Sentinel Mission - private NEO infrared telescope spacecraft

[gary]

The Institute of Electrical and Electronic Engineers (IEEE) Spectrum magazine
has a article dated 29th April 2015 by Harold Reitsema entitled
"Sentinel’s Mission to Find 500,000 Near-Earth Asteroids".

The B612 Foundation in the US, a private non-profit foundation
co-founded by Rusty Schweickart, is moving forward to build and
launch an infrared telescope spacecraft called Sentinel.

Originally Posted by Harold Reitsema, IEEE Spectrum

We expect the mission will cost US $450 million in all, a figure that will cover development, launch, and 6.5 years of operation. B612 is funding Sentinel through philanthropic donations, much as astronomical observatories were funded in the early 20th century. So far, we have raised enough money to build our team, fabricate engineering versions of the infrared detectors, construct a performance model for Sentinel to help plan our observing strategies, and establish our management plans. This is the first time anyone has attempted to fund a scientific, deep-space mission this way, but it’s quite possible it won’t be the last.

The mission has already built an impressive team -
http://sentinelmission.org/our-team/

Originally Posted by Harold Reitsema, IEEE Spectrum

We plan to place sentinel in an orbit around the sun about 50 million km inside Earth’s orbit and not far from the orbit of Venus. There, the telescope will effectively sit with its back to the sun, continually scanning for objects with its 0.5-meter aperture and 30-megapixel infrared camera. This placement will allow Sentinel to see NEOs when they are close to the sun, during a time when they’re at their hottest and therefore radiating strongly at infrared wavelengths.

Sentinel’s proximity to the sun will let it generate twice as much power from its solar panels as it would in Earth orbit, but it will make thermal control more complicated. The spacecraft’s electronics must be held near room temperature, but the telescope must be kept below –208 °C, some 65 degrees above absolute zero, so that it won’t radiate heat at wavelengths that its camera would detect.

Originally Posted by Harold Reitsema, IEEE Spectrum

All told, Sentinel will have an 11-square-degree field of view, more than 50 times the area the moon takes up in the sky when viewed from Earth. Sentinel’s camera will take in this large field of view with a mosaic of 16 individual 1.8-megapixel CMOS detector chips. B612 has already gotten a start on these detectors, which are sensitive to wavelengths of infrared radiation from 5 to 10.2 micrometers, the range where NEOs emit most of their light. Raytheon Vision Systems, which is building the detectors, finished a prototype in 2013. The company is now building a full-scale engineering unit, a carbon copy of what will eventually fly on the telescope.

IEEE Spectrum article here -
http://spectrum.ieee.org/aerospace/s...arth-asteroids

Sentinel Mission web site here -
http://sentinelmission.org/

The Sentinel Mission is seeking donations -
https://donatenow.networkforgood.org...ndation/donate