Another Antarctic balloon experiment, BLAST, was designed for re-usability. On its third flight, the parachute failed to properly detach, and ended up dragging the telescope for more than 100 miles across the ice, mostly destroying it.

This doesn't mean that one shouldn't try to recover and reuse experiments, but it does present new program-level risks.

The answer as to "why don't they?" could be as prosaic as: they didn't get funding for a multi-year, multi-launch program, or couldn't squeeze the reusability and refurbishment into their program budget.

(For those interested, that third mission was the subject of a neat documentary film.)

The ozone hole affects UV absorption. Spider operates in the microwave spectrum where ozone (or its absence) does not play a significant effect.

Water vapor plays a much, much greater role in those wavelengths, and the Antarctic atmosphere is about as good at it gets in that regard.

If there was any justice and sense to the English Language, "common sense" would be a curse word and shunned in polite conversation. Politicians, especially, have bastardized the use of the term for their own ends such that it hardly has any meaning aside from doublespeak.

I find this to be a fun game to play: anytime a politician starts talking about "common sense," replace it in your head with some sort of expletive. My preference is "Fucking Shite", as in

We need Fucking Shite solutions to our problems, not political speeches meant to ignite class warfare

-Rep Martha Roby, (R-AL)

This makes looking through a copy of Thomas Paine's pamphlet on the subject particularly amusing.

I recall reading about the mirror when it was being made, the precision with which it was polished was mind bogglingly accurate

Be careful how you use the terms "precision" and "accuracy," because they have very specific meanings to engineers and metrologists. Yes, the precision was mind-boggling. The accuracy, on the other hand, well...

Despite the slight change in the curvature of the main mirror, Hubble's images were pretty amazing

Amazing maybe, but far below what was promised. There isn't any way to gloss over the fact that the project managed to screw up the single most important component in the telescope. The mirror ended flawed and in orbit not because it was too technically challenging, but because of arrogance, sloppiness, and poor oversight. The taxpayers have a right - even today - to be pretty steamed about it.

Imagine if someone sold you a sportscar, promising it would handle like a dream and hit 200 mph on the straightaway. When you finally receive it and test it out, it shimmies like a banshee and can only manage 100 mph. When you call to complain about it, you find out that during construction, the technicians got drunk one night, ground the cam shaft wrong, and left out one piston. The company sold it to you anyway, not because they were trying to cover anything up, but that they simply didn't know anything was wrong, because they'd never bothered to test drive it before shipping it. Your argument is that we should still have been happy to have it because it's better than the Honda Civic we were used to driving. And, given the etymology of the word , "disaster" is a good choice.

Turn in your geek card. It actually goes...

God creates Dinosaurs
God destroys Dinosaurs
God creates Man
Man destroys God
Man creates Dinosaurs.
Dinosaurs eat Man, Woman inherits the Earth.

A typical laptop battery maxes out at 100 Whr capacity. (Above 100 Whr gets problematic with shipping and air travel regulations.) So picture a stack of about 40 laptop battery packs - that's what Atlas' will be lugging around. In the videos, you can see a large briefcase-like box on the back.

If the ISPs and telecoms are for it, then I'm against it.

Down with Net Neutrality! Damn them all to hell!

Wait, what were we talking about?

Simply changing EPA rules by Presidential decree is dictatorial

The EPA is empowered, by Congress, to make such rules. The EPA falls under the executive branch, and so takes direction from the President, within the broad legislative mandate to protect the environment. In any event, the President hasn't actually issued new rules by decree - he's got certain goals, and has set the EPA to the task of actually drafting the rules and regulations through their normal process (which, for better or worse, includes lawsuits).

A President can't drop such regulations by decree, because that would violate the EPA's mandate and other existing laws enacted for the environment.

I did a bit of reading on the subject from TI, which has FRAM integrated into some of its MSP430 microcontrollers. If anything, the technology seems to be well-suited to the space environment, because bit storage is accomplished via a crystal structure change (polarization), rather than through charge storage.

I'm a huge fan of FRAM

That may be, but it wasn't exactly an option (in the sense of it being readily available and thoroughly tested for spaceflight) when the rovers were being designed 15 years ago. Is it even an option today?

I believe that there is one very high end 3D printer that has made metal weapons that work very well

That weapon was made using a DLMS (direct laser metal sintering) machine, which fuses metal powder using a powerful laser. This kind of machine goes for upwards of $1million, and isn't exactly turnkey. (I know: my company has one, and although it's amazing, it tends to not produce a usable copy of a new part until the 2nd of 3rd try.) Plus, it required a fair bit of post-machining.

Your example reinforces my point - if you want a "reliable and somewhat accurate weapon", you use metal, and metal rapid prototypers are not hobbyist equipment, and may not ever be. Plus, even if it were, you still need a reasonably well-equipped machine shop to finish the metal parts and assemble a working gun.

Do a powered descent with the Dragon Capsule, and return to orbit with Dragon under its own power to rendezvous with the upper stage that will bring it back to Earth

Dragon does not have enough fuel to both land and launch again. SpaceX hasn't demonstrated that it has sufficient capacity to even do a powered landing. I'm not saying itcan't, but you can't look at a Dragon capsule and consider it a vehicle capable of powering itself to orbital launch velocity, even on Mars.

3D printers will allow anyone to print a reliable and somewhat accurate weapon cheaply one day. At the moment they are still expensive, but won't stay that way for long

The notion of a "reliable and somewhat accurate weapon" coming from a $2,000 FDM (fused deposition modeling, i.e., plastic extruder) is laughable and drastically oversells the ability of the technology. Oh, sure, you can produce a gun today that'll kill someone, but don't expect 3D printers to enable the next Continental Army.

Perhaps a gunsmith could say otherwise, but my understanding is that a "reliable and somewhat accurate weapon" requires metal. 3D printing of metal is going to stay expensive for a long time, maybe for good, if only because the power it takes to sinter/melt metal is high and isn't going down. A 40-kW laser in every tinkerer's basement isn't likely. I've seen FDM-like metal printers that are more or less wire welders on an XYZ base, but the results leave much to be desired. Even then, a printed metal part will still need a decent amount of post-machining, in which case you may be better off fab'ing your gun from solid stock.

(I use 3D printing (FDM, SLS, DLMS) in my day-to-day job, have experience with hobbyist 3D printers)

In what way aren't they capable?

Well, the big one I can see is that they lack an airlock for EVAs. They also lack a cargo bay for bringing up tools and replacement parts. Lastly, they don't have a remote manipulator like the shuttle's arm, which was an essential tool for the servicing missions - first for capturing and positioning the telescope, then for moving the astronauts around.

With several launches, you could put together an orbiting service platform that contains these things. Unless things change greatly, however, the cost of putting together such a platform approaches the cost of building a whole new telescope!

I'm sure that we'll get there eventually (a LEO servicing platform), if only because fixing satellites could be a genuine business venture, but I don't think it'll happen within Hubble's remaining life.