Question: Jubal Harshaw is a fictional character featured in "Stranger in a Strange Land", a 1961 science fiction novel by what American author?

Context paragraphs:
Grok: Grok is a word coined by American writer Robert A. Heinlein for his 1961 science fiction novel "Stranger in a Strange Land".  While the "Oxford English Dictionary" summarizes the meaning of "grok" as "to understand intuitively or by empathy, to establish rapport with" and "to empathize or communicate sympathetically (with); also, to experience enjoyment", Heinlein's concept is far more nuanced, with critic Istvan Csicsery-Ronay Jr. observing that "the book's major theme can be seen as an extended definition of the term."  The concept of "grok" garnered significant critical scrutiny in the years after the book's initial publication.  The term and aspects of the underlying concept have become part of communities as diverse as polyamory (in particular the Church of All Worlds) and computer science.

The Cat Who Walks Through Walls: The Cat Who Walks Through Walls is a science fiction novel by American writer Robert A. Heinlein, published in 1985.  Like many of his later novels, it features Lazarus Long and Jubal Harshaw as supporting characters.

Jubal Harshaw: Jubal Harshaw is a fictional character featured in "Stranger in a Strange Land", a novel by Robert A. Heinlein.

Competent man: In literature, the competent man is a stock character who can do anything perfectly, or at least exhibits a very wide range of abilities and knowledge, making him a form of polymath.  While not the first to use such a character type, the heroes and heroines of Robert A. Heinlein's fiction are generally competent men/women (with Jubal Harshaw being a prime example), and one of Heinlein's characters Lazarus Long gives a good summary of requirements:

Stranger in a Strange Land: Stranger in a Strange Land is a 1961 science fiction novel by American author Robert A. Heinlein.  It tells the story of Valentine Michael Smith, a human who comes to Earth in early adulthood after being born on the planet Mars and raised by Martians.  The novel explores his interaction with—and eventual transformation of—Terran culture.  In 2012, the US Library of Congress named it one of 88 "Books that Shaped America".

Red Planet (novel): Red Planet is a 1949 science fiction novel by Robert A. Heinlein about students at boarding school on the planet Mars.  It represents the first appearance of Heinlein's idealized Martian elder race (see also "Stranger in a Strange Land").  The version published in 1949 featured a number of changes forced on Heinlein by Scribner's, since it was published as part of the Heinlein juveniles.  After Heinlein's death, the book was reissued by Del Rey Books as the author originally intended.

Tek Jansen: Tek Jansen is a fictional character featured on "The Colbert Report" and in a comic book series published by Oni Press.  Jansen originated as a recurring joke in the form of a supposed self-published science fiction novel on the "Report", reportedly as a parody of Bill O'Reilly's 1998 novel, "Those Who Trespass".  The character later appeared on the show in a series of animated shorts entitled "Stephen Colbert Presents Stephen Colbert's Alpha Squad 7: A Tek Jansen Adventure", with Jansen voiced by Stephen Colbert, and in 2007 became the protagonist of a five-part comic series.

The Door Through Space: The Door Through Space is a 1961 science fiction novel by American writer Marion Zimmer Bradley.  An expansion of Bradley's story "Bird of Prey", which first appeared in the May, 1957 issue of the magazine "Venture", it is her first novel, and was published by Ace Books, bound tête-bêche with "Rendezvous on a Lost World " by A. Bertram Chandler.

Timescape: Timescape is a 1980 science fiction novel by American writer Gregory Benford (with unbilled co-author Hilary Foister, Benford's sister-in-law, who is credited as having "contributed significantly to the manuscript").  It won the 1981 Nebula and 1980 British Science Fiction Award, and the 1981 John W. Campbell Memorial Award for Best Science Fiction Novel.  The novel was widely hailed by both critics of science fiction and mainstream literature for its fusion of detailed character development and interpersonal drama with more standard science fiction fare such as time travel and ecological issues.

Solaris (2002 film): Solaris is a 2002 American science fiction drama film written and directed by Steven Soderbergh, produced by James Cameron and Jon Landau, and starring George Clooney and Natascha McElhone.  It is based on the 1961 science fiction novel of the same name by writer Stanisław Lem.

Supporting paragraphs: Jubal Harshaw Stranger in a Strange Land
Answer: Robert A. Heinlein