacecraft)
The satellite it crashed into was defunct. From Wikipedia: "The goal was to develop and demonstrate an automated navigation and rendezvous capability in a NASA spacecraft. Currently, only the Russian Space Agency and JAXA have autonomous space craft navigation.".
Interesting snippet: "NASA has said the official 70-page report will not be publicly released because it contains sensitive material protected by International Traffic in Arms Regulations (ITAR)".
This was planned as a "high-risk*, low-budget" mission and I'm sure they learned a lot. (* I suppose high-risk in terms of likelihood of meeting up with the target, not of collateral damage.)
Unfortunately, the faulty design was due to the screw ups of a private contractor, so there goes your "private sector" argument.
It's not offtopic, dumbass. It's orthogonal.
Snore. And out come the free enterprise loonies. The only trouble with your argument is that free enterprise is already perfectly able to indulge in space exploration and, well, hasn't. You can rent time on a launch pad, you can rent space in a rocket. There are many excellent engineering companies who can build more or less any satellite or other space craft you want. But there's no return on doing anything more ambitious than communications satellite. What exactly is the private sector going to do with a Mars probe, say? Sell ad hoardings on the side? (Didn't Beagle II do this?) It's better to regard what NASA and ESA do as a public infrastructure project rather than as competition for private enterprise. The work NASA is doing (mostly competently) is more like building the channel tunnel than a profit-based business. We tried building the tunnel through the private sector, but Eurotunnel has been bailed out by the giovernment and the banks so many times that it's actually ended up costing us far more than it would have done if we'd done it the old fashioned way, even assuming the usual obscene project over-run costs of a public project.
Low-budget
Assembly
Without
Navigaion...
With no structure, they would never convince congress to give them any money. It's good when unstructured research happens, but structured, result-oriented research is always going to be ablt to get more funding.
NASA is clearly poorly managed, but it seems to me that the solution is good management, not no management at all. Of course, I have no idea how to actually implement good management.
Nerd rage is the funniest rage.
But since it was a $110 million project anyway, couldn't the software have been tested in simulation first?
I understand the article says:
"Unbeknownst to engineers at the time, DART's main sensor mistakenly believed it was flying away from the satellite when it was actually moving 5 feet per second toward it, investigators found."
1. Is this just sloppy writing blaming a piece of hardware for a software problem?
2. If the sensor contained significant logic, would it have been that hard to test whether it correctly registered retreat and advancement?
3. Or an interface screwup between the main program and the sensor logic like confusing yards and meters? (And no test of the complete system?)
In any case it might well demonstrate the results when you shoot something up and see what happens without development adequate to the complexity.
One big difference is that Progress needs guidance beacons on the ISS, DART is supposed to be self-contained, able to dock using only it's own sensors.
Sort of true. The real issue is that the return on investment is: A) long-term and B) not easy to monopolize. Without the Apollo program, our computers might still be room-sized behemoths. Unfortunately, corporate America is not interested in any return on investment that is going to take more than a few quarters to be realized. And if the benefits of basic research also accrue to a companies' competitors, the company is unlikely to fund the research.
Censorship is telling a man he can't have a steak just because a baby can't chew it. --Mark Twain
Anyway, on a big scary program, here's how these sorts of problems are spotted :
Step #3 is about as important as step #1, because you absolutely cannot fix every problem. There's neither the time, nor the money.
Something else to keep in mind : if I spotted a problem that would surely doom my project, and can't get engineering leadership/management to agree with me, I should share some of the blame.
And yes, I had the box checked so it would be considered for posting.
It's a curse being ahead of the curve.
We will bankrupt ourselves in the vain search for absolute security. -- Dwight D. Eisenhower
Yes, Yawn. I'm all for the X-Prize and private endeavors into spaceflight, but really, what's been acomplished? They are decades behind. Last I heard, Space Ship One barely managed to reach a sub-orbital altitude and return safely. This is comporable to what the X-15 did in 1960 and is so far removed from the complexety of a single shuttle mission (not to mention Apollo) that it's totally outragous to think the private sector is somehow doing better because they didn't screw it up.. Actually, they did screw it up, just not enough to kill anyone. Besides Rutan, everyone else is still doing test fire's or has had their unmanned rocket explode on the launch pad. It will be a long while before they can reach orbit relatively safely and repeatadly. Will they make less mistakes on their way there? No but that's ok because space is really hard. Meanwhile, NASA has contributed an enourmous amount to planatary scinece and space exploration in the past decades despite seemingly wary public support and a dimished budget. It really is amazing what they've accomplished. Their paradigm has been rightly adjusted to focus on science and exploration. They pursue one of the noblest of human endeavors (and if you don't understand why science and understanding the universe is noble, well..) and in my mind are pretty detached from political and corporate bullshit and burracracy. To bad some of you don't want to pay attention.
If you think Boeing, Raytheon, and Lockheed are merely private contractors, you've not been paying attention. They are as integrated into the current system as they can be while still retaining the title of "corporation". This is part of what Eisenhower was warning us about - when the private sector controls and influences the public sector in an industry, they become intermingled in ways that do not inspire greatness. And it becomes dangerous for the autonomy of the state from private control.
NASA, while purportedly a civilian agency, is obviously tremendously influenced by not only the military but also those private contractors. It's pretty amazing that Scaled Composited was able to even get a bid in on the recent manned capsule designs - and they almost didn't. Notice that their proposal wasn't accepted, though. Whether it wasn't as good (doubtful) or whether there are other barriers to entry (probable) is up for debate.
***
In DART's case, the MIB determined that the first cause for its premature retirement occurred when the estimated and measured positions differed to such a degree that the software executed a computational "reset." By design, this reset caused DART to discard its estimated position and speed and restart those estimates using measurements from the primary GPS receiver.
Careful examination of the software code revealed that upon reset, the velocity measurement from the primary GPS receiver was introduced back into the software's calculations of the spacecraft's estimated position and speed. If the measured velocity had been sufficiently accurate, the calculations would have converged and resulted in correct navigational solutions. However, DART's primary GPS receiver consistently produced a measured velocity that was offset or "biased" about 0.6 meters per second from what it should have been. This had the unfortunate effect of causing the calculations, which were being performed autonomously, to once again diverge until the difference became unacceptable to the pre-programmed computer logic. Once the limit as to how much the calculations could differ was reached, the software executed another reset. As a result, this cycle of diverging calculations followed by a software reset occurred about once every three minutes throughout the mission. These continual resets caused the incorrect navigational data that prompted excessive thruster firings and the higher than expected fuel usage.
Too many pre-programmed resets to the wrong data. Oops. I guess one small thing can cause a whole mission to fail! If you read the report though the rest of the mission was pretty succesful. You would have though they would build in some sort of fail safe ground control method though when there's millions of dollars worth of equipment at stake?
There are a lot of posts concerning NASA, management, the Military-Industrial complex. As someone who has watched the decay of spacecraft operations, I can confidently tell you that much of it has to do with contracting and paychecks.
Quick review: Spacecraft programs contain a number of stages, e.g. design, integration and test, launch, etc. The last stage is Operations. There used to be a day when all stages were properly funded and for Operations, this meant 24/7 console staffing, dynamic simulators, on-site engineers, spacecraft design manuals and lots of legitimate training.
But here's the problem. Prior to the mid 90s, NASA and other agencies used cost plus contracting, and the big contractors settled into a mode where the initial mission budget would be exhausted by about launch minus 1 or 2 years. This is when they would run back to the government organization and ask for more money and after some hand-wringing more money was allocated. Then all of a sudden - poof it's gone. Fixed cost contracting had arrived.
The problem, the big gorilla contractors only know one way to build a spacecraft and as no one likes to change, both contractors and NASA started coming up with inventive ways to defund Operation so they come in close to budget. Buzz-words like "automation" and "lights out operations" reduced console staffing to only the day shift. On-site engineers are never hired - instead "factory" design engineers are dug up IF there is a problem. Without on-site engineering, there's no need for good spacraft docs and simulators and no one to construct legitimate practice exercises. Combine this with upper management's desire to meet schedule, the already rounded corners are shaved even more.
Once formal Operations had evaporated, launch and early orbit was solely in the hands of design engineers, who are not Operations engineers. There's a different mindset between the two. There used to be a day when operation screw ups could be avoided and design flaws caught in advance through legitimate simulation, but that's gone now. Why? NO ONE PAYS FOR IT ANYMORE!
I disagree categorically with the perception that leaving technical people unfettered by management or time pressure will result in better designs, products or concepts. After RTFA, one notes that one reason provided for the failure is that the teams disregarded expert input - a characteristic that I have witnessed time and again within groups of bright technical people. Call it an adjunct of NIH - not invented here.
Another example is the cowboy coder, writing without specifications or testing. For some development methodologies, this may be an efficient way to rapidly prototype a UI or system, but for the most part it generates sh*t for quality. But, it's fun.
Every technical person would love to work in a Xerox- or Bell Labs-style environment of pure research with a virtually unlimited budget. Very innovative ideas are bred from such environments, but they rarely produce market-ready concepts. I think you need to differentiate between science and engineering, and pure research vs. development. NASA is both a research and a development organization. Engineering is all about trade-offs between time, budgetary and technical constraints. Science is about uncovering new knowledge. Science in the absence of constraints is marvelous. Engineering in the absence of constraints and experience is a disaster. Ask any contractor.
The mission failed due to poor engineering and a lack of oversight (no process to detect and correct technical errors). The only way humans can deal with such issues is through management and process. It sucks, but it's all we have.
They must have been using metric feet per second.
The ______ Agenda
Damage depends on the speed *and mass* of the robot, doesn't it?
Try driving your car into a fire hydrant at 3.4 mph and see what that does to the bumper...
c) It was older and had better insurance.
Intron: the portion of DNA which expresses nothing useful.
It has lived up to its name, DART.
'm not faulting the engineers. I'm just saying that if these predicted problems were really as some people painted them (inevitable), then engineers would surely share some of the blame for not communicating properly if it was not fixed.
Engineer: "Don't point the gun at that clown and pull the trigger, because he will die."
Manager: "Don't be absurd, there is a chance I may not even hit him."
Engineer: "Don't point the gun at that clown and pull the trigger, because he will die."
Manager: "Thank you for your analysis of the situation. I've determined that the risk is worth the reward."
The engineer is to blame, how exactly? Managers go against the judgment of Those In The Know all the time, even effectively communicated. If the engineer says "We can't launch, the rocket will explode because of A and B and C, not to mention Z," and the manager decides to push ahead with the launch anyway, how did the engineer not effectively communicate this? You cannot lay blame on someone for someone else's stupidity or willful ignorance.
Sometimes, sure, an engineer may downplay a problem. THAT is something he can surely be blamed for. I was taking exception to your blanket statement where you said that if a project has inevitable problems and is pushed ahead anyway, that the engineers must share the blame (supposedly because Managers never go against advice given to them).