Effects of booms of sounding rockets in flowing plasmas

Abstract

Effects of booms of a sounding rocket on rocket charging and on the local plasma conditions are studied with numerical and analytical models accounting for flowing, ionospheric plasmas. Simulations are carried out with a first principles self-consistent Particle-In-Cell numerical code. It is shown that the booms can affect the charging of the payload and disturb the local plasma to a high degree. The boom-to-plasma potential, which varies with the position due to the convective electric field, can lead to significantly different currents, in particular electron currents, to the booms on either side of the rocket. The analytical models for the collected currents considered in this study show good agreement with the simulations. The potential difference between the plasma and the rocket can electrostatically focus the ions to create regions of enhanced ion density downstream of the rocket and can lead to an asymmetric wake. It is shown that ion focusing can be asymmetric between the booms due to the potential gradient. These effects can have implications for instrument placements and data analysis.

The Spacecraft Wake: Interference With Electric Field Observations and a Possibility to Detect Cold Ions

“…Relevant parameters for LEO (sounding rockets and the International Space Station) are given by Paulsson et al (2019) and Reddell et al (2006), from the solar wind by Eriksson et al (2006Eriksson et al ( , 2007, and from the polar lobes by Engwall, Eriksson, Cully, André, Puhl-Quinn, et al (2009), André et al (2015), and Haaland et al (2017). Sketches of corresponding wakes are given in Figure 1.…”

“…Relevant parameters for LEO (sounding rockets and the International Space Station) are given by Paulsson et al. (2019) and Reddell et al. (2006), from the solar wind by Eriksson et al.…”

Electron Wing‐Like Structures Formed at a Negatively Charged Spacecraft Moving in a Magnetized Plasma

“…The electric field is observed in the spacecraft frame of reference, and the onboard instruments will experience the potential change in the direction. This principle is actively utilized in the electrodynamic tether system (Cosmo & Lorenzini, ), whereas it is also known as a complicating factor for sounding rocket experiments, where the instruments are placed on extended booms (Sanmartin, ; Paulsson et al, ). While in the data analysis the convective electric field is usually easily removed, it is still an open question how the plasma, as seen from the spacecraft, will react to the effective potential of the spacecraft and how it will influence in‐situ measurements.…”

“…With the change in dominant ion species, the spacecraft can be supersonic at low altitudes, and subsonic at high altitudes. In both cases, a wake will form downstream of the spacecraft, which for supersonic flows can extend much farther than the Debye length from the spacecraft surface (Al'pert et al, 1966;Khrapak et al, 2005;Ludwig et al, 2012;Miloch, 2014;Darian et al, 2017;Paulsson et al, 2019).…”

“…Spin‐stabilized spacecraft may probe the wake every spin period, which will contaminate the data and needs to be taken into account in the analysis (Scime et al, ; Paulsson et al, ). Taking the spin plane perpendicular to the flow might reduce this problem and improve data quality.…”