1 Solid fuel is manifestly less safe than liquid, if you remember how Challenger blew up. And it's most certainly not cheaper, because casting costs. There are other downsides as well, for example solids' failure modes develop much faster than liquids and so the early failure detection system and the escape system have to work harder for a solid booster. I'm not even going to bring up the toxicity of solid exhaust, it's for enviros to debate. // Quite aside from the solid debate, Ares-I is a joke. The DIRECT project has proven that a much cheaper system could be built using the same principles, and be truly Shuttle-derived (e.g. not cutting new holes in the launch platform). Ares-I is not Shuttle-derived at all, it's fraud. They have to develop new upper stage engine and essentially new SRB, not to mention the rest of the upper stage. They have to create principially new launch infrastructure. // P.S. Pixy, where are my paragraph breaks?

2

Pete, you probably need to dump your browser cache and reload. Likely one of the Javascript helper files didn't download.

The Challenger failure was caused by a management failure. The investigative record on that is clear (and thank you, Feynman, for preventing NASA's management from covering it up!). There was a temperature range in which the SRBs could be safely used, and that launch was in conditions outside that window. Management was under political pressure to launch anyway, and did. It wasn't an indication of inherent lack of safety of solid fuel, which in operational use has been extremely reliable.

The issue with solid fuel is quality control. With poor quality control, solid fuel is very dangerous. But we've been making solid rockets now for decades, and the quality problem has been solved.

Moreover, while it's true that casting solid fuel is expensive, liquid fuel rocket engines are very expensive, and because of the sheer complexity of them are inherently more prone to failure. As a result, to keep them safe, they have to have extreme (and expensive, and slow) maintenance done. In practice solid fuel ends up being cheaper. The only important moving parts on a solid booster is vector control -- which is difficult, but liquid boosters have that, too.

You have to look at the total cost, the total process. It's true that casting solid fuel is more difficult and expensive than filling a tank. But what you spend there, you more than make back on other things that you don't have to do if you're using solid fuel.

There's a damned good reason why all our ICBMs and SLBMs use solid fuel, and have for decades.

3 Unfortunately, it's pretty messed up.  They have serious weight issues, a potentially terminal vibration issue, and a rocket that was supposed to be "completely derived from" existing parts has turned out to be something completely new built from scratch.  Meanwhile, costs and delays have been spiraling upwards.  There's a number of blogs that have been covering this, but I'll refrain from throwing links around without your say-so.

I am now very pessimistic about NASA and their ability to do anything effectively except soak up money.  I'm desperately crossing my fingers for Falcon 9 or Atlas to prove that it can be done for a lot cheaper (admittedly, Atlas isn't very cheap at all unless you buy a lot of them; but, it's still much cheaper than the Stick).  I'm also crossing my fingers for Bigelow... if he successfully builds and sells space on his station, he'll shake things up dramatically just by providing a market.

4

Some parts of NASA continue to do good stuff -- mainly, the unmanned probe groups. It's the manned flight part of NASA, which has the largest share of the budget, which has gotten incompetent and stupid.

Pity, really.

5 Say what?!? Oh, not that Orion. (And you thought solid rocket exaust was bad...)

6 Cybrludite, don't think of it as a nuclear-bomb-powered space ship, think of it as the world's most powerful pulsejet engine.

...and invest in lead.  Lots and lots of lead.

7 Take off and nu...  Oh.  Okay.  Time for lunch?

8 Hey, we would have totally been to Mars by now if not for such silly, utterly non-technically objections to Project Orion. 

( its not like you'd use the things in-atmosphere. . . )

9

ICBM's tended to use solid fuel so they could be be ready to fire on short notice. The more powerful liquid fuels are cryogenic so not storable (this was what killed Blue Streak, Britain's own ICBM. They didn't realise until too late that by the time they'd filled the tanks the launch site would be radioactive dust).

Personally I'd rather not be sitting on a giant firework, especially as they can't be switched off if anything goes wrong.

From what I've read I don't seen any fundamental reason why rocket engines can't be as reliable as jets (IIRC, rocket technology is comparable to 50's jets in terms of design maturity). Reusability and high flight rate is what makes London to Sydney affordable, which uses the same amount of energy as getting to orbit, IIRC. part of the problem with the shuttles low flight rate is due to the design constrictions, and the fact it was designed to keep the Saturn workforce busy.

I've been following NASA's attempts to replace the shuttles since X-33 in the late 90's. So far all that's been produced are lots of pretty pictures and a dollar bonfire.

 Hopefully we are on at the start of the commercial space age, and we'll find out by trial and error what works best, and what most cost effective. I'm still optimistic I'll be able to retire to the Moon or Belt (Mars doesn't really appear to me)

Andy

10

The problem with private enterprise going into space is that, IIRC, there is, aside from cost issues, a treaty in effect that says a country is ultimately responsible for any private enterprise or citizen's activity in space.  That makes most private activities stillborne.

I am two-minded about Mars, although I do believe humans have to go Mars and else place (Grissom's words come to mind as one motivation, admittingly.) if we are serious about the space effort.  But NASA is definitely the most inefficient single airline to do that.

C.T. 

 

11 There's also the issue that there's no legal settlement for ownership of offworld territory.  That will probably take somebody with "more money than sense" to take a gamble, claim a plot, and force governments to either come to an agreement or de facto acknowledge their claim.

12

I believe it was that treaty that created the blank space regarding how off-world ownership is handled.  From what I remember reading about the treaty, the national liability essentially prevents private ownership because it was the nation, not the person or entity staking the claim, that actually and ultimately had responsibility for it.  No doubt Moscow was quite happy when that treaty came through.

C.T.

13 Well, "possession is nine tenths of the law."

14 Either CSS is broken, or balace of div's and p's is. My comment is shown with line breaks as-is, no br/ elements. But this would only work if only an equivalent of pre was in force. But more importantly, the bottom of the page is not formatted it all, I see everything raw starting adter the word "entry" right below "Powered by Minx". There's even a closing tag of a comment (dash-dash-more) dangling in the open.

15

Your original comment was trashed because the processing code used by the entry box wasn't running when you typed it. Nothing can be done about that.

It didn't turn it into "pre". What it did was turn it into raw text without any markup, which means that line breaks were ignored by the browser when it was formatted.

The javascript file in question does things like this: "Aha! The user just hit "enter". That means he wants what just came before to be a paragraph, so I'll just toss in <p> and </p> tags around it so it'll display properly later." That didn't happen for you.

If you look at the page source, you'll see that your line breaks are present in that comment, where you wanted them. However, because there's no mark-up, because the appropriate javascript file didn't properly load during that session to add the markup where you entered line breaks, those line breaks have no effect on how your comment is displayed now.

The problem is yours, and yours alone, and probably can be fixed by clearing your browser cache and reloading. Then that javascript file will (we hope) load properly and your future comments will be formatted correctly. That won't fix the existing comment, however.

Or the problem is due to you doing something that prevents that javascript from running, in which case you need to figure out what that is and disable it.

16 Just to make something painfully clear: the javascript in question does that formatting when the comment is entered, not when it is displayed.

17 It seems that the fancy editor is not loading for Pete for whatever reason (it only works in Firefox and IE).  By default, the system doesn't convert line-breaks to markup, although it can.

I'm changing the default behaviour so that if there are line breaks, but no markup, it will automatically convert \n to <br>.  That should fix things up.  (There's also a problem with comments imported from Movable Type showing both markup and converted line breaks so that everything is double-spaced; this fix will fix that too.)

18

"That will probably take somebody with "more money than sense" to take a gamble, claim a plot, and force governments to either come to an agreement or de facto acknowledge their claim."

In the words of Leslie Fish, "Queen Isabella, where are you today? The new Chris Columbus is wasting away. The same game is waiting, but no one will play..."