Editing Interorbital Systems (section)

==NEPTUNE Launch Vehicle: Pressure-fed Propulsion System==
The NEPTUNE liquid rocket engines of Interorbital Systems would be fed propellants through a proprietary pressurant system. As a result, the weight of the propellant tank/pressurant system would be equivalent to a traditional propellant tank/pressurant system/pump-fed system.

By removing the propellant pump and the associated heavy electric or gas-generator pump-drive system, Interorbital Systems proposes to significantly reduce both the overall rocket development cost and the manufacturing time. This streamlined approach to the propulsion system is touted as leading to cost savings and improved efficiency in the manufacturing process.<ref name="SynergyMoon20110706">{{cite web |url=https://www.youtube.com/watch?v=xzIx-SzyS-k |title=Synergy Moon Presentation at 2011 GLXP Summit |publisher=[[YouTube]] |date=2011-07-16 |access-date=2013-08-11 |url-status=live |archive-url=https://web.archive.org/web/20151203112144/https://www.youtube.com/watch?v=xzIx-SzyS-k |archive-date=2015-12-03 }}</ref>