Project Hail Mary Problems

This page houses all the Challenge Problems that you all submitted related to Project Hail Mary.

No Full-Point/Half-Point Deadlines

Spin-Drive Acceleration Upon Waking

Chapter 1, Page 19

In Chapter 1, Ryland Grace calculates the artificial gravity created by the The Hail Mary's linear acceleration as it is approaching the Tau Ceti system. He uses a measuring tape to measure a 91 cm height from a table to the floor. He then performs an experiments where he drops a plastic test tube from that height and uses a stop watch to time how long it takes the object to fall the 91 cm. His first measurement is 0.37 seconds, then 0.33 seconds, and so on. He repeats this 20 times to get an average fall time of 0.348 seconds.

Use that information to calculate the artifical gravity Ryland Grace is experiencing.

Reward: +5 Problem Solving

Observing the Petrova Line

The Petrova Line is an infrared emission line with a wavelength of precisely 25.984 µm. Design a method that we could observe the Petrova Line using our modern technology. Evaluate if you think it would be possible for us to observe the Petrova Line.

This one will take some research, critical thinking and problem solving to answer. Your rewards will be based on how deeply you dive into the problem.

Rewards: Up to Research +10; Problem Solving +10; Critical Thinking +10

Energy from Astrophage

Chapter 5, Page 97

When fully charged up, an Astrophage cell has 19 nanograms more mass than when it is fully depleted. The book claims that this corresponds to an energy of 1.5 megajoules of energy. Confirm this number and discuss the mechanism by which Astrophage generates energy.

Rewards: +5 Problem Solving

Breaking Stage Upon Tau Ceti Arrival

Chapter 6

“Actually, it would be worse than that. I’d be hurtling toward Tau Ceti at—I check the info on-screen—7,595 kilometers per second. Wow! A couple days ago, that was over 11,000. That’s what constantly accelerating at 1.5 g’s will do for you. Or “decelerating,” I guess. From a physics standpoint it’s all the same. Point is, I’m slowing down with respect to the star.” 

Solve for exactly how long (in days minutes and seconds) it would take for the deceleration from 11,000 km/s to 7,595 km/s at an acceleration rate of 1.5 g. 

Rewards: +5 Problem Solving