Historical research guide · 1043 · 2015

Human outer solar system exploration via Q-Thruster technology

B. Kent Joosten · Harold G. White

In one minute

Kent Joosten and Sonny White ask a clean question: if the quantum vacuum thruster being tested at NASA Johnson’s Eagleworks laboratory really delivers the thrust its bench results suggest, what does the solar system look like? A Q-thruster carries no reaction mass — it pushes on the quantum vacuum instead of on stored propellant — so its ship keeps almost constant mass and, on nuclear electric power, almost constant thrust. That single fact rewrites mission design. Joosten builds a fast trajectory optimiser, checks it against NASA’s production tool Copernicus, and runs the numbers. At a conservative thrust figure and one megawatt of reactor power, a fifty-five-tonne crewed ship reaches Mars in seventy-five days. More striking than the speed is the freedom: with two new manoeuvres the authors name retro-phasing and gravity-augmented phasing, the launch window disappears entirely — you can leave for Mars on any date if you will accept up to seven months. Jupiter and Saturn open to crews on round trips of nineteen and thirty months.

Connection

Chapter 8 argues that propulsion stops being about throwing mass overboard, and this is the paper that prices that idea in days and tonnes rather than adjectives; chapters 2 and 6 supply the reason the thruster is interesting at all, since the thing it pushes against is the structured vacuum, and a propellantless drive on nuclear power is the first mission architecture that reads like the ones that follow from tapping the vacuum directly.

From the source

The Q-thruster mechanism as the authors state it: through applied electric and magnetic fields the device pushes quantum particles in one direction and recoils to conserve momentum, working on the same magnetohydrodynamic principle as a conventional plasma thruster but drawing its propellant from quantum vacuum fluctuations rather than from a tank, so no onboard propellant is consumed.Section 1, Q-Thruster Overview
The performance figure the whole study rests on is a specific thrust of 0.4 to 4.0 newtons per kilowatt of electrical power with essentially zero onboard propellant, which the authors take from the laboratory results of their reference 2 and describe as one to two orders of magnitude greater than current operational electric thrusters; the analyses then use the conservative end, 0.4, throughout.Abstract and Section 1, Q-Thruster Overview, citing reference 2
Constant thrust acceleration makes the mission problem analytic. For a vehicle of nearly constant mass on nuclear power, minimum-time phase-independent transfers between circular coplanar planetary orbits reduce to closed-form rectilinear expressions, and the resulting minimum flight time depends only on the heliocentric distance to be crossed and the thrust acceleration. The authors verify the result numerically against a generalised-reduced-gradient optimiser and against NASA’s production trajectory tool Copernicus, agreeing to better than three per cent, and to five per cent for the closed-form solution.Section 2, Equations 1 to 5 and Figure 1
The Mars design point: 0.4 newtons per kilowatt, one megawatt of electrical power from a growth SP-100 class reactor, twenty kilograms of power and propulsion hardware per kilowatt, and a thirty-five-tonne habitat for six to eight crew gives a fifty-five-tonne vehicle at 0.74 milli-g of continuous acceleration — a seventy-five-day phase-independent Earth-to-Mars transfer, plus twelve days spiralling out of a four-hundred-kilometre Earth orbit and five days spiralling down to a four-hundred-kilometre Mars orbit.Section 3, Vehicle and Mission Parameters, and Figures 1, 2 and 3
The launch window disappears. Because a propellantless ship pays for bad planetary phasing in flight time rather than in an exponential propellant penalty, two manoeuvres the authors name — retro-phasing, in which the ship reverses its heliocentric motion to let Mars catch up, and gravity-augmented phasing, in which all thrust is aimed sunward so the ship rides an inner orbit some thirty per cent faster than Venus — cover the whole twenty-six-month synodic cycle at transit times from two and a half to seven months, and a complete round trip fits inside three hundred and ninety days even at the worst departure phase angle.Section 3, Any-Phase Transits, Figures 4 to 8
At the same milli-g class the outer system opens: with two megawatts and a ninety-tonne vehicle at 0.91 milli-g, a crewed round trip to Jupiter’s moon Callisto fits in twenty months including six months on station, and Saturn is nine months out, the ship passing one hundred kilometres per second at turnaround, over five times the local solar-system escape velocity. The authors add, making no attempt to design a starship, that the same constant milli-g run reaches Alpha Centauri in ninety-two years without slowing down, arriving at 0.094 of light speed.Section 4, Crewed Jupiter Missions, Crewed Saturn Mission and Interstellar Performance, Figures 10 and 11, Equations 8 to 10

The way in

https://doi.org/10.1109/aero.2015.7118893

Historical source-access record. This guide links to the original; it does not reproduce the paper text.

SOURCE READ IN FULL, BUT NOT REPRODUCIBLE — AND WHY NOT. The complete paper was retrieved and read on 2026-09-08 from the NASA Technical Reports Server, citation 20140013174, report number JSC-CN-32129, a thirteen-page portable document with all five sections, the reference list, the author biographies and appendices A, B and C. It was checked for public-domain status and it does not qualify. Every page of that document carries the publisher’s own copyright footer, 978-1-4799-1622-1/14/$31.00 followed by the copyright symbol and 2014 IEEE — the line an IEEE conference paper carries when it is NOT a United States Government work, in place of the ‘U.S. Government work not protected by U.S. copyright’ notice such papers carry instead. The NASA Technical Reports Server record agrees: its copyright block records belongs-to-US-Government as false, belongs-to-contractor as false and a determination of PUBLIC-USE-PERMITTED, which is a permission to read rather than an absence of copyright. The first author is an independent consultant with MBO Partners, Inc. of League City, Texas, not a civil servant; the second, Harold G. White, is at the NASA Johnson Space Center. This page therefore reproduces no text of the paper at all, not even the abstract, and every locator below points to a numbered section, equation or figure of the document that was read. CHAPTERS. The skeleton carried four chapters. Chapter 4, on the metric tensor and warp drives, is dropped: this paper is a mission-analysis study of a constant-thrust, propellantless vehicle moving through ordinary space, and it works its long-range case in special relativity rather than in metric engineering. Chapters 8, 6 and 2 are kept. NUMBERS. Where the paper writes specific thrust it means newtons of thrust per kilowatt of electrical power, and where it writes vehicle specific mass it means kilograms of power and propulsion hardware per kilowatt of electrical power; both are spelled out below. RELATED PAGE. The laboratory measurement this paper cites as its reference 2 for the thrust numbers is Brady, White, March, Lawrence and Davies, and it is on this site at /library/stm-a46c32725a.

How to cite it

B. Kent Joosten, Harold G. White (2015) Human outer solar system exploration via Q-Thruster technology doi:10.1109/aero.2015.7118893

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