People excited for successful launching of Shenzhou-6

It works by having a chemical reaction in its chamber which is then forced out of a nozzel.

It works on newtons third law
"To every action there is an equal and opposite reaction"

hope that helps .

Regards,

Chinawhite

Random thoughts: this is my first post I hope I don’t get a warning for this

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well nobody in here gets warnings whitout reasons, So you have nothing to fear, welcome to our forum and enjoy...

ahho said:

how does v-2 work????

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really crappy. it used a very primitive form of radio/gyro/gear guidance. thats why the germans were never able to use it on military targets. it could only kill random civilians.

trkl said:

Solid rockets have a lower ISP than liquid rockets, not a higher Isp. The US prefered solid rockets for ICBMs because they are easy to store and can be launched quickly, while most liquid rockeds have to store their fuel seperately and have to be fueled up right before launch. The US orbital launch vehicles have always used liquid fuels, or used rockets with a some solid stages and some liquid stages.

The shuttle uses solid rocket boosters, but its main engines run on liquid O2 and liquid H2. Oviously when you burn H2 and O2 you get H2O, aka water/steam. The US used to use fuels like NO4 and UMDH, they are good rocket fuels, but now the only liquid fuels used are H2/O2 or O2/kerosene due to environmental reasons (NO4 and UMDH are very toxic).

The Russian liquid rocket engines are very good, and in some cases superior to US designs. However, the US has been making throtleable liquid engines for many decades so it is not correct to say that the US uses only solid designs.

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I didn't say the US used Solid fuel propellants exclusively. The US prefers solid fuel rockets for a variety of applications. Military ICBM's and Rocket Boosters are the two biggest applications that favor solid rockets. The US space Shuttle relies overwhelmingly on the SRB (solid rocket boosters) for early liftoff from its launchpad.

Solid rockets are not as efficient as liquid rockets, and I was wrong to compare specific impulses. One reason the US had an endemic aversion to liquid fuelled rockets was due to the much lower reliability of liquid fuel engine ignitions compared to solid fuelled counterparts. That is also why the US preferred strapon boosters to be solid fuelled. If all initial stage engines are not firing simultaneously, the rocket will tear itself apart on the launchpad.

However, over the last 50 years, significant advances had been made in improving the reliability of liquid fuelled engine ignition.


It is no true that the US has been making throttleable liquid engines for 'many decades'. Not in regards to carrier rockets. Of course you can fish up designs for cruise missiles, but that has no manned space program application.
There is no reason for Lockheed martin to spend many millions (billions) of dollars on Soviet era throttle control technology if the US already had it for 'many decades'.

There is a difference between researching a technology for decades and actually having it for use in carrier rockets.

Fairthought said:

It is no true that the US has been making throttleable liquid engines for 'many decades'.

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The XLR-99 engine used on the X-15 in the late 50's is said to be the "first large, man-rated, throttleable, restartable liquid propellant rocket engine". So the US has had this tech since the 50's.

That is incorrect.

The US Experimented with throttleable engine designs going back decades. The X-series were all experimental. That's what the X stands for.


The X-15 has nothing to do with carrier rockets into space anyway. It was a research program that probed the limits of aircraft speed and altitude given the technology of the day. It provided the US with invaluable flight data that was later incorporated into the SR-71 Blackbird.

The X-15, which is an airplane, did have a liquid throttleable re-startable rocket engine. It was dropped from the underbelly of a B-52 at high altitude in order to give the engine plenty of time to start. This is because the liquid throttleable engine still had ignition reliablility problems.This is not something that a carrier rocket could afford to have. As I said before, all the engines in the first stage of a carrier rocket needs to fire simultaneously, or the rocket will tear itself apart. The US did not solve this problem, the liquid rocket engine was discarded and the technology for liquid throttleable engines for use in carrier rockets was never developed. That is, not until the 1990's when the a US corporation bought the technology from Russians.


Which brings us to the discussion of the defining the limit of space.

According to the Federation Aeronautique Internationale, space is arbitrarily defined as the altitude above 100 km over the earth. By this arbitrary definition, the X-15 barely managed to make it into 'space' twice.

However, that altitude is far, far below the minimum altitude needed to maintain low earth orbit. It is of no significance whatsoever to a manned space program unless you severely limit yourself to sub-orbital flights only (which is absurd).

Fairthought said:

This is because the liquid throttleable engine still had ignition reliablility problems.This is not something that a carrier rocket could afford to have. As I said before, all the engines in the first stage of a carrier rocket needs to fire simultaneously, or the rocket will tear itself apart. The US did not solve this problem, the liquid rocket engine was discarded and the technology for liquid throttleable engines for use in carrier rockets was never developed. That is, not until the 1990's when the a US corporation bought the technology from Russians.

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Liquid engines were not discarded, and every large orbital launch vehicle that the US has ever built uses liquid propellants. Many of those liquid engines have been throtleable. For example, ever notice the "go with throttle up" command in the space shuttle launch sequence?

I know that X-15 was a long way from being an orbital launch vehicle. However, it still had a large, throttleable, restartable, liquid engine that was reliable enough to be man-rated. There is really no reason why the engine of the X-15 could not be used in a launch vehicle.

from space.com:

BEIJING (AP) – China's next space flight will carry three astronauts into orbit to perform a spacewalk and prepare for an eventual space station, newspapers reported Thursday.

The government has said the next mission could be launched as early as 2007.

News reports Thursday said the 14 candidates for the next mission include Yang Liwei, Fei Junlong and Nie Haisheng – the three men who flew aboard China's first two manned space missions, Shenzhou 5 and Shenzhou 6.

A report in the Beijing Morning Post said that after Shenzhou 7, China would send two unmanned vehicles into space with equipment to set up a space station.

It is expected to take 6 1/2 years to develop rockets powerful enough to launch the necessary equipment, the paper said, citing Liu Zhusheng, chief designer of China's Long March rocket.

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putting all your eggs in one basket... not a good idea

walter said:

from space.com:

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so that means the rokets for the mission were already under development since 2000?

china better not send all of its former astronauts in one ship. if theres an accident, china would lose all the people with experience