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The FAQ page from the planetary society said that this is because the craft is not very precise with its pointing. LightSail 2's attitude control system does not have the precision to maintain a circular orbit. Therefore, as one side of the spacecraft's orbit rises, the other side will dip lower, until atmospheric drag overcomes the forces of solar ...


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There seems to be very little published information at this stage. There is a main page that has been set up for the initiative (Yuri Milner's Breakthrough Foundation). The most interesting bits seem to be a list of challenges yet to be solved and a long page of research papers. There's an interesting roadmap document too. As for slowing down - no chance....


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NASA JPL optical design team, including Scott Basinger and Mayer Rud and co-investigator Grover Swartzlander at the Rochester Institute of Technology Center for Imaging Science think so! They call them "orbital rainbows" when used as distributed mirrors for a giant telescope. JPL: Glitter Cloud May Serve as Space Mirror YouTube: Orbiting Rainbows: A Space ...


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For reporting back from Alpha Centauri, the roadmap's pages 25-26 and figure 20 predict that an onboard 10 watt laser with narrow spread (and many assumptions, such as at most 40 photons per bit) could transmit from Alpha Centauri to a 30 m reflector mirror on Earth at 70 Mbps. But the power source for a 10 W transmitter is heavy! Plutonium-238's power ...


3

From Lightsails webpage: Link LightSail 2 will then begin swinging its solar sails into and away from the Sun each orbit, giving the spacecraft enough thrust to raise its orbit (technically, the orbit semi-major axis) by several hundred meters per day. This portion of the mission will last one month. Basically When in orbit periapsis, the sails will ...


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materials that are available today That's a tough restriction. A very brief peek at some papers suggests that everyone is theorising about fancier thin film materials that don't exist yet, presumably because all the real-world alternatives are too heavy and heat-intolerant and their absorptance is too high. Solar sail people either don't care as much about ...


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LightSail 1 7 cubes: 4 X 10mm diameter + 3 X 12.5mm diameter https://ilrs.cddis.eosdis.nasa.gov/docs/2014/Appendix_forILRS_Form_20141217.pdf LightSail 2 On LightSail 2, they added more corner cube reflectors in addition to the ones on the +Z end that you linked above, and standardized all of them. The second iteration has 13 cubes in total, all of which ...


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Welcome to Space Exploration Harry. I'm guessing you are talking about the Breakthrough Starshot proposals? The original idea was for a flyby of the target system because it was assumed that there would be no way to slow down the spacecraft once it had accelerated to 20% of the speed of light. As we know from Newton's First Law: An object at rest will ...


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They don't propose slowing down, which is part of why they don't expect high resolution. In fact, they seem to expect most of the acceleration will occur from the beginning, by the time they hit Pluto's orbit, they expect them to be going at a very high speed. The communication is expected to be done via lasers. Maybe they can re-convert their reflective ...


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TL/DR: Over 2000 years for a ridiculously advanced craft travelling at the surface escape velocity of the sun, 620 km/s. The effectiveness of a solar sail is determined by its "lightness factor", the thrust-to-weight ratio under solar gravity. (Since both gravity and radiation pressure obey inverse square law, this is independent of distance from the sun.) ...


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The accuracy of optics is limited, so to get a close perfectly parallel beam of light does require a lens. The larger the distance between the light source and the lens, the better. The basic concept here is not flawed. Close to parallel light from distant objects gets focused in the focal point of the Sun's gravitational lens. Because optics are ALWAYS ...


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This is an answer to "what ground station are they planning to use": Tracking LightSail 2 will be done by International Laser Ranging Service, or ILRS. The ILRS consists of about 40 laser ranging observatories around the world. There's no single overseer or funding body; many government entities contribute to the network for the good of everyone ...


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Any mass added to the vehicle "hinders" a ion engine, in the sense that it reduces the acceleration for a given thrust. Ion engine thrust is proportional to power, more or less, the goal is to produce as much power per unit mass as possible. An suitably shaped mirror can focus the sun to make an image on a photocell array with the same angular diameter as ...


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The image below shows the answer. Lightsail only gets thrust while moving away from the Sun (on the lower half of the orbit as drawn here). Thrusting on one side of an orbit raises (or lowers) the other side but has no effect on the side where you do the thrusting. Meanwhile drag is slowly lowering the whole orbit, so the overall effect is that the orbit ...


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I assume CalPoly is being used for the uplink, as implied by mission control being there. According to eoportal, LighSail uses the same 435 MHz frequency for uplink and downlink. I would expect CalPoly would use one of its standard UHF ground stations shown in this article. All three generations of their ground stations use commercial HAM radios such as ...


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A lightsail capable of achieving any useful speed, let along 0.6c, must be both very large and very low mass. So typical speculative designs are vast sheets of very thin film, or even a mesh of tiny wires with holes smaller than the wavelength of the light used for propulsion. (see Discussion on wikipedia). In all cases I am aware of, the approach to ...


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Solar sails often suggest a couple of modes for slowing down. 1) Have a launch laser at the target location to slow it down the same way. Assumes much infrastructure. 2) Use the solar energy of the target sun to slow the sail down. I.e. Turn it around and spend a longer time decelerating as you get closer and closer. 3) There was a model, where the ...


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