... that's amateur! I mean heck, I was just interviewing for an entry level job and they wanted me to give them an email address that wasn't work related to communicate with. I mean, come on, if entry level employers are that sensitive, what is your million dollar arse doing talking to Google on a Microsoft computer?
... they are missing the point, the point is not that there is no place for using Google in research for stories, Google is just pissed that personal information about their CEO was disseminated. They wouldn't care if you used Yahoo to get it, or MSN even.
The other cost associated with Edwards is the sand - the runways are sand runways, they have to clean out the shuttle with a fine toothed comb. The original mission profile was to launch in Florida, land at Edwards, to keep everyone happy, but after STS1 they said screw that, this damn sand is too much trouble... now Edwards is just a contingency.
Normally the shuttle lands in Florida and launches in Florida.
The other cost associated with Edwards is the sand - the runways are sand runways, they have to clean out the shuttle with a fine toothed comb. The original mission profile was to launch in Florida, land at Edwards, to keep everyone happy, but after STS1 they said screw that, this damn sand is too much trouble... now Edwards is just a contingency.
The problem was hydrogen peroxide. His first engines were built around the stuff. The way hydrogen peroxide works is you catalyze it - that is run it through a mesh of material that reacts with it to liberate steam and hot oxygen, which you then combust with a fuel. Hydrogen Peroxide is a nasty beast. It's hard to find vendors to sell to you (at rocket grade concentrations, 90-98%), and combustion is tricky. After a lot of experimenting (and he himself will tell you - a lot of valuable data gained; he was able to test at rates higher than using other fuel combos) they gave up on it.
Now they are using liquid oxygen as an oxidizer. They aren't stalled. They are exploring their options. If you look at NASA they have really only done things one way, the convergent-divergent regeneratively cooled nozzle, using O2 and H2, occasionally kero. He's sticking his neck out trying something new, it just takes awhile with limited funds. He's not stalled now.
If you would have read through armadillo's website you would see that he has been putting a serious effort in. As an aerospace engineer who has been keeping tabs on John for several years I can assure you he's got his design well thought out.
Throatless rockets aren't new... they've been around for awhile. They aren't as efficient as a throated rocket but they offer some operational advantages (namely in throttling, which is nice for a powered reentry). -everphilski-
The article is a f*ckign rant, however there is some validity to the statement. Without Windows we wouldn't have the popularization of computers we have today. "A computer in every household" and then some (I have four... between my wife and I). Microsoft helped that happen and they do deserve some respect for that.
As for now? Yea, they still hold a >90% market share. You can say what you want, but when it comes down to it the reason is that for many businesses there is no accessible substitute. And this trickes down into the home. Microsoft still deserves some love. Profiteering gluttons, WTFever, I can get a Dell for $299 with Windows installed. (not that I would... just a case in point. I prefer to roll my own)
Linux has its place. But Microsoft has carried the brunt of the load in bringing the desktop to the common man.
My philiosophy is to pay for the hardware, screw everything else. I don't care about reviews. I don't care about extended service contracts (except in rare contracts). Every sales person is out to make a buck, that's a fact of life, if you are so naive as to despise anyone who "works for money" you despise prettymuch everyone in the modern world.
New Egg is great. I've ordered from them multiple times. Only once have I had a defective part (I purchased a refurbished motherboard) and they replaced it promptly, shipping me a replacement before they received the defective part back from me.
You should *NEVER* trust a review on a commerce site. That goes without saying. Always go to an independant source that doesn't have a bias. That's like going to a car dealership and asking the dealer their honest opinion on the car in the window. Stupid.
Mercury escape tower does just that. Coupled with a few heavy lift helicopters for CEV recovery and you are good to go. Escape tower has always been part of the plans for a top-mounted CEV.
Individual ejection seats are a Bad Idea when you are going supersonic.
No, they are going to go back to the schematics and make some changes and re-tool it. The certification scheme wouldn't allow for just taking a J2 off the shelf. And there aren't enough just lying around anyways to support the space program.
I think you misread. The article says odds are 1 in 100. Shuttle odds (according to the engineers - the bese people to ask) are roughly 1/100. A little better than that, actually. The new shuttle derived vehicles are looking to be 1/400.
You have to insulate tanks. Tanks have been insulated since cryogenic propellants have been used.
You can either insulate them from the outside or the inside. Outside you get debris. Inside you get debris. If your vehicle is on top, we don't care about debris outside. Inside, debris clogs our turbopumps and causes us to abort. And insulating the outside is cheaper.
The most expensive part of the shuttle stack is the orbiter. Re-using the ET and the solid rocket boosters would save years of development time and yes, money.
They need to stick the Shuttle in the smithsonian and stick with the pieces that work.
Single-Stage to orbit isnt feasible (yet). We need either a breakthrough in materials technology or propulsion performance. The rocket equation is
Delta-V = g * Isp * ln( MR )
where:
Delta-V: velocity required to achieve LEO (7.6 km/s best case scenario: but you need to add gravity and drag losses, add at least 1 km/s)
g: gravity (9.8 m/s)
Isp: Specific impulse of your propellant. This is an efficiency factor: 1 kg of propellant generates Isp kg of thrust. Hydrogen and Oxygen properly mixed generates an Isp of about 450 [seconds] in a vacuum. That is the upper level of chemical propulsion.
MR: Mass ratio. Mass that sits on the launchpad divided by the mass that achieves orbit.
Play around with that equation and you will see STS0 just doesn't work out yet. Our feasible Isp is way too low and our current material properties won't let us build a ship with a MR of over 10 that can return to earth safely.
Interesting factoid though, if you attached the space shuttle main engines to the external tank and just made that a launch vehicle, as a single stage it could put damn near 100 tons into LEO... as a single stage... but your not coming home. Reinforcing the ET takes such a mass penalty your payload is effectively reduced to zero.
Slashdot Mirror
... but still... you dont bring sh*t like that into your current employers place of business. Nailed his coffin shut.
-everphilski-
... that's amateur! I mean heck, I was just interviewing for an entry level job and they wanted me to give them an email address that wasn't work related to communicate with. I mean, come on, if entry level employers are that sensitive, what is your million dollar arse doing talking to Google on a Microsoft computer?
....Idiot!
(Obligatory Napolean Dynamite quote)
-everphilski-
That's pretty slick, wish you could use a pencil tho...
-everphilski-
Since a cardboard box isn't Digital, and he's not Copying anything, how is DMCA applicable?
Learn the English language. Digital is an adjective modifying millenium (what millenium? the digital one).
And copyright doesn't have to have anything to do with copying; misappropriation of a companies logo bearing property can invoke copyright violations.
-everphilski-
... they are missing the point, the point is not that there is no place for using Google in research for stories, Google is just pissed that personal information about their CEO was disseminated. They wouldn't care if you used Yahoo to get it, or MSN even.
-everphilski-
Wow.
-everphilski-
The other cost associated with Edwards is the sand - the runways are sand runways, they have to clean out the shuttle with a fine toothed comb. The original mission profile was to launch in Florida, land at Edwards, to keep everyone happy, but after STS1 they said screw that, this damn sand is too much trouble... now Edwards is just a contingency.
-everphilski-
Normally the shuttle lands in Florida and launches in Florida.
The other cost associated with Edwards is the sand - the runways are sand runways, they have to clean out the shuttle with a fine toothed comb. The original mission profile was to launch in Florida, land at Edwards, to keep everyone happy, but after STS1 they said screw that, this damn sand is too much trouble... now Edwards is just a contingency.
-everphilski-
The problem was hydrogen peroxide. His first engines were built around the stuff. The way hydrogen peroxide works is you catalyze it - that is run it through a mesh of material that reacts with it to liberate steam and hot oxygen, which you then combust with a fuel. Hydrogen Peroxide is a nasty beast. It's hard to find vendors to sell to you (at rocket grade concentrations, 90-98%), and combustion is tricky. After a lot of experimenting (and he himself will tell you - a lot of valuable data gained; he was able to test at rates higher than using other fuel combos) they gave up on it.
Now they are using liquid oxygen as an oxidizer. They aren't stalled. They are exploring their options. If you look at NASA they have really only done things one way, the convergent-divergent regeneratively cooled nozzle, using O2 and H2, occasionally kero. He's sticking his neck out trying something new, it just takes awhile with limited funds. He's not stalled now.
-everphilski-
pound-force, as contrasted to pound-mass.
-everphilski-
If you would have read through armadillo's website you would see that he has been putting a serious effort in. As an aerospace engineer who has been keeping tabs on John for several years I can assure you he's got his design well thought out.
Throatless rockets aren't new... they've been around for awhile. They aren't as efficient as a throated rocket but they offer some operational advantages (namely in throttling, which is nice for a powered reentry).
-everphilski-
The article is a f*ckign rant, however there is some validity to the statement. Without Windows we wouldn't have the popularization of computers we have today. "A computer in every household" and then some (I have four ... between my wife and I). Microsoft helped that happen and they do deserve some respect for that.
As for now? Yea, they still hold a >90% market share. You can say what you want, but when it comes down to it the reason is that for many businesses there is no accessible substitute. And this trickes down into the home. Microsoft still deserves some love. Profiteering gluttons, WTFever, I can get a Dell for $299 with Windows installed. (not that I would... just a case in point. I prefer to roll my own)
Linux has its place. But Microsoft has carried the brunt of the load in bringing the desktop to the common man.
-everphilski-
My philiosophy is to pay for the hardware, screw everything else. I don't care about reviews. I don't care about extended service contracts (except in rare contracts). Every sales person is out to make a buck, that's a fact of life, if you are so naive as to despise anyone who "works for money" you despise prettymuch everyone in the modern world.
-everphilski-
New Egg is great. I've ordered from them multiple times. Only once have I had a defective part (I purchased a refurbished motherboard) and they replaced it promptly, shipping me a replacement before they received the defective part back from me.
You should *NEVER* trust a review on a commerce site. That goes without saying. Always go to an independant source that doesn't have a bias. That's like going to a car dealership and asking the dealer their honest opinion on the car in the window. Stupid.
-everphilski-
Obligatory Family Guy Quote:
... arrested for "teaching the evolutionary theory that Gil Gerard used a time machine, went back and ejaculated into the primordial ooze" ...
-everphilski-
Blessed are they who have not seen, and yet have believed
Mercury escape tower does just that. Coupled with a few heavy lift helicopters for CEV recovery and you are good to go. Escape tower has always been part of the plans for a top-mounted CEV.
Individual ejection seats are a Bad Idea when you are going supersonic.
-everphilski-
No, they are going to go back to the schematics and make some changes and re-tool it. The certification scheme wouldn't allow for just taking a J2 off the shelf. And there aren't enough just lying around anyways to support the space program.
-everphilski-
Enterprise was an aerodynamic mockup, nothing more.
-everphilski-
Russians have been using chilled Kerosene (chilled to raise the density) for years. It still isn't enough.
... but that required pressurized tanks, which raise your mass fraction.
Amateurs have been exploring propane
-everphilski-
... they still had foam problems on STS1.
-everphilski-
I think you misread. The article says odds are 1 in 100. Shuttle odds (according to the engineers - the bese people to ask) are roughly 1/100. A little better than that, actually. The new shuttle derived vehicles are looking to be 1/400.
-everphilski-
You have to insulate tanks. Tanks have been insulated since cryogenic propellants have been used.
You can either insulate them from the outside or the inside. Outside you get debris. Inside you get debris. If your vehicle is on top, we don't care about debris outside. Inside, debris clogs our turbopumps and causes us to abort. And insulating the outside is cheaper.
Think of it as the lesser of two evils.
-everphilski-
The most expensive part of the shuttle stack is the orbiter. Re-using the ET and the solid rocket boosters would save years of development time and yes, money.
They need to stick the Shuttle in the smithsonian and stick with the pieces that work.
-everphilski-
Single-Stage to orbit isnt feasible (yet). We need either a breakthrough in materials technology or propulsion performance. The rocket equation is
... as a single stage ... but your not coming home. Reinforcing the ET takes such a mass penalty your payload is effectively reduced to zero.
Delta-V = g * Isp * ln( MR )
where:
Delta-V: velocity required to achieve LEO (7.6 km/s best case scenario: but you need to add gravity and drag losses, add at least 1 km/s)
g: gravity (9.8 m/s)
Isp: Specific impulse of your propellant. This is an efficiency factor: 1 kg of propellant generates Isp kg of thrust. Hydrogen and Oxygen properly mixed generates an Isp of about 450 [seconds] in a vacuum. That is the upper level of chemical propulsion.
MR: Mass ratio. Mass that sits on the launchpad divided by the mass that achieves orbit.
Play around with that equation and you will see STS0 just doesn't work out yet. Our feasible Isp is way too low and our current material properties won't let us build a ship with a MR of over 10 that can return to earth safely.
Interesting factoid though, if you attached the space shuttle main engines to the external tank and just made that a launch vehicle, as a single stage it could put damn near 100 tons into LEO
-everphilski- -- Rocket Scientist