NASA - Kuiper Airborne Observatory (KAO) Mission

The mission took place in September 1993 on the Kuiper Airborne Observatory, NASA Ames, California, USA. We did astronomical observation flights with the KAOfor studying fine-structure emission lines at 205 µm of N+ in the objects DR21, S106, W49. I was in control of the acousto-optical spectrometer and the data retrieval and preprocessing during the flight. Core of the heterodyne receiver is the Schottky mixer block. The whisker wire of 25 µm diameter is sharpened to a tip and then contacted mechanically to a diode on the chip with contact areas as small as 250 nm diameter.

From left to right:

1. Heterodyne receiver: CO2 laser optically pumping terahertz gas laser (HCOOH vapor or CH2F2 gas), Schottky diode, 77 K cooled HEMT amplifier mounted in supporting ring of the telescope flansch.
2. Training in low pressure chamber with oxygen deprivation and a mask are required for high altitude flying. Here you see a member of the science team (myself) wearing an oxygen mask.
3. KAO airplane on the field.
4. KAO airplane in hangar with open access doors.
5. Mixer block with corner cube reflector with impedance transformer.
6. Close-up of Schottky chip, antenna and corner cube.