Flyby | Pointing camera at target planet

During an encounter with an exoplanet, the nanocraft’s camera would need to rotate in order to image the target. If the planet were imaged with a focal plane area, it would be necessary to hold the planet still within the image plane during the integration time for exposure.

If an object-to-nanocraft distance of 1 AU and a velocity of 0.2c are assumed, an angular rate of (6x107m/s) / (1.5x1011 m) ~ 80 arc sec/s is needed. The nanocraft would traverse a distance of 1 AU in about 2500 seconds. To stabilize the image, the camera would need to “slew” at this rate.

The slewing would be accomplished either by using the photon thrusters or via motion in the focal plane. For example, using a 4-meter-scale camera array at a distance of 1 AU would provide image resolution of order 40km, assuming visible spectrum imaging. The resolution scale could be improved by closer approaches of less than 1 AU. Extremely efficient image compression and smart feature detection algorithms would be crucial.

Another challenge is locating the planet inside the Alpha Centauri system. This would be achieved through the use of ‘star trackers’ based on the star’s ephemeris (orbital position at specific times) and the planet’s position relative to the star. The star would be very bright and the planet reasonably bright. Dead reckoning navigation is being considered that would be updated by measurements of the location of the star and planet. Image recognition software would be required to decide which target had the highest value, and it currently seems the most promising form of rudimentary artificial intelligence for this mission.

Comments (16)

  1. Breakthrough Initiatives:

    RE:
    "Sep 25, 2016 20:16Stan EvansPosted on: Breakthrough Initiatives
    You could use a network of the crafts at differing distances to use the pressure caused by the atmosphere to mao the direction of the planet."

    Answer:
    Thanks for the response. We will certainly take it into account in the design of the mission.

    - Avi Loeb, Breakthrough Starshot

  2. Ricardo Fedele:

    Hola

    Suponiendo que lancen 1000000 de nano naves, es claro que no todas partirán al mismo momento, pero siendo posible dominar la aceleración y dirección dadas a cada una , variando la potencia o el tiempo de impulso, entonces es posible garantizar que un buen número llegaran todas juntas (mismo dia , hora y mas o menos unos minutos) a una región , supongamos circular de 1UA, con un retraso que se intentara sea mínimo.
    Mediante el uso de radiofrecuencia , al estilo de los GPS, las que ubicaran a las que estén mejor posicionadas, e independientemente del fin que se le de a los láseres a bordo, se puede hacer ,utilizar una fracción del millón de láseres disponibles para apuntar a la vela de una o varias naves, con el propósito de reducir su velocidad, suponiendo un 80% sobrevivan al viaje se pueden tener 800000 W apuntando a una sola nave, no es mi intención aburrir con cálculos , pero con 24 hs de exposición se pueden impulsar 6 o 7 naves , a órbitas gravitacionalmente estables, (elípticas al menos).
    Si la vela puede recargar la batería esas naves enviaran información durante mucho mas tiempo.
    Quizá peco en desconocer el tiempo que puede durar la batería del láser,que impondrá un límite práctico a la idea.
    Es lógico que todo lleva una serie de cálculos, programas de comunicación entre naves, pero sin mas precisiones es solo una linda idea que quería aventurarles, y me gustaría saber si no es molestia, si el tema ya ha sido analizado y descartado, pues me encantaría saber en que falla mi argumento.... saludos , exito, y gracias por leer.

    Ricardo

  3. Breakthrough Initiatives:

    RE:
    Mar 11, 2017 22:52 Ricardo Fedele Posted on: Breakthrough Initiatives

    Answer:
    Thank you very much for your question. We have designed the system to launch one vehicle each day. This sizes much of the system energy usage. From the size of the energy storage facility to the size of the energy generation facilities. This system will be capable of moving material around the solar system. In earth orbit or out to Pluto. It should be boon to exploration. Probes to Mars in days Jupiter in weeks Pluto in months. Using information technology to communicate between the ships will certainly help us achieve our goals.

    - Pete Klupar, Breakthrough Starshot

  4. Robert Clark:

    The Breakthrough Starshot program has been envisioned as a flyby. However, it may be possible to slow it down so it stays within the stellar system. One method is by breaking against the solar wind emitted by the destination star.

    A preliminary calculation suggests that for a 10 meter wide sail carrying a gram sized payload for the solar wind similar to that of the Sun, a craft moving a relativistic speeds should be able to brake against the wind to slow enough speeds to remain inside the stellar system.

    Bob Clark

  5. Meir Schaechter:

    This might only work if a probe passes very close to the star or a very massive planet with powerful a gravitational field, but perhaps the probes could be designed in such a way that the center of mass of the probe lines up with the camera at the very edge of the probe. This would mean that if a probe passes close enough to the star or a planet, the gravitational pull of the body will pull more on the heavier side of the probe, causing that side to rotate towards the body as it passes by. If the camera is placed on this edge, the camera will be rotated to point towards the body. This method of pointing the camera is good because it potentially requires no on-board power source, but instead takes advantage of the gravity of the object the probe is trying to take a picture of.

  6. Breakthrough Initiatives:

    RE:
    Jun 06, 2017 12:53 Robert Clark Posted on: Breakthrough Initiatives

    Answer:
    The possible breaking was indeed discussed by R. Heller and M. Hippke in
    https://arxiv.org/pdf/1701.08803.pdf
    However this scheme requires extremely thin sails and passage very close to the stars in the Alpha Centauri system, which pose major challenges to the survival of the sail due to excessive heating and stress.

    - Avi Loeb, Breakthrough Starshot

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