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DLHill
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How are space shuttles accelerated to escape velocity? Would it be possible to build a rocket at home that would be capable of getting into space if it were to use liquid hydrogen and oxygen as fuel?
By hitching a ride on a powerful rocket much bigger than the shuttle.DLHill said:How are space shuttles accelerated to escape velocity?
With no payload? Probably, depending on the size of your home. But one stray spark, and your home would be in orbit before the rocket!Would it be possible to build a rocket at home that would be capable of getting into space if it were to use liquid hydrogen and oxygen as fuel?
Not possible. While the Shuttle released spacecraft that went to geosynchronous altitude and beyond, the Shuttle itself never went beyond LEO. The highest altitude attained by the Shuttle was 600 km during STS-31.K^2 said:First of all, Shuttles don't reach escape velocity. They never went past geostat, and most missions have been to LEO. Though, in theory, it might have been possible.
DLHill said:How are space shuttles accelerated to escape velocity? Would it be possible to build a rocket at home that would be capable of getting into space if it were to use liquid hydrogen and oxygen as fuel?
Breaking atmosphere is comparatively easy. Still a challenge, but doable. LEO is about 7.8km/s. It takes about 9-9.5 km/s of specific impulse to actually establish such an orbit. The .4 km/s boost due to Earth rotation is wasted if you don't actually establish orbit, so for a small rocket, you would need a little over 2km/s of specific impulse to reach LEO altitudes. High power rocket motor can give you that with the right build.phinds said:I do seem to remember, however, that they HAVE exited the atmosphere (if you're not too picky about defining where the atmosphere ends) before falling back, but that might have been one launched from a high-flying balloon.
256bits said:Home built hydrogen-oxygen rocket.
What is your budget? I think you need more than $100 for this kind of adventure.
Sure, and it's impossible to build an airplane in your garage that will stay in the air for more than a minute, because the Wright Flyer didn't either.voko said:The first satellite launched by the US was about 14 kg. To put in orbit, the four-stage rocket Juno I was used, and that payload was its maximum. The mass of Juno I at liftoff was about 30 tons. I guess that is the closest to a "home rocket" capable of inserting something minimally useful into orbit.
For $1,000, you might be able to build a rocket that breaks sound barrier and goes up a few kilometers.DLHill said:Maybe $1,000. I am going to build it in stages though, so it won't be all at once.
K^2 said:I understand where you are coming from with your comparison, but a regular Joe today has access to composite materials, better fuels, and computational power that could not have been dreamed of in the 50s.
Not for $1000 he doesn't.K^2 said:Sure, and it's impossible to build an airplane in your garage that will stay in the air for more than a minute, because the Wright Flyer didn't either.
I understand where you are coming from with your comparison, but a regular Joe today has access to composite materials, better fuels, and computational power that could not have been dreamed of in the 50s.
On Juno I? Are you joking? There wasn't a single engine on that rocket that exceeded 2.5km/s. LH2/LOX gives you 4km/s+. You can get 4km/s on an aerospike with LH2. Something that wasn't even an option back then. And the difference between 2.5km/s and 4km/s is enormous. On a 9km/s burn, that's a factor of 4 in fuel before I factor in the stages. There is a reason Juno I had to go with a 4 stage design. And that's where bulk of the extra weight came in. An LH2 rocket can be a two-stager easily. SSTO if you are smart about it. Venture Star was designed for a 50:1 liftoff to payload ratio. Compare it to Juno's 2,000:1.voko said:What better fuels? We are talking about liquid oxygen and hydrogen here.
I can buy a modern APCP model rocket engine for under $50. I can buy a carbon fiber tube to use as a body for under $20. I can buy a microcontroller with built in accelerometers and more computational power than Apollo 11 combined for $5 and use it for basic guidance. The remaining $900-something I can pocket, and I'd still have a rocket that makes use of modern fuels, materials, and electronics.russ_watters said:Not for $1000 he doesn't.
I'm the only one actually quoting numbers so far.sophiecentaur said:the actual numbers involved
K^2 said:On Juno I? Are you joking?
An LH2 rocket can be a two-stager easily.
Venture Star was designed for a 50:1 liftoff to payload ratio. Compare it to Juno's 2,000:1.
The reason Soviet-built Soyuz-U rockets are still using kerosene is because tanks for LH2 are extremely heavy, making up the bulk of the stage's mass.
So yes. Using Juno I as an example of how difficult it is to build a rocket is outdated beyond any honest use. This is not a technology standard on which someone with a limited budget is going to build a rocket this day.
The technology standard is going to be something like Falcon 9, which gets 10,000 kg to LEO with a 330,000 kg rocket. That's the difference between using technology of late 1950's and technology of late 2000's.
Now, if you can maintain that 33:1 ratio, and launch a 10kg satellite with a 330kg rocket
And for the second time, no, we are not talking about a hobby basement build. We are talking about "amateur rocketry". Basically, anything that's not built for profit or some sort of scientific gain. Kind of like the Space Shot I mentioned earlier.
Fire a rocket to reach a height of ~100km, let it fall back. delta_v ~ 1.5km/s plus something for air drag + finite burning time. Should be possible with a single stage.DLHill said:Would it be possible to build a rocket at home that would be capable of getting into space if it were to use liquid hydrogen and oxygen as fuel?
A space shuttle reaches escape velocity through a combination of rocket propulsion and gravity assist. The rocket engines provide the necessary thrust to overcome Earth's gravitational pull, while the shuttle's trajectory is carefully calculated to take advantage of the gravitational pull of other celestial bodies, such as the moon or other planets.
The escape velocity for a space shuttle is approximately 25,000 miles per hour, or 40,000 kilometers per hour. This is the minimum speed required for a spacecraft to break free from Earth's gravitational pull and enter into orbit.
The time it takes for a space shuttle to reach escape velocity varies depending on the specific launch trajectory and the type of propulsion system used. Generally, it takes a few minutes for a space shuttle to reach escape velocity.
One of the main challenges for space shuttles when reaching escape velocity is overcoming Earth's gravity. The immense force of gravity requires powerful rocket engines and precise calculations to achieve the necessary speed. Additionally, the extreme speeds and forces involved can put a lot of strain on the shuttle and its components, requiring careful engineering and design.
Yes, a space shuttle can reach escape velocity on its own through the use of its rocket engines. However, as mentioned before, it may also take advantage of the gravitational pull of other celestial bodies to conserve fuel and reach escape velocity more efficiently. Additionally, space shuttles may also receive assistance from launch systems or external boosters to help reach escape velocity.