The Daleth Effect, also known as In Our Hands, the Stars, is a science fiction novel written by Harry Harrison and published in 1970.

[1] Arnie Klein, an Israeli scientist, discovers the 'Daleth effect', a simple and economic way to achieve space travel.

Klein defects to Denmark in order to protect his discovery and develop it without it falling into the hands of the military.

When it is sent into space to rescue two Soviet cosmonauts who are stranded on the Moon, Klein is forced to reveal his secret to the world.

[2] Reviewing the novel in The Magazine of Fantasy & Science Fiction, James Blish described it as "quite straight forward—a driving action story ... and in addition, this is a cautionary tale, like the best of Wells ... at once as exciting and as somber as John le Carré ... though not, I am afraid, as well written.