Variable Specific Impulse Magnetoplasma Rocket - Research and Development

Research and Development

First VASIMR experiment was conducted at MIT starting in 1983 on the magnetic mirror plasma device. Important refinements were introduced to the rocket concept in 1990s, including the use of the “helicon” plasma source, which replaced the initial plasma gun originally envisioned and made the rocket completely “electrodeless” an extremely desirable feature to assure reliability and long life. A new patent was granted in 2002.

In 1995, the Advanced Space Propulsion Laboratory (ASPL) was founded at NASA Johnson Space Center, Houston in the building of Sonny Carter Training Facility. The magnetic mirror device was brought from MIT. First plasma experiment in Houston was conducted using microwave plasma source. The collaboration with University of Houston, University of Texas at Austin, Rice University and other academic institutions was established.

In 1998, the first helicon plasma experiment was performed at the ASPL. The decision was made regarding the official name of VASIMR and VASIMR experiment (VX). VX-10 in 1998 ran up to 10 kW helicon discharge, VX-25 in 2002 ran up to 25 kW and VX-50 - up to 50 kW of RF plasma discharge. In March, 2000, the VASIMR group was given a Rotary National Award for Space Achievement / Stellar Award. By 2005 major breakthroughs were obtained at the ASPL including full and efficient plasma production, and acceleration of the plasma ions in the second stage of the rocket. The VASIMR engine model VX-50 proved to be capable of 0.5 newtons (0.1 lbf) thrust. Published data on the VX-50 engine, capable of processing 50 kW of total radio frequency power, showed ICRF (second stage) efficiency to be 59% calculated as: 90% N_A coupling efficiency × 65% N_B ion speed boosting efficiency. It was hoped that the overall efficiency of the engine could be increased by scaling up power levels.

Ad Astra Rocket Company (AARC) was incorporated in Delaware on January 14, 2005. On June 23, 2005, Ad Astra and NASA signed first Space Act Agreement to privatize the VASIMR Technology. On July 8, 2005, Franklin Chang-Diaz retired from NASA after 25 years of service. Ad Astra’s Board of Directors was formed and Dr. Chang Díaz took the helm as Chairman and CEO on July 15, 2005. In July 2006 AARC opened the Costa Rica subsidiary in the city of Liberia at the campus of Earth University. In December 2006, AARC-Costa Rica performed first plasma experiment on the VX-CR device utilizing helicon ionization of argon.

100 kW VASIMR experiment was successively running in 2007 and demonstrated efficient plasma production with an ionization cost below 100 eV. VX-100 plasma output is tripled over the prior record of the VX-50. In the same year, AARC moved out from NASA facility to its own building in Webster, TX.

Model VX-100 was expected to have the N_B ion speed boosting efficiency of 80%. There were, however, additional (smaller) efficiency losses related to the conversion of DC electric current to radio frequency power and also to the superconducting magnets' auxiliary equipment energy consumption. By comparison, 2009 state-of-the-art, proven ion engine designs such as NASA's HiPEP operated at 80% total thruster/PPU energy efficiency.