I think I know what they mean (first time in 70 years for this comet), but the ambiguity is surely deliberate.

For the record: Bennett, Hyakutake, and Hale-Bopp were all very visible - glorious spectacles. Source: I saw all three.

Three reasons come to my mind:

• Mechanical failure of the holddown clamps or associated structures

• Clamps were not engaged in the first place

• Sequencer didn't have clamp release disabled for the test

While not of the test stand itself, this footage isn't bad. Also decent is this footage.

None of which I'm aware. However, there was apparently a fear of such on one Shuttle flight, where a distressed payload specialist asked about the possibilities of opening the hatch while still in orbit after his experiment failed. On some flights thereafter, said hatch was padlocked with the commander holding the key.

"Early on when we were flying payload specialists, we had one payload specialist that became obsessed with the hatch. "You mean all I got to do is turn that handle and the hatch opens and all the air goes out?" It was kind of scary. Why did he keep asking about that?"

While it’s not possible to go faster than light, there are several ways to bypass it.

Sadly that's not so. The issue pops up frequently enough I have a semi-canned response ...

By all understanding, FTL travel between two points in space appears to be impossible even when attempting to bypass direct FTL travel through that space via wormholes or Alcubierre drives. Alcubierre himself has doubts regarding his drive, indicating it has the potential to violate causality, a point supported by Prof. Allen Everett. Such violation is anathema to most cosmologists and physicists.

Put another way, the speed of light is set not by light itself, but by causality. It is deeply fundamental to the nature of the universe. Even were FTL travel possible, it'd only be through phenomena such as multiple forking universal timelines, that is, one way trips out of "our" universe.

Regarding FTL, I agree completely. However, that's not the end of it. Longevity advances, generational ships (O'Neil colony-like), and hibernation are concepts that might make crossing the (nearer) vast distances within reach.

Almost certainly a reentering spacecraft, disintegrating and burning up because of its high speed entry into the atmosphere. Which spacecraft it might be, I don't know.

Further to /u/peterabbit456's explanation, follow the links here. 

Yes, it is. Nevertheless, there's no evidence in it supporting the assertion: "Zero/micro gravity rapidly decreases the life span of humans."

I've not noticed that, but instead recall hearing their names almost always being mentioned together.

I attempted to collate a list of all astronauts and cosmonauts who spent more than six months in orbit. Here's what I found, with current age or age of death:

There is nothing noteworthy in the ages here, certainly nothing supporting your claim of rapidly decreased lifespans.

(this guy runs to his basement in fear of the sky)

Putting aside there not having been an attempt thus far, this is yet more FUD. Did the naysayers all have a conference a couple of weeks ago to coordinate their stories?

Not below 500 km it isn't. 

Why are you reluctant to type the word "SpaceX"? Based on your comment history, it's clear you have an irrational dislike of the company. Regardless, beyond the technobabble, oozing sense of superiority, belittling, and attempt to discredit me by perceived negative association, the claim is nevertheless extraordinary and thus requires extraordinary proof.

I'll leave it there for your no doubt scintillating retort. Have a good day.

360 metric tons of aluminum oxide clusters per year from satellites.

Can reach. Less than one gram per square km per year. To claim such a small amount would have any meaningful effect is IMO extraordinary.

Stepping back, there's been a flurry of such negativity recently, much of it smacking of the fear, uncertainty and doubt peddled for example by the NASA doctors coming up with every excuse to delay the Mercury astronauts. Thankfully they were ignored.

Were Kessler syndrome so likely as some fear, LEO is the best place for satellites. Were the worst to happen, all debris - with the typically lower ballistic coefficients - would deorbit within at worst a handful of years.

Low earth orbit makes it easier to accommodate changing communication traffic rates and permits low latency, the latter being impossible via the much higher Clarke orbit.

Depending on references, roughly 15,000 to 40,000 tonnes of material enters and/or burns up in our skies every year - a large percentage of it metallic - all naturally occurring. This dwarfs projected human activity.

CNES is not happy about it, reiterating demands that "all European institutional satellites are launched on small and large European launchers.”

Full replay of conference here.

Brief summary of notable points:

• Overriding initial 45 day limit on the CM's batteries

• No new leaks detected

• Thrusters operating between 80% and 100%

• No exact schedule yet for return

ETA: Full replay of conference here.

User Finds Something Clicky in Bait Retreived From Yahoo.