How do you clean up 170 million pieces of space junk?
In March, NASA released the most comprehensivefinancial analysis on space debris. For the first time, this report illuminates the financial costs and benefits of various paths forward to combat one of the fastest-growing dangers in Earth’s orbit.
With increased activity in space, debris is a growing threat to Low Earth Orbit (LEO), the most accessible area of space. There may be as many as170millionpieces of debrisin orbit, with the vast majority too small to track due to limits in current technology, but no less dangerous. Of the55,000 pieces我们可以跟踪的碎屑，有27,000多个物体，例如用过的火箭助推器，活跃的卫星和死卫星，都受到监视Department of Defense’s global Space Surveillance Network (SSN).
由于物体在狮子座中移动的速度（大约17,000英里 /小时), the impact of even a small object, like a乒乓球, can cause significant damage or completely shatter existing infrastructure, producing more fragments of trackable and detectable size. Twice in the last month, theInternational Space Station had to perform maneuvers躲避碰撞。除了立即的狮子座拥塞外，凯斯勒综合症,当前碎片创建一个成长和self-replicating cascade of orbital junk, is also a growing possibility. Political leaders have begun to pay attention: Sen. John Hickenlooper (D-CO)–one of the leaders in Congresson this issue–has said “Because of the threats from debris already in orbit, simply preventing more debris in the future is not enough.”
Technological efforts to limit debris include making reusable rockets and maneuverable satellites. Certain satellites can adjust their position through a satellite operator, a person or entity that manages a satellite. For example, the International Space Station performed what is called anin-orbit maneuverto dodge debris. To meet the needs of clean-up, industries have developed debris-cleaning tech like ground laser nudges, space tugs, and space lasers. Policy has not随着快速增长的步伐of the emerging commercial space industries. Industries are also hesitant to use and effectively implement new technologies because costs have been uncertain.
There has never been a comprehensive cost-benefit analysis of debris clean-up (remediation) methods despite robust data on the number of objects in space being available. This new NASA analysis provides the cost of tech and the time to recover the costs, giving industries a better idea of how to implement new technologies effectively.
为了创建报告，NASA科学家创建了一个模型，该模型根据符合清理成本所需的时间以及所使用的清理方法来指定对卫星运营商施加的经济风险碎片。然后，科学家将模型应用于两种情况：优先考虑大量碎片分解和清除碎片（又称空间中最大，最容易受到关注的物体），并瞄准去除小碎屑（消除了100,000块碎屑，从1-10厘米的1-10 cm In In In In In尺寸）。
度均nt Methods of Debris Management Technology
|碎片管理方法||Application to Debris Size||Description||估计成本（低）||估计成本（高）||Development Costs|
|拖船进行控制的再入||大（≥10厘米）||捕获一个物体并调节其轨道，以便以特定角度重新进入大气，以使浓缩区域中的碎屑崩溃。||~$4,000 per kilogram||~$60,000 per kilogram||n/a|
|拖船进行不受控制的再入||Large (≥10 cm)||Catch an object and adjust its orbit so it re-enters the atmosphere freely with no predesignated fall area and unclear reentry timing.||〜每公斤$ 3,000||~$40,000 per kilogram||n/a|
|Ground Laser Nudges||Large (≥10 cm), Small debris (1 cm–10 cm)||Uses a laser to move an object without physical contact from the surface of the Earth. Requires a lot of energy.||~$300 per kilogram||~$6,000 per kilogram||~$600 million|
|太空激光轻推||Large (≥10 cm), Small debris (1 cm–10 cm)||Uses a laser to move an object without physical contact from space. Uses less energy from ground-based lasers since much of the energy won’t be lost going through the atmosphere.||~$300 per kilogram||〜每公斤$ 3,000||〜3亿美元|
|通过激光轻推（JCA）的及时碰撞（JCA）||Large (≥10 cm)||Used to prevent predicted collisions between large pieces of orbital debris, like satellites and debris by informing laser nudges.||100千克对象的$ 6介于每辆车上的9,000千克对象$ 500||100千克对象的$ 700之间 - $ 60,000-每一个机动的9,000千克对象||n/a|
|Just-in-time collision avoidance (JCA) via Rapid Response Rockets||Large (≥10 cm)||Used to prevent predicted collisions between large pieces of orbital debris, like satellites and debris by informing Rapid Response Rockets(RRR). These rockets would meet with specific debris and alter the target debris’ orbit.||$30 million per nudge||$60 million per nudge||n/a|
|Physical Sweeping||Large (≥10 cm), Small debris (1 cm–10 cm)||直接影响碎屑移动或搬迁。||$90,000 per kilogram||每公斤900,000美元||$90,000 million|
|回收碎片||Large (≥10 cm)||Gathering and processing debris and processing it in space to use as fuel or other utilities.||~$1.4 billion at 15,000/kg||n/a||n/a|
Even though it is initially expensive, removing small debris would produce a net benefit in under a decade:
NASA的模型表明，除去不可痕迹的碎片的碎片清除工作可以立即带来好处。对于可追踪的碎片，弥补初始成本只需3 - 4年。
Finding 2. Spacecraft operators can recover the initial upfront cost quickly using reusable technologies that clean up debris using controlled and uncontrolled reentry.
For the 50 largest objects in space, which can be effectively removed using controlled re-entry, especially when done using reusable vehicles, cost recovery would be seen in around three decades.
Finding 3. Recycling space debris does not provide overwhelmingly clear enough financial benefits over other debris cleanup methods.
While there are potential economic and climate benefits to recycling space debris, recycling in space reduces the risk of有害化学物质being released into the upper atmosphere as it burns upon reentry and limits the amount of debris remnants in the upper atmosphere.
Investing in debris recycling facilities has a large upfront cost, and it is not guaranteed that a market for such facilities will emerge in the next decade. This makes projections for the value of recycling uncertain. The report indicates, however, that debris recycling is a potential solution to long-term efforts of debris management. This can be done throughin-space manufacturing and assembly(ISAM), a practice that involves factories and utility services in space and covers servicing, assembly, and manufacturing. These facilities can be used to收集并回收数十亿美元价值空间碎片的美元，并帮助创建“圆形空间经济”使用现有碎片处理，回收，建造和加油空间基础设施。
我们的想法已经有助于解决空间碎片。第一天项目贡献者林德西·格雷（Lyndsey Gray）outlined five policy solutions to space debris remediation. Highlighted below are the three most relevant ones below:
This is a strong start. Creating a list of large debris (>10 cm) by impact and prioritizing nudging large debris like non-functioning satellites, spent rocket stages, and other large debris using ground lasers will allow increased benefits for less cost. Additionally, NASA should prioritize destroying non-trackable and other small debris.
Their report finds that remediating smaller debris not only demonstrates results faster but is a lighter financial lift. Surveying debris size and impact can be done alongside removing smaller debris, maximizing impact.
Recommendation 2. The Space Force, in collaboration with the Department of Commerce (DOC), should fund removal and/or recycling of a set number of large debris objects each year, thereby creating a reliable market for space debris removal.
We recommend that the nascent Space Force and Department of Commerce provide funding for technical solutions to remove and recycle larger debris objects. If we are to tackle the space debris problem at all, we need funding. The amount of large debris is already extensively cataloged. This is doable with the completion of a trackable list of large debris from Recommendation 1.
Space debris isn’t going to go away, but we can start minimizing the threat it poses.
The NASA report indicates that taking action immediately will have minimal financial drawbacks, with a high debris-cleaning impact within a few years. Technologies like ground and space laser nudges provide low-cost alternatives to other debris mitigation methods currently in use. The report also provides insight into industries’ understanding of the true financial costs associated with cleaning space debris. This can incentivize innovation and create even more cost-effective technologies to manage and clean up debris. There is also an immediate need to address the space debris problem: existing U.S. government and commercial infrastructure (the International Space Station and commercial internet and science satellites) is at risk. The faster space debris is addressed, the more space innovation and invention we will see in the coming decades.