154505 has a missing [d]
Who was suppose to be the next President?
Expand your thinking.
Q
"suppose" not "supposed"
D can be Deuterium. I don't see another obvious candidate.
Iridium and Deuterium are involved together in some physical interactions (not to say that this one in particular is it) e.g. https://www.sciencedirect.com/science/article/pii/S0040402003004228