Kryten

They couldn't. The current Iridium company is the company that bought the assets of the original company in a bankruptcy auction.

Can you provide a mechanism by which the comet could change in shape so dramatically without an obvious outburst?

Can you imagine how rich a corporation would get if they had a source of infinite free energy? They'd basically own the entire economy. Why would they bury it and try to sell some guns, or whatever it is you're trying to say?

Allows the second stage to fire before separation without damaging itself. Means you don't have to start the engine in freefall, or include separation motors.

Dragon v1 doesn't dock, it berths. It might sound nitpicky, but that means it takes a considerable amount of time for it to actually separate, and it requires use of Canadarm to do so. Not something you want to have to arrange in a hurry.

It's very difficult to prove someone wrong when they're not saying anything coherent in the first place, but as far as I can tell he's talking about producing energy from gravitational and/or electrical fields, which is what comes out of the north side of a south-facing bull. Fields simply do not work that way.

There are words for what this is, but I can't use them on this forum.

'Big bang cosmology' is the observation that the universe is expanding at all, and that such expansion must logically have a beginning. Dark energy doesn't contradict that, just add to it.

Multiple complete LKs were built and tested in earth orbit, complete with full simulated landings worth of engine firings. Everything was ready except for N1. EDIT: Is there a 'somebody has posted since you started writing, you may want to reconsider your post' function for this forum software? I've seen it elsewhere.

The active ones have been given above; if we restrict ourselves to plausible, actually planned and funded (rather than proposed) missions then it should be easy enough to collate one. Here's my effort, tell me if I've missed anything; (Dates are subject to slippage, especially Russian ones) 2014 Hayabusa 2: JAXA; launches November 30th; planned to rendezvous with asteroid 1999 JU3 and return samples to earth. Carries a joint DLR/CNES 'hopper' lander called MASCOT and multiple smaller JAXA landers called MINERVA II PROCYON: JAXA/University of Tokyo; launches November 30th (secondary payload on Hayabusa 2 launch); planned to perform an asteroid flyby using ion engine, exact target to be determined after a test of the engine performance after launch 2015 Barcelona Moon Team Lander/Rover; Barcelona moon team/China Great Wall Industry Corporation; launches June 2015; planned to be first privately-funded moon lander as part of the Google lunar x prize (there are other competitors, but no confirmed launches) 2016 Exomars 2016; ESA/Roscosmos; January; mars mission, with an orbiter (the Trace Gas Orbiter), and a lander demonstrator (Schiaperelli) Insight; NASA; March; Mars lander with seismometer and heat flow instrument Bepicolombo; ESA/JAXA; July 9th; Mercury orbiter mission, with two separate orbiters; JAXA's Mercury Magnetospheric Orbiter and ESA's Mercury Planetary Orbiter Mars Observation Mission; ISRO (India); Mars orbiter 2017 Solar Orbiter; ESA; July; Solar orbiter, planned to approach to within 60 solar radii OSIRIS-Rex; NASA; September; Asteroid sample return mission Chang'e 4; CNSA; Lunar lander with rover, very similar to flown Chang'e 3 mission Chandrayaan II; ISRO; lunar lander with small rover 2018 Orion EFT-1; NASA; No later than November; test of to-be-crewed spacecraft, lunar flyby Solar Probe Plus; NASA; Solar orbiter probe, planned to approach within less than nine solar radii Chang'e 5; CNSA; Lunar lander and orbiter, sample return mission with lunar-orbit rendezvous 2019 Luna-Glob lander/Luna-25; Roscosmos; lunar lander, mostly technological demonstration for later missions, will land near to south pole Asteroid Retrieval Spacecraft/Asteroid Redirect Robotic Mission; NASA; To capture asteroid and bring to earth vicinity for later crewed visit 2020 Lunar Orbiter; KARI (South Korea) Lunar lander and rover; KARI Exomars 2018 (see what I meant about slippage?); ESA/Roscosmos; large, exobiology-focused Mars rover 2020 Rover; NASA; large rover, identical chassis to MSL/Curiosity, will cache samples for future sample return mission Mars Global Remote Sensing Orbiter/Unnamed Rover; CNSA; first Chinese Mars mission, to deliver small rover to surface 2021 Luna-glob Orbiter/Luna-26; Roscosmos; Lunar orbiter 2022 Interglio-Zond-1; Roscosmos; Solar orbiter probe, will approach within 60-70 solar radii of the sun JUICE; ESA; Jupiter mission intended to ultimately enter Ganymede orbit; will study the outer three Gallilean moons, the Jovian magneotosphere, and Jupiter Europa Clipper; NASA; 'midyear'; intended to make multiple flybies of Europa 2023 Interglio-Zond-2; Roscosmos; Solar orbiter probe, will approach within 60-70 solar radii of the sun Luna-Resurs/Luna-27; Roscosmos; lunar lander, similar to Luna-25 but with much larger scientific payload Unnamed Mars Mission; CNSA; to deliver large rover to surface 2024 Venus Exploration Orbiter; CNSA; an Orbiter to Explore Venus 2025 Main Belt Asteroid Sample Return; CNSA; to Return Samples from Main Belt Asteroid (apparently Ceres) 2027 Solar Polar Orbit Observer; CNSA; to Observe Sun from Polar Orbit, minimum distance as yet unknown 2028 Jupiter Orbiter; CNSA; to Orbit Jupiter

That's a comparison of comet Tempel 1 during the 2005 Deep Impact flyby and the 2011 Stardust/NEXT flyby; it's in a roughly similar orbit to 67/P. Does it look like it'd be unrecognisable after twice that time to you?

Do you mean just planetary missions, or actually all space missions?

Why do people think things like this? A significant portion of the world's population already believes in aliens, they're not murdering each other over it.

RP-1 is a hydrocarbon. Why produce any hydrocarbon if you have the option of producing hydrogen? The higher density of hydrocarbons and higher thrust of hydrocarbon engines are a lot less useful when you're not starting in a deep gravity well.

Tank mass is lower because it's a lot easier to contain. Same reason ISS gets oxygen supplied as water then electrolyses it; liquid tanks, even cryogenic ones, are far lighter than pressurised gas tanks.

The kickstarter is looking a bit dubious; nearly half the money put in is in pledges of over £1,200, and average pledge per person is about twice the KS average.

I'm not sure what you're trying to say. Expansion is speed per unit distance; any two points will experience expansion between them, but at lower distances the speed is low enough to be negligible and/or completely overwhelmed by whatever attractive forces there may be.

Expansion is applied to the space between the galaxies, it's not a force pulling the galaxies apart. The more distance there is, the more expansion between them there will be-this doesn't require a centre.

Andromeda is simply close enough that it's gravitational attraction towards us overwhelms the effects of expansion. There are a few (dwarf) galaxies even closer that are actively orbiting ours, for the same reason.

NASA's own requirement is four-figures higher than that are being bandied about by the developers themselves, but flights with those numbers are very unlikely.

They already have a replacement engine lined up for Soyuz 2.1V; RD-193. The NK-33s would have be replaced soon due to the limited stock, this just makes it sooner.

Stop talking about things you know nothing about, it's pretty clear you don't even know the difference between acetylcholine and acetylcholinisterase-this is high-school level stuff. Given the major differences in biological pathways we already have between organisms, and how easy you're suggesting producing lethal toxins by chance is, why isn't the world already completely full of poisons? There's just as much reason for an alien organism to produce Sarin as there is for most plants to, given they don't utilise acetylcholinisterase; why hasn't your scenario already come to pass?

Theoretically possible according to who? Under what conditions is tungsten supposed to be able form covalent bonds with itself?

Sarin acts by forming a covalent bond with the acetylcholinisterase active site, not competitive inhibition; it's not structurally related to acetylcholine or particularly similar to any naturally occurring molecules. It's also the end result of about a century's work on modifying organophosphate pesticides to be ever more potent-it's not like it was just stumbled upon by chance.

I get 40km/s, assuming a Brachistochrone trajectory (i.e. accelerate half way, turn ship around, decelerate half way), using the calculations provided here. There's a good chance I've converted something incorrectly or missed something because I'm pretty tired right now, but it sounds about right to me. It's theoretically possible for a ship with VASIMIR to provide that kind of delta-V, but it'd require hige amounts of power, with all the caveats that brings in space (radiators et.c.).