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Interorbital Releases Design for Orbital Neptune Space Tourism Vehicle

By Doug Messier
Parabolic Arc
February 19, 2008
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Interorbital Press Release

Mojave, CA, February 19, 2008—-Interorbital Systems (IOS) today made public the design of its manned orbital launch vehicle, Neptune, and passed a major milestone by completing the propellant tank construction of its Sea Star MSLV (microsatellite launch vehicle). Sea Star is a subscale version of and testbed for the Neptune six-passenger orbital tourism ship. Both vehicles employ a novel modular, pressure-fed, two-stage-and-a-half-to-orbit configuration. “IOS is now one step closer to the flight-test phase, and one step closer to launching its orbital tourism services. The Sea Star launches will flight-test and space-validate many of the rocket system design elements that the follow-on vehicle, Neptune, will use.” said Roderick Milliron, IOS President and Chief Design Engineer.

Neptune will be the first of a new generation of low-cost and highly reliable manned orbital launch vehicles. It is designed for minimum cost and maximum reliability. Unnecessary expensive, complex, failure-prone, and sometimes performance-limiting systems such as wings, ignition systems, and turbopumps have been eliminated from the design. Both the Sea Star and Neptune vehicles are partially reusable, and are deployed by a reusable canister ocean-launch system.
Compared to land–based launches, sea-based launch logistical costs will be nearly insignificant, and launch scheduling will be based on customer demand, not on the long lead-times associated with conventional spaceports.

A major innovation in the Neptune design is the re-use of one of the propellant system’s pressurant tanks on-orbit, converting the huge cylinder into a spacious habitat—an orbiting hotel, or ‘orbitel.’ Randa Milliron, CEO and Cofounder explained, “Interorbital’s rocket designs and launch service concepts are completely different from those of other companies competing for the space tourist and space launch dollar. IOS employs streamlined, reliable systems; ultra low-cost, on-demand deployment methods; aggressively adaptive re-use of rocket tankage; and no-fuss, storable ‘green’ hypergolic propellants—-it’s a winning combination.”

Milliron continued, “Most space tourism operators plan to offer 15-minute suborbital, up-and-down flights; IOS will conduct real spaceflight, in a system that’s a cross between the Air Force’s MOL (Manned Orbiting Laboratory) program and the original Sky Lab “wet workshop” concept. It’s all about vertical staged rocket blast-off, roomy on-orbit accommodations, real orbital space experience with sustained weightlessness, and Apollo-style capsule reentry with ocean splashdown—-space tourism doesn’t get any more exciting than this!”

Interorbital Systems differs from its space tourism competitors by taking its customers on a multi-day orbital (not suborbital) expedition for $2.5 million—-with an EVA option priced at $5 million. The Neptune launcher will carry six working crewmembers on an orbital adventure. As a one-time opportunity, Interorbital is offering a limited number of promotional fare tickets priced at $250,000—with a full rebate two years after the space tourist completes his or her flight. IOS originally offered 10 of these tickets; at present, one is sold and one is reserved—leaving only eight ‘Free Tickets to Space’ available. The price returns to $2.5 million after the remaining 8 tickets are sold.

As Interorbital nears the completion of the Sea Star MSLV flight demonstrator construction, public and customer interest continues to rise. IOS is in discussion with three microsat producers who want to take advantage of the special academic launch pricing (under $500,000 for a 12-CubeSat, 50-lb payload to LEO) now in force for initial Sea Star launches, which translates to satellite launch for as little as $35,000 per single CubeSat. Interorbital Systems’ CEO Milliron stated, “We’re offering an open invitation to academic institutions who’ve, due to launch cost restraints, never thought it possible to consider building a satellite or conducting space-based science. We’re announcing that a new opportunity for affordable launch has emerged—and it’s called Sea Star.”

IOS plans to conduct its launches from the ocean off the coast of California for polar launches, and from the waters near the Kingdom of Tonga for equatorial orbits. More details on Interorbital Systems’ rockets and launch service programs are available at

Interorbital Systems

Contact: Randa Milliron, CEO Telephone: 661.965.0771 Fax: 661.824.1662
Email: [email protected] or [email protected]
Websites: and
PO Box 662, Mojave, CA 93502-0662

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