October 2015 Science Snack
October 6, 2015
Hello, and a special welcome to those of you joined my monthly mailing list/newsletter at the book signing with Buzz Aldrin at JSC on October 2. I call it Science Snacks because I discuss one cool science fact or news item (the “snack”) in each issue that I think other writers and readers of science fact & fiction will enjoy.
“I knew it was hopeless, but I tried firing up the communications array. No signal, of course. The primary satellite dish had broken off … The Hab had secondary and tertiary communications systems, but they were both just for talking to the MAV (Mars Ascent Vehicle), which would use its much more powerful systems to relay to Hermes. Thing is, that only works if the MAV is still around… I have no way to communicate with Hermes or Earth.”
The Martian by Andy Weir, Chapter 1
Communications Failure in The Martian Realistic?
The loss of communications plays a critical role in The Martian. As someone who loves to poke holes in movie “science,” I had to ask myself, is it a viable premise that Mark Watney is left with no way to communicate with Earth? Well, not really given that no Martian dust storm would ever have winds strong enough to knock out the primary antenna which author Andy Weir says, “acted like a parachute, getting torn from its foundation and carried with the torrent.” It also wouldn’t be buried in sand which (you geologists correct me if I’m wrong) is too heavy to be picked up by Martian wind in such quantity. The wind is also insufficient to knock over the MAV, which, being critical hardware, would be designed with this in mind if it were true!
But those of us who have worked real flights know that despite all our contingency plans, training, and malfunction procedures, things fail, explode, melt, freeze, or just plain refuse to function. And communications systems are notorious for finding creative new ways to not work. Shoot, even if the communications systems work, computers (also notoriously creative in failure modes) can keep them from delivering any meaningful data. Certainly no one anticipated the fire that took out the Mission Operations Computer during STS-5, severing all communications with the orbiter (at a time when the backup MOC was also down). If communications weren’t restored within about three hours, because of Columbia’s deteriorating state vector which required communications to update, the crew might have had to do an emergency landing in Africa.
What, you never heard about this near-miss abort? You can blame that on communication failures, too. Public Affairs decided not to bother the news media until after the smoke cleared, literally. This aspect of communications is also reflected in The Martian when NASA decides not to release the data about Watney being alive until they have a rescue plan to offer.
To restore communications, Watney (played by Matt Damon) treks to the Pathfinder site to retrieve its hardware. He first uses a Yes/No/? system and then devises a clever way for the camera to rotate in a circle marked off with the numbers 1-9 and letters A-F to represent the alphabet in hexadecimal code (41 is A, 5A is Z). Engineers back at JPL figure out what he’s up to and get the old Pathfinder out of storage. During the STS-5 fire, we created our own version of the Yes/No/? communications using the teleprinter, a single font, one-line-at-a-time teletype we flew on the early flights. Unlike voice and data, it didn’t require the MOC. We readied a one-way message to send the crew if necessary. The INCO team (led by Bob Castle) prepared an actual (just like the movie!) hexadecimal message that could be read up through one of the ground stations to have the crew manually clear the state vector alarm.
During STS-5, the Ground Control team was able to get the MOC restored with two minutes to spare. And Watney, thanks to his knowledge of how things work and trusting that Mission Control would be listening, is able to restore communications. Was this believable? Absolutely! (Which of you would be the one with a printout of hex code in your bag?!)
There’s more about the STS-5 fire in my memoir, A Passion for Space: Adventures of a Pioneering Female NASA Flight Controller which is now available in eBook and print from Springer and Amazon or through my website or at one of my events (see below).If you want to discuss other aspects of The Martian, please find me on Facebook!
Speaking of Science
- Thursday, November 5, 2:30-4 PM, JSC Gilruth Center, Lone Star Room (2nd floor), Houston, 77058, Discussion of A Passion for Space.
- Thursday, November 5, 7:30 PM, LPI, 3600 Bay Area Blvd. Houston, Dr. Bruce Banerdt of JPL/CalTech, InSight Mission to Mars
- Saturday, December 5, 10-4, Freeman Library, 16616 Diana Ln, Houston, 77062, Local Authors book signing benefiting Friends of the Library
If there is a particular science topic you’d like me to address in a future Science Snacks, please send me an email. Note, you can order copies of my books via Amazon or autographed copies via my website.