Comments (9)

  1. michael.million@sky.com:

    If we can use the kinetic energy of the craft via magnetic coils or capacitance devices we will have no problems with energy needs, even at 4 grams there is an enormous amount of energy available.

  2. michael.million@sky.com:

    Perhaps we could have some sails dedicated to a special task say one for optical, one for the ISM, magnetic fields and one for relay communications between crafts and to and from Earth and so on.

  3. Breakthrough Initiatives :

    In the vicinities of the Earth and of AC the solar sail could collect from about 20W (10 AU) to 2KW (1 AU) of power (see summary). It would take the nanosat about 14 hours to cover 20 AU near AC, thus enough time to transmit back to Earth.
    A radioisotope power source would keep the nanosat in a safe, low functional mode during cruise, while possibly storing some energy in a battery.
    Power is also imparted to the nanosat by the interstellar hydrogen (1 atom per cm3) in the form of 20 MeV protons and 10 keV electrons (see summary). The 15 nm solar sail does not stop either protons or electrons. 10keV electrons will stop in about 1μm of Al, while 20MeV protons will stop in 2 mm of Al (or 0.5 g/cm2).
    The about 20mW power delivered by protons stopping in a 1 cm2 component, could be used to charge a storage device for periodic communications with Earth.

    – Sasha Buchman, Breakthrough Initiatives

  4. sda1950a@gmail.com:

    Power could best be provided by taping the electrical charge created by spacecraft charging. this phenomenon is usually a problem created by cosmic radiation impacting the S/C, but if the charge is isolated from the electronics and drawn off, it could power the S/C.

  5. Breakthrough Initiatives:

    RE:
    "Oct 10, 2016 23:50sda1950a@gmail.comPosted on: Breakthrough Initiatives
    Power could best be provided by taping the electrical charge created by spacecraft charging. this phenomenon is usually a problem created by cosmic radiation impacting the S/C, but if the charge is isolated from the electronics and drawn off, it could power the S/C."

    Answer:
    This approach has never been used but it has significant merit. A preliminary scientific discussion of this idea can be found at the paper available at https://arxiv.org/pdf/1608.05284.pdf
    There are practical problems related the isolation systems. Also, charging in deep space has rarely been measured and the ability to design such a system is not well understood. Significant trades will need to be performed to find the best way to harvest energy for the StarChip.

    - Avi Loeb, Breakthrough Starshot

  6. michael.million@sky.com:

    I find the needle like probe, '1sq cm' more problematic than a thin disc profile of 1 sq cm, at least with the edge on disc heat and sputtered material has an escape route to the sides limiting damage, shallow angle deflection also aids the craft especially if the edge is very sharp.

  7. Breakthrough Initiatives:

    RE:
    "Jan 07, 2017 20:20 michael.million@sky.com Posted on: Centauri Dreams
    I find the needle like probe, '1sq cm' more problematic than a thin disc profile of 1 sq cm, at least with the edge on disc heat and sputtered material has an escape route to the sides limiting damage, shallow angle deflection also aids the craft especially if the edge is very sharp."

    Answer:
    Thank you for your consideration. I would agree the needle form is problematic. The simpler the shaper the likely we will be able to get the material to attain the shape. But the biggest trouble today is to define the problem. What is the composition of the InterStellar Medium. Currently the experts are not in agreement on exactly what is in the ISM. Depending on whose model one believes one comes up with vastly different answers.

    - Pete Klupar, Breakthrough Starshot

  8. Pete Firside:

    probably a bit simplistic this, but here goes....Can't you get some of the power from the laser itself which is pushing you along?
    I mean the laser is giving you thrust, but is there any way you can also use it to power some of the components as well?

  9. Breakthrough Initiatives:

    RE:
    Feb 28, 2017 20:48 Pete Firside Posted on: Breakthrough Initiatives

    Answer:
    Thanks for your response. It is true we are using 100GW of power to push the sail. However, when we are close to the laser we do not need much energy. We need the energy when we are far from the laser, at least 1 light year from earth. One of the physical constraints we must live by is the laser beam diverges at about the rate of 30 milliradians. At the range of 1 light year the beam has diverged so much that the energy density is very low and therefore it impossible to harvest the energy from the laser. If we could increase the size of the laser array we could possibly get power in this way.

    - Pete Klupar, Breakthrough Starshot

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