That sounds like The Sirens of Titan, a novel by Kurt Vonnegut, Jr., which was also the answer to this old question among others.
The main character, Malachi Constant, is a very rich man, not an actor. Mrs. Rumfoord is the "widow" of Winston Niles Rumfoord, who is in a weird condition as a result of a mishap in space:
Winston Niles Rumfoord had run his private space ship right into the heart of an uncharted chronosynclastic infundibulum two days out of Mars. Only his dog had been along. Now Winston Niles Rumfoord and his dog Kazak existed as wave phenomena—apparently pulsing in a distorted spiral with its origin in the Sun and its terminal in Betelgeuse.
The earth was about to intercept that spiral.
Rumfoord materializes on Earth from time to time. The story begins with Constant paying a visit to the Rumfoord estate, where Rumfoord is due to materialize:
"You—you really can see into the future?" said Constant. The skin of his face tightened. His palms perspired.
"In a punctual way of speaking—yes," said Rumfoord. "When I ran my space ship into the chronosynclastic infundibulum, it came to me in a flash that everything that ever has been always will be, and everything that ever will be always has been." He chuckled again. "Knowing that rather takes the glamour out of fortunetelling—makes it the simplest, most obvious thing imaginable."
"You told your wife everything that was going to happen to her?" said Constant. This was a glancing question. Constant had no interest in what was going to happen to Rumfoord's wife. In asking about Rumfoord's wife, he was being coy.
"Well—not everything," said Rumfoord. "She wouldn't let me tell her everything. What little I did tell her quite spoiled her appetite for more."
"I—I see," said Constant, not seeing at all.
"Yes," said Rumfoord genially "I told her that you and she were to be married on Mars." He shrugged. "Not married exactly—" he said, "but bred by the Martians—like farm animals."
Constant wakes up after a big party:
The pool had once been covered uniformly by un undulating blanket of gardenias. But a persistent morning breeze had moved the blooms to one end of the pond, as though folding a blanket to the foot of a bed. In folding back the blanket, the breeze revealed a pool bottom paved with broken glass, cherries, twists of lemon peel, peyotl buttons, slices of orange, stuffed olives, and the ruins of a white grand piano. Cigar butts and cigarette butts, some of them marijuana, littered the surface.
He gets a message from the president of the company he owns:
Constant stood unsteadily, rubbing his face with his hands. "Quitting?" he said dully. "Old Ransom K. Fern quitting?"
"Yah," said the woman. She smiled hatefully. "He says you can't afford to pay his salary any more. He says you better come in and talk to him before he goes home." She laughed. "He says you're broke."
A couple of disguised recruiters for the Army of Mars (humans) shanghai Constant and take him to Mars, where his memory is erased and his comrades call him Unk.
There are also scenes on Mercury and on Saturn's moon Titan.