The VASIMR concept originated in 1977 with former NASA astronaut Franklin Chang Díaz, who has been developing the technology ever since. ==Design and operation== VASIMR is a type of electrothermal plasma thruster/electrothermal magnetoplasma thruster.
To counter this latter effect, two thruster units can be packaged with magnetic fields oriented in opposite directions, making a net zero-torque magnetic quadrupole. The required power generation technology for fast interplanetary travel does not currently exist and is not feasible with current state-of-the-art technology. ==Research and development== The first VASIMR experiment was conducted at Massachusetts Institute of Technology in 1983.
Important refinements were introduced in the 1990s, including the use of the helicon plasma source, which replaced the plasma gun originally envisioned and its electrodes, adding to durability and long life. As of 2010, Ad Astra Rocket Company (AARC) was responsible for VASIMR development, signing the first Space Act Agreement in 23 June 2005 to privatize VASIMR technology.
Franklin Chang Díaz is Ad Astra's chairman and CEO, and the company had a testing facility in Liberia, Costa Rica on the campus of Earth University. ===VX-10 to VX-50=== In 1998, the first helicon plasma experiment was performed at the ASPL.
VASIMR experiment 10 (VX-10) in 1998 achieved a helicon RF plasma discharge of up to 10 kW and VX-25 in 2002 of up to 25 kW.
VASIMR experiment 10 (VX-10) in 1998 achieved a helicon RF plasma discharge of up to 10 kW and VX-25 in 2002 of up to 25 kW.
Based on novel theoretical work in 2004 by Alexey V.
Important refinements were introduced in the 1990s, including the use of the helicon plasma source, which replaced the plasma gun originally envisioned and its electrodes, adding to durability and long life. As of 2010, Ad Astra Rocket Company (AARC) was responsible for VASIMR development, signing the first Space Act Agreement in 23 June 2005 to privatize VASIMR technology.
By 2005 progress at ASPL included full and efficient plasma production and acceleration of the plasma ions with the 50 kW, thrust VX-50.
Published data on the 50 kW VX-50 showed the electrical efficiency to be 59% based on a 90% coupling efficiency and a 65% ion speed boosting efficiency. ===VX-100=== The 100 kilowatt VASIMR experiment was successfully running by 2007 and demonstrated efficient plasma production with an ionization cost below 100eV.
In contrast, 2009 state-of-the-art, proven ion engine designs such as NASA's High Power Electric Propulsion (HiPEP) operated at 80% total thruster/PPU energy efficiency. ===VX-200=== On 24 October 2008, the company announced in a press release that the helicon plasma generation component of the 200 kW VX-200 engine had reached operational status.
December 18, 2008. NASA documents Technical Paper: Rapid Mars Transits with Exhaust-Modulated Plasma Propulsion (PDF) Variable-Specific-Impulse Magnetoplasma Rocket (Tech Brief) Advanced Space Propulsion Laboratory: VASIMR Propulsion Systems of the Future Emerging technologies Magnetic propulsion devices Plasma physics Rocket propulsion Ion engines
Electrically speaking, NEXT is almost twice as efficient, and successfully completed a 48,000 hours (5.5 years) test in December 2009. New problems also emerge with VASIMR, such as interaction with strong magnetic fields and thermal management.
In contrast, 2009 state-of-the-art, proven ion engine designs such as NASA's High Power Electric Propulsion (HiPEP) operated at 80% total thruster/PPU energy efficiency. ===VX-200=== On 24 October 2008, the company announced in a press release that the helicon plasma generation component of the 200 kW VX-200 engine had reached operational status.
Managing and rejecting that waste heat is critical. Between April and September 2009, 200 kW tests were performed on the VX-200 prototype with 2tesla superconducting magnets that are powered separatelyand not accounted for in any "efficiency" calculations.
Important refinements were introduced in the 1990s, including the use of the helicon plasma source, which replaced the plasma gun originally envisioned and its electrodes, adding to durability and long life. As of 2010, Ad Astra Rocket Company (AARC) was responsible for VASIMR development, signing the first Space Act Agreement in 23 June 2005 to privatize VASIMR technology.
During November 2010, long duration, full power firing tests were performed, reaching steady state operation for 25 seconds and validating basic design characteristics. Results presented in January 2011 confirmed that the design point for optimal efficiency on the VX-200 is 50 km/s exhaust velocity, or an I of 5000s.
In 2010 NASA Administrator Charles Bolden said that VASIMR technology could be the breakthrough technology that would reduce the travel time on a Mars mission from 2.5 years to 5 months.
During November 2010, long duration, full power firing tests were performed, reaching steady state operation for 25 seconds and validating basic design characteristics. Results presented in January 2011 confirmed that the design point for optimal efficiency on the VX-200 is 50 km/s exhaust velocity, or an I of 5000s.
The 200 kW VX-200 had executed more than 10,000 engine firings with argon propellant at full power by 2013, demonstrating greater than 70% thruster efficiency relative to RF power input. ====VX-200SS==== In March 2015, Ad Astra announced a $10 million award from NASA to advance the technology readiness of the next version of the VASIMR engine, the VX-200SS to meet the needs of deep space missions.
Compared to traditional rocket engines with very complex plumbing, high performance valves, actuators and turbopumps, VASIMR has almost no moving parts (apart from minor ones, like gas valves), maximizing long term durability. ===Disadvantages=== According to Ad Astra as of 2015, the VX-200 engine requires 200 kW electrical power to produce of thrust, or 40 kW/N.
The 200 kW VX-200 had executed more than 10,000 engine firings with argon propellant at full power by 2013, demonstrating greater than 70% thruster efficiency relative to RF power input. ====VX-200SS==== In March 2015, Ad Astra announced a $10 million award from NASA to advance the technology readiness of the next version of the VASIMR engine, the VX-200SS to meet the needs of deep space missions.
The SS in the name stands for "steady state", as a goal of the long duration test is to demonstrate continuous operation at thermal steady state. In August 2016, Ad Astra announced completion of the milestones for the first year of its 3-year contract with NASA.
In August 2017, the company reported completing its Year 2 milestones for the VASIMR electric plasma rocket engine.
It appears as though the planned 200 kW design is being run at 100 kW for reasons that are not mentioned in the press release. In August, 2019 Ad Astra announced the successful completion of tests of a new generation radio-frequency (RF) Power Processing Unit (PPU) for the VASIMR engine, built by Aethera Technologies Ltd.
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