Explanipedia

Applying the Plasma Brake for Active Debris Removal: revolutionarily high downmass/upmass ratio Open

P. Janhunen, Olli Knuuttila, María Genzer, Petri Toivanen, Leo Nyman , et al. · 2025

The Plasma Brake is a propellantless method for deorbiting objects from Low Earth Orbit (LEO). It is based on charging a long and thin metallic tether (a microtether) to high negative voltage (1 kV) so that the electric field around the te…

Multi-Wire μ-Tether for Plasma Brake and Space Debris Mitigation Open

Petri Toivanen, P. Janhunen, Jarmo Kivekäs, Jouni Polkko, María Genzer , et al. · 2025

Plasma Brake is a compact module to be mounted to a spacecraft or to a piece of space junk for orbital braking and ultimate atmospheric demise. The braking force is generated by the ionospheric plasma Coulomb drag that is analogous to the …

Plasma Brake Payloads onboard CubeSat Missions of FS-1, EC-2, and FS-1p Open

Jarmo Kivekäs, Petri Toivanen, Jouni Polkko, P. Janhunen, María Genzer · 2025

We have developed a Coulomb drag propulsion device that accommodates a 50-m electrostatic tether that can be biased to a high voltage with respect to the ambient space plasma. The high voltage electrostatic sheath around the tether serves …

Charon: a system capable of deorbiting satellites with no platform dependencies Open

Tuomas Simula, Perttu Yli-Opas, María Genzer, Leo Nyman, P. Janhunen , et al. · 2025

The increasing number of satellites launched constitutes a risk in the form of growing space debris, especially in low Earth orbit. With more objects in orbit, the risk of collisions and creation of additional space debris grows significan…

Referee report. For: Fusion Propulsion Constraints Required by Robust Exoplanet Exploration [version 1; peer review: 1 approved] Open

P. Janhunen · 2025

Special Issue: Advances in CubeSat Sails and Tethers (1st Edition) Open

Andris Slavinskis, P. Janhunen · 2024

Currently, most space missions rely on chemical and electric propulsion systems, both of which are limited by the propellent tank volume whose “wet mass” is launched from the Earth [...]

Launching mass from the Moon helped by lunar gravity anomalies Open

P. Janhunen · 2024

Normally a passive object launched from the Moon at less than the escape velocity orbits the Moon once and then crashes back to the launch site. We show that thanks to lunar gravity anomalies, for specific launch sites and directions, a pa…

Electric Sail Test Cube–Lunar Nanospacecraft, ESTCube-LuNa: Solar Wind Propulsion Demonstration Mission Concept Open

Andris Slavinskis, Mario F. Palos, Janis Dalbins, P. Janhunen, Martin Tajmar , et al. · 2024

The electric solar wind sail, or E-sail, is a propellantless interplanetary propulsion system concept. By deflecting solar wind particles off their original course, it can generate a propulsive effect with nothing more than an electric cha…

Robust Flight Tether for In-Orbit Demonstrations of Coulomb Drag Propulsion Open

Petri Toivanen, P. Janhunen, Jarmo Kivekäs, Meri Mäkelä · 2024

A new method of producing robust multi-wire tethers for Coulomb drag applications was developed. The multi-wire structure required for redundancy against the micrometeoroid flux of the space environment is realised through the method of wi…

Foresail-2: Space Physics Mission in a Challenging Environment Open

Marius Anger, Petri Niemelä, Kiril Cheremetiev, Bruce Clayhills, Anton Fetzer , et al. · 2023

Electric Sail Mission Expeditor, ESME: Software Architecture and Initial ESTCube Lunar Cubesat E-Sail Experiment Design Open

Mario F. Palos, P. Janhunen, Petri Toivanen, Martin Tajmar, Iaroslav Iakubivskyi , et al. · 2023

The electric solar wind sail, or E-sail, is a novel deep space propulsion concept which has not been demonstrated in space yet. While the solar wind is the authentic operational environment of the electric sail, its fundamentals can be dem…

3D GUMICS Simulations of Northward IMF Magnetotail Structure Open

Laura Fryer, R. C. Fear, Imogen Gingell, John Coxon, Minna Palmroth , et al. · 2023

This study presents a re‐evaluation of the Kullen and Janhunen (2004, https://doi.org/10.5194/angeo-22-951-2004 ) global northward interplanetary magnetic field (IMF) simulation, using the Grand Unified Magnetosphere–Ionosphere Coupling Si…

Interplanetary Student Nanospacecraft: Development of the LEO Demonstrator ESTCube-2 Open

Janis Dalbins, Kristo Allaje, Hendrik Ehrpais, Iaroslav Iakubivskyi, Erik Ilbis , et al. · 2023

Nanosatellites have established their importance in low-Earth orbit (LEO), and it is common for student teams to build them for educational and technology demonstration purposes. The next challenge is the technology maturity for deep-space…

Review of: "A Case for Nature in Long-Haul Space Exploration" Open

P. Janhunen · 2023

Project DragLiner: Harnessing plasma Coulomb drag for satellite deorbiting to keep orbits clean Open

María Genzer, P. Janhunen, Harri Haukka, Antti Kestilä, Maria Hieta , et al. · 2023

When a high-voltage charged tether is put into streaming space plasma, the tether’s electric field disturbs the flow of plasma ions and thereby taps momentum from the plasma flow [1-4]. The effect is called electrostatic Coulomb drag…

Cubesat experiments for Coulomb drag propulsion for interplanetary missions and space debris mitigation Open

Petri Toivanen, P. Janhunen, Jarmo Kivekäs, Sean Haslam, Jouni Polkko , et al. · 2022

<p>Two 3-unit cubesats, FORESAIL-1 and ESTCube-2 soon to be launched (2022), both accommodate an electrostatic tether that can be charged to a high voltage with respect to the ambient ionospheric plasma in low-Earth orbit. The high v…

Observations and simulations of northward IMF magnetotail structure Open

Laura Fryer, R. C. Fear, Imogen Gingell, John Coxon, Minna Palmroth , et al. · 2022

<p>We investigate the dynamic coupling between the solar wind and Earth’s magnetosphere during northward IMF conditions. The high latitude lobe regions of the magnetosphere during such conditions are generally characterised…

FORESAIL-1 and ESTCube-2 Cubesat experiments of Coulomb drag propulsion Open

P. Janhunen, Petri Toivanen, Jarmo Kivekäs, Matias Meskanen, Jouni Polkko · 2021

Coulomb drag propulsion taps momentum from a natural plasma stream to generate propellantless low-thrust propulsion for a spacecraft. The plasma is attached to by means of a long, thin, charged metallic tether. The tether's electrostatic f…

Verification of Tether Deployment System aboard CubeSat through Dynamics Simulations and Tests Open

Hiraku Sakamoto, Muhammad Rizwan Mughal, Andris Slavinskis, Jaan Praks, Petri Toivanen , et al. · 2021

This paper proposes a proper model selection strategies for the dynamic simulations of the tether deployment mission aboard a CubeSat. Space tether technology will enable innovative space missions in the near future. The Coulomb Drag Propu…

Aalto-1, multi-payload CubeSat: Design, integration and launch Open

Jaan Praks, Muhammad Rizwan Mughal, Rami Vainio, P. Janhunen, Jouni Envall , et al. · 2021

Aalto-1, multi-payload CubeSat: In-orbit results and lessons learned Open

Muhammad Rizwan Mughal, Jaan Praks, Rami Vainio, P. Janhunen, Jouni Envall , et al. · 2021

Terraforming the dwarf planet: Interconnected and growable Ceres megasatellite world Open

P. Janhunen · 2020

We analyse a megasatellite settlement built from Ceres materials in high Ceres orbit. Ceres is selected because it has nitrogen, which is necessary for an earthlike atmosphere. To have $1 g$ artificial gravity, spinning habitats are attach…

Aspects of nanospacecraft design for main-belt sailing voyage Open

Iaroslav Iakubivskyi, Laurynas Mačiulis, P. Janhunen, Janis Dalbins, Mart Noorma , et al. · 2020

Shielded dumbbell L5 settlement Open

P. Janhunen · 2020

We present a two-sphere dumbbell configuration of a rotating settlement at Earth-Moon L5. The two-sphere configuration is chosen to minimize the radiation shielding mass which dominates the mass budget. The settlement has max 20 mSv/year r…

Coulomb drag propulsion experiments of ESTCube-2 and FORESAIL-1 Open

Iaroslav Iakubivskyi, P. Janhunen, Jaan Praks, Viljo Allik, Kadri Bussov , et al. · 2019

Particle telescope aboard FORESAIL-1: Simulated performance Open

P. Oleynik, Rami Vainio, Hannu‐Pekka Hedman, Arttu Punkkinen, Risto Punkkinen , et al. · 2019

Control of habitat's carbon dioxide level by biomass burning Open

P. Janhunen · 2019

Consider a free-space settlement with a closed ecosystem. Controlling the habitat's carbon dioxide level is a nontrivial problem because the atmospheric carbon buffer per biosphere area is smaller than on Earth. Here we show that the probl…

Steam balloon concept for lifting rockets to launch altitude Open

P. Janhunen, Petri Toivanen, Kimmo Ruosteenoja · 2019

Launching orbital and suborbital rockets from a high altitude is beneficial because of e.g. nozzle optimisation and reduced drag. Aircraft and gas balloons have been used for the purpose. Here we present a concept where a balloon is filled…

Parallel grid library for rapid and flexible simulation development Open

Ilja Honkonen, Sebastian von Alfthan, A. Sandroos, P. Janhunen, Minna Palmroth · 2019

This program has been imported from the CPC Program Library held at Queen's University Belfast (1969-2018) Abstract We present an easy to use and flexible grid library for developing highly scalable parallel simulations. The distributed ca…

Natural illumination solution for rotating space settlements Open

P. Janhunen · 2018

Cylindrical kilometre-scale artificial gravity space settlements were proposed by Gerard O'Neill in the 1970s. The early concept had two oppositely rotating cylinders and moving mirrors to simulate the diurnal cycle. Later, the Kalpana One…

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