Spontaneous-fission half-lives:of the heaviest nuclei are analyzed in
a multidimensional deformation space. They are calculated in a dynamic
al approach, without any adjustable parameters. The potential energy i
s obtained by the macroscopic-microscopic method and the inertia tense
r by the cranking method. The action integral is minimized by a variat
ional procedure. Even-even nuclei with proton number Z=104-114 and neu
tron number N=142-176 are considered. The results reproduce existing e
xperimental data rather well. Relatively long half-lives are predicted
for many unknown nuclei, sufficient to detect them if synthesized in
a laboratory.