I didn't find this press on AW either, and I can't check P&E...
Per Aspera Press (founded in 2003) was added to RP as their SF imprint in 2015. Press release here.
FYI, Per Aspera published Shannon Page and Jay Lake's Our Lady of the Islands in 2014. Their own Twitter looks dead [and I'd think an imprint would keep Tweeting, but hey]. Ragnarok only lists two sf books under Per Aspera.
Anyone have any news, as author, customer, and/or freelancer, to report?