ALD21: Clarice Phelps, Nuclear Chemist

Clarice Phelps

Clarice Phelps is a nuclear chemist who was part of the Oak Ridge National Laboratory (ORNL) team that worked with the Joint Institute for Nuclear Research to discover tennessine (element 117). She is the first African-American woman to have contributed to the discovery of a chemical element. 

Tennessine, a synthetic superheavy element, is the second heaviest element in the periodic table. Phelps was part of the ORNL team that purified the berkelium-249 which would be fused with calcium-48 in a high-energy particle accelerator in Russia to create tennessine. 

“We spent months pouring over calculations, preparing reagents, putting items in the glove box, going over everything over and over and over again,” Phelps told The Brilliant

Berkelium-249 has a half-life of 330 days, but the sample needed to be used within six months for the experiment to work. Despite Russian officials rejecting the package twice due to incomplete paperwork, the berkelium-249 eventually made it to Russia in June 2009. The discovery of tennessine was announced in April 2010 and officially recognised in 2015. 

Phelps is now the program manager for the Ni-63 and Se-75 industrial use isotope programs at ORNL, and is working on methods for separating actinide and lanthanide isotopes for medical use.

You can follow her work here:

Twitter: @ClaricePhelps39.

Further reading

ALD21 Books: Headstrong, Rachel Swaby

Rachel Swaby

Headstrong: 52 Women Who Changed Science – And The World, Rachel Swaby

In 2013, the New York Times published an obituary for Yvonne Brill. It began: “She made a mean beef stroganoff, followed her husband from job to job, and took eight years off from work to raise three children.” It wasn’t until the second paragraph that readers discovered why the Times had devoted several hundred words to her life: Brill was a brilliant rocket scientist who invented a propulsion system to keep communications satellites in orbit, and had recently been awarded the National Medal of Technology and Innovation. Among the questions the obituary – and consequent outcry – prompted were, Who are the role models for today’s female scientists, and where can we find the stories that cast them in their true light?      

Headstrong delivers a powerful, global, and engaging response. Covering Nobel Prize winners and major innovators, as well as lesser-known but hugely significant scientists who influence our every day, Rachel Swaby’s vibrant profiles span centuries of courageous thinkers and illustrate how each one’s ideas developed, from their first moment of scientific engagement through the research and discovery for which they’re best known. This fascinating tour reveals 52 women at their best – while encouraging and inspiring a new generation of girls to put on their lab coats.

Order the book on here and your purchase will support a local independent bookshop of your choice!

You can follow her work here:

Twitter: @rachelswaby

ALD21: Dr Gladys West, Mathematician

Dr Gladys West

Dr Gladys West is a mathematician whose models of the shape of the Earth were integral to the development of the Global Positioning System (GPS). 

In 1956, West began work as a computer programmer at the Naval Proving Ground in Dahlgren, Virginia, collecting satellite data and using it to calculate their exact position. She was only the second black woman employed there, and one of only four black employees.

West worked on the data-processings systems used to analyse altimetry data from satellites such as GEOS 3. In 1978, she became the project manager for SEASAT, the first satellite that could remotely sense oceans, and used its data to measure ocean depths. Using an IBM 7030 Stretch computer, she developed complex algorithms to account for variations in gravitational, tidal and other forces that distort the shape of the Earth, also known as the geoid. Her work significantly improved the precision of calculations used to model the geoid. 

In 1986, she published a technical report, Data Processing System Specifications for the Geosat Satellite Radar Altimeter, which outlined how to increase the accuracy when estimating geoid heights and vertical deflection, which are important aspects of satellite geodesy, or the use of satellites to measure the dimensions of the Earth. West’s models of the geoid formed the basis of GPS.

In 2000, she finished her PhD in public administration and policy affairs, at the age of 70. In 2021, her contributions to science were recognised by the UK’s Royal Academy of Engineering which awarded her the Prince Philip Medal, their highest individual honour. 

Further reading

ALD21 Podcasts: The Cosmic Savannah, Dr Jacinta Delhaize & Dr Daniel Cunnama

The Cosmic Savannah, Dr Jacinta Delhaize & Dr Daniel Cunnama

Africa’s beautiful dark skies and vast plains make it an ideal place for cutting-edge astronomy research. Presented by Dr Jacinta Delhaize and Dr Daniel Cunnama, The Cosmic Savannah podcast showcases the world-class astronomy and astrophysics coming from the African continent. Hear about the fascinating people and discoveries coming out of Africa and how they are relevant on the world stage, as well as the indigenous people of South Africa’s relationship with the cosmos, pulsars, what we can learn from thermonuclear explosions on white dwarfs and rising stars of African astronomy. 

Recent episodes include conversations with: 

  • Dr Marisa Geyer, pulsar astronomer and commissioning scientist at the South African Radio Astronomy Observatory (SARAO), who explains her research on pulsars and mysterious Fast Radio Bursts;
  • Dr Miriam Nyamai, who studies thermonuclear eruptions on the surface of white dwarf stars; and,
  • Dr Michelle Lochner, senior lecturer at the University of the Western Cape, who is developing new machine learning and artificial intelligence tools to analyse the massive astronomical datasets of next-generation telescopes.

You can follow her work here:

Twitter: @jdelhaize and @cosmicsavannah

ALD21: Olga González-Sanabria, Chemical Engineer

Olga González-Sanabria

Olga González-Sanabria is a Puerto Rican chemical engineer who developed the long cycle-life nickel-hydrogen batteries that have been used on the International Space Station, the Hubble telescope and Mars Odyssey.

González-Sanabria worked as the Director of Engineering at NASA’s Glenn Research Center in Cleveland, Ohio, responsible for engineering design and development, fabrication, systems engineering and integration, and systems analysis.

Originally from Patillas, Puerto Rico, she started her academic career at the University of Puerto Rico. She earned her master’s degree in chemical engineering at the University of Toledo in Ohio.

Over the three decades that she worked for NASA she earned several awards, the most notable being the NASA Outstanding Leadership Medal and the NASA Exceptional Service Medal. In 2021 she was inducted into the NASA Glenn Research Center Hall of Fame for her lifetime achievements, and was the highest-ranking Hispanic at NASA Glenn. Now retired from NASA after 32 years service, she currently works as a consultant.

You can follow her work here:


Further reading