Below is an context that describes a sql query, paired with an question that provides further information. Write an answer that appropriately completes the request.  # noqa: E501
### Context:
CREATE TABLE table_name_20 (name VARCHAR, mission VARCHAR, age_at_first_step VARCHAR)
### Question:
Which astronaut went on the Apollo 16 mission at the age of 36y 6m 18d to step on the moon?
### Answer:
SELECT name FROM table_name_20 WHERE mission = "apollo 16" AND age_at_first_step = "36y 6m 18d"