Interorbital has released the TubeSat Personal Satellite (PS) Kit, a low-cost alternative to the CubeSat with three-quarters of the mass (0.75-kg) and volume of a CubeSat, but with plenty of room for most experiments or functions.

The price of the TubeSat kit actually includes the price of a launch into Low-Earth-Orbit on an IOS NEPTUNE 30 launch vehicle. As the TubeSats are placed into self-decaying orbits 310 kilometers (192 miles) above the Earth's surface, they do not contribute to any long-term build-up of orbital debris. After a few weeks of operation, they will safely re-enter the atmosphere and burn-up. TubeSats are designed to be orbit-friendly. Launches are expected to start in the fourth quarter of 2010. The total price of the TubeSat Kit including a launch to orbit is $8,000.

A TubeSat is designed to function as a Basic Satellite Bus or as a simple stand-alone satellite. Each TubeSat kit includes the satellite's structural components, safety hardware, solar panels, batteries, power management hardware and software, transceiver, antennas, microcomputer, and the required programming tools. With these components alone, the builder can construct a satellite that outputs enough power to be picked up on the ground by a hand-held HAM radio receiver. Simple applications include broadcasting a repeating message from orbit or programming the satellite to function as a private orbital HAM radio relay station as just two examples. The TubeSat also allows the builder to add his or her own experiment or function to the basic TubeSat kit. Examples of add-on experiments or functions include the following:

• Earth-from-space video imaging
• Earth magnetic field measurement
• Satellite orientation detection (horizon sensor, gyros, accelerometers, etc.)
• Orbital environment measurements (temperature, pressure, radiation, etc.)
• On-orbit hardware and software component testing (microprocessors, etc.)
• Tracking migratory animals from orbit
• Testing satellite stabilization methods
• Biological experiments
• On-orbit advertising
• Private e-mail

As long as the experiment or function satisfies the volume and mass restrictions, it can be integrated into the TubeSat. These restrictions provide a unique intellectual challenge for the experiment or function designer. TubeSats are also available as Double TubeSats, Triple TubeSats, or Quadruple TubeSats. The length, volume, and mass of these expanded TubeSats are based on the multiplying factor. 32 TubeSats can be integrated into and launched by a single NEPTUNE 30 launch vehicle. Prior to launch, each TubeSat is inserted into one of the rocket's 32 Satellite Ejection Cylinders. They never come into contact with the other TubeSats. Once on-orbit, the satellites are released according to a pre-programmed timing sequence. The timing sequence is designed to prevent satellite clustering. Interorbital expects to launch a set of 32 TubeSats per month. The NEPTUNE 30 TubeSat launches will take place at the IOS Spaceport Tonga, located on the southern tip of the island of 'Eua in the South Pacific Kingdom of Tonga. (Thanks, Brian!)