Uncontrolled reentries of space objects create a collision risk with aircraft in flight. While the probability of a strike is low, the consequences could be catastrophic. Moreover, the risk is rising due to increases in both reentries and flights. In response, national authorities may choose to preemptively close airspace during reentry events; some have already done so. We determine the probability for a rocket body reentry within airspace over a range of air traffic densities. The highest-density regions, around major airports, have a 0.8% chance per year of being affected by an uncontrolled reentry. This rate rises to 26% for larger but still busy areas of airspace, such as that found in the northeastern United States, northern Europe, or around major cities in the Asia-Pacific region. For a given reentry, the collision risk in the underlying airspace increases with the air traffic density. However, the economic consequences of flight delays also increase should that airspace be closed. This situation puts national authorities in a dilemma—to close airspace or not—with safety and economic implications either way. The collision risk could be mitigated if controlled reentries into the ocean were required for all missions. However, over 2300 rocket bodies are already in orbit and will eventually reenter in an uncontrolled manner. Airspace authorities will face the challenge of uncontrolled reentries for decades to come.

Plans for over one million satellites have been submitted to the International Telecommunications Union, a United Nations agency, in the last 6 years. Either many of these satellites will launch, and cause environmental problems on Earth and in orbit, or companies and governments are inflating their numbers, suggesting more satellites than they plan to launch.

There is a growing risk to aircraft in flight from collisions with debris produced by the breakup of uncontrolled rocket bodies and satellites during atmospheric reentry. On one hand, the aviation industry has grown to almost 39 million flights per year, with a 63% increase between 2004 and 2019. On the other hand, the number of successful rocket launches more than doubled between 2015 and 2023, from 87 to 212, respectively. During those 212 launches in 2023 128 rocket bodies were abandoned in orbit, left to reenter uncontrollably. Such uncontrolled space object reentries are hard to predict, making mitigation measures difficult. In November 2022, a reentering Long March 5B rocket caused the closure of airspace over Europe, delaying 645 flights and having a plausible economic impact of millions of Euros. There are international and domestic laws that might enable the recovery of economic losses resulting from uncontrolled reentries, but such losses should not be allowed to occur in the first place. Instead of leaving the location of a reentry to chance, controlled reentries can be achieved with existing technologies and mission designs, directing reentries away from areas of high aircraft traffic. Moving to a controlled reentry regime would create a cost to space operators – but that cost is currently being externalized to the aviation industry. Multilateral solutions to create a controlled reentry regime should be pursued, as recommended in the 2023 Montreal Recommendations on Aviation Safety and Uncontrolled Space Object Reentries, before there is a tragedy caused by an aircraft collision with debris from a rocket body or satellite.

Approximately 70 % of launches in 2022 resulted in an uncontrolled rocket body reentry, creating an unnecessary casualty risk to people on the ground, at sea, and in aircraft. Rocket bodies have masses ranging from tens of kilograms to 20 tonnes. Using known rocket body masses and correlations between mass and casualty area, we present revised estimates for the expected risk, finding a 20–29 % probability of one or more casualties over the next decade.Some states use a 1-in-10,000 threshold for accepting an uncontrolled reentry casualty risk when approving a space activity. This threshold, which is not universally agreed upon, represents a risk acceptance by one country, but imposed on the world population. As the use of space expands, with a record 180 successful launches in 2022, states and other launch providers should adopt technologies and mission designs that ensure controlled reentries. Uncontrolled reentries, particularly of large rocket bodies, constitute an unsafe and unnecessary practice.

The existing rendezvous profiles of Russian crew vehicles in some flight phases are not adapted to contingencies which can be caused by an autonomous rendezvous system failure. If it occurs, the crew can complete the rendezvous in manual mode only at a range of less than a kilometer. However, at a long range the manual rendezvous mode is complicated because the on-board algorithm of the motion control system generates free trajectories that do not provide the crew with a convenient manual control. As a rule, in this case re-rendezvous is required with shifting the docking to the next day. In the case of fast rendezvous profiles (which allow to get to the ISS in 3 h) re-docking should be scheduled only in two days because of the crew adaptation to the weightlessness. In order to allow the crew to complete the rendezvous in manual mode without delaying the docking, it is required to create a more simple procedure for calculating and performing transfer burns. From the Gemini, Apollo and ATV spaceflight heritage, the technique for approaching the target from a coelliptical orbit has been known, that provides a uniform motion and convenient control of the crew vehicle in manual mode. The paper proposes the fast rendezvous profile with the insertion of the crew vehicle into an intermediate orbit coelliptical with the target orbit. In this approach, in case of automatic rendezvous failure, the crew, having a complete understanding of the relative motion, is able to perform the transfer to the target in manual mode without increasing the duration of the flight till the docking. The paper presents the results of testing this approach on a simulator, which in the long term will allow to reduce the rendezvous duration of Russian vehicles to a single orbit.

We present observations of 23 Starlink satellites in the $g'$ bandpass, obtained from the Dominion Astrophysical Observatory's Plaskett 1.8 metre telescope. The targets include a mixture of satellites with and without brightness mitigation measures (i.e., visors). At the time of the observations (16 July 2021), Starlink satellites were sunlight throughout the night, and even with strict elevation and azimuth limits, there were over 800 candidate Starlink arcs. The satellites altogether have a median absolute brightness (550 km) of $\overline{H}_g^{550} =5.3$ mag. Dividing the targets into those without and with visors, their median absolute magnitudes are $\overline{H}_g^{550}(no~visor)=5.1$ and $\overline{H}^{550}_g(visor)=5.7$ mag, respectively. While the visor sample is dimmer in aggregate, the absolute brightness distribution ranged from $H_g^{550}=4.3$ mag to 9.4 mag, with the brightest being a visored satellite and the dimmest a satellite with no mitigation. The intrinsic brightness dispersion among the full sample is $\sigma_g = 0.5$ mag.

Most space launches result in uncontrolled rocket body reentries, creating casualty risks for people on the ground, at sea and in aeroplanes. These risks have long been treated as negligible, but the number of rocket bodies abandoned in orbit is growing, while rocket bodies from past launches continue to reenter the atmosphere due to gas drag. Using publicly available reports of rocket launches and data on abandoned rocket bodies in orbit, we calculate approximate casualty expectations due to rocket body reentries as a function of latitude. The distribution of rocket body launches and reentries leads to the casualty expectation (that is, risk to human life) being disproportionately borne by populations in the Global South, with major launching states exporting risk to the rest of the world. We argue that recent improvements in technology and mission design make most of these uncontrolled reentries unnecessary, but that launching states and companies are reluctant to take on the increased costs involved. Those national governments whose populations are being put at risk should demand that major spacefaring states act, together, to mandate controlled rocket reentries, create meaningful consequences for non-compliance and thus eliminate the risks for everyone.

Autonomous on-orbit servicing and active debris removal are promising emerging markets in the commercial space industry. However, their advent brings legal challenges that must be overcome for a smooth adoption of the services. This article outlines the history and context of autonomous on-orbit servicing and key legal issues that must be addressed. The lack of clear definition of fault is discussed in the context of close proximity missions, as well as the issue of ownership of debris should a collision occur. Furthermore, the legal implications of the dual use of servicing satellites are discussed. For the commercial market to grow, these legal issues must be addressed through an initial inter-state mission, and the continued development of best practices for on-orbit servicing and active debris removal.

Satellite constellations represent a new paradigm of space activities, with vast numbers of smaller satellites operated in the so-called NewSpace industry. With the tide of potential applications and benefits to mankind come risks, notably that of the increased population of low Earth orbit and potential for increases in space debris. This article discusses the legal ramifications of the proposed constellations, including the current legal framework around space debris and collisions, and potential challenges, including lack of legal definitions for space debris and fault making liability difficult to prove. Potential mechanisms for clarification are also discussed.