As a research scientist at MIT, Prof. Cui participated in the construction, test, and operation of the All-Sky Monitor (ASM) aboard RXTE. The activities included: testing and characterizing the ASM; trouble shooting (e.g., high-voltage breakdowns); selecting flight detectors; testing the assembled ASM in a simulated space environment; integrating the ASM to the spacecraft and conducting end-to-end tests; and performing final pre-launch checks at the Kennedy Space Center. Moreover, Prof. Cui designed and coded a sophisticated planning software system for scheduling ASM observations. For a decade and a half, the ASM served as the eyes and ears of RXTE, by routinely monitoring more than 100 bright X-ray sources in the sky and providing alerts of transient events for Target-of-Opportunity observations with more sensitive instruments aboard. It was also responsible for the discovery of dozens of new X-ray sources.

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