What is the maximum data rate from JWST in megabits per second? The answer is 28 Mbps.
JWST sends science and engineering data to Earth through a Ka-band radio link using NASA’s Deep Space Network. The telescope’s high-rate downlink is specified at up to 28 megabits per second.
The figure 28.6 is associated with data volume, not transmission speed. Under a nominal contact schedule, JWST can transmit at least 28.6 gigabytes of recorded science data during a four-hour ground contact.
JWST also has lower-rate communications links for telemetry and commands. Its Ka-band system is the high-rate channel used primarily for returning stored scientific observations.