Debris removal spacecraft

Abstract

The core of this invention is the introduction of a third object (or objects) launched from a servicing spacecraft. The third object, which may be a simple, disposable device, must simultaneously perform two functions: deceleration and capture. The third object is launched from a distance greater than the size of the target debris object. This is not simply a combination of two functions, but something that would not normally be thought of. A simple combination of two existing functions would never solve the technical challenges that this invention overcomes. Instead, this invention realizes non-contact, multiple space debris removal using microsatellites to nanosatellites, a method that has never been conceived before.

Description

[Technical Field]

[0001] The present invention relates to a spacecraft that removes debris from a flying orbit in order to safely utilize low earth orbital space and to shorten the orbital life and decay period.

[0002] The content is characterized by the phrase "non-contact and multiple space debris removal using microsatellites to nanosatellites." The increasing number of launched and abandoned spacecraft has raised the issue of space debris, threatening the use of low Earth orbit.

[0003] A large number of research and patents have been proposed and published in debris removal, which envision a servicing spacecraft built to access a target debris object. The servicing spacecraft must be sophisticated enough to automatically access the target debris object while actively and accurately representing its attitude and translational motion relative to the target debris object.

[0004] The present invention proposes the idea of ​​using one or more simple, disposable torpedo-like third objects in addition to a first object (servicing spacecraft) and a second object (target debris object). The third objects are released from the first object at a distance greater than the size of the second object when the first object reaches the target debris object. The present invention also proposes a method and system for launching one or more third objects from the first object. The present invention requires that the third object simultaneously carry both a projectile-type capture device and an inflatable or extendable atmospheric drag deceleration device. This invention thus solves many technical problems in debris removal.

[0005] This invention makes it possible to remove multiple debris particles from microsatellites to nanosatellites without contact in a single flight. [Background technology]

[0006] Debris removal has been a comprehensive issue for decades. As stipulated by international regulations, the threat of orbital debris objects must be eliminated. The presence of orbital debris objects literally poses a threat to the shared low Earth orbit space. Furthermore, anti-satellite weapons can create anomalous debris objects that can disrupt the peaceful use of the region. Therefore, debris removal is an urgent task for society.

[0007] Many studies and patents have been proposed and published in the field of debris removal. The casting of nets to capture debris objects is well known and not new. They are commercially available as gun nets or net guns (hereafter referred to as "cast nets"). Figure 1 shows a typical scenario using a net cast from a servicing spacecraft, which utilizes a propulsion system to decelerate and deorbit the target debris object. In a typical conventional scenario, a propulsion system is used to deorbit the target debris object.

[0008] Debris removal by atmospheric drag deceleration is also well known and not new. It precludes the use of a propulsion system. This is represented, for example, by an inflatable ballute device, an inflated balloon, or a stretchable membrane. Figure 2 shows a schematic of a ballute strategy. A servicing spacecraft accesses the target debris object and, if necessary, equips the ballute to the target debris object via an attachment. Historically, NASA's Echo satellite was built and launched as a ballute, an inflated balloon, by NASA back in the 1960s.

[0009] Therefore, combining the two types of devices is an automatic idea that a skilled and experienced engineer can easily come up with. Attaching the two types of devices to a target debris object through direct contact manipulation by a servicing spacecraft is an automatic idea. There is nothing new about this. However, such a simple combination does not solve the problems pointed out in this description, and does not provide the capability of the present invention to remove multiple pieces of space debris in a non-contact manner using micro- to nano-scale servicing satellites.

[0010] The novelty of the present invention is the use of one or more simple, disposable third objects(s) that are released from the servicing spacecraft at a distance greater than the size of the target debris object, thereby providing a solution to the technical problem pointed out by the present invention in this description regarding debris removal.

[0011] [Non-Patent Document 1] describes some of the current status regarding debris removal. The article is titled "Removing Space Junk Is Not Going Well." The article states that "Despite the demonstration of promising technologies, there is no silver bullet solution to the growing problem of removing orbital debris."

[0012] There are numerous studies, patents and research on atmospheric drag moderators.

[0013] [Patent Document 1] proposes the use of an atmospheric drag deceleration device, such as a balloon, which is an inflatable device. However, [Patent Document 1] does not combine this with the use of a projected net to capture the target debris object. Furthermore, it does not consider the use of a third object, a disposal device with two simultaneous functions, as claimed in this invention.

[0014] [Patent Document 2] only relates to the restraint scheme. It deals only with the fastening mechanism and has nothing to do with the non-contact feature claimed in the present invention. This document does not mention the use of a third object with a projectile capture device and a resistive deceleration device.

[0015] There have also been numerous studies and investigations into the capture of space debris objects with projected nets. This is a very obvious and straightforward approach and many published reports have been published. However, capture alone does not provide a practical solution to the technical problems of debris removal that this invention addresses.

[0016] [Non-Patent Document 2] is a study on the use of guns, but does not address the use of nets projected to capture debris objects.

[0017] [Non-Patent Document 3] is a study on the use of tethered nets. However, it does not mention the "untethered" method proposed by the present invention. The "untethered" method means that the net is not projected from a first object, which is a servicing spacecraft, as claimed in the present invention, but from a third object launched from the first object.

[0018] [Non-Patent Document 4] and [Non-Patent Document 5] study scenarios up to capture by a projected net, but do not provide a deorbit strategy for the target debris object.

[0019] [Non-Patent Document 6] deals with a completely different removal scheme, the electromagnetic approach, but this adds further complexity and is not practical.

[0020] As a result, combining these two devices or functions in a debris removal application seems almost automatic and a scheme that a skilled and experienced engineer would easily come up with. However, this still requires the servicing spacecraft to make difficult and direct contact with the target debris object, and does not solve the problem presented in this description. The present invention presents a solution.

[0021] The idea of ​​using one or more simple, disposable third objects that simultaneously carry both devices is not simple. The idea is small but revolutionary. Summary of the Invention [Problem to be solved by the invention]

[0022] There are four major problems with existing debris removal methods. First, advanced technology is assumed and considered unavoidable. Second, contact reaction forces and torques are considered unavoidable. Third, the consumption of large amounts of propellant and fuel is considered unavoidable. Fourth, an increase in the cost of debris removal is assumed unavoidable, since expensive bus systems must be disposed of one by one each time debris is removed.

[0023] refinement

[0024] In most cases, the servicing spacecraft will need to be highly sophisticated in order to access the target debris object.

[0025] This requires that the servicing spacecraft have sophisticated, precise, and accurate attitude and translation representation and management capabilities.

[0026] Accessing non-cooperative targets is the subject of research and may not be very realistic or practical in real-world flight applications except in the most simplistic configurations, geometries, or laboratory demonstrations.

[0027] Additionally, small satellites do not appear to be capable of providing such performance and capabilities, making them unsuitable for debris removal.

[0028] Contact Reaction Force and Torque

[0029] Existing concepts assume that the servicing vehicle must be firmly bound or tethered to the target debris object. Binding necessarily involves reaction forces and torques on the servicing vehicle. If the binding fails, the contact forces in turn stimulate the movement of the target debris object, making subsequent binding attempts much more difficult. The servicing vehicle must also be strong enough to withstand the contact reaction forces.

[0030] Propellant, fuel consumption

[0031] There are two types of deceleration methods. One is to propel the target debris object along with the servicing spacecraft itself. The other is to increase the drag deceleration or reduce the ballistic coefficient of the target debris object. If the servicing spacecraft performs the removal by propulsion, it must carry a large amount of propellant. As a result, the size of the servicing spacecraft tends to be comparable to or larger than the target debris object it is removing.

[0032] Debris removal is not really designed for debris objects larger than the servicing spacecraft, which makes the cost of debris removal services prohibitively high, and the servicing spacecraft cannot remove multiple debris objects in one flight. Also, small satellites are not considered suitable for debris removal.

[0033] Cost increase

[0034] The most costly part of a spacecraft system is the development of a bus system, including attitude and orbit control and propulsion systems. Current methods require the consumption of a bus system each time a debris object is removed. This increases the removal cost. If a servicing spacecraft carries a large amount of propellant, multiple removals can be performed with one bus system. However, this further increases the removal cost, and the servicing spacecraft becomes increasingly larger. The corresponding bus system becomes expensive.

[0035] Current solutions lack low cost, small size, non-contact, and multiple removal capabilities. Low cost and small size limit and restrict sophistication. Non-contact, while desirable, has never been conceived for debris removal. Multiple removal capabilities are limited both by the amount of propellant and fuel on board and the increased costs mentioned above. [Means for solving the problem]

[0036] The solution is to use one or more third objects, each carrying both one or more atmospheric drag deceleration devices and one or more projectile-type capture devices, which are projected and launched from the first object, the servicing spacecraft. Figure 3 shows a schematic diagram of the third object being launched from the first object, the servicing spacecraft, toward the target debris object.

[0037] The present invention solves the above four major problems and provides a debris removal spacecraft system and method that is low-cost, small-sized, non-contact, and can simultaneously achieve multiple removal functions.

[0038] The following is an example of a process sequence provided by the present invention.

[0039] Once released, the third object projects one or more nets toward the target debris object to capture it, as shown in Figure 4. The third object then begins expanding the ballute using the inflation gas carried by the third object, as shown in Figure 5. This sequence does not require advanced functionality or capabilities. Once captured by the projected net and decelerated by the ballute, the target debris object's trajectory begins to rapidly reduce its orbital lifetime. The third object can be constructed small enough so as not to increase the mass and volume of the decelerating complex. The target debris object and the third object constitute the complex.

[0040] The idea underlying this invention is not easy to come up with. It is not an automatic solution. Simply put, past and current concepts always assume only two objects, two actors: one is the servicing spacecraft, and the other is the target debris object. While this is implicit and comprehensive, it leaves behind the difficulties associated with the aforementioned issues and is rarely applicable to practical, commercial debris removal services. These concepts lack the use of a third object (or objects) launched from a distance greater than the size of the second object (the target debris object) from the first object (the servicing spacecraft).

[0041] Definition of first and third bodies The present invention defines a third object as a spacecraft or object that is separated or released from a first object, which is a servicing spacecraft.

[0042] This is defined regardless of instrumentation or sophistication. Even third-party objects may be equipped with active attitude control and / or propulsion, but such configurations are complex and therefore practically useless.

[0043] A servicing vehicle (here, the first object) is defined as a spacecraft, with or without propulsion, that, once in orbit, actively approaches a target debris object. In some cases, the servicing vehicle may be guided to the target debris object using atmospheric drag. A spacecraft that is released from a so-called dispenser and actively approaches a target debris object is considered a third object as described in this invention. However, a spacecraft that is released from a dispenser but does not actively approach a target debris object is outside the scope of the third object referred to in this invention. This invention requires the presence of a first object.

[0044] This invention does not claim any configuration in which the servicing spacecraft itself projects the net by attaching one end of the tether to itself, without using a third object(s), and the servicing spacecraft itself inflates the ballute on board. Such a configuration would require a huge ballute to decelerate the target debris object together with the servicing spacecraft. This is not an efficient method and is outside the scope of this invention.

[0045] The configuration claimed by this invention refers to a third object that simultaneously carries a projectile-type capture device and a deployable drag deceleration device. If the third object only carries a projectile-type capture device and does not carry a deployable drag deceleration device, such a configuration is outside the scope of the invention. If the third object only carries a deployable drag deceleration device and does not carry a projectile-type capture device, such a configuration is also outside the scope of the invention. [Effects of the Invention]

[0046] "Non-contact" in this context does not mean the use of lasers or radio waves. "Mechanical but non-contact" opens the door to a new era of sustainability in low-Earth orbit space. Furthermore, this invention does not create any new debris objects. A projection-type capture device on a third object, launched from a first object, the servicing spacecraft, achieves non-contact capture of the first object. Such capture does not require extraordinary attitude and translational precision. This relaxes the requirements for high attitude and translational control, and does not require sophisticated capabilities from the servicing spacecraft. Furthermore, the servicing spacecraft can avoid contact reaction forces and torques. Furthermore, by utilizing a resistive deceleration device to shorten the life of the debris object, significant propellant and fuel consumption is eliminated. The servicing spacecraft can be constructed very compactly, significantly reducing the construction costs of the servicing spacecraft and debris removal system. The advantage of this invention is that all four major technical problems associated with debris removal are avoided. The significance of this invention is that it allows multiple debris to be removed during a single flight. This is primarily due to the non-contact nature of this invention, allowing the servicing vehicle to be reused without sacrificing itself or experiencing significant loss or damage to its functionality. Existing strategies require a servicing vehicle for each debris removal.

[0047] When the method invented here is used for active debris removal, there is no need to equip a large propulsion system, and debris removal services can be provided by micro to nano satellites. These satellites can carry multiple third objects, multiple projectiles, and provide debris removal services to multiple target debris objects during a single flight. Without this invention, current solutions would not be able to offer these benefits. This will significantly reduce debris removal costs, allowing even start-up companies to start debris removal services.

[0048] The key issue is the peaceful and sustainable use of low-earth orbital space. In some situations, enemy satellites may be shot down, raising concerns about the availability of low-earth orbital space. If the invented methods and means are made public, all countries will know about them. This invention will deter any country from shooting down satellites by ballistic, mechanical, or destructive means. This will contribute to the sustainable use of low-earth orbital space. Furthermore, the invented method will mitigate and eliminate the buildup of orbital debris.

[0049] The global debris removal business could change dramatically, with existing debris removal demonstrations being replaced by this method, which is beneficial for space-faring nations. Debris removal services are now entering the realm of small micro- to nano-satellites with a small investment, which could attract global interest. [Brief explanation of the drawings]

[0050] In the drawings, the following symbols are defined to represent the debris removal system described in this invention: 100 Debris Removal Service Spacecraft, First Object 110 Propulsion Systems onboard Service Spacecraft 120 Tethers connecting the net to either a servicing spacecraft, a target debris object, or a third object. 130 The second object is a net that is projected to capture the target debris object. The net may be projected from either the servicing spacecraft or a third object. 131 Tip mass at the end of the net for pulling out the net and closing the net 140 Atmospheric resistance decelerator, Ballut. The device may be inflated while in communication with either the servicing spacecraft, the target debris object, or a third object. 150 Attachment between the ballut and the target debris object, a second object. The other end of the device can be coupled to a target, either a debris object, a third object, or a net. 160 Fixture, a handler on a servicing spacecraft, which equips the attachment coupled with the ballutt to the target debris object. 200 A third object, a torpedo-like projectile launched from the servicing spacecraft, simultaneously carrying one or more nets, a projectile-type capture device, and one or more atmospheric drag deceleration devices. 300. A debris object that is the target. A second object that is captured and decelerated.

[0051] [Figure 1] Existing debris removal strategies use both projected nets and propulsion systems onboard servicing spacecraft. [Figure 2] Existing debris removal strategies use both target debris objects and coupled ballots operated by servicing spacecraft. [Figure 3] Release of a third object from the servicing spacecraft to the target debris object [Figure 4]A debris object that is a target caught in a net projected from a third object [Figure 5] A ballot inflated by a third object while the target debris object was caught in a projected net. [Figure 6] 3U Nanosatellite Demo Sequence: Ballut Retraction, Capture, and Inflation (Left to Right) DETAILED DESCRIPTION OF THE INVENTION [Example]

[0052] The Echo satellite flew for about 8 years, starting from an altitude of 1000 km. Using the Echo parameters, we estimate a preliminary typical ballute size for deorbiting a satellite debris object with a dry mass of 100 kg. We conclude that the diameter of the sphere is 5 m (65.5 m in volume). 3 , cross-sectional area is 20m 2 ). The thickness of the aluminized Mylar film is assumed to be 5 microns, giving the sphere a mass of 534 grams, ideally occupying 0.4 liters. Assuming the same liquefied gas as Echo 1, the gas mass is 639 g (3.57 mol). Both the sphere and the liquefied gas fit comfortably within a cube of about 1 liter. A 12U class satellite can carry two or more sets of ballistic devices per flight.

[0053] The fuel consumption estimates here are for a 100 kg servicing vehicle deorbiting a 100 kg dry mass class target debris object, assuming a specific impulse (Isp) of 300 seconds. In reality, the mass required for a servicing vehicle may be much heavier.

[0054] The orbital decay period corresponds to the orbital lifetime. Ballistic coefficient 100 (kg / m 2For a conventional satellite with a solar flux of F10.7 of 150 SFU, starting from an altitude of 600 km, the decay period is 15 years and the thrust removal to deorbit is approximately 11 kg or more. For a departure from an altitude of 750 km, the decay period is 100 years and the thrust removal to deorbit is approximately 17 kg or more.

[0055] On the other hand, if the ballistic coefficient is 5 (kg / m 2 ), a ballute equipped debris object with solar radiation F10.7 of 150 SFU would decay in just 0.75 years without fuel consumption if launched from an altitude of 600 km, and only 5 years without fuel consumption if launched from an altitude of 750 km.

[0056] Aerodynamic damping can cause spacecraft to stay too long near the altitude of the International Space Station (ISS). This may sound like a risk, but it is actually not that significant. Near the ISS altitude (400 km), natural debris has a ballistic coefficient of 100 (kg / m) within a 10 km corridor around the ISS altitude. 2 ) for one month, but the ballistic coefficient is reduced to 5 (kg / m 2 ), the stay period will be shortened to 1.5 days. By monitoring debris above the ISS altitude, safety management will be thorough. [Example]

[0057] Here, we present an example of evaluating the rendezvous and access capabilities to the target debris object. The servicing spacecraft approaches the target satellite using its own propulsion unit. Meeting the target satellite is key to the debris removal mission. Typical modern launch vehicles can accurately inject the debris removal and servicing spacecraft into their designated orbits. Eccentricity, or altitude control of 20 km, requires a delta-V (velocity correction) of approximately 10 m / s. Correcting a typical tilt variance of 0.1 degrees, or out-of-plane variance, requires a delta-V of approximately 10 m / s. A 20 km altitude change controls the ascending node longitude by approximately 0.01 degrees per day. Therefore, a typical variance of 0.2 degrees is corrected over 20 days by the aforementioned delta-V of 10 m / s. This means that the delta-V required to perform an approach to a single target debris object is approximately 30 m / s. This indicates that even a cold gas jet thruster with a very modest Isp of 30 seconds can be served by 10% of the servicing spacecraft's propellant mass per debris removal.

[0058] Here, we assume that each target debris object weighs 100 kg dry mass. Below is an outline of a typical 12U, 12-liter class debris removal service spacecraft. This spacecraft carries two sets of torpedo-like projectiles and a third object, occupying a volume of approximately 4U (2x2U), or about 4 liters. Each weighs 1.7 kg, consisting of 0.55 kg of ballute, 0.65 kg of expansion gas, and 0.5 kg of associated mechanics. The size of the ballute is determined by its cross-sectional area; here, the diameter is 5 m.

[0059] The servicing spacecraft will be equipped with modest cold-gas thrusters using liquefied gas propellant. The assumed ISP is very modest, at 30 seconds. The total mass of the 12U servicing spacecraft is approximately 18.5 kg. This size is suitable for startups and universities. The spacecraft will carry two sets of net projectors, each weighing 1.7 kg and fitting into a 1U, 1-liter volume. The spacecraft will carry 3.7 kg of cold-gas liquid propellant and 1.5 kg of associated mechanics. This will occupy a 2U, 2-liter cube. The total mass of the spacecraft will be 18.5 kg, including a 6U, 6-liter, 6-kg satellite bus system. The 6U, 6-liter bus system includes an atmospheric drag deceleration device and a ballut module for disposal of the servicing spacecraft itself, occupying a 1U, 1-liter volume. [Example]

[0060] The first demonstration can also be performed on a smaller 3U, 3L-class satellite. Despite its small size, it can carry a 2U, 2L-class torpedo-like projectile, as assumed for the 12U, 12L debris removal service vehicle in Example 2. The demonstration does not require a separate artificial target debris object. A 1U, 1L-sized hub module can serve the dual roles of service vehicle and target debris object. The demonstrator itself is decelerated by a ballut and deorbits under its own power. As shown in Figure 6, the 3U, 3L demonstrator detaches a 2U, 2L-sized third object, leaving a 1U, 1L-sized cube-shaped hub portion in orbit. The hub portion transforms into a virtual debris object to be captured. The third object casts a net toward the dummy debris object, the hub, and captures it. The third object then inflates the onboard ballut. This is a very simple and affordable demonstration that can be carried out even at a university level. The demonstration requires no propulsion system or fuel. [Example]

[0061] Any kind of resistive deceleration device and any kind of capture device do not affect the core of the invention.

[0062] The resistive moderator need not be a balloon, but could be a membrane, film, kite, etc. Any deployable, inflatable, or stretchable device is encompassed by and compatible with the present invention. Some weight is required, especially with respect to the gas produced by vaporization for inflation. The balloon need not be a simple single-layer balloon; the gas-filled section can be multi-layered or stretched with expandable ribs to conserve gas mass. A double-layer gas-filled spherical shell with expandable ribs is one example. Rapidly curing gases are also an option. The gas can be made of a material that cures under elevated temperatures, such as ultraviolet light or sunlight. The balloon material can also be self-curing without a gas. Any type of resistive moderator is suitable for the present invention.

[0063] Any selection of a projection-type capture device also fits within the core of the present invention. It is not necessary for a net to be projected. Any tether with a specific hook at the end also fits within the present invention. Adhesives, magnets, wraps, etc. also fit within the present invention as long as they are projected without contact from a third object. This is because this process is contactless with respect to the servicing spacecraft, i.e., the first object. [Industrial Applicability]

[0064] Even micro to nano satellites can carry multiple launch vehicles and third objects, allowing them to provide debris removal services to multiple target debris objects during a single flight. This invention will significantly reduce debris removal costs. Even start-up companies can start providing debris removal services.

[0065] The global debris removal business could change dramatically, with existing debris removal demonstrations being replaced by this invented method, a win-win for space-faring nations. Debris removal services are now entering the small, micro-to-nano satellite space with a small investment, potentially attracting global attention. [Prior art documents] [Patent documents]

[0066] [Patent Document 1] US patent 06830222 [Patent Document 2] US patent 20140042275 A1 [Non-patent literature]

[0067] [Non-Patent Document 1] Space Junk Net Successfully Completes Capture Test (https: / / www.popularmechanics.com / space / satellites / a23335998 / space-junk-net-successfully-completes-capture-test / ) [Non-patent document 2] Shankar Bhattarai and Jie-Rou Shang, Space Debris Removal Mechanism Using CubeSat with Gun Shot Facilities, American Journal of Applied Sciences, 2018, 15 (9): 456.463, DOI: 10.3844 / ajassp.2018.456.463 [Non-patent document 3] Michele Lavagna, et. Al., Debris removal mechanism based on tethered nets, Conference: International Symposium on Artificial Intelligence, Robotics and Automation in Space (iSAIRAS 2012), https: / / www.researchgate.net / publication / 299447996 [Non-patent document 4] Umberto Battista, et. Al. DESIGN OF NET EJECTOR FOR SPACE DEBRIS CAPTURING, Proc. 7th European Conference on Space Debris, Darmstadt, Germany, April 2017, published by the ESA Space Debris Office, Ed. T. Flohrer & F. Schmitz, (http: / / spacedebris2017.sdo.esoc.esa.int, June 2017) [Non-patent document 5] David Szondy, ESA's potential space garbage collector nets itself a drone, (https: / / newatlas.com / esa-drone-net-capture / 43777 / ) [Non-patent document 6] Chongyuan Hou, et. Al., Electromagnetic-launch-based method for cost-efficient space debris removal, https: / / doi.org / 10.1515 / astro-2020-0016, Received May 29, 2020; accepted Jul 03, 2020 [Non-Patent Document 7] Staugaitis, C. & Kobren, L. "Mechanical And Physical Properties of the Echo II Metal-Polymer Laminate (NASA TN D-3409)", NASA Goddard Space Flight Center (1966)

Claims

1. a servicing spacecraft, which is a first object, that controls relative motion between the first object and a second object, the debris object, to actively approach the second object; a third object that is initially held by and released from the first object, and that is not equipped with a direct contact capture device [0020] nor with sophisticated, precise and accurate attitude and translation control capabilities [0025], but is equipped with a projectile capture device and a deployable atmospheric drag deceleration device [0036], and that moves away from the first object while remaining in a state of non-contact with the second object without tethering the first object [0017]; a capture device that is projected from the third object to the second object after the third object is released from the first object for the purpose of restraining the third object to the second object, the capture device being tethered only to the third object; an atmospheric drag deceleration device deployed after the third body is tethered to the second body to act on the composite of the second body and the third body to increase aerodynamic drag deceleration so as to reduce the orbital lifetime of the composite; A spacecraft system that aims to shorten the orbital lifetime of orbital space debris objects.

2. 10. The spacecraft system of claim 1, wherein the capture device is a net released from one or more of the third bodies having one or more tip masses.

3. 3. The spacecraft system according to claim 1, wherein the atmospheric drag deceleration device is one or more expansion-type devices coupled to or placed on the third object.

4. The spacecraft system according to claim 1 , wherein a plurality of the third objects are released from the first object toward the second object.

5. The spacecraft system according to claim 1 , wherein the number of the second objects is plural.

6. (A) actively bringing a servicing spacecraft, which is a first object, close to a second object, which is the debris object, by controlling the relative motion between the first object and the second object; (B) a third object is initially held by and released from the first object, not equipped with sophisticated, precise and accurate attitude and translation control capabilities [0025] nor with a direct contact capture device [0020], but equipped with a projectile capture device and a deployable atmospheric drag deceleration device [0036], and leaving the first object without tethering the first object [0017] and while remaining out of contact with the second object; (C) projecting a capture device, which is tethered only to the third object, from the third object to the second object after the third object is released from the first object for the purpose of restraining the third object to the second object; (D) deploying an atmospheric drag deceleration device after the third object is tethered to the second object to increase aerodynamic drag deceleration on the second object and the third object to reduce the orbital lifetime of the composite. A method for reducing the orbital lifetime of an orbital space debris object, comprising:

Images