New answers tagged propulsion
3
Not only could it be done, but you could in fact get the hardware right now.
Behold, the RB2000 rocket belt:
We can work out the probable $\Delta_v$ of the rocket via the good old rocket equation:
$$\Delta_v = g_0 \cdot I_{sp} \cdot \ln \left( \frac{M}{M_e} \right)$$
Where $g_0$ is a standard gravity, $M$ is the fully fuelled mass of the rocket and $M_e$ ...
4
You have it correct, but you are looking at a very narrow range of ISP.
The BepiColombo mission to mercury uses an ion thruster with a ISP of 4,200 seconds(41,202 M/s). The same formula yields a mass ratio of 11.325.
The NEXIS ion thruster can achieve 8000 seconds (78,200 m/s)
The European DS4G innovative thruster manages 19,300 seconds (188,200 m/s) ...
6
It appears to be unworkable.
If Burns had properly accounted for the total momentum of the box+ring
system, which must include the energy/momentum of the applied fields
and forces required to accelerate the individual components (like the
ring) inside the box, he would have noted that the total momentum
never changes, even under relativistic ...
1
The krypton engine used in starlink satellites could have been developed in Poland. at the Institute of Plasma Physics and Laser Mixing. It is important that the working factor is krypton, which is many times cheaper than xenon.
http://www.elektroonline.pl/news/4555,Polacy-zbudowali-elektryczny-silnik-plazmowy-napedzany-kryptonem
1
The bright particles you see flying from the Souyz nozzle are the pieces of the "nozzle cowling". It is kinda ceramic material coating of the nozzle. The amount of coating is calclulated for the nozzle operation. It wears off gradually during the nozzle serving time.
0
Ion thrusters need a power source. And power sources can be massive.
This was a major objection to Franklin Chang Diaz' claim that VASIMR could get to Mars in 39 days. He assumed an alpha of .5 kg/KWe. Which isn't doable with present day state of the art. So what would a power source look like that cranks out a kilowatt electricity per half kilogram? I ...
0
The engines aren't particularly heavyweight, but we're handling lots of power in a very tiny volume. Lots of power means cooling. Gas accelerated to these energies becomes an extremely corrosive plasma, best held at bay by magnetic fields because otherwise the engine will be burning through itself. So - heavy electromagnets to guide the propellant. The ...
13
You can't directly convert them; they're two different measures. As Organic Marble points out, thrust is loosely analogous to a car's horsepower; specific impulse is loosely analogous to a car's gas mileage.
Thrust in newtons is equal to the propellant mass exhaust flow rate in kg/s times the specific impulse in N·s/kg (which is dimensionally equivalent to ...
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