SAN FRANCISCO — Interorbital Systems, a small aerospace company based in Mojave, Calif., is scheduled to conduct the first test flight in late February or early March of the common propulsion module, the basic building block of the company’s Neptune 30 rocket. If that test is successful, the firm will continue test-launching rockets throughout the year with the goal of launching dozens of microsatellites into low Earth orbit in December, said Randa Milliron, Interorbital chief executive.

“We don’t want to put people’s hard work and money on an untested vehicle,” Milliron said. “Before we do an orbital launch, we want to make sure that all systems are working perfectly. The only way you can do that is by flight testing.”

Funding for the rocket tests is coming from sales of Interorbital System’s TubeSat Personal Satellite Kit, a cylindrical bus designed to accommodate payloads weighing approximately 250 grams. For $8,000, customers can buy the satellite and its ride on the Neptune 30 rocket into low Earth orbit.

While Interorbital Systems, a privately held company, does not discloses sales figures, Milliron said the company has completed seven TubeSat sales, including some orders for multiple satellites, and has 22 additional sales pending. Interorbital Systems has announced TubeSat sales to the U.S. Naval Postgraduate School in Monterey, Calif.; InterAmerican University of Puerto Rico; Morehead State University in Kentucky; the Aslan Academy, a private school in Cypress, Calif.; and Project Calliope, a group of space and music fans developing a satellite to stream to Earth the natural sounds of the ionosphere.

In addition, the University of California, Irvine paid Interorbital Systems $12,500 to launch a CubeSat miniature satellite on the first Neptune 30 orbital flight. The Neptune 30 is designed to launch CubeSats and TubeSats as well as experiments housed in double or triple CubeSat or TubeSat modules.

One of Interorbital Systems’ first TubeSat customers was Bob Twiggs, co-inventor of the CubeSat and founder of Stanford University’s Space Systems Development Laboratory in Palo Alto, Calif. Now a professor at Morehead State University’s Space Science Center in Kentucky, Twiggs said he jumped at the opportunity to purchase the low-cost satellite and launch.

“Buying the launch and kit for $8,000 is one of the best educational investments I have ever made,” Twiggs said. “Now I have got a launch scheduled, which means the students have to get a satellite built.”

Twiggs said he also plans to pay Interorbital Systems to carry two student-built payloads on the first Neptune 30 suborbital test flight scheduled for late February or early March. Those rides are selling for $500 per kilogram, Milliron said.

While his primary goal is to inspire his students, Twiggs said he also is glad to help Interorbital Systems develop an extremely low-cost launch option. “If I can support them a little bit and they are successful, it will revolutionize launch costs,” Twiggs said.

Similarly, Alex Bordetsky, director of the Naval Postgraduate School’s Center for Network Innovation and Experimentation, said he has purchased three TubeSat orbital launches and two suborbital flights for a variety of space-based experiments. Naval Postgraduate School students will design satellites to relay data among airborne and ground units. In addition, the students will attempt to create a small, satellite-based server for maritime applications.

Bordetsky said he is optimistic that Interorbital Systems will succeed in launching the small satellites. “They have a very well thought-out strategy from my perspective as an experimental researcher trying to put picosatellites into low Earth orbit,” he said. The term picosatellite refers to satellites that weigh less than 1 kilogram.

Milliron and her husband, Roderick Milliron, Interorbital Systems president and chief designer, have been working to develop low-cost rockets since 1995. “We understood that it would not be cost-effective to copy a complicated launch vehicle like the Delta, Atlas or any other existing rocket,” Randa Milliron said.

In an effort to drastically decrease launch costs, Roderick Milliron simplified every aspect of the rocket and created a launch vehicle that could be built on an assembly line by semi-skilled workers. The result of that design effort is the Common Propulsion Module, which includes a liquid rocket engine, two valves, two fuel tanks and a computer, Randa Milliron said.

The Neptune 30, which is composed of five Common Propulsion Modules, is designed to send 30 kilograms into low Earth orbit. As part of the Synergy Moon team competing for the Google Lunar X Prize, Interorbital Systems plans to assemble a Neptune 1000 with 33 Common Propulsion Modules. The Neptune 1000 will carry 1,000 kilograms into low Earth orbit or approximately 60 kilograms to the Moon, Randa Milliron said.

To further limit launch costs, Interorbital Systems plans to operate its own spaceport in the South Pacific nation of Tonga. In January, Tonga’s King George Tupou V approved plans for the spaceport, according to the Tongan national news magazine Matangi Tonga. Now, Interorbital Systems and Tongan government officials are working with the Federal Aviation Administration’s Office of Commercial Space Transportation to obtain a U.S. license for the Neptune 30 launch, Randa Milliron said.

In late summer, Interorbital Systems plans to begin building the launch pad for the Neptune 30, which is scheduled to be completed in time to support an orbital launch in December. “We are creating a very minimal infrastructure,” Randa Milliron said. “A lot of the equipment is portable.”

Debra Werner is a correspondent for SpaceNews based in San Francisco. Debra earned a bachelor’s degree in communications from the University of California, Berkeley, and a master’s degree in Journalism from Northwestern University. She...