Breakthrough Starshot

Breakthrough Starshot is a research and engineering project by the Breakthrough Initiatives to develop a proof-of-concept fleet of light sail spacecraft named StarChip,[1] to be capable of making the journey to the Alpha Centauri star system 4.37 light-years away. It was founded in 2016 by Yuri Milner, Stephen Hawking, and Mark Zuckerberg.[2][3]

"Starshot" redirects here. For the clay target, see Starshot (target).

On 24 August 2016, ESO hosted a press conference to discuss the announcement of exoplanet Proxima b at its headquarters in Germany. In this picture, Pete Worden giving a speech.

A flyby mission has been proposed to Proxima Centauri b, an Earth-sized exoplanet in the habitable zone of its host star, Proxima Centauri, in the Alpha Centauri system.[4] At a speed between 15% and 20% of the speed of light,[5][6][7][8] it would take between twenty to thirty years to complete the journey, and approximately four years for a return message from the starship to Earth.

The conceptual principles to enable this interstellar travel project were described in "A Roadmap to Interstellar Flight", by Philip Lubin of UC Santa Barbara.[9][10] Sending the lightweight spacecraft involves a multi-kilometer phased array of beam-steerable lasers with a combined coherent power output of up to 100 GW.[11]

General

The project was announced on 12 April 2016 in an event held in New York City by physicist and venture capitalist Yuri Milner, together with cosmologist Stephen Hawking, who was serving as board member of the initiatives. Other board members include Facebook CEO Mark Zuckerberg. The project has an initial funding of US$100 million to initialize research. Milner places the final mission cost at $5–10 billion, and estimates the first craft could launch by around 2036.[6] Pete Worden is the project's executive director and Harvard Professor Avi Loeb chairs the advisory board for the project.[12]

Leaders

Management and Advisory Committee[13]

  • Pete Worden, Executive Director, Breakthrough Starshot; former Director of NASA Ames Research Center
  • Avi Loeb, Chairman, Breakthrough Starshot Advisory Committee; Harvard University
  • Jim Benford, Microwave Sciences
  • Steven Chu, Nobel Prize winner, Stanford University
  • Bruce Draine, Princeton University
  • Ann Druyan, Cosmos Studios
  • Louis Friedman, Planetary Society, JPL
  • Robert Fugate, Arctelum, LLC, New Mexico Tech
  • Giancarlo Genta, Polytechnic University of Turin
  • Olivier Guyon, University of Arizona
  • Mae Jemison, 100 Year Starship
  • Joan Johnson-Freese, US Naval War College
  • Pete Klupar, Director of Engineering, Breakthrough Starshot; former Director of Engineering, NASA Ames Research Center
  • Jeff Kuhn, University of Hawaii Institute for Astronomy
  • Geoff Landis, SA Glenn Research Center
  • Kelvin Long, Journal of the British Interplanetary Society
  • Greg Matloff, New York City College of Technology
  • Claire Max, University of California, Santa Cruz
  • Kaya Nobuyuki, Kobe University
  • Kevin Parkin, Parkin Research
  • Mason Peck, Cornell University
  • Saul Perlmutter, Nobel Prize winner, Breakthrough Prize winner, UC Berkeley and Lawrence Berkeley National Laboratory
  • Martin Rees, Astronomer Royal
  • Roald Sagdeev, University of Maryland
  • Ed Turner, Princeton University, NAOJ

Objectives

The Breakthrough Starshot program aims to demonstrate a proof-of-concept for ultra-fast, light-driven nano-spacecraft, and lay the foundations for a first launch to Alpha Centauri within the next generation.[14] Secondary goals are Solar System exploration and detection of Earth-crossing asteroids.[15] The spacecraft would make a flyby of, and, possibly photograph any Earth-like worlds that might exist in the system.

Target planet

The European Southern Observatory (ESO) announced the detection of a planet orbiting the third star in the Alpha Centauri system, Proxima Centauri in August 2016.[16][17] The planet, called Proxima Centauri b, orbits within the habitable zone of its star. It could be a target for one of the Breakthrough Initiatives' projects.

In January 2017, Breakthrough Initiatives and the European Southern Observatory began collaborating to search for habitable planets in the nearby star system Alpha Centauri.[18][19] The agreement involves Breakthrough Initiatives providing funding for an upgrade to the VISIR (VLT Imager and Spectrometer for mid-Infrared) instrument on ESO's Very Large Telescope (VLT) in Chile. This upgrade will increase the likelihood of planet detection in the system.

Concept
A solar sail concept

The Starshot concept envisions launching a "mothership" carrying about a thousand tiny spacecraft (on the scale of centimeters) to a high-altitude Earth orbit for deployment. A phased array of ground-based lasers would then focus a light beam on the crafts' sails to accelerate them one by one to the target speed within 10 minutes, with an average acceleration on the order of 100 km/s2 (10,000 ɡ), and an illumination energy on the order of 1 TJ delivered to each sail. A preliminary sail model is suggested to have a surface area of 4 m × 4 m.[20][21] An October 2017 presentation of the Starshot system model[22][23] examined circular sails and finds that the beam director capital cost is minimized by having a sail diameter of 5 meters.

The Earth-sized planet Proxima Centauri b is part of the Alpha Centauri system habitable zones. Ideally, the Breakthrough Starshot would aim its spacecraft within one astronomical unit (150 million kilometers or 93 million miles) of that world. From this distance, a craft's cameras could capture an image of high enough resolution to resolve surface features.[24]

The fleet would have about 1000 spacecraft. Each one, called a StarChip, would be a very small centimeter-sized vehicle weighing a few grams.[1] They would be propelled by a square-kilometre array of 10 kW ground-based lasers with a combined output of up to 100 GW.[25][26] A swarm of about 1000 units would compensate for the losses caused by interstellar dust collisions en route to the target.[25][27] In a detailed study in 2016 Thiem Hoang and coauthors[28] found that mitigating the collisions with dust, hydrogen and galactic cosmic rays may not be as severe an engineering problem as first thought.[29]

Technical challenges

Light propulsion requires enormous power: a laser with a gigawatt of power (approximately the output of a large nuclear plant) would provide only a few newtons of thrust.[26] The spaceship will compensate for the low thrust by having a mass of only a few grams. The camera, computer, communications laser, a nuclear power source, and the solar sail must be miniaturized to fit within a mass limit.[26][30] All components must be engineered to endure extreme acceleration, cold, vacuum, and protons.[27] The spacecraft will have to survive collisions with space dust; Starshot expects each square centimeter of frontal cross-section to collide at high speed with about a thousand particles of size at least 0.1 μm.[26][31] Focusing a set of lasers totaling one hundred gigawatts onto the solar sail will be difficult due to atmospheric turbulence, so there is the suggestion to use space-based laser infrastructure.[32] According to The Economist, at least a dozen off-the-shelf technologies will need to improve by orders of magnitude.[26]

StarChip

StarChip is the name used by Breakthrough Initiatives for a very small, centimeter-sized, gram-scale, interstellar spacecraft envisioned for the Breakthrough Starshot program,[1][33] a proposed mission to propel a fleet of a thousand StarChips on a journey to the Alpha Centauri star system, the nearest extrasolar stars, about 4.37 light-years from Earth.[34][6][35][5][36][37] The journey may include a flyby of Proxima Centauri b, an Earth-sized exoplanet that is in the habitable zone of its host star.[4] The ultra-light StarChip robotic nanocraft, fitted with light sails, are planned to travel at speeds of 20%[1][6][35][5] and 15%[5] of the speed of light, taking between 20 and 30 years to reach the star system, respectively, and about 4 years to notify Earth of a successful arrival.[6] The conceptual principles to enable practical interstellar travel were described in "A Roadmap to Interstellar Flight", by Philip Lubin of UC Santa Barbara,[9] who is an advisor to the Starshot project.

In July 2017, scientists announced that precursors to StarChip, called Sprites, were successfully launched and flown through Polar Satellite Launch Vehicle by ISRO from Satish Dhawan Space Centre.[38] Sprites were also to be flown on the KickSat-2 mission that was scheduled for November 2018.

Components

Each StarChip nanocraft is expected to carry miniaturized cameras, navigation gear, communication equipment, photon thrusters and a power supply. In addition, each nanocraft would be fitted with a meter-scale light sail, made of lightweight materials, with a gram-scale mass.[1][33][34][6][36][37][39][40]

Cameras

Five sub-gram scale digital cameras, each with a minimum 2-megapixels resolution, are envisioned.[1][41]

Processors

Four sub-gram scale processors are planned.[36][42]

Photon thrusters

Four sub-gram scale photon thrusters, each minimally capable of performing at a 1W diode laser level, are planned.[33][43][44]

Battery

A 150 mg atomic battery, powered by plutonium-238 or americium-241, is planned.[6][37][45]

Protective coating

A coating, possibly made of beryllium copper, is planned to protect the nanocraft from dust collisions and atomic particle erosion.[37][46]

Light sail

The light sail is envisioned to be no larger than 4 by 4 meters (13 by 13 feet),[1][47] possibly of composite graphene-based material.[1][34][6][37][40][48] The material would have to be very thin and be able to reflect the laser beam while absorbing only a small fraction of the incident energy, or it will vaporize the sail.[1][6][49] The light sail may also double as power source during cruise, because collisions with atoms of interstellar medium would deliver 60 Watt/m2 of power.[45]

Laser data transmitter

Laser communicator, utilizing light sail as the primary reflector, would be capable of data rates 2.6-15 baud per watt of transmitted power at distance to the Alpha Centauri, assuming 30m diameter receiving telescope on Earth.[50]

Other potential destinations

The table below lists possible target stars for similar photogravitational assist travel.[51] The travel times are for the spacecraft to travel to the star and then enter orbit around the star (using photon pressure in maneuvers similar to aerobraking).

NameTravel time
(yr)		Distance
(ly)		Luminosity
(L☉)
Proxima Centauri1214.20.00005
α Centauri A101.254.361.52
α Centauri B147.584.360.50
Sirius A68.908.5824.20
Procyon A154.0611.446.94
Vega167.3925.0250.05
Altair176.6716.6910.70
Fomalhaut A221.3325.1316.67
Denebola325.5635.7814.66
Castor A341.3550.9849.85
Epsilon Eridani363.3510.500.50
  • Successive assists at α Cen A and B could allow travel times to 75 yr to both stars.
  • The light sail has a nominal mass-to-surface ratio (σnom) of 8.6×10−4 gram m−2 for a nominal graphene-class sail.
  • Area of the light sail, about 105 m2 = (316 m)2
  • Velocity up to 37,300 km s−1 (12.5% c)

Other applications

The German physicist Claudius Gros has proposed that the technology of the Breakthrough Starshot initiative may be used in a second step to establish a biosphere of unicellular microbes on otherwise only transiently habitable exoplanets.[52][53] A Genesis probe would travel at lower speeds, about 0.3% of the speed of light. It could hence be decelerated using a magnetic sail.[54]

gollark: How is fueling trains a hard problem?
gollark: Add more production (perpendicular to the bus) for the relevant thing.
gollark: Anyway, if I was doing hyperscale™ I'd make a dedicated green circuit facility from conveniently placed copper and iron patches.
gollark: Main bus designs are supposed to alleviate that.
gollark: We just pull from the bus and hope everything can sustain the necessary throughput.

See also

References
  1. Gilster, Paul (12 April 2016). "Breakthrough Starshot: Mission to Alpha Centauri". Centauri Dreams. Retrieved 14 April 2016.
  2. F, Jessica (14 April 2016). "Stephen Hawking, Mark Zuckerberg, Yuri Milner Launch $100M Space Project Called Breakthrough Starshot". Nature World News.
  3. Lee, Seung (13 April 2016). "Mark Zuckerberg Launches $100 Million Initiative To Send Tiny Space Probes To Explore Stars". Newsweek. Retrieved 29 July 2019.
  4. Chang, Kenneth (24 August 2016). "One Star Over, a Planet That Might Be Another Earth". The New York Times. Retrieved 24 August 2016.
  5. Staff (12 April 2016). "Breakthrough Starshot". Breakthrough Initiatives. Retrieved 12 April 2016.
  6. Overbye, Dennis (12 April 2016). "Reaching for the Stars, Across 4.37 Light-Years; A Visionary Project Aims for Alpha Centauri, a Star 4.37 Light-Years Away". The New York Times. Retrieved 12 April 2016.
  7. Stone, Maddie (12 April 2016). "Stephen Hawking and a Russian Billionaire Want to Build an Interstellar Starship". Gizmodo. Retrieved 12 April 2016.
  8. Staff (12 April 2016). "Breakthrough Initiatives – Breakthrough Starshot". Breakthrough Initiatives. Retrieved 14 April 2016.
  9. Lubin, Philip (2016). "A Roadmap to Interstellar Flight". Journal of the British Interplanetary Society. 69: 40. arXiv:1604.01356. Bibcode:2016JBIS...69...40L.(file available at University of California, Santa Barbara here Archived 17 April 2016 at the Wayback Machine Accessed 16 April 2016)
  10. Hall, Loura (7 May 2015). "DEEP IN Directed Energy Propulsion for Interstellar Exploration". NASA News. Retrieved 22 April 2016. NASA is pleased to hear that Professor Lubin has received external funding to continue the work started in his NIAC study.
  11. "Breakthrough Initiatives". breakthroughinitiatives.org. Retrieved 25 December 2017.
  12. "Starshot Leadership".
  13. Breakthrough Starshot, Leaders, Management and Advisory Committee
  14. "Breakthrough Initiatives". breakthroughinitiatives.org. Retrieved 10 January 2017.
  15. Scharf, Caleb A. "Can Starshot Work?". scientificamerican.com. Retrieved 25 August 2016.
  16. "Planet Found in Habitable Zone Around Nearest Star – Pale Red Dot campaign reveals Earth-mass world in orbit around Proxima Centauri". www.eso.org. Retrieved 10 January 2017.
  17. Witze, Alexandra (25 August 2016). "Earth-sized planet around nearby star is astronomy dream come true". Nature. 536 (7617): 381–382. Bibcode:2016Natur.536..381W. doi:10.1038/nature.2016.20445. PMID 27558041.
  18. "VLT to Search for Planets in Alpha Centauri System – ESO Signs Agreement with Breakthrough Initiatives". www.eso.org. Retrieved 10 January 2017.
  19. "Breakthrough Initiatives". breakthroughinitiatives.org. Retrieved 10 January 2017.
  20. Lightsail, Integrity under thrust.
  21. Lightsail | Stability on the beam.
  22. TVIW (20 October 2017), 2. Breakthrough Starshot System Model, retrieved 29 October 2017
  23. Parkin, Kevin. "Starshot System Model".
  24. "Breakthrough Initiatives". breakthroughinitiatives.org. Retrieved 25 August 2016.
  25. "Breakthrough Starshot: Concept". 12 April 2016. Retrieved 14 April 2016.
  26. "A new plan to send spacecraft to the stars: replace rockets with lasers". The Economist. 12 April 2016. Retrieved 13 April 2016.
  27. Emspak, Jesse (15 April 2016). "No Breakthrough Yet: Stephen Hawking's Interstellar 'Starshot' Faces Challenges". Space. Retrieved 15 April 2016.
  28. Hoang (2017). "The Interaction of Relativistic Spacecrafts with the Interstellar Medium". The Astrophysical Journal. 837 (1): 5. arXiv:1608.05284. Bibcode:2017ApJ...837....5H. doi:10.3847/1538-4357/aa5da6.
  29. Timmer, John (24 August 2016). "Just how dangerous is it to travel at 20% the speed of light?". Science. Ars Technica. Retrieved 28 August 2016.
  30. "Potential Challenges for Starshot". Breakthrough Initiatives. Retrieved 14 April 2016.
  31. "Interstellar Dust". Breakthrough Initiatives. Retrieved 15 April 2016.
  32. The Andromeda Study: A Femto-Spacecraft Mission to Alpha Centauri. Andreas M. Hein, Kelvin F. Long, Dan Fries, Nikolaos Perakis, Angelo Genovese, Stefan Zeidler, Martin Langer, Richard Osborne, Rob Swinney, John Davies, Bill Cress, Marc Casson, Adrian Mann, Rachel Armstrong. Initiative for Interstellar Studies. arXiv, 2017.
  33. Greene, Kate (13 April 2016). "What Will Make Interstellar Travel a Reality?". Slate. Retrieved 16 April 2016.
  34. Clery, Daniel (12 April 2016). "Russian billionaire unveils big plan to build tiny interstellar spacecraft". Science. doi:10.1126/science.aaf4115. Retrieved 15 April 2016.
  35. Stone, Maddie (12 April 2016). "Stephen Hawking and a Russian Billionaire Want to Build an Interstellar Starship". Gizmodo. Retrieved 12 April 2016.
  36. Domonoske, Camila (12 April 2016). "Forget Starships: New Proposal Would Use 'Starchips' To Visit Alpha Centauri". NPR. Retrieved 15 April 2016.
  37. Emspak, Jesse (15 April 2016). "No Breakthrough Yet: Stephen Hawking's Interstellar 'Starshot' Faces Challenges". Space.com. Retrieved 15 April 2016.
  38. Staff (26 July 2017). "In Quest To Reach Alpha Centauri, BreakThrough Starshot Launches World's Smallest Spacecraft – First Prototype 'Sprites' – Precursors to Eventual 'StarChip' Probes – Achieve Low Earth Orbit". BreakThroughInitiatives.org. Retrieved 28 July 2017.
  39. Staff (12 April 2016). "Breakthrough Starshot: Potential Challenges". Breakthrough Initiatives. Retrieved 14 April 2016.
  40. Staff (16 April 2016). "Starship enterprise". The Economist. Retrieved 15 April 2016.
  41. Staff (12 April 2016). "Breakthrouth Starshot: Gram-Scale Starchip Components – 4 Cameras". Breakthrough Initiatives. Retrieved 15 April 2016.
  42. Staff (12 April 2016). "Breakthrouth Starshot: Gram-Scale Starchip Components – 4 Processors". Breakthrough Initiatives. Retrieved 15 April 2016.
  43. Staff (12 April 2016). "Breakthrouth Starshot: Gram-Scale Starchip Components – 4 Photon Thrusters". Breakthrough Initiatives. Retrieved 15 April 2016.
  44. Gilster, Paul (21 October 2013). "Laser Travel by Photonic Thruster". Centauri Dreams. Retrieved 16 April 2016.
  45. Staff (12 April 2016). "Breakthrouth Starshot: Gram-Scale Starchip Components – Battery". Breakthrough Initiatives. Retrieved 15 April 2016.
  46. Staff (12 April 2016). "Breakthrouth Starshot: Gram-Scale Starchip Components – Protective Coating". Breakthrough Initiatives. Retrieved 15 April 2016.
  47. Staff (12 April 2016). "Breakthrough Starshot: Lightsail, Integrity under thrust". Breakthrough Initiatives. Retrieved 16 April 2016.
  48. Staff (12 April 2016). "Breakthrouth Starshot: Gram-Scale Starchip Components – Lightsail – Structure". Breakthrough Initiatives. Retrieved 15 April 2016.
  49. Patel, Neel V. (15 April 2016). "The Starshot Breakthrough Light Beam Is Really a Million Lasers, Which Is Insane". Inverse. Retrieved 16 April 2016.
  50. Parkin, Kevin L. G. (2020). "A Starshot Communication Downlink". arXiv:2005.08940 [astro-ph.IM].
  51. Heller, René; Hippke, Michael; Kervella, Pierre (2017). "Optimized trajectories to the nearest stars using lightweight high-velocity photon sails". The Astronomical Journal. 154 (3): 115. arXiv:1704.03871. Bibcode:2017AJ....154..115H. doi:10.3847/1538-3881/aa813f.
  52. Gros, Claudius (2016), "Developing ecospheres on transiently habitable planets: The genesis project", Astrophysics and Space Science, 361 (10): 324, arXiv:1608.06087, Bibcode:2016Ap&SS.361..324G, doi:10.1007/s10509-016-2911-0
  53. Jessica Boddy: Q&A: Should we seed life on alien worlds?, Science, 9. September 2016.
  54. James Romero, "Should we seed life through the cosmos using laser-driven ships?", New Scientist, 13 November (2017).
This article is issued from Wikipedia. The text is licensed under Creative Commons - Attribution - Sharealike. Additional terms may apply for the media files.