SCHEMA:
CREATE TABLE table_name_52 (time_elapsed VARCHAR, launched VARCHAR, closest_approach VARCHAR)
USER:
What Time elapsed has both the Launched of 15 October 1997 and the Closest approach of 24 June 1999?

QUERY:
SELECT time_elapsed FROM table_name_52 WHERE launched = "15 october 1997" AND closest_approach = "24 june 1999"