Trans Lunar Injection (TLI) How'd they know where to point the rocket once in orbit?

[@rexhallinan1785]

Pretty good for 1968 when Apollo 8 did it

[@bobcastro9386]

The Free Return Trajectory was invented by two mathematicians working for NASA at the Marshall Space Flight Center in Huntsville Alabama. Lem Hooper and Byrd Tucker came up with the idea of a spaceflight path that would automatically return the spacecraft to earth if the mission ran into trouble on the way to the moon and couldn't easily correct its initial trajectory leaving earth (the trans-lunar injection burn). I know this because one of them, William "Byrd" Tucker, went to Gwinnett Church, outside Atlanta Georgia. One Sunday, after service, I was standing in line waiting to speak to the pastor when I engaged Byrd in conversation and was told his amazing story of hailing from Alabama, one of thirteen children, son of a sharecrop farmer with no prospects beyond scraping dirt (in his description) until his mathematical skills were recognized in service by the U.S. Army. He then transferred to the Redstone Arsenal in Huntsville, AL and worked for the Army Ballistic Missile Agency and then for NASA. In 2019, I drove Byrd to an IMAX screening of "Apollo 11" then in theaters marking the 50th anniversary of the first manned lunar landing. Seeing the impressive film sequence explaining the Trans Lunar Injection (TLI) burn while sitting next to the co-author of the Free Return Trajectory was the thrill of a lifetime for me. Later, Byrd showed me his NASA paper describing the technique (most of it went completely over my head) but wouldn't allow scanning or copying- it was still a restricted document. After Byrd passed in 2021, the church created a tribute video to his legacy: One Small Step / The Byrd Tucker Story: kzbin.info/www/bejne/oJakp4tjqJeqlbs

[@rexhallinan1785]

Thanks .Even though I knew most of this

[@lakshyachaudhary3803]

I knew more than you