The Bulwark defensive satellite, known as the AN/SLE-159 in UNSC service, was a piece of technology developed by the Alliance of Sangheili Clans specifically for use by the United Nations Space Command, as a short term, rapidly deployable answer to the problem of UNSC ships' vulnerability to Covenant energy weapon fire. The Bulwark satellite was roughly fifteen metres in diameter and was deployed by Sangheili Defence Force and UNSC Navy warships, where it would remain stationary and project a round, one-way shield 'disc' three hundred and fifty metres across. This shield would allow a UNSC warship to fire on Covenant vessels while itself remaining protected from Covenant return fire. While intended as an ultra short-term solution (it was expected that UNSC capital ships could be retrofitte