Shuttle Is Dead : What Have We Got To Deal With Emergencies?

Originally posted by Maslo
reply to post by nobodysavedme

Nope, even with 4 engines thrust to weight ratio is well below 1. Also, you cannot accelerate slowly because then you run out of fuel before reaching orbital speed.

edit on 30/12/11 by Maslo because: (no reason given)

edit on 30/12/11 by Maslo because: typo

the 747 has fuel endurance of at least 12 hours minimum and up to 20 hours.

the f16 fighting falcon has ratio of:- Thrust/weight: 1.095 from wiki.

thrust to Weight Ratios of all Fighter Planes

TWR or T/W ratio = (Max Thrust of Engine[s] / (Empty Weight + (3.505 Tonnes of Fuel & Weapons, or only Internal Fuel)))

1.30 - Su-35BM
1.29 - F-15K
1.26 - Su-27S
1.25 - Eurofighter
1.24 - Mig-35
1.23 - Su-27SK & J-11A
1.19 - Rafale C
1.19 - Mig-29M/M2
1.19 - F-15C
1.18 - F-22 (T/W = 1.37 with Round nozzles)


many other fighters have even higher thrust/weight ratio.


and that is an old plane with old engines from many years ago and have improved since.

we could equip the 747 with new engines allowing # Thrust/weight: 1.095 or similar and it would fly using wing lift up to 60000 feet which is the ceiling and then at an upward angle of 45 degrees using onboard oxygen augmentation for the jet/turboprop hybrid engines.

most of the fuel is used in a conventional rocket within 5 minutes.

this would be the opposite of the rocket.

reply to post by nobodysavedme


Aside from the hugh wings waste of a 747 design, you cannot operate a jet engine with LOX. Airflow into a turbofan engine has to be compressed to subsonic speeds. It requires a ramjet or scramjet engine to operate with supersonic airflow through the engine but a scramjet can't operate at slower than supersonic speed thus you cannot take off from a standstill with only a scramjet. Scramjets have no movable parts like turbojet engines so a hybrid to do the work of both is not reality. Also a scramjet is air breathing and can't be liquidly fueled.

This is why rockets are used, they operate in and out of the atmosphere.

Scramjets are under development by at least a dozen countries.

I tried to give you a link for the only real concept development for scaled up passenger/cargo hypersonic experimental design submission that was cancelled in 93 due to costs and questionable proof of operational capacity, the X-30.

That concept led to miniature concept hypersonic experiments like X-43 and on to today's X-51.

Links in those articles illustrate why even concept designs of turborocket engines cannot operate in space. Would also help to familiarize yourself with the developmental stages of the SR-71 Blackbird engines. Its just not efficient to have both systems in one when there are rocket engines, or rockets like the Pegasus dropped from B-52s leaving the hugh aircraft behind.

Of current technology a rocket is the only propulsion that doesn't require two different systems, ion thrusters don't have the trust to lift through the atmosphere, they can only be started in space for any usable thrust to energy requirements.

Originally posted by nobodysavedme
it is a fallacy you need to go to mach 2 OR MACH 20 to go into orbit.

look at atmospheric study balloons reaching very high earth altitude by just FLOATING UP.....SLOWLY.

First you need to understand what an "Orbit" is. An orbit isn't simply about going high. An orbit is achieved by moving a certain speed "sideways" or parallel to the ground.

An orbit is really all about falling back to Earth. An object being pulled back to Earth actually defines the orbit. The space station is actually in a free-fall, being pulled back toward the earth by Earth's gravity -- THAT'S what defines its orbit.

Things in orbit are always falling back toward the earth due to the pull of gravity. When something is going fast enough while moving parallel to the surface of the Earth, that object can't "fall" to the ground because the Earth is curved and it curves away from the object before it hits the ground.

See "Newton's Cannonball" to get an explanation about how orbits work:
Newton's Cannonball

In fact, if something was going fast enough, it could orbit the Earth at just a meter off of the ground (assuming the Earth was smooth). The further out you are, the slower you need to go to achieve an orbit. The Space Station (and formerly the shuttle) is in low-Earth orbit at only 250 miles up. Because it is relatively low, it needs to move sideways at 17,000 mph to stay in orbit (basically to "miss the ground" as the Earth curves under it). A satellite 23,000 miles up only needs to move sideways at about 1000 mph to stay in orbit.

Therefore, for your 747 to achieve an orbit like that of the space station, it would need to be moving 17,000 mph parallel to the ground by the time it runs out of fuel, or else gravity would pull it back down, crashing it to the Earth. I suppose if it was at a higher altitude, it wouldn't need to move as fast to achieve an orbit, but getting to that higher altitude takes a lot more fuel.

I remember reading all about the space shuttle, including its operational history and scope. I'm asking here as it is on topic but I seem to remember about reading that the shuttle when first launched back in the day. Was capable of so much more than it has done, granted it wasn't designed to go fast but it could make it.

I remember reading about NASA claiming that it could reach the moon and land when the shuttle first came out, that it was capable of going much farther than it has gone in its operational lifetime. I wonder, if any one else remembers this? I could be wrong, after all I could have just confused the whole matter with a movie, or fictional book for all I know. Let me know either way guys I look forward to hearing from you!

reply to post by Reaper2137


The Space Shuttles had a 60 foot long by I think a 13 foot in diameter cargo bay before it's internal fuel and turbo pumps for it's main engines. Instead of hauling cargo out to space and fitted instead with liquid oxygen and liquid hydrogen tanks it would not be inconceivable that it couldn't achieve earth escape velocity if launched with enough power for it to conserve the fuel it carried, perhaps 4 solid rocket boosters instead of just two. The main engines on the shuttle were very powerful but also very thirsty, but from LEO its over million pounds of thrust could conceivably propelled it to earth escape velocity but it was very mission specific, like most launches are.

It likely would have to slingshot around the moon to return to earth though, forget about it landing and taking off from the moon that is a ludicrous proposition. Its thermal protective tiles likely would provide for better radiation protection than what the Apollo spacecrafts used, layers of burnable aluminum alloys that peeled away during reentry, at around MACH 25.

To answer the question NO, I never heard about or read about any missions other than LEO planned for the Space Shuttles. It was quite a big craft just to get to LEO.

This is most of the Galileo launched from the cargo bay, that went to Saturn.

The relative size of the Shuttle next to a Soyuz.

Originally posted by Reaper2137
I remember reading about NASA claiming that it could reach the moon and land when the shuttle first came out, that it was capable of going much farther than it has gone in its operational lifetime.

The Shuttle was designed to be for Earth orbit only. It was never intended to go anywhere else. It's a very inefficient design for interplanetary travel, with lots unnecessary weight (wings, tail, landing gear, etc). If the Shuttle were to re-enter the atmosphere at the same speed that the Apollo missions did, when returning from the Moon, it would snap those wings right off.

reply to post by nobodysavedme

many other fighters have even higher thrust/weight ratio.

Keyword is fighters. I dont get why are you fixated on 747, which does not have T/W ratio higher than 1 even with 4 modern engines, considering that it is a passenger plane. But even with fighters, it is impossible to achieve orbit.

the 747 has fuel endurance of at least 12 hours minimum and up to 20 hours.

Not at high thrust, but at cruising flight. At thrust above T/W of 1, any plane would run out of fuel long before achieving orbital speed.

reply to post by LightAssassin


Yep, we have our top secret space fleet, you know the stuff that Gary saw when he was hacking, that will keep us all safe in such an event.

reply to post by nobodysavedme


This link will surely interest you, a single-stage to orbit spaceplane being developed, similar to your concept:

Skylon

Note that it still uses the engine as a rocket when above the atmosphere, because that is the most-fuel efficient way to reach orbital speed. Payload capacity is also poor when compared to conventional rockets.

Thanks you guys for the reply's, I just remember reading about boasting what the shuttle could do before the first launch. I'm not older than the shuttle at least I don't think I am. I am just an avid reader. I didn't think it would work well as an interplanetary space craft. I just remember reading that NASA originally said that it was possible.

although like I said I could be wrong. I think it would be nice to see the replacement that NASA had come back online, It looks like a modern upgrade of the Saturn V, Apollo rockets.The Crew compartment looks like a spot on albeit larger version. I've often wondered were NASA would be right now if Obama hadn't killed the program. I think that was the worst mistake of his presidency. The other mistake was his winning the race in the first place. (that is another debate)

I thank the posters for their time, and you guys have no ideal how good it feels to not have people yelling or calling me stupid for being wrong. you guys are the reason I joined this site in the first place. Keep up the good work and being the nice and great people you are!

reply to post by Reaper2137

I've often wondered were NASA would be right now if Obama hadn't killed the program. I think that was the worst mistake of his presidency.

It would be in even deeper state of despair. Constellation program made little technical and economical sense, and was seriously underfunded and delayed. When it comes to spaceflight, Obamas policy is actually similar to that of Tea party, utilising existing commercial systems. If you want to blame someone, then it is the Congress that pushes the SLS and cuts for commercial.

Originally posted by Maslo
reply to post by Reaper2137

 

I've often wondered were NASA would be right now if Obama hadn't killed the program. I think that was the worst mistake of his presidency.

It would be in even deeper state of despair. Constellation program made little technical and economical sense, and was seriously underfunded and delayed. When it comes to spaceflight, Obamas policy is actually similar to that of Tea party, utilising existing commercial systems. If you want to blame someone, then it is the Congress that pushes the SLS and cuts for commercial.

I agree with you except that I think all Obama cared about was cutting or at least containing NASA's budget, so he could spend the money on other priorities.

reply to post by cloudyday

I agree with you except that I think all Obama cared about was cutting or at least containing NASA's budget, so he could spend the money on other priorities.

Actually, over the past years white house proposed a small increase and then a freeze on NASA budget. It was the congress that is responsible for cuts.

reply to post by Wirral Bagpuss



Its ok the Chinese are working on a comprehensive space program.. Give them 5 or 10 years and we will have a new generation of shuttles...

Originally posted by Maslo
reply to post by nobodysavedme

 

This link will surely interest you, a single-stage to orbit spaceplane being developed, similar to your concept:

Skylon

Note that it still uses the engine as a rocket when above the atmosphere, because that is the most-fuel efficient way to reach orbital speed. Payload capacity is also poor when compared to conventional rockets.

edit on 3/1/12 by Maslo because: rocket

edit on 3/1/12 by Maslo because: payload

i know about skylon.

it is a paper pipe dream.

the 747 exists already.

we could trade the long fuel endurance of the 747 for higher thrust to achieve orbit.

how long does it take to accelerate from 0 to 11200 metres per second at a net acceleration of an average 1 metres/second.

v/a=11200 seconds =4 hours.

remember the acceleration will be lower at the start and will increase as the aircraft rises higher due to lowering of air resistance.

also the aircraft will be at an angle of 45 degrees up 60000 feet wing lift ceiling and will be lighter due to fuel use.

Originally posted by Maslo
reply to post by nobodysavedme

 

many other fighters have even higher thrust/weight ratio.

Keyword is fighters. I dont get why are you fixated on 747, which does not have T/W ratio higher than 1 even with 4 modern engines, considering that it is a passenger plane. But even with fighters, it is impossible to achieve orbit.

the 747 has fuel endurance of at least 12 hours minimum and up to 20 hours.

Not at high thrust, but at cruising flight. At thrust above T/W of 1, any plane would run out of fuel long before achieving orbital speed.

the bigger the rocket the more load you can carry...hence the 747...little point in putting up dinky toys in space like the useless shuttle which could only go into LEO.

the 747 engines can be replaced with improved ones.

we could trade the long fuel endurance of the 747 for higher thrust to achieve orbit.

how long does it take to accelerate from 0 to 11200 metres per second at a net acceleration of an average 1 metres/second.

v/a=11200 seconds =4 hours.

remember the acceleration will be lower at the start and will increase as the aircraft rises higher due to lowering of air resistance.

also the aircraft will be at an angle of 45 degrees up 60000 feet wing lift ceiling and will be lighter due to fuel use.

reply to post by nobodysavedme

the 747 exists already. we could trade the long fuel endurance of the 747 for higher thrust to achieve orbit.

Once again, 747 is incapable of achieving T/W above 1. Even if it could, it is impossible to achieve it for 4 hours for any aeroplane under the sun, period.

Just give it up already, you are not the first one to get this idea, and far more qualified people than you or me dismissed it quickly

Originally posted by Maslo
reply to post by cloudyday

 

I agree with you except that I think all Obama cared about was cutting or at least containing NASA's budget, so he could spend the money on other priorities.

Actually, over the past years white house proposed a small increase and then a freeze on NASA budget. It was the congress that is responsible for cuts.

True, but emphasis on the word "small". As I recall it was barely equivalent to inflation, but maybe I'm remembering wrong.