Earth takes 365.25 days to complete its orbit around the Sun.
Asteroid 2001 US16 (also known as 89136) takes 577 earth days to complete it's orbit around the Sun.
to see the orbit of 2001 US16, go to 
https://ssd.jpl.nasa.gov/sbdb.cgi?sstr=2001%20US16;old=0;orb=1;cov=0;log=0;cad=0#orb
My question is, at what time in the orbit of Earth would be best to launch a rocket to 2001 US16 that can travel 36,000 miles per hour (0.00038728081 au) to this asteroid?