Discussion
The latest NASA Mars probe has just been successfully launched in the last 15 minutes using an Atlas Centaur rocket. It looks like it is now in earth orbit. In a few hours time, once the systems have been checked out, the Centaur upper stage will fire again to place the probe on a trajectory to Mars where it will arrive next spring.
>> Edited by Eric Mc on Friday 12th August 13:01
>> Edited by Eric Mc on Friday 12th August 13:01
NASA's record is pretty good. Most of their probes end up in the right place, including Uranus (if that was the intended target - as it was for Voyager 2).
At the moment NASA has two healthy rovers operating on the Martian surface plus the Mars Global Surveyor sending back pictures of Mars in precedented detail. The new probe (MRO) will send back pictures 100 times more detailed than the MGS.
The European Space Agency's Mars Odyssey is also sending back fantastic pictures from Mars orbit.
It's actually getting a bit busy up there at the moment.
>> Edited by Eric Mc on Friday 12th August 13:24
At the moment NASA has two healthy rovers operating on the Martian surface plus the Mars Global Surveyor sending back pictures of Mars in precedented detail. The new probe (MRO) will send back pictures 100 times more detailed than the MGS.
The European Space Agency's Mars Odyssey is also sending back fantastic pictures from Mars orbit.
It's actually getting a bit busy up there at the moment.
>> Edited by Eric Mc on Friday 12th August 13:24
A science teacher of mine years ago said it was possible to create a hydrogen powered rocket which would run on hydrogen molecules found in space, and slowly accelerate. the faster it moves, the more hydrogen it uses, thus increasing its speed greatly reducing the time required to get to its destination. Would this be possible, given that there is no (or very little?) oxygen in space?
Rocket engines need oxygen to ensure the fuel mix can react in the combustion chamber and provide thrust. However, an ion drive spaceship does not need oxygen as it is firing out a low energy plasma beam from its exhaust. I'm sure free floating hydrogen atoms could be used as the raw fuel for an ion drive spacecraft but the problem is that hydrogen atoms are spaced very far apart in outer space. This would mean that the "intake" for the hydrogen atoms would have top be huge, maybe hundreds of kilometres accross.
The Centaur upper stage is about to fire to send the probe to Mars NOW.
The Centaur upper stage is about to fire to send the probe to Mars NOW.
UKBob said:
A science teacher of mine years ago said it was possible to create a hydrogen powered rocket which would run on hydrogen molecules found in space, and slowly accelerate. the faster it moves, the more hydrogen it uses, thus increasing its speed greatly reducing the time required to get to its destination. Would this be possible, given that there is no (or very little?) oxygen in space?
That's Red Dwarf, not real life I believe. Ion drives seem quite popular at the moment.
How long will this probe stay in orbit of Mars for? I've heard it can be used as a relay station for probes in years to come, and it will only be there for 4 years, anyone know?
UKBob said:
A science teacher of mine years ago said it was possible to create a hydrogen powered rocket which would run on hydrogen molecules found in space, and slowly accelerate. the faster it moves, the more hydrogen it uses, thus increasing its speed greatly reducing the time required to get to its destination. Would this be possible, given that there is no (or very little?) oxygen in space?
How much space would you need to have 1 ton of hydrogen ? and how many tons of hydrogen would you need to accelerate a 100 ton shuttle to a decent speed ?
Any scientists around?
>> Edited by scorp on Friday 12th August 13:55
UKBob said:
A science teacher of mine years ago said it was possible to create a hydrogen powered rocket which would run on hydrogen molecules found in space, and slowly accelerate. the faster it moves, the more hydrogen it uses, thus increasing its speed greatly reducing the time required to get to its destination. Would this be possible, given that there is no (or very little?) oxygen in space?
He was referring to a design called a 'Bussard Ramjet'.
It presuposes we have cracked the fusion problem. Plenty on the web, or Larry Niven Sci Fi books.
scorp said:
UKBob said:
A science teacher of mine years ago said it was possible to create a hydrogen powered rocket which would run on hydrogen molecules found in space, and slowly accelerate. the faster it moves, the more hydrogen it uses, thus increasing its speed greatly reducing the time required to get to its destination. Would this be possible, given that there is no (or very little?) oxygen in space?
How much space would you need to have 1 ton of hydrogen ? and how many tons of hydrogen would you need to accelerate a 100 ton shuttle to a decent speed ?
Any scientists around?
>> Edited by scorp on Friday 12th August 13:55
Decent speed is a difficult one!
In space fast is never (ever) fast enough. Even the speed of light is too slow to be ideal. It's more a question of how quickly can you accellerate/decellerate.
This is not true for rockets, but it is true for Ion propulsion, and this potential hydrogen idea.
The other thing to think about is that space is about the best vacuum you're likely to find. If it had lots of hydrogen, then it wouldn't be a vacuum.
Overall Ion propulsion, can get a small satellite to the moon (IIRC) in about a year. We Brits are doing that (cos it's cheap).
The hydrogen idea, would more than likely be of far poorer performance than a standard Ion propulsion system.
By way of comparison, a rocket, gets to the moon in about three days.
The hydrogen idea would work well for interstellar travel however. Unlike the Ion propulsion system, the fuel is genuinely free. Space is pretty big, and once the sun has gone, there is no other fuel, than starlight.
Since space is so big, and time is so long, it doesn't matter if accelleration is slow. Even if it takes a thousand years to add 100mph, you'll get to the speed of light eventually.
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Now theres an image I would rather not see on NASA's website !!!