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ProfRob
ProfRob
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They can, but would be less efficient than solar sails.

First, you would have to add the mass of the light-producing equipment and whatever powered it to your spacecraft, meaning you need more force to get the same acceleration.

Second you lose a factor of two in the rate of change of momentum, because a light sail is designed to be reflective. This means an incidenta photon of momentum $p$ incident on a reflective sail gives $\sim 2p$ of momentum to the spacecraft, whereas simply ejecting the same photon from the spacecraft would give a momentum boost of just $p$.

Of course sails can have other problems (e.g. difficult to use when you are far away from any light source).

They can, but would be less efficient than solar sails.

First, you would have to add the mass of the light-producing equipment and whatever powered it to your spacecraft, meaning you need more force to get the same acceleration.

Second you lose a factor of two in the rate of change of momentum, because a light sail is designed to be reflective. This means an incident photon of momentum $p$ gives $\sim 2p$ of momentum to the spacecraft, whereas simply ejecting the same photon from the spacecraft would give a momentum of just $p$.

Of course sails can have other problems.

They can, but would be less efficient than solar sails.

First, you would have to add the mass of the light-producing equipment and whatever powered it to your spacecraft, meaning you need more force to get the same acceleration.

Second you lose a factor of two in the rate of change of momentum, because a light sail is designed to be reflective. This means a photon of momentum $p$ incident on a reflective sail gives $\sim 2p$ of momentum to the spacecraft, whereas simply ejecting the same photon from the spacecraft would give a momentum boost of just $p$.

Of course sails can have other problems (e.g. difficult to use when you are far away from any light source).

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ProfRob
ProfRob
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They can, but would be much less efficient than solar sails.

First, you would have to add the mass of the light-producing equipment and whatever powered it to your spacecraft, meaning you need more force to get the same acceleration.

Second you lose a factor of two in the rate of change of momentum, because a light sail is designed to be reflective. This means an incident photon of momentum $p$ gives $\sim 2p$ of momentum to the spacecraft, whereas simply ejecting the same photon from the spacecraft would give a momentum of just $p$.

Of course sails can have other problems.

They can, but would be much less efficient than solar sails.

First, you would have to add the mass of the light-producing equipment and whatever powered it to your spacecraft, meaning you need more force to get the same acceleration.

Second you lose a factor of two in the rate of change of momentum, because a light sail is designed to be reflective. This means an incident photon of momentum $p$ gives $\sim 2p$ of momentum to the spacecraft.

They can, but would be less efficient than solar sails.

First, you would have to add the mass of the light-producing equipment and whatever powered it to your spacecraft, meaning you need more force to get the same acceleration.

Second you lose a factor of two in the rate of change of momentum, because a light sail is designed to be reflective. This means an incident photon of momentum $p$ gives $\sim 2p$ of momentum to the spacecraft, whereas simply ejecting the same photon from the spacecraft would give a momentum of just $p$.

Of course sails can have other problems.

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ProfRob
ProfRob
  • 136.4k
  • 16
  • 302
  • 486

They can, but would be much less efficient than solar sails.

First, you would have to add the mass of the light-producing equipment and whatever powered it to your spacecraft, meaning you need more force to get the same acceleration.

Second you lose a factor of two in the rate of change of momentum, because a light sail is designed to be reflective. This means an incident photon of momentum $p$ gives $\sim 2p$ of momentum to the spacecraft.