  The detection of primordial gravitational waves is one of the biggest
challenges of the present time. The existing (Wilkinson Microwave Anisotropy
Probe) observations are helpful on the road to this goal, and the forthcoming
experiments (Planck) are likely to complete this mission. We show that the
5-year Wilkinson Microwave Anisotropy Probe $TE$ data contains a hint of the
presence of gravitational wave contribution. In terms of the parameter $R$,
which gives the ratio of contributions from gravitational waves and density
perturbations to the temperature quadrupole, the best-fit model produced
$R=0.24$. Because of large residual noises, the uncertainty of this
determination is still large, and it easily includes the R=0 hypothesis.
However, the uncertainty will be strongly reduced in the forthcoming
observations which are more sensitive. We numerically simulated the Planck data
and concluded that the relic gravitational waves with $R=0.24$ will be present
at a better than 3$\sigma$ level in the $TE$ observational channel, and at a
better than 2$\sigma$ level in the `realistic' $BB$ channel. The balloon-borne
and ground-based observations may provide a healthy competition to Planck in
some parts of the lower-$\ell$ spectrum.
