I think you are nitpicking the definition of "available". Yes, the fuel existed at the time, that doesn't mean the fuel was available for this mission. A high risk, relatively low reward, limited life lander almost certainly doesn't merit using 1/10th of the available reserves.

Don't think it was high risk? The lander failed in multiple different ways on deployment and was able to do science by little more than dumb luck (not discounting their success, dumb luck plays in important part in everything and it was their engineering and planning that allowed the landing to succeed despite those issues). Don't think it was low reward? Most of the science the lander was designed for was completed on batteries during the 60 hour window after landing. Don't think it's limited life? In a few months, the comet is going to start out gassing and the lander will almost certainly be disabled.

If Pu-238 were still in production the math works out differently. If the lander had been a more central part of the mission it might be different. If the comet were on it's way out of the system instead of in that could change things too (though then Rosetta would also need an RTG). The point is: it's not binary. It's not "the fuel is right there lets use it". There's a cost, and a benefit to using it in this probe rather than the next one.

If the rocket blew up in atmosphere you would have had to recover the still solid, single piece RTG core. Not only is the total amount of nuclear fuel relatively small, the cores are also designed to survive catastrophic rocket failure intact. RTGs flew on Apollo 12 through 17, the Curiosity rover, nearly a dozen Earth orbiting satellites, the Viking landers, Cassini, New Horizons, both Voyagers, and more. At least one failed to reach orbit, another burned up when it's satellite reentered, another survived a rocket explosion intact.

The problem is not one of risk. It's one of availability. The amount of suitable fuel available is small (think perhaps a dozen RTGs total could still be made) and no one is currently manufacturing more due to it being expensive and nuclear proliferation concerns. Finally, you can't just slap an RTG on in place of your solar cells and call it a day. There are only a handful of standardized designs, most of which mass significantly more than the equivalent power generating capacity in solar cells. Then you need to worry about heat, since all current RTGs produce several times more heat than they do power.

Worse, it's not even informed opinion. You can't just "slap an RTG" on a probe and hope for the best. There are engineering, cost, and benefits considerations to make.

I really feel like people forget that the lander was an afterthought. The primary science of the mission was and is being performed by the Rosetta spacecraft. It was a "nice to have" that everyone was thrilled to see work as well as it did but wasn't critical for the success of the mission. Furthermore, it performed the vast majority if it's planned science activities during the 60 hour battery period after initial landing.

Yes, obviously, probes and landers can and do outperform their initial program goals. But treating the lander like a failure when it was anything but is dishonest. Using it as a soapbox to push your agenda (whether it's one I agree with or not) is insulting to the 2000+ people who worked to make the mission the fabulous success that it is and was.

I see lots of comments like yours, but after clicking 3 of the linked stories I don't see anything about the proposed curriculum. It's possible that it is, like you seem to assume, merely computer work and training.

It's also possible that it is in fact age appropriate computer science education. No, your kindergartner can't write C, but they can learn how to follow a flowchart to do a task that would be otherwise too complicated for them. They can play games and activities with sorting and filtering. They can learn about '0'. You can even introduce the concepts behind the basic data structures to a kindergartner if you do it right. The kids need not touch a computer at all in a young "computer science" course.

TL;DR.

A group of lawyers who set up a system of shell companies to send out settlement records to people downloading illegal pornography. The lawyers were utterly eviscerated when one judge and defending attorney finally said "what's this then?" and starting looking into their actions.

Highlights include:
Shell companies set up using other people's identities without their knowledge.
Sending out settlement letters for works they don't own the rights to.
Setting the settlement price at just below the cost of an adequate defense.
Failure to show up when summoned to court.
Lying to the court... so... so many times.
Not paying the settlements levied against them.

And this wasn't a single court hearing. This was over dozens of court appearances over a timespan of well over a year. They continue to dig the hole they find themselves in deeper and deeper. The saddest part of the whole mess (other than all the people that they bilked out of thousands of dollars) is that they still haven't been disbarred.

To be fair, when it comes to SpaceX I doubt any of category 2 have any concept of how much money has been funneled to the old guard launch services over the years. And not just money, but also R&D, no-bid contracts, communications services for launches, etc, etc. It's probably 10-20x more than SpaceX will ever receive and most people probably believe the answer is 0.

I think you're find that many of the times storm troopers failed to hit anything it could be argued that they were failing to hit anything on purpose. The most obvious instance is when the hero's escape the death star, it's clear Vader knew there were people on board the Falcon and wanted to use it to find the rebel base planet. Their escape was allowed because their ship was already lowjacked.

But they're also achieving things that government programs might never have achieved. I honestly think landing a Falcon 9 boost stage will, in the long run, do more to advance space capabilities than the moon landings did.

I think you'll find that if all the rich people in the world have joint problems, joint problems will quickly become a fixable (and profitable) problem.

Honest question. Is this even theoretically possible with chemical rockets?

Lets say you're using Saturn V's to lift people, and you only need 300lbs of payload to LEO (seems unrealistically low, but in this scheme I assume you'll be mining some asteroids somewhere for the interplanatary ships and fuel). Each Saturn V can lift ~850 people. Sounds pretty good. Except that at current rates, 250 people are born every minute globally. Granted, that number would probably slow given universal longevity. If it drops to 40% the current rate, you would need to Launch a Saturn V sized rocket more than once every 10 minutes. That seems extremely implausible, even from a pad maintence perspective. If you had 1000 launch sites around the world, you'd still need to light off more than 1 rocket per day at each of them to keep up.

Ok, so you use something better than a Saturn V, and maybe you can lift 1600 people. Numbers still don't work. Ok, so you take drastic measures to cut the birth rate by another 50%. You're still lighting off dozens of huge rockets every day for the foreseable future.

TL;DR; If you want to evacuate the planet, you need to invest in a non-rocket launch system of some kind. And even then the numbers are going to be challenging.

No ads designed to mislead. If you are a download page and you have dozens of "Click here for your download" ads you are getting adblocked or simply not visited. If you care so little about your website that you can't be bothered to protect it's users from malicious and misleading ads, you don't get my ad views.

"Prove" is a dangerous word. Everyone involved in the testing of this device is someone who wants desperately to see it succeed. When the effects you're measuring on on the order of 50 microNewtons, it doesn't take much of anything to screw up the results. Read about the history of N-Rays for a historical example of how even (or maybe especially) very intelligent, informed people can fool themselves into believing poor experimental results.

Three experiments does not overturn 300 years of experimental evidence in support of conservation of momentum. Extraordinary claims require extraordinary evidence. So far the evidence has been interesting, but not extraordinary. Like the article says, show me an experiment with thrust correlating with power input. Show me another one where the device runs for a month. But most importantly, show me one performed by skeptics!

$0.50. That's how much savings one full charge/discharge can save you at current rates. That's $182 per year. Even people that plan ahead balk at a 5 year payoff, so you'd have to have the cost for a 10kWh battery be under $1000 to get people to buy in. Even $2k seems unlikely at technology and market levels.

Obviously those numbers change if the peak/off peak ratio changes, but $0.05 isn't enough of a difference to make it practical for that usage. Of course, it also functions as backup power or quite possibly can be used to increase the effective efficiency of renewables. I'm not trying to say that the system isn't impractical, just not economically sound for the on/off peak power shifting.

This is actually quite the opposite. I find it hard to believe that there wasn't a single person in the back of class just trying to get their work done and get out. Not everyone swears in their day to day life, let alone at authority figures. Not everyone cheats. Not everyone lies.

He is certainly incompetent. Any idiot could see that the university wouldn't let a blanket fail stick, you can't fail an entire class based on group behavior that's just not the way academics works. If everyone in the class was really that bad, he should have been documenting specific incidents and then failed them individually at the end of the semester.