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This is based on the supposition that the MET provides higher specific impulse, or in simpler terms more thrust for the amount of fuel. Another advantage is that because microwaves can be collected and fed directly into the thrust chamber, the MET is extremely compatible with space transport.
Snap, [6] or jounce, [2] is the fourth derivative of the position vector with respect to time, or the rate of change of the jerk with respect to time. [4] Equivalently, it is the second derivative of acceleration or the third derivative of velocity, and is defined by any of the following equivalent expressions: = ȷ = = =.
Delta-v (also known as "change in velocity"), symbolized as and pronounced /dɛltə viː/, as used in spacecraft flight dynamics, is a measure of the impulse per unit of spacecraft mass that is needed to perform a maneuver such as launching from or landing on a planet or moon, or an in-space orbital maneuver.
Spacecraft performance can be quantified in amount of change in momentum per unit of propellant consumed, also called specific impulse. This is a measure of the amount of impulse that can be obtained from a fixed amount of reaction mass. The higher the specific impulse, the better the efficiency.
Negative gearing is a form of financial leverage whereby an investor borrows money to acquire an income-producing investment and the gross income generated by the investment (at least in the short term) is less than the cost of owning and managing the investment, including depreciation and interest charged on the loan (but excluding capital repayments).
In a Hall thruster, the attractive negative charge is provided by an electron plasma at the open end of the thruster instead of a grid. A radial magnetic field of about 100–300 G (10–30 mT ) is used to confine the electrons, where the combination of the radial magnetic field and axial electric field cause the electrons to drift in azimuth ...
The VX-200 engine, for example, requires 200 kW electrical power to produce 5 N of thrust, or 40 kW/N. This power requirement may be met by fission reactors, but the reactor mass (including heat rejection systems) may prove prohibitive. [13] [14] Another challenge is plasma erosion.
The first successful demonstration of an ion engine was NASA SERT-1 (Space Electric Rocket Test) spacecraft. [19] [20] It launched on 20 July 1964 and operated for 31 minutes. [19] A follow-up mission launched on 3 February 1970, SERT-2. It carried two ion thrusters, one operated for more than five months and the other for almost three months ...