Space sunshade
A space sunshade or sunshield is a
A sunshade is of particular interest as a
Modern proposals are based on some form of distributed sunshade composed of lightweight transparent elements or inflatable "space bubbles" manufactured in space to reduce the cost of launching massive objects to space.[7][8]
Designs for planetary sunshade
Cloud of small spacecraft
One proposed sunshade would be composed of 16 trillion small disks at the Sun-Earth L1
The individual autonomous flyers building up the cloud of sunshades are proposed not to reflect the sunlight but rather to be transparent lenses, deflecting the light slightly so it does not hit Earth. This minimizes the effect of
The remaining solar pressure and the fact that the L1 point is one of
Such a group of sunshades would need to occupy an area of about 3.8 million square kilometers if placed at the L1 point[12] (see other lower disc size estimates below).
It would still take years to launch enough of the disks into
Lightweight solutions and "Space bubbles"
A more recent design has been proposed by Olivia Borgue and Andreas M. Hein in 2022, proposing a distributed sunshade with a mass on the order of 100,000 tons, composed of ultra-thin polymeric films and SiO2 nanotubes.[7] The author estimated that launching such mass would require 399 yearly launches of a vehicle such as SpaceX Starship for 10 years.[7]
A 2022 concept by MIT Senseable City Lab proposes using thin-film structures ("space bubbles") manufactured in outer space to solve the problem of launching the required mass to space.[15] MIT scientists led by Carlo Ratti believe deflecting 1.8 percent of solar radiation can fully reverse climate change. The full raft of inflatable bubbles would be roughly the size of Brazil and include a control system to regulate its distance from the Sun and optimise its effects.[16] The shell of the thin-film bubbles would be made of silicon, tested in outer space-like conditions at a pressure of .0028 atm and at -50 degrees Celsius.[16] They plan to investigate low vapor-pressure materials to rapidly inflate the bubbles, such as a silicon-based melt or a graphene-reinforced ionic liquid.[16]
One Fresnel lens
Several authors have proposed dispersing light before it reaches the Earth by putting a very large lens in space, perhaps at the
In 2004, physicist and science fiction author
The cost of such a lens has been disputed. At a science fiction convention in 2004, Benford estimated that it would cost about
One diffraction grating
A similar approach involves placing a very large
Other Lower Disc Size Estimates
Recent work by Feinberg (2022)[21] illustrate that lower disc area sizes (factor of approximately 3.5 reduction) are feasible when the background climate response is considered. For example, the background Earth climate would yield less re-radiation and feedback. In addition, disc area sizes can be further reduced by 50 times using an Annual Solar Geoengineering approach as indicated by Feinberg (2024).[22]
Spacecraft sunshades
The James Webb Space Telescope (JWST) infrared telescope has a layered sunshade to keep the telescope cold.
For spacecraft approaching the Sun, the sunshade is usually called a heatshield. Notable spacecraft [designs] with heatshields include:
- Messenger, launched 2004, orbited Mercury until 2015, had a ceramic cloth sunshade
- Parker Solar Probe (was Solar Probe Plus), launched 2018 (carbon, carbon-foam, carbon sandwich heatshield)
- Solar Orbiter, launched Feb 2020
- BepiColombo, to orbit Mercury, with Optical Solar Reflectors (acting as a sunshade) on the Planetary Orbiter component.
See also
- Solar sail – Space propulsion method using Sun radiation
- Space mirror (geoengineering)– Artificial satellites designed to change the amount of solar radiation that impacts Earth
- Space-based solar power – Concept of collecting solar power in outer space and distributing it to Earth
- Spacecraft thermal control – Process of keeping all parts of a spacecraft within acceptable temperature ranges
- Starshade– Proposed occulter
- Sunshield (JWST)– Main cooling system for the infrared observatory
References
- Die Rakete zu den Planetenräumen(in German). Michaels-Verlag Germany. pp. 87–88.
- ^ Oberth, Hermann (1970) [1929]. ways to spaceflight. NASA. pp. 481–506. Retrieved 21 December 2017 – via archiv.org.
- ^ Oberth, Hermann (1957). Menschen im Weltraum (in German). Econ Duesseldorf Germany. pp. 125–182.
- ^ Oberth, Hermann (1978). Der Weltraumspiegel (in German). Kriterion Bucharest.
- S2CID 148608737.
- ^ a b Gorvett, Zaria (26 April 2016). "How a giant space umbrella could stop global warming". BBC. Archived from the original on 20 December 2016. Retrieved 7 December 2016.
- ^ S2CID 254479656.
- ^ "Space Bubbles Could Be the Wild Idea We Need to Deflect Solar Radiation". Popular Mechanics. 7 July 2022. Retrieved 23 May 2023.
- ^ a b "Space sunshade might be feasible in global warming emergency". EurekAlert. 3 November 2006. Archived from the original on 23 October 2020. Retrieved 11 November 2010.
- ^ "Global Sunshade". BBC News. 19 February 2007. Archived from the original on 1 March 2007. Retrieved 11 November 2010.
- ^ Tnenbaum, David (23 April 2007). "Pies in the Sky: A Solution to Global Warming". Astrobiology Magazine. Archived from the original on 2 February 2016. Retrieved 14 November 2010.
- ^ PMID 17085589.
- ^ Konecny, Pavel (6 December 2018). "We need SpaceX BFR not just get us to MARS but to save EARTH from Global Warming". Medium. Archived from the original on 22 November 2021. Retrieved 11 March 2019.
- ^ "Space Sunshade Might Be Feasible In Global Warming Emergency" (Press release). University of Arizona. 6 November 2006. Archived from the original on 16 March 2010. Retrieved 29 April 2009.
- ^ "Space bubbles". MIT Senseable City Lab. Retrieved 24 May 2023.
- ^ a b c "Space Bubbles Could Be the Wild Idea We Need to Deflect Solar Radiation". Popular Mechanics. 7 July 2022. Retrieved 23 May 2023.
- Bibcode:1989JBIS...42..567E. This proposal is also discussed in footnote 23 of Edward Teller; Roderick Hyde & Lowell Wood (1997), Global Warming and Ice Ages: Prospects for Physics-Based Modulation of Global Change (PDF), Lawrence Livermore National Laboratory, archived(PDF) from the original on 27 January 2016, retrieved 30 October 2010.
- ^ a b See Russell Dovey, "Supervillainy: Astroengineering Global Warming Archived 4 August 2012 at archive.today and Bill Christensen, "Reduce Global Warming by Blocking Sunlight" Archived 2009-04-17 at the Wayback Machine.
- ^ Edward Teller; Roderick Hyde & Lowell Wood (1997), Global Warming and Ice Ages: Prospects for Physics-Based Modulation of Global Change (PDF), Lawrence Livermore National Laboratory, archived (PDF) from the original on 27 January 2016, retrieved 30 October 2010. See pages 10–14 in particular.
- ^ Edward Teller, Roderick Hyde & Lowell Wood (2002), Active Climate Stabilization: Practical Physics-Based Approaches to Prevention of Climate Change (PDF), Lawrence Livermore National Laboratory, archived (PDF) from the original on 13 May 2009, retrieved 30 October 2010
- ISSN 2624-9553.
- ISSN 2225-1154.
External links
- Marchis, Franck; Sánchez, Joan-Pau; McInnes, Colin R. (2015). "Optimal Sunshade Configurations for Space-Based Geoengineering near the Sun-Earth L1 Point". PLOS ONE. 10 (8): e0136648. PMID 26309047.