... Planes could be fuelled by hydrogen. Only a few hundred major airports would need changing, unlike the millions of car gasoline stations. Cars suffer...
I guess this would be both an engineering and financial problem -- but not an insoluble one. At first glance, though, wouldn't this require larger, sturdier...
... I think the main problem is physics: energy density. Jet Fuel has an energy density of 42.8 MJ/kg (weight) or 33 MJ/L (volume). For hydrogen it would...
... but not an insoluble one. At first glance, though, wouldn't this require larger, sturdier fuel tanks, making planes even heavier? ... Nice aircraft. I...
Hydrogen would a good substitute fuel, but it was tried over and over again around the turn of the last century thru the nineteen-thirties, but it was its own...
Space ElevatorHi, group... I mostly just lurk, and the exchanges here have always been very interesting. I saw an article on Space.com recently that NASA is...
... Nah, it's not much more explosive than gasoline. Lots of rockets use it without too much problem in fact. It's fiddly to handle safely, but done routinely....
At Mach 5 or higher it does not really make sense to push through the atmosphere. This is why the future of intercontinental travel is outside the atmosphere. ...
... It pretty much isn't anyway. Supersonic aircraft fly very high, hypersonics, higher. There's hardly any air up there. ... If you mean rockets, no. ... No,...
... That makes sense. As you increase speed and altitude, though, isn't there a point somewhere when rockets become more efficient than jets? Is that point...
... Around 3-4. Also depends on what you call efficient, time to target or mpg. My experience with Hydrogen, and I have some, is the tanks are big balloons...
Jerry Irvine
01rocket@...
Jul 18, 2008 9:41 pm
8347
... It's a complicated question. As a rough rule of thumb, rockets work best at speeds around mach 8-12; and up, but are very inefficient below about Mach 5....
I disagree, A climber that can take a laser hit that could take out plane, would not be very practical for a transportation system. I do agree that ther might...
If you introduce Hydrogen power plane, then some mix of NERVA rockets, and scram jets should make a single stage to orbit. I am suggesting that the rocket and...
... Making something laser proof is not hard- wrapping it in shiny foil works very well. The problem is that most civil infrastructure is not wrapped in foil. ...
... Pretty much. But the power and cost of the lasers is very high. You need about 1MW of laser per kg of payload to orbit, and there's a minimum size. -- -Ian...
... But ICBMs don't glide. If I understand the antipodal rocket concept correctly, most of the way to the other side of the Earth is done by unpowered...
... Exactly right. What are you missing? The energy requirement to punch through the atmosphere to an altitude and speed sufficient to do that is very...
Jerry Irvine
01rocket@...
Jul 19, 2008 4:22 am
8356
Hey all, Today was the first day of the 2008 Space Elevator Conference in Redmond Washington! For those of you unable to make it Marc Bouchard at the Space...
... A good glide helps quite a bit, you can gain hundreds of kilometers. Glide ratios at hypersonic speeds are maybe 6, so at an altitude of 30 km, you might...
... One significant problem with rockets is during the acceleration phase; rockets just thow a lot of propellant out the back *way too fast* (all jet engines...
... Most of the propellant is burnt at low speed though, where efficiency is appalling. The combustion efficiency of the shuttle is about 60+% maybe, but the...
... here have always been very interesting. ... looking at SBSP - space based solar power. ... physical connection, instead of microwave or laser? ... ...
If SPS were based on the orbital ring concept, where the rings are in low earth orbit, then a power line of only a few hundred miles would be required, instead...
