Showing posts with label NASA. Show all posts
Showing posts with label NASA. Show all posts

Monday, August 24, 2020

The Martian, Computer Science, and College

This summer, the school asked professors if they would be interested in leading book discussions with incoming first-year students in Computer Science.  I, along with many other professors, volunteered, where each of us could select our specific title to discuss.  I proposed reading, The Martian, by Andy Weir.  What follows is not a review of the book, which I really enjoyed, but rather a summary of the discussion points from the hour we had together.

The following text contains many book spoilers.

We started the discussion with a short summary of my background and then a student asked about the Martian rover hacking.  It is in my opinion, plausible.  It depends on several assumptions, such as the rover's driver being able to be modified so easily to log the malformed network data (sent by the probe).  It would then be reasonable to send commands to the probe to broadcast the necessary data to construct an executable on the rover.  Then assuming that Mark can run it with sufficient privileges or that there is a known vulnerability allowing the executable to gain the privilege, the probe's data could be a patch.  Personally, I enjoyed the thought of using ASCII to communicate and myself and my TAs agree, "man ascii".  Besides, I carry an ASCII chart in my wallet.

We discussed how there was significant cooperation in solving the problems.  The crew worked together.  NASA had many teams working on the problems.  Internationally, China also provided assistance.  The people working on these problems were diverse.  And there were continual concerns about the crew's mental state and about Mark's.  Similarly, Computer Science students will need to learn to work with others, to work in groups with diverse backgrounds and skill sets, and know that there are many many more people that are wanting to see and willing to support them in having successful lives and taking steps whenever circumstances dictate.

Mark Watney survives in part by having a diverse education and training.  Being a fictional character, he has the right skills to survive, but this is based in reality.  Astronauts are trained in a diverse set of skills, particularly to maximize the value gained from their time in space.  They are not experts, but rather trained well to exercise the guidance of experts on Earth.  And similarly, I reinforced to the students that their studies should work to give them a broad foundation beyond Computer Science.

The final topic brought up by the students was about ethics.  First, should NASA tell the crew of the Hermes that Mark Watney was alive on Mars, when it was first determined.  Or instead, NASA would censor all communication to ensure that they were not informed that they abandoned Mark.  What is the trade-off between the truth and mission results?  Second, the Chinese scientists had to make a decision, is the life of one astronaut worth their probe?  Should they give up their long-prepared mission of great scientific value to instead make a "grocery delivery"?  How much is one life worth?  Third, when the Rich Purnell plan presented an alternative to rescuing Mark, was NASA obligated to consult the crew in evaluating this option?  And related, the crew of the Hermes decided to return to Mars (on the low chance of killing everyone plan) to save Mark Watney, and also extending their mission duration.  Also briefly discussed was that governments also have to decide how much a life is worth.  It is noted that the science that Mark can perform makes up for the cost of his rescue, which addresses this concern in story.

I think that the 20 or so students appreciated the hour we had together.  I hope to some day be able to meet and ultimately teach them in person.

Wednesday, October 10, 2018

NASA Talk: Making Miracles Happen

Dr. Thomas H. Zurbuchen the Associate Administrator of NASA's Science Mission Directorate gave a talk today about some key lessons he has learned and observed from his years with NASA, as well as years before.  The following is my quick notes from his talk.

Planning for the future, Voyager launched with the plan to visit Jupiter and Saturn.  But the scientists still had plans for the possibility to visit Uranus and Neptune based on that launch window.  And also, that in the lifetime of the probes, they may leave the Heliosphere.  Imagine that over 40 years after launch, there are still papers to be written in Nature or Science from the mission.  Voyager 2 is nearing this mark, which Voyager 1 already crossed.

Solar probe problem was to explore near to the Sun.  The desire was there from 60 years ago.  And eventually from decades of other work, the technology was there to support components such as solar panels that can operate close to Sun.  Once the technology was available, the proposal was based on a $4 billion probe, which was outside the budget.  But NASA offered to design / launch for $1 billion.  This forced a complete redesign.  The original mission used a single Jupiter flyby to bring the probe to 4 solar radii.  For $1 billion, the flight path would instead use Venus to do repeated flybys and eventually lower the perihelion to 9 solar radii.  While 9 > 4, the Venus flight path provides many flybys of the Sun, which provides a richer dataset from each flyby.  This probe is the Parker Solar Probe, also exceptionally named for the still living scientist Eugene Parker.

Cassini reinforced the need for teams to have diverse backgrounds and training.  That greater success is possible from having the great teams.

Hubble provided the research, just last year alone, for ~1000 publications.  On the initial launch, there was the well known flaw in the mirror, when NASA had been predicting great images.  After studying the results, a tech worked out that the mirror was slightly out of position, and by a small shift of the sensor, everything worked.

Shortly after finishing his PhD, Dr. Z came up with a new sensor in '98 to be possibly part of Messenger, at its launch in 2004, which was multiple times added and removed from the craft.  And even after the launch, it took Messenger 7 years to complete the orbital path and remove sufficient energy so that the probe could enter orbit of Mercury.  This requires patience.

When working in teams, he tells about being the Swiss army.  Barbed wire had to be placed around the camp.  This was the job given to those in trouble.  But he talked with them on this duty and helped.  So eventually, rather than just being the trouble job, the team was a good team, and some soldiers wanted to work on those teams.  Better to be on a good team doing a bad task, than a bad team doing a good task.

The National Academy of Science sets the science priorities (this process from priority to mission I read significantly about in Chasing New Horizons), but ultimately the specific mission to meet the science priority is decided by Dr. Z.  Then that mission moves through multiple steps and reviews.  And one of the key steps is that while Dr. Z makes the decision, these decisions are based on the good advice from the experts.

For the missions flown, Dr. Z has about 5 failures for every success.  These failures are things like being removed from the program or the mission being canceled.  And sometimes it is for technical failures of the device or the probe.  Things will fail.  At every launch, he goes there to watch and has a large mission plan.  Most of that mission plan covers what to do if things go wrong.  Plan for the failure.