TECHNOLOGY AREA(S): Space Platforms
OBJECTIVE: Develop a self-contained device that can be deployed from a host satellite in proximity to an orbiting defunct rocket body, attach to or capture the rocket body, and cause sufficient increase in drag, using no power after deployment, to remove the rocket body from orbit.
DESCRIPTION: Rocket bodies from decades of launch of satellites into Earth orbit are the largest component of space debris by mass, and they may pose a significant present and future threat to operation of space systems in certain orbits. Most of these objects will remain in place for several more decades before they re-enter the Earth’s atmosphere and eventually burn up. Recognizing the broader challenges of space debris, multiple organizations have created concepts for mitigating that debris and de-orbiting space junk. The concepts include attaching propulsion modules, electrodynamic tethers, and drag enhancement devices including sails and balloons. The Air Force is interested in long term reduction in the number of large rocket bodies in low earth orbits, especially near-polar and sun synchronous orbits to help preserve and extend the effective use of space. A specific interest in this solicitation is in clearing critical orbits and accelerated de-orbiting through drag augmentation, and methods to attach such augmentation devices to resident space objects. A useful system would cause a rocket body to de-orbit at least ten times faster than the body would de-orbit without drag augmentation. As other space infrastructure matures, including rideshare launches, small satellites and space vehicle propulsion systems, the feasibility and affordability of such an approach to debris mitigation has increased. This research will focus on the final engagement with rocket bodies, and the attachment and deployment of drag-enhancing devices. The research can assume the existence of a satellite host vehicle, with sufficient propulsion and attitude control capability to enter and maintain a co-orbital trajectory with the target debris and an orientation that enables a precise release of the debris mitigation payload in the proximity of the target debris. The payload is assumed to passively rendezvous with the target debris, for example a rocket body, which may be tumbling. The payload must attach to or capture the rocket body and deploy a device of sufficient area and stiffness to enhance the drag of the coupled system, increasing the decay rate to accelerate re-entry of the system. The system must not create more debris, and must consider the potential fragility of target debris that have been exposed to the space environment for decades. A broader service may contain multiple copies of the debris mitigation payload carried by a delivery vehicle, and the design and concept of operation of this payload should allow several engagements with different rocket bodies as the maneuverable satellite host delivers a separate device to each of the bodies in turn.
PHASE I: Identify representative rocket bodies and determine their orbits, mass, volume, shape and rotation rates. Develop a satellite payload with low size, weight, and power that separates from a co-orbital satellite host at close proximity to the body, then attaches to or captures the body with low risk to the host and low probability of creating additional debris. Increase drag of the rocket body to alter its trajectory, causing it to de-orbit at >10X natural rates. The device must maintain structural integrity and minimize the creation of additional debris during the expected duration of the de-orbit.
PHASE II: Based on the Phase I effort, design and build a debris mitigation payload that can be integrated in a satellite host. Perform simulations to demonstrate the engagement with and capture of the candidate rocket body, deployment or engagement of the drag enhancement device, and the subsequent decrease in orbital lifetime of the rocket body. Perform a ground based hardware demonstration that supports feasibility of the design concept.
PHASE III: A number of commercial space ventures are exploring the use of massive (100s or 1000s of satellite) constellations in LEO to provide imaging and communications services. The availability of unpopulated orbits, with reduced probability of collision with resident rocket bodies and other debris, could make commercial debris mitigation services viable. Furthermore, these existing rocket bodies pose a potential for creating more debris in these orbits, which could make them unusable for government or commercial purposes, and the government may step in to help mitigate this danger with public-private partnership funding to clean up specific orbits. The device developed under this effort could be the key element of such a debris mitigation system, either commercial or government operated.
1: Liou, J.-C., Active Debris Removal – A Grand Engineering Challenge For The Twenty-First Century, AAS 11-254 Preprint, https://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/20110011986.pdf
2: Sorge, M.E, and G. Peterson, How to Clean Space: Disposal and Active Debris Removal, Aerospace Crosslink Magazine, Fall 2015
3: Kaplan, M H., Survey of Space Debris Reduction Methods, AIAA Proceedings, AIAA Space 2009 Conference & Exposition, Pasadena, California, 14-17 Sep 2009.
4: Forshaw, Jason L.; Massimiani, Chiara;Richter, Martin;Viquerat, Andrew; Simons, Ed, Surrey space centre: A survey of debris removal research activities, Proceedings of the International Astronautical Congress, Vol 4, 2015-01-01
KEYWORDS: Space Debris, Debris Mitigation, Grapple Mechanism, Attachment Mechanism, Passive De-orbit, Orbital Drag