Emanuel 'Emil' Skrabek, spacecraft engineer, inventor of thermoelectric power source for Mars Curiosity Rover, dies

Emanuel A. “Emil” Skrabek, a Baltimore-born spacecraft engineer who co-invented a thermoelectric material that powered the Mars Curiosity Rover and other deep-space probes, died at his home in Lutherville on March 14 of progressive supranuclear palsy and Parkinson’s disease, his family said. He was 85.

A brilliant and accomplished scientist who spent more than 50 years in the complex, demanding field of space nuclear power, Mr. Skrabek took joy in coaching his daughters’ youth recreational softball teams, attending Baltimore Symphony Orchestra concerts with his wife, and volunteering as a Eucharistic minister at the Church of the Nativity, where he was a longtime member.


“He was a family man,” said his daughter, Alison Skrabek, 42, of New York City. “It was always very balanced. You have your career, but you have your family, and you have your faith.”

Emanuel Andrew Skrabek was born March 3, 1934, to Joseph Skrabek, a Highlandtown tavern owner, and the former Catherine Frazier, a cosmetologist. After his father died when Mr. Skrabek was 4 years old, he and his mother lived with his grandparents in Highlandtown, where he grew up.


Mr. Skrabek attended Mount St. Joseph High School and graduated in 1952. He earned a chemistry degree at the University of Maryland, College Park in 1956, a master’s degree in radiation chemistry at the University of Wisconsin in 1958 and a Ph.D. in physical chemistry at the University of Pittsburgh in 1962.

Five years later, while working at the Martin-Marietta Corp., Mr. Skrabek co-invented the TAGS-85 material with Donald Trimmer. It recharges spacecrafts’ batteries without the need for solar panels, and it far outperformed pre-launch expectations and extended missions, expanding mankind’s knowledge of space.

The material was — and remains — a key component of the nuclear power systems of unmanned spacecraft sent to probe Mars, Saturn, Jupiter, Uranus and other corners of the solar system.

It was used in the Pioneer 10 and 11 spacecraft; the Viking Mars Landers 1 and 2; the Galileo, Ulysses, Cassini and Pluto-New Horizons missions; and the Multi-Mission RTG (radioisotope thermoelectric generator) and Mars Surface Landers, including the Curiosity Rover, which NASA calls “the largest and most capable rover ever sent to Mars.”

While alternatives are being researched, the power system is still used by NASA, including on the Mars 2020 rover mission, said Heros Noravian, a longtime colleague of Mr. Skrabek’s at Orbital Sciences Corp.’s Space Systems Group, where the two worked together on NASA and defense contracts.

“That’s the only material NASA has, as of today, that we can build RTGs with for deep-space programs,” Mr. Noravian said.

Mr. Skrabek married the former Geraldine Bonsall, a nurse, in Baltimore on Jan. 2, 1972, and the couple settled into a home on Margate Road in Timonium, where they raised two daughters and attended the Church of the Nativity.

Their 47 years of marriage were characterized by camping, fishing and hiking trips with their daughters, volunteering at church and attending lots of national and international conferences and lectures, Mrs. Skrabek said. Mr. Skrabek loved going to the symphony and entertaining family on holidays. He volunteered on the parish council, chaired various church committees, and taught religious education classes.


“He did have a really good sense of humor,” Mrs. Skrabek said. “Because he was that way, it was easy to live with him. He was a wonderful father and husband.”

Mr. Skrabek, who holds 10 patents for thermoelectric alloys, was diagnosed with Parkinson’s in 2011 but continued to commute to his office in Washington from his home in Lutherville until his declining health forced him to retire from Orbital (formerly Fairchild Space and Defense Corp.) in 2013. Other previous employers included Teledyne Energy Systems, Dynatherm Corp. and Sun Oil Co.

“He would still be working today if he were alive,” Mrs. Skrabek said.

Friends and neighbors gravitated to Mr. Skrabek, but that wasn’t because of his engineering accolades, said his elder daughter, Lisa Skrabek Koonce, 46, of Pelham, N.Y.

“It was because he was a good friend and neighbor,” Mrs. Koonce said. “He liked people. He cared about people. He was respectful to people. … He was always very generous with his time and knowledge.”

A Mass of Christian burial was offered at the Church of Nativity on March 20.


In addition to his wife and daughters, Mr. Skrabek is survived by three grandchildren.