Rusty Schweickart of Apollo 9 and the Sentinel Mission Demonstrates a Thermal Imager

At Ball Aerospace, we used a FLIR camera with thorium fluorite lenses to see our faces and the sensitivity to heat, with a sun-warmed meteorite in his right hand compared to an outdoor rock on his left.

The Sentinel Mission will fly a Mercury Cadmium Telluride sensor supercooled to 40° above absolute zero to minimize noise. That sensor could detect one of these black rocks against the black sky 3,000 miles away. It needs to look into the deep infrared (10 micron wavelengths).

Why space? The infrared light that we are looking for does not get through Earth’s atmosphere. Asteroids are dark, like charcoal, but warm from orbiting the sun.

Why a near-Venus orbit?
1) Passively looking away from the sun at all times
2) NEOs inside of Earth’s orbit have a higher statistical chance of impact
3) We see the hot sun-facing side if it’s not rotating orthogonally
4) Shorter orbital period around the sun affords a faster survey

Sentinel: a satellite the size of a Cadillac Escalade taken to a Venus-like orbit by a Falcon 9 rocket. Ball estimates that it will take 50 months to design and build with 1000 people, 100K parts and a million labor hours. The Ball President told us that this is the most exciting project they have ever undertaken (and that includes a rich history of Webb, Kepler, Hubble, Chandra, and Spitzer).