In December 1984, project management consultant David Andrews issued an eight-page critique of the programme, noting that the design was optimised for the ascent while exposing itself to extended thermal loads during descent due to a low level of drag. He also claimed that the vehicle offered no capability that was not already available; BAe responded that the criticisms made had been answered. In April 1985, the Ministry of Defence's research and development department deputy controller James Barnes claimed that HOTOL lacked a justification, and that there was no defence requirement for such vehicles. He also noted that the "engineering problems are considerable" and that it was unlikely to enter service until the 2020s; Barnes also observed the HOTOL engine to be "ingenious".