Wednesday, December 9, 2020

Secret Science Club Zoom Lecture: Handprints on Hubble

Yesterday, I goofed, thinking that this month's Secret Science Club Zoom lecture was to take place last night.  Tonight, my great and good friends at the Secret Science Club are featuring the triumphant return of Dr Kathryn Sullivan, scientist, deep sea explorer, astronaut, former head of NOAA, author, and general supercool individual.  Dr Sullivan is the first American woman to have walked in space, and was instrumental in getting the fabulous Hubble Space telescope into orbit.

About a year ago, in the Before Times, Dr Sullivan delivered a lecture for the SSC North at the scintillating Symphony Space.  The lecture, which began with a tale of an almost-aborted launch straight out of a techno-thriller, was broadcast on C-Span's Book TV and can be seen at this link.

Dr Sullivan began the lecture by congratulating the eighteen astronauts chosen for the Artemis mission.  She then celebrated the lifespan of the Hubble Space Telescope (twice the expected time) and the skill of the engineers (not just the pocket protector crew, but individuals of great imagination and passion) and astronauts who created the tools and techniques which allowed for the repair of the invaluable telescope.

The lecture proper began with a celebration of Hubble, the bus-sized orbital telescope which started taking shape in the early 1970s.  The telescope had to be maintained by astronauts in bulky spacesuits (picture two snowmobile suits, heavy gloves, and a bucket on your head), in orbit.  In 1985, Dr Sullivan was chosen to shepherd Hubble into orbit, and had to undergo training with various tools to make sure that mishaps would be avoided.  The training took place in water tanks in which a mockup of the telescope was submerged.  Much of the work involved choreography, some involved fine detail work, such as replacing electrical connectors with specially designed tools (she broke two ninety-degree connector tools, ratchet wrench-like devices designed to remove connectors, before a proper tool was built).  Platforms used to lock astronauts' feet into place so they could turn a connector rather than spinning themselves around, had to be designed.

In 1990, another platform with a rigid tether had to be developed (the shuttle's robotic arm had to hold the Hubble in place) for the repair of the Hubble's mirror.  This tether is still in use.  Hubble was designed to be maintained and repaired in modular fashion- instruments were built into various boxes which could be swapped out for upgrades as detectors, electronics, and cameras improved.  Dr Sullivan characterized the Hubble as being one thousand times better than the original space mirror.

Dr Sullivan then pivoted to the topic of exploration of the Challenger Deep in the Mariana Trench, part of the Hadal Zone, below six thousand meters depth, which contains about 40% of the oceans' water.  The Challenger Deep is approximately 10,994 meters in depth.  The surface ship involved in this exploration is the DSSV Pressure Drop, a former submarine chaser purchased by explorer Victor Vescovo.  The Pressure Drop plays host to a submersible which is approximately 12x15x5 feet in dimension.  The submersible, which has a manipulator arm, takes about four hours to submerge to the bottom of the Challenger Drift.  An oceanographer, Dr Sullivan noted that the dimples on the ocean floor indicated that the muddy bottom was 'busy' with polychaete worms and sea cucumbers.  The seafloor is cold, dark, and food poor.

Dr Sullivan noted that her greatest source of pride lays not in her individual achievements, but in the team activity that has allowed humanity to achieve feats never before accomplished.

The Zoom lecture was followed by a Q&A session.  The first question came from a young listener, about Dr Sullivan's role as a pioneer- again, Dr Sullivan's pride is a pride in exploration more than a pride in being in the record books.  The next question regarded space junk- space junk cannot be tracked, statistical analysis has to be employed... Hubble cannot 'dodge' space junk.  The next question came from a seven year old who wants to be the first astronaut on Mars and wanted advice- Dr Sullivan joked that she would have to race her, and stated that learning as much as possible is the key... a student must be 'all in', and must continue learning every single day.  Another question involved spacesuits, of which there are many types.  During a shuttle launch, sealed pressure suits are worn, but for space walks, another type of suit must be worn.  The suits are pressurized to sea level, so there's no ear-popping like one would feel on an airplane flight.  The next question involved the hours of training involved- Dr Sullivan noted that space walks are not physically demanding, microgravity being delightful, but that the academic requirements are stringent, equivalent to graduate level crash courses in aeronautical/astronautical engineering, physiology, and the particular tasks one has to perform.  Asked about the pressure at depths of 30,000 feet below sea level, Dr Sullivan joked that the pressure was the equivalent of a hippopotamus wearing a single stiletto heel standing on every single square inch of the submersible.  Regarding the budget for space exploration, and whether that money would be better spent elsewhere, Dr Sullivan noted that only half a penny per dollar spent goes to NASA, and the satellites which NASA and NOAA maintain allow weather monitoring and ocean analysis- the benefits from the space budget are invaluable.  Even more valuable is the pride in space exploration, the motivational and aspirational effects on young people, the unifying nature of projects such as Apollo.  She would round that expenditure to one whole penny.  Another question involved Dr Sullivan's wildly divergent adventures in highly specialized craft- she joked that there was a 'Magic School Bus' effect, but her engineering training gave her a familiarity with the conveyances.  The real surprise is voyaging into exotic, lethal environments.  She could eat a tuna fish sandwich while wearing shirtsleeves while voyaging in a place she had no business being in.  The one experience which took her breath away was seeing the Earth from orbit for the first time.  A question regarding the submerible... it's an untethered craft.  Asked about her favorite space movie, she mentioned that 'Space Cowboys' had laughable physics but the jokes rang true.  Her favorite space movies are 'Apollo 13', based on a true story, and 'The Martian', a fictional movie (no dust storm could knock over a craft like that) but one which was a celebration of the scientific method, and problem solving.

Once again, Dr Sullivan delivered a fantastic lecture, hitting that 'Secret Science Sweet Spot' which encompasses hard science, adventure narrative, and advocacy, leavened with humor.  Kudos to the good doctor and to Margaret and Dorian.  As an added bonus, which warmed my heart, several of the questions in the Q&A were from children.  I miss the Bell House lectures, but having an all-ages audience is a benefit of these Zoom lectures.

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