Mating of NISAR's upper and lower antenna boom assembly at NASA's Jet Propulsion Laboratory.

Engineers check NISAR’s fully deployed 9-meter (29.5-foot) antenna boom assembly at NASA's Jet Propulsion Laboratory in Southern California.

The NISAR spacecraft's radar antenna boom has a four-hinge deployment system that precisely locates the 12-meter radar antenna reflector over the L-band (24 cm wavelength) and S-band (12 cm wavelength) radar feed assemblies. In this photo, JPL mechanical integration and test team members mate the upper and lower boom assemblies for end-to-end alignment measurements.