## 5 Conclusions  
The present study explored a possible scheme of a plasma thruster, utilizing high-speed plasma flows comprising electrons, ions, and heavy multiply charged dust particles. These high-speed particle flows are generated from captured matter by utilizing solar radiation as the spacecraft follows a specific trajectory. Certainly, it would be interesting to analyze this conception from the point of view of long-range flights in the solar system. However, at present, the region of near-Earth space is the most well-studied region. Therefore, using information about the interplanetary medium near Earth, we considered the proposed scheme of a plasma engine for flights only in near-Earth space. It should be noted that we greatly simplified our calculations; we disregarded the contribution of solar wind and focused solely on stationary interplanetary dust in a vicinity of approximately 1 \(A.U.\) As a result, the findings presented in this study should be regarded as a lower rough estimate that highlights the potential for the technical realization of the proposed scheme. Also, we would like to point out that there are many technical applications and developments for the proposed idea (see [31; 45; 46]). From graphs depicted in Figure 5, it follows that the use of the proposed scheme for small velocities is impractical, as one requires a huge trap (\(D>10^{4}\) m). However, bearing in mind the dependence (23), one can expect that the proposed approach shall be effective at high spacecraft speeds. It is also worth noting that in the present estimations, we used a very low-density value of captured matter, \(n_{\Sigma}=10\) cm\({}^{-3}\), whereas from the estimates of Section 2, it follows that the real density value can be increased by at least four times, which means the size of \(D\) may be reduced by a corresponding number of times. Figure 7: Thrust as a function of spacecraft velocity \(v\) for different values of \(D\). Curve 1 corresponds to \(D=2\times 10^{2}\) m, and curve 2 corresponds to \(D=2\times 10^{3}\) m.  
Note that the coupling of the trap and plasma accelerator chamber can be carried out in various ways; this point strictly depends on the interplanetary medium composition, as well as the method for plasma generation and the acceleration of plasma flow. A sample of such coupling is presented in Figure 5a, where the neutral dust flow accumulated in the trap is directly introduced into the discharge chamber through a set of inlet holes. If only solar wind particles are used as fuel for a plasma thruster, one can abandon the conical trap and replace it with a magnetic trap (see [24; 29] and the references therein). The charged particles can be collected in the proposed magnetic field (so-called magnetic mirrors [47]) and guided into an inlet of the plasma accelerator. In this case, we escape the problems with the size and weight of the conical trap, and there is no need for a discharge chamber; the magnetic trap shall act as a brake. In this regard, we would again like to emphasize that in the discussed case, there is no need for a large number of trapped particles to create acceptable thrust since the exacted thrust value can be obtained owing the relativistic increase in the momentum of the rejected particle flow. Moreover, it is crucial to account for the energy losses associated with the implementation of low-pressure discharge and the method of plasma acceleration, along with the transformation of solar energy within the solar cells. To abstract away from the considerations of such points, we introduced an energy conversion factor \(\zeta\) which accounts for the impacts of these processes and for any unknown factors. In this context, we set \(\zeta=10^{-3}\). One should expect that the value of \(\zeta\) can be enhanced; hence, the current estimates should only be viewed as preliminary. They principally exhibit the feasibility of implementing the discussed scheme, and we intend to discuss these questions in our forthcoming works. Conceptualization, A.R.K. and P.A.M.; methodology, A.R.K.