New Mexicans for Science and Reason
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Since they are tied to our hard-copy newsletter and monthly meetings, look for Puzzle Updates, usually on the Friday before the Second Wednesday of each Month!
Next Puzzle Posting: September 8th, 2019
AUGUST 2019 PUZZLE - "Pricy Trash Run"
Submitted by Dave Thomas
Suppose you have a rocketload of undesirable trash (perhaps radioactive sludge, or vain politicians’ tweets), and you’ve managed to get it off Earth, and into an Earth-like circular orbit (radius R ~ 1.5x10^11 meters, orbital speed ~ 30,000 meters/second ~ √(GM/R)). Now, you want to dump the trash barge right into the Sun.
The August Bonus:
Of the two methods outlined below, which is the most economical approach? Also, estimate how many joules per kilogram of barge will be required for both methods?
(A) Fire the trash barge’s rockets in the opposite direction of its orbit around the Sun, bringing it to a standstill, from which it would plummet directly into the sun. (This is the inner orbit shown above.)
(B) Briefly fire the barge's rockets in the same direction of motion as the rocket, giving it an elliptical orbit with the perihelion near Earth’s orbital radius, and an aphelion near Jupiter's orbital radius (~7.8x10^11 meters). Once the barge reaches aphelion, then fire the rockets in the opposite direction of its orbit around the Sun, bringing it to a standstill, whereupon it will plunge into the Sun. (This is the outer orbit above.)
Note: assume both Earth and Jupiter are considered "elsewhere" in the solar system for the entire duration, and are shown for scale only. They will not affect the barge in its orbit around the sun. In other words, sun and barge are a 2-body problem.
Hall of Fame (August Puzzle Solvers):
Earl Dombroski (NM)