Question: When was the English astronomer many years before which Albert Einstein once attempted a steady-state model of the expanding universe born? 

Context paragraphs:
Einstein Tower: The Einstein Tower (German: "Einsteinturm") is an astrophysical observatory in the Albert Einstein Science Park in Potsdam, Germany built by Erich Mendelsohn.  It was built on the summit of the Potsdam "Telegraphenberg" to house a solar telescope designed by the astronomer Erwin Finlay-Freundlich.  The telescope supports experiments and observations to validate (or disprove) Albert Einstein's relativity theory.  The building was first conceived around 1917, built from 1919 to 1921 after a fund-raising drive, and became operational in 1924.  Although Einstein never worked there, he supported the construction and operation of the telescope.  It is still a working solar observatory today as part of the Leibniz Institute for Astrophysics Potsdam.  Light from the telescope is directed down through the shaft to the basement where the instruments and laboratory are located.  There were more than half a dozen telescopes in the laboratory.

Albert Einstein Award: This award should not be confused with many others named after the famous physicist, such as the Albert Einstein World Award of Science given by the World Cultural Council (since 1984), the Albert Einstein Medal given by the Albert Einstein Society (since 1979), nor with the Hans Albert Einstein Award, named after his son and given by the American Society of Civil Engineers (since 1988).  It was established much earlier than these, when Einstein was still alive and was a professor at the Institute for Advanced Study.  It has been called "the highest of its kind in the United States" by "The New York Times".  Some considered it as "the prestigious equivalent of a Nobel Prize".

Albert Einstein Science Park: The Albert Einstein Science Park is located on the hill Telegrafenberg in Potsdam, Germany.  The park was named after the physicist Albert Einstein.  The best known buildings in the park are the Einstein Tower, an astrophysical observatory that was built to perform checks of Einstein's theory of General Relativity; and the Great Refractor of Potsdam, which today belong to the Astrophysical Institute Potsdam.  These buildings, along with various astronomical, meteorological, and geophysical observatories were integrated into an English country garden.

Cormac O'Raifeartaigh: Cormac O’Raifeartaigh (Cormac O’Rafferty) is an Irish physicist based at Waterford Institute of Technology in Ireland.  A solid-state physicist by training, he is best known for several contributions to the study of the history and philosophy of 20th century science, including the discovery that Albert Einstein once attempted a steady-state model of the expanding universe, many years before Fred Hoyle

Fred Hoyle: Sir Fred Hoyle FRS (24 June 1915 – 20 August 2001) was an English astronomer who formulated the theory of stellar nucleosynthesis.  He also held controversial stances on other scientific matters—in particular his rejection of the "Big Bang" theory, a term coined by him on BBC radio, and his promotion of panspermia as the origin of life on Earth.  He also wrote science fiction novels, short stories and radio plays, and co-authored twelve books with his son, Geoffrey Hoyle.

Einstein–de Sitter universe: The Einstein–de Sitter universe is a model of the universe proposed by Albert Einstein and Willem de Sitter in 1932.  On first learning of Edwin Hubble's discovery of a linear relation between the redshift of the galaxies and their distance, Einstein set the cosmological constant to zero in the Friedmann equations, resulting in a model of the expanding universe known as The Friedmann-Einstein universe.  In 1932, Einstein and de Sitter proposed an even simpler cosmic model by assuming a vanishing spatial curvature as well as a vanishing cosmological constant.  In modern parlance, the Einstein–de Sitter universe can be described as a cosmological model for a flat matter-only Friedmann–Lemaître–Robertson–Walker metric (FLRW) universe.

Steady State theory: In cosmology, the Steady State theory is an alternative to the Big Bang model of the evolution of the universe.  In the steady-state theory, the density of matter in the expanding universe remains unchanged due to a continuous creation of matter, thus adhering to the perfect cosmological principle, a principle that asserts that the observable universe is basically the same at any time as well as at any place.

Steven Libutti: Steven K. Libutti, M.D., F.A.C.S. (born April 18, 1964) is an American surgeon and scientist.  In January 2017, he became the third permanent Director of the Rutgers Cancer Institute of New Jersey, Vice Chancellor for Cancer Programs for Rutgers Biomedical Health Sciences and the Senior Vice President for Oncology Services for RWJBarnabas Health, the largest health system in New Jersey.  He is a tenured Professor of Surgery at the Rutgers Robert Wood Johnson Medical School.  Libutti's work on the study of tumor angiogenesis and the tumor microenvironment has led to novel approaches for the treatment of cancer.  He is also one of the pioneers of regional and targeted cancer therapy.  He was the founding Director of the Montefiore-Einstein Center for Cancer Care, and served as the Associate Director of the Albert Einstein Cancer Center and Vice-Chairman of the Department of Surgery at Montefiore Medical Center and the Albert Einstein College of Medicine from 2009-2017.  Libutti was a tenured Professor of Surgery and Genetics at the Albert Einstein College of Medicine in the Bronx, New York and a Professor of Surgery at the Uniformed Services University of the Health Sciences in Bethesda, Maryland.  In September, 2009, Libutti was invested as "The Marvin L. Gliedman, M.D. Distinguished Surgeon" in the Department of Surgery at Montefiore Medical Center.  Libutti is the Editor-in-Chief of the Springer Nature journal, Cancer Gene Therapy.

The Friedmann–Einstein universe: The Friedmann–Einstein universe is a model of the universe published by Albert Einstein in 1931.  The model is of historic significance as the first scientific publication in which Einstein embraced the possibility of a cosmos of time-varying radius.

Physical cosmology: Physical cosmology is the study of the largest-scale structures and dynamics of the Universe and is concerned with fundamental questions about its origin, structure, evolution, and ultimate fate.  Cosmology as a science originated with the Copernican principle, which implies that celestial bodies obey identical physical laws to those on Earth, and Newtonian mechanics, which first allowed us to understand those physical laws.  Physical cosmology, as it is now understood, began with the development in 1915 of Albert Einstein's general theory of relativity, followed by major observational discoveries in the 1920s: first, Edwin Hubble discovered that the universe contains a huge number of external galaxies beyond our own Milky Way; then, work by Vesto Slipher and others showed that the universe is expanding.  These advances made it possible to speculate about the origin of the universe, and allowed the establishment of the Big Bang Theory, by Georges Lemaitre, as the leading cosmological model.  A few researchers still advocate a handful of alternative cosmologies; however, most cosmologists agree that the Big Bang theory explains the observations better.

Supporting paragraphs: Cormac O'Raifeartaigh Fred Hoyle
Answer: 24 June 1915