http://www.endtime.com/pdf/archives/ETM-2006-07-Red-Heifer.pdf
The above link says the red heifer was 3 1/2 in 2006. That means that if that was true and the red heifer is still alive, then sacrifices could begin after the temple is completed. There have been no ashes of a red heifer since 70 AD. This article provides further background information for anyone unfamiliar with this matter.
Robert