From Namebright's Terms of Service:
"Upon expiration of your domain name, your nameservers will be changed to expired1.namebrightdns.com and expired2.namebrightdns.com as is required by ICANN's ERRP (Expired Registration Recovery Policy)."
I think Namebright renews the domain, so it won't be deleted during the redemption period. Their Knowledge Base says they drop expired domains. You may want to ask them about it. If they don't auction them off, find a good backorder service or services.