[6] The NEPTUNE rocket, a two-stage vehicle design from Interorbital Systems, would use high-performance liquid oxygen and densified propane propellants.

[7][1] The first stage would be equipped with four stationary throttleable ablatively cooled liquid rocket engines, each capable of generating 4,500 pounds of thrust.

[citation needed] In 2006, IOS held an active launch license from the Office of Commercial Space Transportation for Tachyon,[10] a sounding rocket designed for suborbital flights reaching an apogee of 120 miles.

These kits are constructed using an aluminum frame and are designed for conducting simple experiments, as well as for receiving and transmitting radio signals.

[citation needed] According to their claims, the kits will be launched into self-decaying orbits at an altitude of 310 km (192 mi), eventually burning up in the Earth's atmosphere.

[13][non-primary source needed] Interorbital Systems became a member and launch provider for Team Synergy Moon in the Google Lunar X Prize competition in June 2016.

[14][3] The team proposed using a modified version of the NEPTUNE rocket consisting of 36 modules to transport their lunar rover to the surface of the Moon.