The $25 billion from this program is supposed to be used to get real technology on the roads. Companies can use the grants and loans to "re-equip, expand, and establish manufacturing facilities in the U.S. to produce light-duty vehicles and components that make meaningful improvements in fuel economy performance."
My understanding is that Tesla applied for somewhere around $400 million to help finance their Model S sedan: all-electric, 200+ miles per charge, $60k base price (I assume a real price closer to $70-75k). Each new generation lowers the cost of electric cars and Tesla would be building up the valuable knowlege needed for a true consumer car while at the same time expanding it's manufacturing capabilities. In short, if Tesla gets the Model S on the road, it will have gone much further than any other car company in getting electric cars on the road in the US.
This is investment money and was designed as such. The real danger in my mind would be if Congress decided to take these funds and turn it into a Big 3 bailout. That would significantly set back the plans to get new generations of energy-efficient cars on the road.
Good point - I was neglecting orbital motion and only thinking along radial paths. But then, you can't really equate the problem with a sailboat on water. It'd be more like a sail-hovercraft sliding frictionlessly in a bowl-shaped valley, but whatever...
1) The 5 year solar sail propelled mission to Pluto - is there a way to decelerate as you reach Pluto? Actually, is it really 5 years constant thrust or does the solar sail's thrust decrease as an inverse square law as you get more distant from the sun?
2) Can you sail "upstream" into the solar wind? Is it possible to tack and jibe in a solar sail propelled craft?!
The answer to 2 is no. On the water, you use a rudder to redirect the force on the sail in a different direction. In space, there is no "water" for a rudder to work in, so you can't make any headway against the wind. As a result, the answer to 1 is that you can't slow down using the wind. You could always cut the sail and let the Sun's gravity slow you...
And for those of you wanting a quick description on how sailing "into the wind" works, here it is: If you turn your flat sail at an angle (a1) to the wind (a1 < 90 degrees), it will be pushed in the direction of a1. Now, if you have a rudder starting at a right angle to the sail, you can turn it an angle (a2) toward the wind - this will redirect the force on the sail to push the boat in the direction of a2 (where a2 < 90 degrees). So, if a1+a2 > 90 degrees, you can sail "into the wind".
All your points are valid, but they don't really add up. The only benefit of a GPS-style system is that it's easier and quicker to use than traditional navigation. In the case of space programs, we've already almost perfected celestial navigation, and we have the facilities to do it. The expense of sending all that GPS equipment to mars, calibrating it, and compensating for any failures, is simply not worth the minimal benefit in conveniance it has over tradional navigation.
You're forgetting an important point - autonamous navigation. With one-way light-times of up 20 minutes, real-time navigation just isn't an option and GPS can go a long way toward simplifying that autonomy. This isn't a case of laziness - we're talking about puting a useful long term asset around a plant that is going to save us $millions over the long haul and give us science to boot. Besides, that "almost perfect celestial navigation" you mentioned is only "almost" and not "perfect" because we lack a GPS-like system to perform pinpoint landings.
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The $25 billion from this program is supposed to be used to get real technology on the roads. Companies can use the grants and loans to "re-equip, expand, and establish manufacturing facilities in the U.S. to produce light-duty vehicles and components that make meaningful improvements in fuel economy performance."
My understanding is that Tesla applied for somewhere around $400 million to help finance their Model S sedan: all-electric, 200+ miles per charge, $60k base price (I assume a real price closer to $70-75k). Each new generation lowers the cost of electric cars and Tesla would be building up the valuable knowlege needed for a true consumer car while at the same time expanding it's manufacturing capabilities. In short, if Tesla gets the Model S on the road, it will have gone much further than any other car company in getting electric cars on the road in the US.
This is investment money and was designed as such. The real danger in my mind would be if Congress decided to take these funds and turn it into a Big 3 bailout. That would significantly set back the plans to get new generations of energy-efficient cars on the road.
Good point - I was neglecting orbital motion and only thinking along radial paths. But then, you can't really equate the problem with a sailboat on water. It'd be more like a sail-hovercraft sliding frictionlessly in a bowl-shaped valley, but whatever...
1) The 5 year solar sail propelled mission to Pluto - is there a way to decelerate as you reach Pluto? Actually, is it really 5 years constant thrust or does the solar sail's thrust decrease as an inverse square law as you get more distant from the sun?
2) Can you sail "upstream" into the solar wind? Is it possible to tack and jibe in a solar sail propelled craft?!
The answer to 2 is no. On the water, you use a rudder to redirect the force on the sail in a different direction. In space, there is no "water" for a rudder to work in, so you can't make any headway against the wind. As a result, the answer to 1 is that you can't slow down using the wind. You could always cut the sail and let the Sun's gravity slow you...
And for those of you wanting a quick description on how sailing "into the wind" works, here it is: If you turn your flat sail at an angle (a1) to the wind (a1 < 90 degrees), it will be pushed in the direction of a1. Now, if you have a rudder starting at a right angle to the sail, you can turn it an angle (a2) toward the wind - this will redirect the force on the sail to push the boat in the direction of a2 (where a2 < 90 degrees). So, if a1+a2 > 90 degrees, you can sail "into the wind".
All your points are valid, but they don't really add up. The only benefit of a GPS-style system is that it's easier and quicker to use than traditional navigation. In the case of space programs, we've already almost perfected celestial navigation, and we have the facilities to do it. The expense of sending all that GPS equipment to mars, calibrating it, and compensating for any failures, is simply not worth the minimal benefit in conveniance it has over tradional navigation.
You're forgetting an important point - autonamous navigation. With one-way light-times of up 20 minutes, real-time navigation just isn't an option and GPS can go a long way toward simplifying that autonomy. This isn't a case of laziness - we're talking about puting a useful long term asset around a plant that is going to save us $millions over the long haul and give us science to boot. Besides, that "almost perfect celestial navigation" you mentioned is only "almost" and not "perfect" because we lack a GPS-like system to perform pinpoint landings.