"solar sun simulator", 1960's patent

[Leifer]

There is a small buzz online, claiming that NASA has a patent that imitates the sun, and are likely using it to create a false sun (or a 2nd sun), seen from the earth.
Artificial Sun

(it's a lengthy video, much is guesswork....)

Here is one of the patents mentioned, from 1966.... http://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/19710020816.pdf
(see patent lines 18 to 35)

I spent an hour researching this, and this is what I found, and wrote about it.....

The old 1960's NASA sun simulator STAR (nickname), was for an environmental test chamber right here on earth, to simulate the sun found in space. It was used to test: electronics, metal and plastic materials, lenses (glass and plastic), and anything else that would be subject to outer-atmosphere solar ray testing. It was for simulating the "outer space" sun....here on earth, in a person-sized chamber that could be vacuumed of air... It's still done today with more modern methods and light sources

Anyone care to add or correct this explanation ?

 

[Mick West]

There's plenty of Sun Simulators, of various types.
https://www.google.com/search?q="sun+simulator"&num=50&tbm=isch

The most common use now is for testing solar panels. The simulator provides a consistent amount of light at a similar spectrum to the sun, and they can measure the response of the panel. Some of them rotate to test at different angles.

http://imtsolar.com/sun-simulator-susi/

IMT has been building quality and dependable Sun Simulators for our customers since 1993. While many of these systems where designed to custom specifications for our clients with Photovoltaic or Solar Thermal testing needs, it is important to know we have a series of standard packages ranging from the Mini-Susi (used for PV cell R&D and testing) to the Lab Production SUSI enabling the testing of large PV and Thermal Panel Products. Designs incorporating both vertical and horizontal light paths are common – but so too are options like cold sky, 45 degree tilt beams/beds and even variable irradiance output capability to provide ranges from 200 to 1100w/m2 in one Simulator.

NASA, of course, has their own needs - as sunlight is a bit different in space, with no atmosphere to filter it. Here's some technical details of recent work on this - comparing a commercial X-25 sun simulator to one of their own design.
http://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/20050206366.pdf

Simulating the sun in a laboratory for the purpose of measuring solar cells has long been a challenge for engineers and scientists.1,2,3 Multi-junction cells demand higher fidelity of a solar simulator than do single junction cells, due to a need for close spectral matching as well as AM0 intensity. A GaInP/GaAs/Ge solar cell for example, requires spectral matching in three distinct spectral bands (figure 1). A commercial single source highpressure xenon arc solar simulator such as the Spectrolab X-25 at NASA Glenn Research Center, can match the top two junctions of a GaInP/GaAs/Ge cell to within 1.3% mismatch, with the GaAs cell receiving slightly more current than required. The Ge bottom cell however, is mismatched +8.8%. Multi source simulators are designed to match the current for all junctions but typically have small illuminated areas, less uniformity and less beam collimation compared to an X-25 simulator. It was our intent when designing a multi source simulator to preserve as many aspects of the X-25 while adding multi-source capability

 

[Leifer]

Yes, thanks. I assumed the light would be adjusted for sun rays (perhaps gamma rays too ?)
As you have noted.....the technology has vastly increased since the early 60's.
....but nowhere does this old patent claim to "create a false sun overhead" in the sky.
The old patent was referring to a terrestrial test chamber, but people like to hunt-and-peck the patent for words and phrases that seem to fit their story.

I remember back in art school (1980's), photosensitive printing plates could be "left in the sun", or more quickly and accurately could be exposed by a burnt rod arc light in a machine, like a xerox machine on super steroids....(more like a welding rod).....lol

 

[Leifer]

Vague attempts were proposed for mirrors to beam light to the earth, from sun-facing mirrors placed in orbit...

The idea of using mirrors in space to beam sunlight
down to earth for terrestrial solar electric power generation
is not new. Dr. Krafft Ehricke first proposed this idea in
1978 (1, 2) as shown in figure 1 under the title Power
Soletta. Because of the simplicity of mirrors compared to
the complexity of the Space Power Satellite concept, his
idea was brilliant particularly for the time in which it was
first proposed.
http://www.nss.org/settlement/ssp/library/Mirrors_in_Space_for_Electric_Power_at_Night_2012.pdf

 

[Gridlock]

Good job they got that patent or we'd have dozens of suns by now...