Draft:Solar mirrors in the stratosphere

Several groups think large hot air balloons can fly long term in the stratosphere, using solar energy to heat the air that provides the lift. Besides transponders that serve cellphones and provide some of the same purposes as communications satellites; steerable mirrors can beam sunlight through holes in the clouds to existing solar energy sites.

Space power application
"Solar dynamic" energy systems have been proposed for various spacecraft applications, including solar power satellites, where a reflector focuses sunlight on to a heat engine such as the Brayton cycle type.

Space reflectors for night illumination
Another advanced space concept proposal is the notion of Space Reflectors which reflect sunlight on to small spots on the night side of the Earth to provide night time illumination. An early proponent of this concept was Dr. Krafft Arnold Ehricke, who wrote about systems called "Lunetta", "Soletta", "Biosoletta" and "Powersoletta".

A preliminary series of experiments called Znamya ("Banner", a space mirror) was performed by Russia, using solar sail prototypes that had been re-purposed as mirrors. Znamya-1 was a ground test. Znamya-2 was launched aboard the Progress M-15 resupply mission to the Mir space station on 27 October 1992. After undocked from Mir, the Progress deployed the reflector. This mission was successful in that the mirror deployed, although it did not illuminate the Earth. The next flight Znamya-2.5 failed. Znamya-3 never flew.

Solar mirrors
Research "in solar mirrors is attracting a lot of attention, for instance, in the areas of anti-soiling coatings, mirror materials with high reflectance and high-temperature mirrors for secondary concentrators."

"The question of whether climate change is produced by anthropogenic global warming (henceforth AGW) has triggered an increasingly contentious confrontation over the conduct of science, the question of what constitutes scientific certainty, and the connection between science and policymaking."

"Mainstream science is scientific inquiry in an established field of study that does not depart significantly from orthodox theories. In the philosophy of science, mainstream science is an area of scientific endeavor that has left the process of becoming established. New areas of scientific endeavor still in the process of becoming established are generally labelled  protoscience or fringe science. A definition of mainstream in terms of protoscience and fringe science can be understood from the following table: Def. a "belief, not based on human reason or scientific knowledge, that future events may be influenced by one's behaviour in some magical or mystical way" is called a superstition.

Def. any "body of knowledge purported to be scientific or supported by science but which fails to comply with the scientific method" is called a pseudoscience.

"Pseudoscience is notoriously lax in rigorous application of the scientific method. Reproducability is typically a problem."

"Bad science might more properly be labelled "poor science" in that it is typically characterized by substandard or "sloppy" methodology."

"Junk science is used to describe agenda-driven research that ignores certain standard methodologies and practices in an attempt to secure a given result from an experiment."

Def. an "unscientific field of study which later becomes a science", a "field of study at the initial phase of the scientific method, involving information gathering and hypothesis formulation, but is not yet falsifiable, or if it is, its predictions have not yet been observed", or a "new area or field of science in the process of being established" is called a protoscience.

"A protoscience is a field of inquiry which is not yet considered a real "science", but which nevertheless bears some resemblance to the norms of the scientific method."

"There are, of course, a variety of possible responses if climate scientists’ predictions turn out to be valid [including] the placement of vast solar mirrors in space to deflect solar radiation".

Balloons for technology
Balloons provide a long-duration platform to study any atmosphere, the universe, the Sun, and the near-Earth and space environment above as much as 99.7 % of the Earth's atmosphere. Unlike a rocket where data are collected during a brief few minutes, balloons are able to stay aloft for much longer. Balloons for technology offer a low-cost, quick-response method for conducting scientific investigations. They are mobile, meaning they can be launched where the scientist needs to conduct the experiment, in as little as six months.

The Ultra Long Duration Balloon (ULDB) Project is developing new composite materials and a new balloon design, a standard gondola including power, global telemetry/command and an altitude control system. The ULDB is seeking to improve mission control and operations and the integration of scientific instruments. It is the potential for longer duration flights that has been the driver for the resurgence of interest in balloons by the scientific community. In recent years, the manned global ballooning attempts have called attention to the difficulty of achieving “longer”.

"High altitude balloons are an inexpensive means of getting payloads to the brink of space [The first test shown in the image on the left] was launched from McMurdo Station in Antarctica. The balloon reached a float altitude of more than 111,000 feet and maintained it for the entire 11 days of flight. [...] The flight tested the durability and functionality of the scientific balloon’s novel globe-shaped design and the unique lightweight and thin polyethylene film. It launched on December 28, 2008 and returned on January 8, 2009."

"The University of Hawaii Manoa’s Antarctic Impulsive Transient Antenna launched December 21, 2008, and is still aloft. Its radio telescope is searching for indirect evidence of extremely high-energy neutrino particles possibly coming from outside our Milky Way galaxy."

Solar sails
LightSail 2 is a fully functional spacecraft intended to demonstrate true solar sailing, and incorporates the lessons learned from LightSail 1.

Both LightSail spacecraft measure 10 × 10 × 30 cm in their stowed configuration. After sail deployment, the total area of each spacecraft is 32 m2.