Solar Sails

[Alecto]

Solar sails are actual sails that are deployed in space. The sail is made from super-thin material which has light particles bounce off it and propel the sail, and whatever its attached to, through space. The initial thrust is significantly less than a chemical rocket, but over time it can build up to enormous speeds.

My question is this. If light particles can propel a solar sail FOREWARDS, what about backwards? Isnt ambient light from other stars and just the rest of the solar system going to effect the sail?

Its like putting a sail on a skateboard and pushing it along with a hair-dryer, then as your pushing it along, you get close to a giant room fan and the fan over-rides the pushing power of the hair-dryer

 

[Sagan_Disciple]

Remember that the flux per unit area associated with electromagnetic energy falls off as 1/(distance)^2. Solar sails work because spacecraft employing this method of propulsion are close enough to the Sun to allow for sufficient energy extraction from the solar EM flux. The EM flux from distant stars is negligible compared to the Sun making star light an impractical means spacecraft propulsion.

Some other form of propulsion would be required (chemical, gravity assistance, etc.) for a spacefact to propel itself against the oncoming solar EM flux.

 

[simplicity]

Dude, if you're thinking of using solar sails on your boat, keep an eye out for solar sharks and giant solar squid. You'll get sucked into a big vortex, flung over an event horizon and diced like dried parsley by the rings of Saturn.

 

[Alecto]

Dude, if you're thinking of using solar sails on your boat, keep an eye out for solar sharks and giant solar squid. You'll get sucked into a big vortex, flung over an event horizon and diced like dried parsley by the rings of Saturn.

Solar sails arent designed for boats, theyre designed for spacecraft. A solar sail wouldnt do you squat on earth because its not enough to resist gravity and the material would probably rip or tear in any sort of wind because its so extremely thin.

Remember that the flux per unit area associated with electromagnetic energy falls off as 1/(distance)^2. Solar sails work because spacecraft employing this method of propulsion are close enough to the Sun to allow for sufficient energy extraction from the solar EM flux. The EM flux from distant stars is negligible compared to the Sun making star light an impractical means spacecraft propulsion.

Some other form of propulsion would be required (chemical, gravity assistance, etc.) for a spacefact to propel itself against the oncoming solar EM flux.

What about carrying something with you that would direct light against the sails? A high intensity laser that could be powered by solar energy pannels

 

[Iron Sun 254]

My question is this. If light particles can propel a solar sail FOREWARDS, what about backwards? Isnt ambient light from other stars and just the rest of the solar system going to effect the sail?

I'm not sure if the material is reflective on both sides, but if it is, then yes, other light would slow it down...somewhat. The amount of light pushing it forward is equivalent to amount of light you see in the middle of the day in the summer. The amount of light pushing it back is equivalent to the amount of light you see at midnight in an area far away from any city or town. The amount it will slow the sail downis negligible

 

[anunbeliever]

Whilst near the solar system, the light from other stars would be negligible compared with the Sun. A craft with solar cells would be accelerated by the sun until it leaves the solar system. Then the sail would be doing squat. As the craft approches the destination system, that systems star would brake the craft via its sail.

 

[whatiswatanabe]

Solar sails are actual sails that are deployed in space. The sail is made from super-thin material which has light particles bounce off it and propel the sail, and whatever its attached to, through space. The initial thrust is significantly less than a chemical rocket, but over time it can build up to enormous speeds.


My question is this. If light particles can propel a solar sail FOREWARDS, what about backwards? Isnt ambient light from other stars and just the rest of the solar system going to effect the sail?

Not much

Its like putting a sail on a skateboard and pushing it along with a hair-dryer, then as your pushing it along, you get close to a giant room fan and the fan over-rides the pushing power of the hair-dryer

Good analogy

 

[whatiswatanabe]

What about carrying something with you that would direct light against the sails? A high intensity laser that could be powered by solar energy pannels

This like putting a fan on your boat to fill the sails with wind.

Just take the same energy and make an Ion Rocket. You'll be happy you did.

 

[one love]

Solar sails created the fastest man mad moving object, helios which went 150000mph as it orbitted the sun.

 

[Yamialpha]

Is it the material itself that is reflective or is it coated with another material that makes it reflective?