NASA has a fine track record when it comes to winning space races, so it should come as no surprise that the space agency's Dawn spacecraft has set a new record for velocity change produced by spacecraft propulsion somewhere out in the middle of the asteroid belt. The Jet Propulsion Laboratory reported yesterday that the ion-propelled Dawn has accumulated 9,600 miles per hour of velocity since separating from its final rocket stage, setting a record for engine-powered spacecraft.
The new record eclipses the previous record for change in velocity held by Deep Space 1, which launched in 1998 but had its ion propulsion engines shut down years ago. By earthly standards, the build-up to Dawn's record may not appear so exciting; it took the spacecraft four days to go from 0 to 60 miles per hour after separating from its final rocket phase (the numbers herein are all recorded after separation from the carrier rocket, as it wouldn't be accurate to attribute to the ion engines the thrust from the initial rocket launch).
Why the slow start? Ion engines are incredibly efficient, which makes them well suited to deep space travel. Accelerating 60 mile per hour consumes a mere 37 ounces of the xenon propellant on board, and that propellant has to last. Dawn is expected to operate for eight or more years, and there are no refueling stations out there.
But by firing its three ion engines one at a time over 620 days -- accumulating another 60 miles per each day -- Dawn has reached its current astronomical speed and has no plans of slowing down. The three ion engines will log 2,000 days of operation over the course of the mission -- a full five-and-a-half years of continuous service -- creating a change in velocity of more than 24,000 miles per hour (and 3 billion miles traveled) by the time all is said and done. That won't come close to touching the all time speed record in space -- the Helios probes, aided by the Sun's gravity, topped out at more than 150,000 miles per hour -- but for an engine-powered craft that's nothing to scoff at.
As for mission duration under powered space flight, Deep Space 1 gets to keep that record for another few months until Dawn eclipses that record as well on August 10. Dawn's mission will take it to the asteroid Vesta in 2011 and 2012, and to the dwarf planet Ceres in 2015. Scientific data will start rolling in sometime in mid- to late 2011, when Dawn enters Vesta orbit.
hehe, even though it's technically Twin Ion Engine in Star Wars, Dawn is still a TIE Fighter with it's Three or Triple Ion Engines.
Is there Xenon on the moon? What's the biggest gas can we could build in orbit? Build a deep space probe with enough Xenon to reach Alpha Centauri.
One idea that I've heard was to use hydrogen because it is the most abundant element in space. It would burn the outside gases to propel it forward or collect it then burn it using the ion thrusters. Either way is difficult because you would have to always be looking for more hydrogen and if you can't find any then your screwed. Oh and I did the math. Traveling at 24,000 MPH it would take 64,427,259,600 years to get there, that's 64.4 Billion years. Sorry to inform you haha. If we could travel at light speed it would only take 4.37 years.
Remeber that its speed it 24,000mph OVER its speed granted by the initial rocket propulsion. The Dawn's fuel is also rather low, because thats all it needs. We could get going a LOT faster, and if we spent enough money, we could probably get enough propellant into space to have a spacecraft accelerate to a significant fraction of the speed of light, reducing the time to travel to 400-1000 years to get to Alpha-centary. Longer if you account for accelerating to top speed just before you need to start reducing your speed to prepare for orbit.
It still doesn't seem practical. We can barley achieve that speed right now. The speed of light is roughly 11,220,000 MPH. If a human went that fast they would die. 400 years is also not practical. There is a theory about how alien space craft would work and that theory is the only way deep space travel would work. That theory is to create a space craft that can basically create its own space/time bubble around it. This is because it would not be affected by the outside space and time therefore gravity, time, objects, etc. would not affect it and its contents. This ship could also be used to travel through time. Obviously this technology doesn't exist but some scientists believe that with some new elements it could be done.
Jonny2010: No,if you went the speed of light,you wouldn't die,time would stop for you (Einstein's general theory of relativity).Of course,you could never reach the speed of light,as the power required to achieve it becomes infinite (again,the theory of relativity).
However,travelling at a significant percentage of the speed of light would allow you to survive the 400 years to Alpha Centuri,as much less time would pass on your spacecraft.However,people you leave back on earth would age normally by 400 years.
jonny2010 said "If a human went that fast they would die. 400 years is also not practical."
As Einstein said, "Speed is relative." If you are on a craft traveling 11,220,000 MPH, it is only relative to some other place such as Alpha Centauri. On board the craft you would not feel any speed at all. Acceleration can kill a person easily, but with ion or plasma or magnetic or whatever propulsion the acceleration is low. In fact if they could maintain 1G acceleration things would be more comfortable. The ion engines being used now are accelerating the craft at a small fraction of G.
The idea about creating a space/time bubble around a craft is science fiction. True, many science fiction ideas have become real, but that one is pure science fiction. The main fallacy in a space/time bubble is that time is a function of energy. That means that time as an entity does not exist. If you are in a location with no energy, then you are in a location with no time. Yes, I know that the universe is filled with all sorts of energy and there is no such place as a place with no energy. But there is no such thing as a time particle or time wave. There is only change. We mark the change by other changes that make sense to us. Our clocks are based on the radioactive decay of cesium. That is a measurable change, and we set the length of seconds to the speed of that change. Our ability to measure change creates what we call time. That is why so many science fiction space adventures freeze the voyagers during their travel. Something frozen does not change. So, when the traveler is unfrozen, to him, no time has passed because he can see no change in himself.
:-D Pay Attention!
I have invented also a much more effective propulsion system. It's an electric mechanical engine, which means it converts electricity directly into mechanical force instead of using fuel. It's a novel concept and it's hard to explain how it works and creates thrust because some people (as I expected) told me it violates conservation of momentum. In theory yes but in practice I don't think so. I hope I will have a prototype of it fabricated and put to test soon. You may check it out on my website:
-Hossein Nabipour, inventor of the first practical interstellar propulsion engine