Distance to Mars
Discussion
MiseryStreak said:
mrmr96 said:
Update, European Space Agency has unveiled a video with a concept for a Mars Surface Sample Retrieval Device:
http://www.space.com/23654-esa-unveils-spherical-m...
Seems like the idea is that this will allow us to bring part of Mars back to Earth!
Hmmm...strange. Why go to all the effort?http://www.space.com/23654-esa-unveils-spherical-m...
Seems like the idea is that this will allow us to bring part of Mars back to Earth!
http://en.wikipedia.org/wiki/Martian_meteorite
benters said:
fascinating graphic OP. . .cant help but think its a huge waste of money though this sort of thing. We should be applying the efforts the brains and the cash into solving some real issues on earth before going looking for new ones, in my opinion (flame suit on and ready)!
Often, breakthroughs in technology and science come from doing the more off beat research and development work. If the (very limited) funds that are currently spent on Mars missions were diverted to (say) cancer research, the cancer research would hardly notice the increase but the Mars research would be stopped for good.
The two aspect of science are not mutually exclusive - do both.
Eric Mc said:
benters said:
fascinating graphic OP. . .cant help but think its a huge waste of money though this sort of thing. We should be applying the efforts the brains and the cash into solving some real issues on earth before going looking for new ones, in my opinion (flame suit on and ready)!
Often, breakthroughs in technology and science come from doing the more off beat research and development work. If the (very limited) funds that are currently spent on Mars missions were diverted to (say) cancer research, the cancer research would hardly notice the increase but the Mars research would be stopped for good.
The two aspect of science are not mutually exclusive - do both.
As you suggest though, the trade off will bring innovations, and i expect the progress of all things is to the detriment of others which seemingly seem more obvious choices to put right first.
benters said:
i cant imagine that all that gets spent on looking at going to Mars is less than cancer research. . . i hope your right, but i would be suprised.
As you suggest though, the trade off will bring innovations, and i expect the progress of all things is to the detriment of others which seemingly seem more obvious choices to put right first.
Cancer Research UK spends £350 million each year and that's just a charity, by the time you add in all the big pharma companies the money we're talking is huge (to put things in perspective, each drug that gets to market costs about $1 billion to research and can get cancelled after spending $900 million) the drug company Novartis has a total research budget of $8 billion.As you suggest though, the trade off will bring innovations, and i expect the progress of all things is to the detriment of others which seemingly seem more obvious choices to put right first.
NASA's planetary science budget is about $1.5 billion.
If you want a specific example of space technology helping cancer, a version of the robot arm on the space station is now being used for treating cancer.
http://www.nasa.gov/station/research/news/igar/#.U...
FunkyNige said:
benters said:
i cant imagine that all that gets spent on looking at going to Mars is less than cancer research. . . i hope your right, but i would be suprised.
As you suggest though, the trade off will bring innovations, and i expect the progress of all things is to the detriment of others which seemingly seem more obvious choices to put right first.
Cancer Research UK spends £350 million each year and that's just a charity, by the time you add in all the big pharma companies the money we're talking is huge (to put things in perspective, each drug that gets to market costs about $1 billion to research and can get cancelled after spending $900 million) the drug company Novartis has a total research budget of $8 billion.As you suggest though, the trade off will bring innovations, and i expect the progress of all things is to the detriment of others which seemingly seem more obvious choices to put right first.
NASA's planetary science budget is about $1.5 billion.
If you want a specific example of space technology helping cancer, a version of the robot arm on the space station is now being used for treating cancer.
http://www.nasa.gov/station/research/news/igar/#.U...
NASA's budget has taken a knock then. . .wonder what it was through the Shuttle years ?
I'm sure this is a dumb question but, hey, we're not born with knowledge. 
What stops us simply fitting a bigger engine and getting there faster? Is it fuel usage? As space is a vacuum, can't you theoretically keep accelerating indefinitely...?
Granted, you might want to slow down at the other end but that's another department's problem.
What stops us simply fitting a bigger engine and getting there faster? Is it fuel usage? As space is a vacuum, can't you theoretically keep accelerating indefinitely...?
Granted, you might want to slow down at the other end but that's another department's problem.
NASA's budget is tiny and has been shrinking inexorably from as far back as 1966.
In fact, 1966 was the peak year for the funding of NASA - which makes sense as this was the period when the bulk of the massive infrastructure needed for the moon landings was being put together.
An awful lot of that infrastructure - which is now over 50 years old in some instances - is still being used today.
DARPA (the military agency that runs the US Defence space projects) has outspent NASA for quite a bit for decades.
In fact, 1966 was the peak year for the funding of NASA - which makes sense as this was the period when the bulk of the massive infrastructure needed for the moon landings was being put together.
An awful lot of that infrastructure - which is now over 50 years old in some instances - is still being used today.
DARPA (the military agency that runs the US Defence space projects) has outspent NASA for quite a bit for decades.
durbster said:
I'm sure this is a dumb question but, hey, we're not born with knowledge.
What stops us simply fitting a bigger engine and getting there faster? Is it fuel usage? As space is a vacuum, can't you theoretically keep accelerating indefinitely...?
Granted, you might want to slow down at the other end but that's another department's problem.
Rockets go through their fuel supply very rapidly. Typically, 90% of a booster's fuel supply is used up in the first 10 minutes of powered flight. Therefore, rockets have to make sure they impart the necessary acceleration and target speed to the payload in that ten minute window. The size and weight of the payload is what determines the size of the booster required.What stops us simply fitting a bigger engine and getting there faster? Is it fuel usage? As space is a vacuum, can't you theoretically keep accelerating indefinitely...?
Granted, you might want to slow down at the other end but that's another department's problem.
To get a payload into earth orbit, the rocket needs to accelerate the payload to a height of at least 100 miles and to a speed relative to the earth of 17,500 mph.
To head for the moon, the rocket needs to accelerate the payload to at least 25,000 mph.
To head out into the Solar System, the speed needed is more like 30,000 to 40,000 mph relative to the sun.
The more speed required, the bigger and heavier the rocket required.#
Mission always try to keep the payload weight down as much as possible and they also try to keep the rocket weight down too. One way to do this is to use other techniques to get "free" boost to the spacecraft's speed - such as using other planets to "slingshot" the spacecraft and give it extra speed, essentially for nothing. This technique has been used quite a few times and is of great benefit in keeping rocket weight (and therefore costs) down.
The downside to using "gravity assist" is that it can add years onto the journey time of a mission.
Regarding acceleration in a vacuum - you cannot accelerate indefinitely. You can only accelerate as long as the rocket is producing thrust. Once the rocket motor shuts down (usually when the fuel is exhausted - an event which is timed in advance to a fraction of a second), the spacecraft stops accelerating but will coast indefinitely at a fixed speed.
However, as mentioned above, "free" acceleration and speed boosts can be obtained by using planets and moons as "accelerators".
Eric Mc said:
However, as mentioned above, "free" acceleration and speed boosts can be obtained by using planets and moons as "accelerators".
Here's something I don't fully understand: This "Slingshot" technique.If the gravitational force of the planet or moon you're "slingshotting around" accelerates the space craft by pulling it in, then why doesn't the same gravitational force slow the space craft back down again once it's passed by?
Clearly the technique does work, but I just don't currently understand it. Any insight?
Cheers
The craft picks up speed as it falls towards the planet or moon. After it has picked up the speed and starts moving away from the planet of moon, it does indeed start slowing down - but the important thing is that it starts moving away from the moon at a higher exit speed than it had when it started falling towards the planet or moon. Now, you may be thinking - that seems to imply that you are getting free energy at no cost - in other words, creating energy out of nothing, which is against the laws of physics. And you would be right.
The "loser" in this case is the planet or moon itself. The extra energy imparted to the spacecraft is "lost" by the planet or moon. However, with the average spacecraft only weighing a few hundred pounds and the average moon or planet weighing billions or trillions of tons, the energy lost by the planet or moon has an almost negligible effect on the planet or moon.
The "loser" in this case is the planet or moon itself. The extra energy imparted to the spacecraft is "lost" by the planet or moon. However, with the average spacecraft only weighing a few hundred pounds and the average moon or planet weighing billions or trillions of tons, the energy lost by the planet or moon has an almost negligible effect on the planet or moon.
mrmr96 said:
Here's something I don't fully understand: This "Slingshot" technique.
Make your own 
http://www.testtubegames.com/gravity.html
otolith said:
Ayahuasca said:
A million to one, he said.
In the euphoria after the first manned moon landings, I wonder how many ordinary people grasped how far away a manned mission to Mars remained? I'm sure many people must have thought incorrectly it would be in their lifetime.
Gassing Station | Science! | Top of Page | What's New | My Stuff