About this Research Topic
Spacecraft flying in Low Earth Orbit (LEO) include, but are not limited to, the International Space Station (ISS), past missions from the Space Transportation System (STS or Space Shuttle), the majority of nanosatellites and picosatellites and most scientific satellites (SEE http://earthobservatory.nasa.gov/Features/OrbitsCatalog/page2.php), and all vehicles and debris projected to be de-orbited. Placing spacecraft in LEO requires less energy than higher orbits, allows observation of Earth, and allows the ground track to cover more locations than a geosynchronous orbit.
Because spacecraft are generally placed in LEO, it is vital to coordinate their relative motion to avoid collisions. Much debris already exists in LEO, and inter-collisions can produce further debris, known as Kessler Syndrome, which may render LEO too hazardous for spacecraft. Additionally, constellations of spacecraft can be used to visualize the entire Earth. Precise formation flight is necessary to maintain the desired separation and relative locations.
Much previous work has been performed on using differential drag techniques to control the relative motion between spacecraft by varying the ballistic coefficient. Additionally, work has also been done in controlled re-entry of spacecraft, with the goal of either landing in a controlled location, or recovering the spacecraft after landing.
Characterization of atmospheric density is key to drag-based maneuvering and controlled re-entry of spacecraft. Additionally, the concepts involved can be extended to interplanetary missions, where the same principles can be applied to any space body with a sufficiently dense atmosphere.
We welcome submissions of articles presenting original research, review, mission and spacecraft description, or techniques and procedures, based on:
1) spacecraft formation flight in LEO,
2) controlled de-orbit and re-entry of spacecraft,
3) modeling and forecast of LEO atmosphere,
4) differential drag-based formation flight, and 5) clearing of LEO debris.
Important Note: All contributions to this Research Topic must be within the scope of the section and journal to which they are submitted, as defined in their mission statements. Frontiers reserves the right to guide an out-of-scope manuscript to a more suitable section or journal at any stage of peer review.