LARAMOTIONS: a conceptual study on laser networks for near-term collision avoidance for space debris in the low Earth orbit

Abstract

A conceptual study has been carried out on laser station networks to enhance Space Situational Awareness and contribute to collision avoidance in the low Earth orbit by high-precision laser tracking of debris objects and momentum transfer via photon pressure from ground-based high-power lasers. Depending on the network size, geographical distribution of stations, orbit parameters, and remaining time to conjunction, multipass irradiation enhances the efficiency of photon momentum coupling by 1–2 orders of magnitude and has the potential to eventually yield a promisingly significant reduction of the collision rate in low Earth orbit.

Can the Orbital Debris Disease Be Cured Using Lasers?

“…For the beam transmission, we assumed an optical aperture with a diameter of D T = 4 m and an initial radius of the effective laser beam of w 0 = 0.715•D T /2, which corresponds to a 2% power loss at the transmitter from intensity clipping at the aperture edge. The ground station was anticipated to be operated in junction with an optical system for target acquisition and continuous laser tracking of the debris object during its station pass, exhibiting a low tracking uncertainty of σ t = 0.1 arcsec enabled by adaptive optics and laser guide star (LGS) usage in the downlink from the object [22]. This allows for the needed high-precision pointing of the high-energy laser beam while the real-time data from ranging can be used to dynamically adapt the focus length of the transmitter to achieve a focus of the beam at the actual range of the debris object throughout the entire pass.…”

Laserbehandlung gegen Weltraumschrott

“…Genauere Bahndaten lassen sich sehr präzise durch Laser‐Laufzeitmessungen (Laser Ranging) ermitteln. Während auf diese Weise metergenaue Messungen der Objektpositionen möglich sind, steigt die Vorhersageunsicherheit für den weiteren Bahnverlauf nach einer Messung aufgrund der unterschiedlichen Einflüsse schnell wieder an [6].…”

“…In einer Studie für die ESA wurde am DLR zusammen mit Kooperationspartnern aus Forschung und Industrie untersucht, wie eine solche Art der Kollisionsvermeidung praktisch aussehen könnte. Ergebnis war ein globales Netzwerk aus mindestens zehn hybriden Bodenstationen, die in absehbarer Zeit dazu in der Lage sein könnten, mit kommerziell verfügbaren Lasern einer Leistung von 40 kW Photonendruck auf Schrottobjekte auszuüben [6]. Zudem würden die Stationen über leistungsstarke gepulste Lasersysteme (50 W im zeitlichen Mittel) verfügen, um rund um die Uhr hochpräzise Laser‐Laufzeitmessungen zu potenziell gefährlichen, auch kleineren, Schrottobjekten durchzuführen.…”

Impact of material and surface properties on thermo-mechanical coupling in laser-based orbit modification of space debris

“…In the UNU report, risk mitigation strategies are categorized and assessed introducing a new metric of four different mitigation features: avoid, adapt, delay, and transform. All these strategies can already be found in space operations: Regulations like the 25-year deadline for post-mission disposal of satellites [5] aim to avoid the creation of new space debris, laser-based collision avoidance for space debris objects focuses on the delay of the Kessler syndrome [6], the exploration of very low Earth orbits (below 450 km altitude) [7] constitutes an adaptation to the possible future down state of the currently highly frequented orbits, and efforts for space debris removal from orbit aim to transform the situation in the near orbital environment.…”