The thread for space cadets!

The flip side of "international cooperation" in space exploration.

-> If there are tech transfer/licence/export restriction problems even between individual ESA members (France-Italy), imagine their scale when applied to projects involving Russia, the US, or (gods forbid) China.

No matter how politicians and high-level executives like to talk about doing all the nice and inspiring stuff in space on the basis of international cooperation, the real-life facts are that we're living in a bureaucratic/particularist hell where nobody cares about what are you trying to accomplish, only whether you've got all the rubber stamps. Sigh :sad:
 
Onboard cam video from the latest Ariane-5/ATV launch. Don't miss the EPC separation at about 7:00.

[YOUTUBE-OLD]Dj12cOhaDCg[/YOUTUBE-OLD]
 
751199main_ionengine_946-710-500x375.jpeg


Saturday Space Sight: The Engine Burns Blue

This image shows a cutting-edge solar-electric propulsion thruster in development at NASA’s Jet Propulsion Laboratory, Pasadena, Calif., that uses xenon ions for propulsion. An earlier version of this solar-electric propulsion engine has been flying on NASA’s Dawn mission to the asteroid belt.
 
751199main_ionengine_946-710-500x375.jpeg


Saturday Space Sight: The Engine Burns Blue

This image shows a cutting-edge solar-electric propulsion thruster in development at NASA’s Jet Propulsion Laboratory, Pasadena, Calif., that uses xenon ions for propulsion. An earlier version of this solar-electric propulsion engine has been flying on NASA’s Dawn mission to the asteroid belt.
Variant of VASIMR?
 
No Ion-Drive

Ionises Xe and accelerates them over a potential. Low thrust but high endurance.
 
Sometimes, the SpaceX fanboyism and hype gets on my nerves. Seriously, these guys are almost better at PR than at rocketry.

Anyway, watching this video:


Link to video.

makes me wonder. They want to make their rockets reusable (a lofty goal, but I totally agree that *someone* has to try), first by having the 1st stage fly back on its tail, based on the grasshopper concept they're developing:


Link to video.

My question is - fly back *where*? By the time the first stage separates, its probably (I don't have exact numbers) hundreds of kilometres downrange, over the ocean. It doesn't have any wings to just use the atmosphere to turn and glide back. In the animation, it looks like it lands back at the Cape, but that seems to me like utter nonsense if they wanted to accomplish it purely with rocket power. The stage would basically had to cancel its forward momentum (several kilometres per second), and *then* fly all they way back to cape. Needless to say, the stage needs some fuel to do even the most basic landing after ballistic re-entry, and this fuel is tantamount to "dead weight" during launch. The more you need, the lesser the performance of the rocket. This applies to the (much further off) 2nd stage reusability as well, where you also have thermal protection, landing legs, etc. to eat your mass margins.

Also, how reusable are the Merlin engines, anyway? Anybody knows?
 
Ouch... and touché... :(

A Space Pseudo-Program
Posted on January 29, 2013 by Paul Spudis

A half-century ago, historian and Librarian of Congress Daniel Boorstin writing in his book The Image, took note of and characterized a societal trend that he found disturbing. Genuine accomplishment was being gradually replaced by what he termed the “pseudo-event,” something seemingly real but in actual fact, an occurrence representing no significant accomplishment or any real milestone. According to Boorstin, a pseudo-event has four characteristics:

  • It is not spontaneous, but planned.
  • Its principal purpose is to be reported and thus, it is arranged for the convenience of the media.
  • Its relation to any underlying reality is ambiguous; parts of the event may somehow relate to genuine accomplishment, but that relation is either uncertain or unknown.
  • It is intended as a self-fulfilling prophecy – it is important because its promoters proclaim it to be so.

Boorstin was concerned with both the increasing triviality of cultural and political discourse, and with the rise of the cult of celebrity in America. A classic example of the latter at the time The Image was published was the career of Zsa Zsa Gabor, a minor Hollywood starlet whose main claims to fame were being married nine times and appearing on television talk shows to brainlessly chat in a Hungarian accent. Yet when pressed, most people who had heard of her could not say exactly why she was famous. She was simply famous for being famous. For younger readers who know nothing about Zsa Zsa, think of Kim Kardashian, Paris Hilton, or Snooki.

Recently, I’ve been struck by how closely Boorstin’s concept of the pseudo-event describes the current sorry state of our civil space program. Specifically, the program is more notable for what it purports to be (or for what it says it intends to become) rather than for what it is actually doing. For as long as I can remember, the alleged “ultimate destination” for people in space has been Mars. The agency endlessly talks about it, even when they are specifically told not to. Enshrined in agency lore is the belief that every space activity must ultimately contribute to the attainment of Mars. If we talk about going somewhere else, such as an L-point or NEO, it is always in preparation for (ultimately) a human Mars mission.

The NASA human Mars mission is the archetypical pseudo-event for space. With the Vision for Space Exploration, the mission of using the Moon to learn how to live and work on another world was specifically laid out in the founding announcement of the program. But as far as NASA was concerned, getting to Mars was the only reason we were going to the Moon. Thus a lunar return morphed into a touch the Moon and go to Mars event thus becoming, yet again, another too expensive and summarily axed move beyond LEO.

NASA has become a master of the space pseudo-event. The announcement of a new mission or objective becomes the event. We’re not really going to an asteroid – we’re just announcing that we’re going to an asteroid. We don’t actually have to design the machines and build the equipment to do a mission – we’re on a flexible path. We’ll simply have endless committee meetings and produce PowerPoint shows and high-quality CGI graphic animations of people visiting distant space destinations. The absence of flight hardware doesn’t mean anything – we are developing technology to be able to do it “eventually.” The media has become the message.

While this modus operandi certainly applies to NASA and many of its programs, it equally (and in some ways, more so) applies to many “New Space” companies, whose announcements of spectacular new vehicles, missions and programs continue on a monthly basis. Recently, we have been regaled with tales of suborbital tourism on a routine basis, unlimited wealth extracted from near-Earth asteroids, national pride trips to and from the Moon for a variety of countries, and giant vacation resorts in Earth orbit where one can play weightless Olympic games. Not only are we told that these wonders will soon appear but that they will be affordable for the vast majority of people. No longer will space be the exclusive domain of government engineers and scientists – “Space-access power to the people!” is the clarion call to the uninformed.

In this sense, New Space is following in the footsteps of its governmental predecessor, only without having previously experienced the latter’s older record of actual accomplishment. From a whole new set of providers, we now have pseudo-missions instead of real missions. Instead of a space agency promising (but not delivering) expensive stunt missions by a few astronauts to exotic destinations, New Space is promising (and not delivering) cheap, meaningful and lasting space accomplishments for all. Talk about a paradigm shift….

The net effect of the advent of a space pseudo-program is to make the average citizen (who thinks little about space on a daily basis but is broadly supportive of it) believe we are progressing in space, when in fact nothing is being accomplished except that some people are making a career out of pretending that we are accomplishing something. We have a national space agency that doesn’t know where it is going or what it is doing. Critical national spaceflight assets and facilities carefully built over several generations are being lost – decaying from neglect, being inexpertly mothballed or sold off. A trained and dedicated technical workforce is disappearing like a vapor, as if it had never existed. New Space companies cheer and proclaim the advent of a new era in spaceflight, but their launch manifests don’t begin to match the pace and predictability of their press releases. Their endless demands to re-direct shrinking NASA funds to them belies their proclamation of being either “new” or “commercial.”

One of the most astonishing aspects of the space pseudo-program is how few seem to recognize its advent. Shell-shocked by a continuous flood of misinformation, the public tends not to analyze news stories in detail, accepting them as the straightforward relation of new facts even though that function of the news media has long since become obsolete and is now more akin to cheerleading for their “team.” New media (and this most certainly includes Internet journalism) eagerly regurgitates press releases and presents them as reality to the public, thereby hiding (willingly or otherwise) the essential hollowness of the U.S. space program.

Got a wild idea for a space mission? You say you want to build a vacation resort on Jupiter? Hold a press conference and you’ll have instant credibility as a space “entrepreneur.” As for any skeptics in the audience – just ignore them or label them dinosaurs, old space fossils, cold-war warriors, senile, or shills for government space “pork.” Got a difficult question for the space entrepreneur? There’s the exit. Don’t let the door hit you on the way out.

The Moon landings are renowned for the fact that many believe they never happened. What a remarkable development for American spaceflight – we once had a real space program that some thought was faked; now we have a fake space program that many believe is real.
 
The flip side of "international cooperation" in space exploration.

-> If there are tech transfer/licence/export restriction problems even between individual ESA members (France-Italy), imagine their scale when applied to projects involving Russia, the US, or (gods forbid) China.

No matter how politicians and high-level executives like to talk about doing all the nice and inspiring stuff in space on the basis of international cooperation, the real-life facts are that we're living in a bureaucratic/particularist hell where nobody cares about what are you trying to accomplish, only whether you've got all the rubber stamps. Sigh :sad:
Sadly this is true. I mean, on the one hand, I get the concerns. I also wouldn't trust working with the Chinese in many situations given how notorious they are for stealing tech. However, if Italy and France (or the US-EU) can't trust each other and every joint project has layers of bureaucratic suspicion and interference, it really doesn't bode well for the future.

There is also the negative impact such heavy-handedness will have on purely commercial ventures. These days, many corporations operate multinationally and that's where the bureaucracy really hurts. I read a book that was basically a series of interviews with experience aerospace movers-and-shakers and that kind of interference came up quite a bit. One executive explained how a huge satellite contract was torpedoed by export controls at the last minute. Basically, this guy's company was contracted to build a satellite that would be mounted to another country's rocket and launched. There was no sharing involved and the company could guarantee that the other country would have nothing to do with the satellite development and would simply mount it and launch it. They went as far as offering to post guards to accompany the payload up through launch and to mount it to the rocket themselves. But it was still classified as a transfer, so it all fell through.

I expect that kind of thing to get worse, not better with time. Particularly where the US is involved as our Senate tends to get hyper-protective about this kind of stuff. Also, even though the Republicans claim to be pro-business their paranoia about our tech overrides that and they are more than happy to put up barriers against private enterprise. Not that the Democrats are better, mind you, but the Republicans are supposed to be against exactly this type of government interference.

China launches Shenzhou-10 to its orbital lab/test vehicle

-> Note in the article that ESA is already considering cooperating with China in human spaceflight, should the Chinese put up their own space station. Interesting...

Anyway, I am wondering when the Chinese get the LM-5 flying already.
I thought the LM-5 was already flying? Or is that the one that's been in development for decades? Either way, I expect them to operate according to their own schedule and continue there slow, steady and unrelenting progress. I do think if the US program gets it's deep-space components up and running that the Chinese will quicken their pace. However, even though I'm optimistic, I don't hold my breath when it comes to the US placing their program on serious footing.

Have you seen any pics or video from the lecture they sent down from their space station? It's hard to tell but it looks pretty spiffy from the inside. It looks better than the hardware the Russians fly in any case.

Sometimes, the SpaceX fanboyism and hype gets on my nerves. Seriously, these guys are almost better at PR than at rocketry.

Anyway, watching this video:


Link to video.

makes me wonder. They want to make their rockets reusable (a lofty goal, but I totally agree that *someone* has to try), first by having the 1st stage fly back on its tail, based on the grasshopper concept they're developing:


Link to video.

My question is - fly back *where*? By the time the first stage separates, its probably (I don't have exact numbers) hundreds of kilometres downrange, over the ocean. It doesn't have any wings to just use the atmosphere to turn and glide back. In the animation, it looks like it lands back at the Cape, but that seems to me like utter nonsense if they wanted to accomplish it purely with rocket power. The stage would basically had to cancel its forward momentum (several kilometres per second), and *then* fly all they way back to cape. Needless to say, the stage needs some fuel to do even the most basic landing after ballistic re-entry, and this fuel is tantamount to "dead weight" during launch. The more you need, the lesser the performance of the rocket. This applies to the (much further off) 2nd stage reusability as well, where you also have thermal protection, landing legs, etc. to eat your mass margins.

Also, how reusable are the Merlin engines, anyway? Anybody knows?
How they fly back - I have no clue. You raised really important questions and all I know is that to get a first stage to fly back, they are going to have to sacrifice a lot of performance to do that wrt to payload capabilities. That or they are going to have to re-engineer the whole thing which will add significantly to the cost. In that case, I'm still skeptical they could get enough flights out of each rocket to break even on the cost, but I'm not privy to their business models. It's great to see them developing the tech to do this, but I am not really sure of any 'reusable' systems that were ever commercial viable, even on paper, without making super-unrealistic assumptions (we're going to fly the Space Shuttle 2 times a week year-round! :rolleyes:).

About the Merlin engines - I doubt they are reusable at all. If they were, I don't expect more than 2-5 flights out of them. The Space Shuttle Main Engines got that much use before they were basically rebuilt. I think the boosters only got 5 or 6 reuses as well and they were much simpler. So I don't really expect SpaceX to do better in that regard as the simply mechanics of rocket engines mean they are working at the absolute edge of mechanical and material science for every launch and thus burn out (pun not intended) after just one use, more if you are willing to throw billions of R&D dollars at the problem for marginal benefit.
Ouch... and touché... :(

Yeah, that's pretty damning and holds a lot of truth. In fact, just yesterday the House of Representatives in the US Congress passed a NASA authorization bill (funding bill) that completely nixed the asteroid mission in favor of moon and Martian bases. I mean, I'm all for those things as well - but it's about time we pick a goal and work towards it. This back and forth is terrible for the overall program and leads to massive cost and time overruns which then makes Congress slash NASA's budget. It's ridiculous! At least they have been funding the SLS adequately and that seems to be progressing according to schedule (and I'll just ignore the fact that according to the old Constellation Program, we should be launching basically the exact same rocket right now). However, the article I read specifically mentioned that the Republican bill (they control the House) kills the asteroid mission and mandates Lunar and Martian bases - but doesn't fund them. The bill basically says: well we mandate these things and NASA has to work on them but we don't have the money now and we'll pony up the cash at some point in the future, maybe.

Where have I seen that plan go wrong before?

:mad:

Edit: I'm also getting really sick of telling my real life friends 'Hey look at these cool things NASA is doing/going to do' only to have everything fall through and change in short order.
 
, the article I read specifically mentioned that the Republican bill (they control the House) kills the asteroid mission and mandates Lunar and Martian bases - but doesn't fund them. The bill basically says: well we mandate these things and NASA has to work on them but we don't have the money now and we'll pony up the cash at some point in the future, maybe.

Where have I seen that plan go wrong before?

:mad:

Edit: I'm also getting really sick of telling my real life friends 'Hey look at these cool things NASA is doing/going to do' only to have everything fall through and change in short order.

What?? That asteroid mission was going to do double duty as a test bed for deflecting catastrophic orbit crossing asteroids, no?

$50B tax payer money per year to people making more than $150,000 for the sake of subsidizing their mortgages. :wallbash:

Priorities. USA's are whack.
 
What?? That asteroid mission was going to do double duty as a test bed for deflecting catastrophic orbit crossing asteroids, no?

$50B tax payer money per year to people making more than $150,000 for the sake of subsidizing their mortgages. :wallbash:

Priorities. USA's are whack.

It's only a House Bill, so it's not set in stone yet. As Obama's sort-of pet project, I expect him to fight back on it. I also expect NASA to fight against it as well purely out of self interest. They have to know that since the Bill doesn't fund these ambitious goals, it's a dead-end no matter how awesome Lunar and Martian bases sound on paper. Meanwhile, the SLS program (of which the asteroid mission is tied up with and dependent on) is going forward and if they fund the SLS but defund the asteroid mission and fail to provide funding for bases, then what the heck are they going to do with the system?

It's just a huge mess. :\

But yeah, the new authorization Bill mandates the bases on a pay-as-we can afford basis. That comes across as a bit disingenuous to me from the get-go seeing how the Republicans are willing to kill off freakin Sesame Street 'because we can't afford it'. It's almost like they are purposely setting up NASA to fail which is itself a massive waste of taxpayer money and a complete waste of one of the most powerful forces of innovation and economic growth ever created.
 
I expect that kind of thing to get worse, not better with time. Particularly where the US is involved as our Senate tends to get hyper-protective about this kind of stuff. Also, even though the Republicans claim to be pro-business their paranoia about our tech overrides that and they are more than happy to put up barriers against private enterprise. Not that the Democrats are better, mind you, but the Republicans are supposed to be against exactly this type of government interference.

Thales (a premier satellite manufacturer in Europe) was recently forced to book a launch of its payload on Falcon-9 instead of a Chinese rocket because of ITAR. Thales usually markets its products as 100% ITAR free (meaning no US components so that these imbecilic regulations don't apply, with obvious consequences for us companies who can't participate as subcontractors), but the US Senate (I think it was senate) has recently expanded the list of components falling under ITAR, forcing this change.

And as you said, while I agree that the West should in general be VEEEERY careful what it gives to China due to the Chinese propensity to reverse-engineer it, produce knock-off copies and sell them around the world for 1/10th of the price (since they don't need to account for R&D costs), common sense should apply.

I thought the LM-5 was already flying? Or is that the one that's been in development for decades? Either way, I expect them to operate according to their own schedule and continue there slow, steady and unrelenting progress. I do think if the US program gets it's deep-space components up and running that the Chinese will quicken their pace. However, even though I'm optimistic, I don't hold my breath when it comes to the US placing their program on serious footing.

I mean this rocket(s).

China currently flies CZ-2, CZ-3, and CZ-4 series (CZ-2F is their man-rated rocket for Shenzhou launches). CZ-5 should replace these with a new modular set of pieces, namely a 5.2 metre main LH2/LOX core, a 2.25 m LOX/Kerosene booster, and a 3.35 LOX/Kerosene booster. The boosters alone can be used as first stages of derivative rockets. In its most powerful configuration, CZ-5 should be able to lift about 25 tonnes to LEO, or 14 tonnes to GTO.

The first CZ-5 is *supposed* to fly in 2014, but the programme has suffered some delays. Personally, I think this has to be expected, since China is basically developing a brand new rocket technology, i.e. new and powerful kerolox and hydrolox engines, while it previously only used N2O4/UDMH hypergolic propellants. It's been in development since 2000, if the article has it right. CZ-5 is also meant to lift the core modules of the future Chinese space station, which should be in the 20-tonne range.

As for the pace of the Chinese programme... well, everybody says it is slow. I ask, slow compared to what? To the 1957-1969 space race between the US and the USSR? Definitely. But look at it from their perspective. They launched the first man in 2003 and will most likely have a Mir-class space station up orbiting the Earth in 2020, with a set of automated and piloted spacecraft tending it. That's basically what the Russians did in ~40 years compressed into less than two decades.

The Chinese are following the traditional Asian way of development - "obtain" technology from the West (that also includes Russia in their perception), reverse engineer it, learn how to build it all on your own, modify/improve it as you go, and then mass produce it. China doesn't have to learn everything the hard way; they've got a lot of know-how just from watching the Russians, Americans and Europeans do their things in space. They can buy or steal a lot of techs the West had to painstakingly develop at huge expense. They also have the "advantage" of their political system, which favours long-term planning. If something gets included in a 5-year plan, then you have CERTAINTY, a rock-solid assurance, that the funding and political support for your project will be there and you can count on it. Compare it with the US situation where the House or the Senate keep screwing NASA over two or three times A YEAR by constantly changing its mandate and funding.

So, the Chinese may be moving forward slowly, methodically, without all the bluster and wide-eyed plans, but I wouldn't be surprised if ultimately it was them having bases on the Moon while the West squanders its lead in pointless diversions and arguments about funding. (I read that they're studying a Saturn-V class booster now. I wonder why...)

Have you seen any pics or video from the lecture they sent down from their space station? It's hard to tell but it looks pretty spiffy from the inside. It looks better than the hardware the Russians fly in any case.

Definitely. The Chinese space programme is 7/10ths propaganda, and it wouldn't work well if they showed dingy, dark space modules full of trash flying around now would it? ;) BTW notice how they keep sending women up, they've surely got their constituencies covered...

How they fly back - I have no clue. You raised really important questions and all I know is that to get a first stage to fly back, they are going to have to sacrifice a lot of performance to do that wrt to payload capabilities. That or they are going to have to re-engineer the whole thing which will add significantly to the cost. In that case, I'm still skeptical they could get enough flights out of each rocket to break even on the cost, but I'm not privy to their business models. It's great to see them developing the tech to do this, but I am not really sure of any 'reusable' systems that were ever commercial viable, even on paper, without making super-unrealistic assumptions (we're going to fly the Space Shuttle 2 times a week year-round! :rolleyes:).

I wondered whether they plan to set up a landing pad on some island in the Atlantic, or perhaps land the stages directly on a boat... It's just, the animation doesn't explain much, so I was wondering whether I've missed something.

BTW, additional question - they show the Dragon capsule landing using thrusters only, no parachute. Do you think that's realistic? How much fuel (in terms of mass and delta-v) would the Dragon need to carry for a precision soft landing on a pad?

About the Merlin engines - I doubt they are reusable at all. If they were, I don't expect more than 2-5 flights out of them. The Space Shuttle Main Engines got that much use before they were basically rebuilt. I think the boosters only got 5 or 6 reuses as well and they were much simpler. So I don't really expect SpaceX to do better in that regard as the simply mechanics of rocket engines mean they are working at the absolute edge of mechanical and material science for every launch and thus burn out (pun not intended) after just one use, more if you are willing to throw billions of R&D dollars at the problem for marginal benefit.

I read *somewhere* (meaning I have no idea whether this is true or not) that the Russians successfully consecutively test-fired some of their kerolox engines numerous times before they failed, and they were not even aiming for reusability at all. I also read that the Merlin engines were designed with reusability in mind, but it's hard to cut through all the hype on the internet and decide what true and what's just recycled SpaceX's PR. We'll see, I guess.

Edit: I'm also getting really sick of telling my real life friends 'Hey look at these cool things NASA is doing/going to do' only to have everything fall through and change in short order.

Yup. It's hard to be a space nut without becoming incredibly cynical.
 
Crap, the format of reddit really throws me. I don't like it and I don't have the patience to figure it out. :\ derpa derp on me

Anywho, from what I can gather, it's not exactly fully funded. Obama's 2014 budget proposal has it fully funded, but that's a looooooong way from actually passing a budget through Congress, which hasn't passed a budget in years. Then there's the issue of the House Republicans who want to shut it down so I don't know....did I miss something? I hope I missed something.
 
Crap, the format of reddit really throws me. I don't like it and I don't have the patience to figure it out. :\ derpa derp on me.

Think of it as a news/story/meme/post/whatever aggregator, where the most popular crap ends up at the top, both in terms of stories, as well as posts. So, if we reddified this particular thread for example, the most interesting posts would come first - so you could easily find them by looking at the beginning of the thread.

The consequence of this is that the most interesting, the funniest, or the posts with the most useful information usually end up at the top. This makes it harder to hold a real conversation with people per se, but you win some, you lose some. It's really good for news stories I find - if the story is BS, the top comments will tell you why. If there's an interesting angle - top comments will give you those insights. You don't have to look far to get insightful comments.
 
Crap, the format of reddit really throws me. I don't like it and I don't have the patience to figure it out. :\ derpa derp on me

Anywho, from what I can gather, it's not exactly fully funded. Obama's 2014 budget proposal has it fully funded, but that's a looooooong way from actually passing a budget through Congress, which hasn't passed a budget in years. Then there's the issue of the House Republicans who want to shut it down so I don't know....did I miss something? I hope I missed something.

You're right - it's not fully funded. My bad:
Mason Peck said:
In fact, it's the President's 2014 budget request that enables NASA to do this. The entire initiative is in the 2014 budget, which is publicly available, and the White House has been fully supportive of both the asteroid mission and the Grand Challenge.

Regarding Reddit, I really think you're missing out on a profound resource if you don't learn how to make it work for you. This coming from someone who *still* hasn't figured it out, but it mostly works for me.
Think of it as a news/story/meme/post/whatever aggregator, where the most popular crap ends up at the top, both in terms of stories, as well as posts. So, if we reddified this particular thread for example, the most interesting posts would come first - so you could easily find them by looking at the beginning of the thread.

The consequence of this is that the most interesting, the funniest, or the posts with the most useful information usually end up at the top. This makes it harder to hold a real conversation with people per se, but you win some, you lose some. It's really good for news stories I find - if the story is BS, the top comments will tell you why. If there's an interesting angle - top comments will give you those insights. You don't have to look far to get insightful comments.
I'll just add some things to this:
The default format of the comment display is to sort by best. That means that everyone who has made an account and chooses to upvote or downvote are crowdsourcing the best and worst comments - in theory - and the comments with the "most" upvotes will be at the top of the page.

If you don't care for that sorting, you can choose to have the comments displayed in chronological order by clicking on the "sorted by" drop down found at the header just above where the comments start after the text bubble of the OP. Civfanatics is basically displayed in "old" view - every comment follows the previous, sorted by time stamp.

You can choose to reply to a comment (make up a name and a password - make a new one every day!), or, like me, primarily lurk. I read a lot, comment rarely, and upvote/downvote almost never.

It can be overwhelming at first because there's so much garbage - but once you make a user name you can choose which subreddits display on login. I don't subscribe to Pics, Funny, Politics, Worldnews, AdviceAnimals, Aww, Music, Movies, Politics, TIL, and I'm considering dumping Gaming. Dropping these cleared up my news feed drastically. I've added:
TrueReddit
DepthHub
Futurology
Simulate
Engineering
AskEngineering
AskHistorians
AskScience
Science
Space
LearnProgramming
WhatIsThisThing
NeutralPolitics
MildlyInteresting
and a few city-specific ones

Give it a week. I practically guarantee that you'll find it useful. As a teaser, Consider The Folllowing:
http://www.reddit.com/r/IAmA/comments/1h47je/we_are_engineers_from_planetary_resources_we_quit/
 
BTW, additional question - they show the Dragon capsule landing using thrusters only, no parachute. Do you think that's realistic? How much fuel (in terms of mass and delta-v) would the Dragon need to carry for a precision soft landing on a pad?

I actually think it is pretty realistic. The way they are doing it is they are basically dragging their launch-escape system up to orbit with them as it's built into the capsule instead of jettisoning it. Given that the system is designed to haul the capsule off of a supersonic exploding ball of fire, chances are it could handily slow down a capsule. I assume they will use a really blunt capsule to slow it down the old fashioned way and that will take care of the bulk of the velocity they need to shed.

I have no idea how they would make it work without a parachute though as a parachute, even a drogue, can kill so much more velocity. Maybe the retro's can handle it all on their own. I would guess that they'd need at least 300m/s delta V, (a little less than what it takes to go from Mach 1 --> 0m/s) but really that depends on so many other factors like how accurate constitutes a 'precision landing' and how much they can slow down due to aerodynamic forces.
 
asteroid-resources-mining-130122b-02.jpg

Long a staple of science fiction, space mining could soon become a reality. Here is a look at what’s out there and how we might get it.

These bodies of rock, metals and ice range in size from a few feet across up to 610 miles (975 kilometers) in the case of the largest, Ceres. Asteroids are often classified according to their spectral type, which has to do with the type of light they reflect.

C-type (carbonaceous): 75 percent of asteroids are made of dark materials (example: 253 Mathilde)

S-type (silicon-based, or stony) comprise about 17 percent of the asteroids (example: Eros)

In addition to these major classes, there is also an X-group that includes various types with similar spectra, but likely different compositions, as well as other smaller asteroid classes.

The study of meteorites, space rocks that have fallen to Earth, reveals a variety of useful materials that could be extracted:

• Platinum: precious metal used in electronics and as a catalyst in chemical reactions. Carmakers used $7 billion worth of platinum in 2012

• Palladium: harder than platinum, similar uses

• Water: can be broken into hydrogen and oxygen for use as rocket fuel or life support for humans

The majority of asteroids orbit in a belt between the planets Mars and Jupiter. These objects may be remnants from the early formation of the solar system. Other groups of asteroids, such as the Trojans and Greeks, hang out in stable points near the orbit of Jupiter. Near-Earth asteroids are those that traverse the inner solar system and can pass close to or cross the orbit of the Earth.

Much of the energy required to get anywhere in the solar system is used in just getting off the Earth. Reaching a near-Earth asteroid requires less total energy than landing on the moon. Reaching an asteroid belt destination is easier than landing on Mars.

Planetary Resources revealed in 2012 its intention to extract valuable materials from asteroids. First, the Arkyd-100 space telescope would be located in low Earth orbit to gather spectral data to determine asteroids’ composition and market value. Swarms of low-cost robot spacecraft would crisscross an asteroid to extract its resources. Small ice-rich objects could be captured for towing back to the vicinity of Earth for extraction of their water.

Deep Space Industries announced in 2013 an ambitious scheme ultimately involving robotic manufacturing plants that could 3D print components from asteroid metals. First, tiny Firefly cubesats would be sent into the inner solar system on one-way reconnaissance missions to targeted asteroids. Then, larger Dragonfly spacecraft would be sent to capture samples (or even small asteroids) for return to Earth. Later the Harvestor tug would be developed, capable of towing an entire asteroid back to Earth orbit. Eventually, manufacturing could be done in space; for example, 3D printing of components for a space habitat.

Launching humans to an asteroid has been mentioned by NASA in recent years as a possible goal. New vehicles capable of traveling in deep space would have to be developed. The job is complicated by the very low surface gravity of an asteroid, requiring different equipment than that developed to operate in either the microgravity of Earth orbit or the one-sixth gravity of our moon’s surface.

The new company Planetary Resources, Inc., is backed by a team of billionaire investors and luminaries like filmmaker/explorer James Cameron with a single goal: to mine near-Earth asteroids for precious resources like rare metals and water ice. The project is aimed at tapping into the resources of the solar system while furthering space exploration in an audacious way. See how asteroid mines like those envisioned by Planetary Resources could work in the SPACE.com infographic above
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Here's a link to a slideshow about various private space ventures.
 
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