Phobos-Grunt, seen here before its launch last week, could reenter in the next several weeks unless controllers are able to restore control of the spacecraft. (Credits: Roscosmos).

Source: Michael Listner for The Space Review:

For the third time in as many months the potential exists for a large space object to fall out of orbit and impact the surface of the Earth. Unlike the prior two incidents where the space objects involved were derelict research satellites, the space object in question is a probe launched by the Russian Federation on November 9, 2011, destined to travel to Mars. This essay will briefly address some of the legal issues and the potential for mitigating the impact the spacecraft may have when it reenters.

Phobos-Grunt is the latest attempt by the Russian Federation to send a probe to the Red Planet (see “Red moon around a Red Planet”, The Space Review, November 7, 2011). The configuration of Phobos-Grunt consists of a return vehicle/capsule for the soil sample, the main lander/probe, the Chinese-built Yinghou-1 orbiter and a cruise stage based on the Fregat upper stage, which includes fuel tanks and the connecting structure. It also has an expendable external fuel tank that was intended to be jettisoned after the spacecraft moved out of its parking orbit. The spacecraft fully fueled weighs 14.6 tons with about 12 tons being highly toxic fuel. The mission was particularly ambitious because it intended to deploy the Yinghou-1 orbiter into Mars orbit and then land the main probe on the Martian moon Phobos, where it would retrieve and return a soil sample to Earth by 2014.

However, the Phobos-Grunt mission was beset with the same bad luck as its predecessor missions. Shortly after the second stage of the Zenit rocket released the spacecraft into its parking orbit, the first burn that was intended to boost the spacecraft out of its initial parking orbit utilizing fuel from the external drop-tank failed to occur. What happened afterwards is a matter of speculation at this point. According to one theory, the spacecraft’s flight control computer reset itself to a pre-launch state and was awaiting a signal to restart its flight program. This problem was exacerbated by the fact that the external drop-tank, which was supposed to be jettisoned after the first burn, physically blocked an antenna on the spacecraft’s cruise stage preventing it from receiving uplink commands that may have allowed ground controllers to restart the flight computer.1 With ground control unable to communicate with the spacecraft after repeated attempts, Phobos-Grunt’s parking orbit will eventually decay and the spacecraft will renter the atmosphere. US Strategic Command’s Joint Space Operations Center (JSpOC) is tracking Phobos-Grunt.2 A preliminary date for reentry is November 26, according to one report, but Russian officials report it could stay in orbit for up to sixty days. Obviously, as the decay of the spacecraft’s orbit progresses, these timelines will change.

The reentry of Phobos-Grunt, like the reentry of UARS and ROSAT, presents the potential to cause damage on the surface of the Earth, but in contrast to the other two spacecraft, Phobos-Grunt presents a more dangerous scenario. It is possible that fuel within the spacecraft’s tanks could survive reentry, which potentially makes Phobos-Grunt a greater threat to the public than the reentry of the USA 193 reconnaissance satellite, which was shot down by an American SM-3 missile in 2008 to avoid an uncontrolled fall back to Earth.3 Most experts believe the fuel will likely stay liquid if the probe explodes at an altitude of about 80 kilometers (50 miles). However, if some of the fuel is frozen it could survive reentry and be released on impact.4 If surviving fuel tanks from the spacecraft impact on land or, worse, in a populated area, the resulting contamination could cause significant damage to the environment as well as to persons and property.

In addition to the potential for contamination from surviving fuel, there is also concern about the cobalt-57 onboard the spacecraft, which is intended as a gamma ray source for the probe’s soil spectrometers. While the amount of material is reportedly small, its mere presence raises the specter of Cosmos 954 and its contamination of an area in the Canadian Northwest 1979.

Liability analysis

The Liability Convention of 1972 expands upon the principles of liability for damage caused by space objects established in Article VII of the Outer Space Treaty of 1967. It envisions two scenarios where damage might be caused by a space object. The first scenario, which the reentry of Phobos-Grunt would implicate, envisions a space object that causes damage to the surface of the earth or an aircraft in flight.5 It applies a strict liability standard where the launching state is held strictly liable for any damage caused by a space object even in the face of circumstances that are outside its control. Under this standard, if more than one state is responsible for the launch of the space object in question then that State will be held jointly and severally liable for any damage caused.

Article I(c) defines “launching State” as a state that launches or procures the launching of a space object, and/or a state from whose territory or facility a space object has been launched. The first analysis is whether the Russian Federation is considered a “launching State.” One condition of the definition in Article 1(c) would be satisfied seeing that the launch of Phobos-Grunt was procured by the Russian Federation on board a Ukrainian Zenit rocket, thus making the Russian Federation a launching State and strictly liable for any damage caused by Phobos-Grunt under the first scenario.

However, the Russian Federation would not be solely liable for any damage caused by Phobos-Grunt. Article I(c) further defines “launching State” as the territory or facility from where a space object has been launched. The Zenit rocket carrying Phobos-Grunt was launched from the Baikonur Cosmodrome in Republic of Kazakhstan.6 The Cosmodrome is leased by the government of Kazakhstan to the Russian Federation, which also operates the facility. Under Article 1(c), the government of Kazakhstan would also be considered a launching state and thus be held jointly and severally liable with the Russian Federation for any damage caused by Phobos-Grunt.

However, Article V(2) allows launching states that are jointly and severally liable to enter into agreements apportioning the amount of damages or indemnifying them all together. The lease agreement between the Kazakh government and the Russian Federation may anticipate an occurrence where the Republic of Kazakhstan is held jointly and severally liable as a launching State. The term of the lease may require the Russian Federation to indemnify the Kazakh government for its portions of damages, or it might specify the amount of damages that the Kazakh government would be responsible for.

More tenuous is the liability of the People’s Republic of China, which was part of the mission with its Yinghou-1 orbiter. China participated to the extent that it provided the orbiter and some other hardware for the mission, but there is no indication that it was involved in the actual launch or in procuring the launch of Phobos-Grunt. Neither was Phobos-Grunt launched from the PRC’s territory or any of its facilities, and its participation appears to be ancillary to the launch of Phobos-Grunt. This would lead to the conclusion that the PRC would not be a launching state and would not be held jointly and severally liable even if was determined that debris from the Yinghou-1 orbiter caused damage.7 However, while the PRC is not considered a launching state, it may have a contractual relationship with the Russian Federation to compensate the PRC for the loss of Yinghou-1.

The final analysis to consider is whether the Ukraine would be considered a launching state and as a result be held jointly and severally liable for damage that may be caused by Phobos-Grunt. The Zenit rocket that launched Phobos-Grunt was procured from the Ukraine by the Russian Federation. Other than the contractual relationship providing the Russian Federation with the Zenit rocket, there is no indication that the Ukraine performed the launch nor that it procured the launch of Phobos-Grunt. Neither is there any indication that the launch of Phobos-Grunt was within Ukrainian territory or with Ukrainian facilities. Therefore, it can be determined that the Ukraine is not a launching state, and it would not be jointly and severally liable for any damage caused by Phobos-Grunt.

Mitigating damages

The Russian Federation and its co-launching state have limited methods to mitigate their absolute liability if Phobos-Grunt causes damage on the surface of the earth. Article VI(1) of the Liability Convention does offer exoneration from absolute liability if the launching state can show that the damage caused was due to the gross negligence of the party harmed (the claimant state.) However, in the case of Phobos-Grunt, it is unlikely that any potential claimant state would be in a position to perform a grossly negligent act that would cause damage from the reentry of the Phobos-Grunt. Therefore, the only recourse for the Russian Federation is to mitigate the potential damage Phobos-Grunt may cause. The most effective way to do that is to neutralize the threat the fuel could pose before the spacecraft reenters the atmosphere.8

The situation with Phobos-Grunt has been analogized to that of the United States reconnaissance satellite designated USA 193. That spacecraft failed shortly after launch and threatened to reenter the atmosphere with a full complement of hydrazine fuel, like that carried by Phobos-Grunt. The United States responded to the threat posed by the hydrazine by planning and executing an intercept of USA 193 using an ancillary capability of its anti-ballistic missile system (ABM). Comments made in various forums following the Phobos-Grunt mission have suggested the Russian Federation might perform a similar action to prevent the hydrazine contained within the fuel tanks of the spacecraft from reaching the ground. Taking this action would mitigate the potential for damage and as any resulting liability. However, performing an intercept involves technical and political impediments that the Russian Federation may either not be capable of or willing to overcome.

A significant technical factor is whether the Russian Federation has the capability to perform an intercept of Phobos-Grunt. The former Soviet Union did possess a co-orbital ASAT capability with its Istrebitel ASAT system, but it is uncertain whether they ever had or presently possess a direct-ascent ASAT system capable of performing an intercept of Phobos-Grunt. An intercept could be performed by an ABM system as was demonstrated by the ancillary use of components of the United States’ ABM system. However, it is unclear what ABM capabilities the Russian Federation has aside from the Cold War era Gazelle (SH-08/ABM-3) missiles, which surround Moscow. It is unlikely that these missiles, which originally carried a 10-kiloton nuclear warhead, have the capability to precisely target Phobos-Grunt as it orbits above.

Even if the Russian Federation has a direct-ascent ASAT or an ABM system with an ancillary capability to perform the intercept, it is unclear whether they would reveal that capability. The revelation of a previously unknown ABM/ASAT capability would implicate the Russian Federation’s national security and gain the attention of its allies and adversaries alike. It would also detrimentally implicate the Russian Federation in its diplomatic standoff with the United States and NATO over the proposed ABM system to be deployed in Europe.

In the absence of an indigenous ASAT capability, the Russian Federation might turn to the People’s Republic of China to utilize it direct-ascent ASAT capability and intercept Phobos-Grunt. As analyzed above, the PRC is not considered a launching State of Phobos-Grunt and therefore would not be liable for any damage that it might cause. However, if the PRC acquiesced to a theoretical request by the Russian Federation, it could reap a substantial soft power bounty. The known capabilities of the PRC’s ASAT coupled with the orbit of Phobos-Grunt passing over Chinese territory makes an intercept technically possible. Aside from a further technical validation of its ASAT capability, the PRC would also demonstrate a non-aggressive use of its direct-ascent ASAT. This could give the PRC significant leverage to silence the critics of its direct-ascent ASAT program and perhaps alleviate some of the political fallout from the test against its FY-1C satellite in 2007.

An intercept of Phobos-Grunt would also give the PRC more influence with regards to its stance on the PPWT, a treaty proposed by China and Russia to ban weapons in space. The current draft of the PPWT excludes direct-ascent ASATs from the definition of “space weapon”, which is a major concern among the countries opposing the draft accord. A peaceful application of its direct-ascent ASAT technology would give the PRC significant leverage to resist international pressure to include direct-ascent ASATs as banned “space weapons” in the PPWT. However, the PRC would be mindful that an intercept could either fail to intercept Phobos-Grunt on the first try or, worse, fail to intercept the spacecraft at all. Either way, a failure would not go unnoticed by the PRC’s allies and adversaries, and it would call into question the effectiveness of its direct-ascent system. This possibility alone might convince the PRC to reject a request by the Russian Federation for assistance.

Alternatively, if Phobos-Grunt’s reentry is projected to occur over a populated area, the Russian Federation may decide to approach the United States to perform an intercept of Phobos-Grunt. The situation would be dire indeed for the Russian Federation to make such a request, and it would be an option of last resort since it would directly implicate Russian national prestige and its bargaining position in regard to the ABM system that is planned for deployment in Europe. On the other hand, these concerns would not preclude the United States from taking advantage of the opportunity to apply some soft power of its own. In the absence of a request from the Russian Federation, the United States could make a high profile diplomatic overture to the Russian Federation to use its ancillary ASAT capability to intercept Phobos-Grunt. Unless the situation was such that many lives were on the line, the offer would undoubtedly be rejected by the Russian Federation.

Notwithstanding the technical and national security issues surrounding an intercept of Phobos-Grunt, there is a political angle concerning the stance the Russian Federation decided to take when the United States announced and performed the intercept of USA 193. In an exercise of Cold War era soft power, the Russian Federation accused the United States of embellishing the hydrazine worries of USA 193 noting that extraordinary measures had never been needed before to deal with a spacecraft that was falling to earth. Specifically, the Russian defense ministry charged that the United States was using the hydrazine worries that it was promoting as the rationale for the intercept as a cover story for the test of direct-ascent ASAT.9

With the proverbial shoe on the other foot, the Russian Federation could find itself in a political catch-22. It has the choice to take to either take the political blow of admitting it misjudged the United States’ intentions with the intercept of USA 193 and allow a similar intercept of Phobos-Grunt, or it can choose to roll the political dice that Phobos-Grunt will not become an incident similar to or worse than Cosmos 954, where one of its spacecraft contaminates or brings about damage or injury within the territory of another sovereign nation.

A discussion of an intercept would not be complete without analyzing the relevance of Article IX of the Outer Space Treaty. Article IX requires a state to adopt measures to prevent the contamination of outer space in the course of its space activities and to make international consultations prior to any activities that may cause harmful interference with the space activities of other States. Article IX has never been invoked, although the PRC’s 2007 ASAT test certainly may have qualified. Furthermore, the United States had an opportunity to invoke Article IX in preparation for the intercept of USA 193, but it determined that the circumstances surrounding the intercept did not trigger Article IX.10

The question is whether an intercept of Phobos-Grunt would trigger Article IX. The nature of the potential fuel load and the radioactive material, however minimal, coupled with the potential intercept at a higher altitude might be enough to trigger the consultation mandate in Article IX. In that case, both the Russian Federation and the entity performing the intercept would be required to consult with Committee on the Peaceful Use of Outer Space as well as its sub-committees concerning the nature of the intercept. However, there is the possibility that the parties involved in the intercept would decide that Cold War rules apply and/or the circumstances surrounding the intercept do not trigger or necessitate Article IX. From the standpoint of international space law, choosing not to invoke Article IX would discard an opportunity to enhance the standing of the Outer Space Treaty and may have international ramifications should an intercept attempt create more hazards than it was intended to eliminate.


However the impending demise of Phobos-Grunt is handled in the political and diplomatic arena, the ideal outcome, like UARS and ROSAT, is that the remnants of Phobos-Grunt fall harmlessly into the ocean and do not cause harm to person or property. Regardless of how that outcome plays out, the role of international space law as a silent sentinel and its validity in today’s international arena is not easily set aside.


1 Phobos-Grunt launch, Russian Space Web, November 10, 2011.

2 Phobos Grunt is being tracked by the United States and has been assigned the designation NORAD 37872.

3 Stephen Clark, “Russia trying to salvage Phobos-Grunt mission”,, November 9, 2011.

4 “Russia struggles to save Mars moon probe”, Associated Press.

5 The second scenario envisions a space object causing damage to a celestial body or another space object in outer space. For a discussion of the second scenario see Michael Listner, “Revisiting the Liability Convention: reflections on ROSAT, orbital space debris and the future of space law”, The Space Review, October 17, 2011.

6 Kazakhstan acceded to the Liability Convention on June 11, 1998. Although it hasn’t ratified the treaty, the act of acceding means that the Kazakh government has agreed to be legally bound by the treaty.

7 There are experiments from several nations including a life experiment from the Planetary Society. These experiments would also be considered ancillary and would not make these participating nations a launching state.

8 It has been suggested that ground controllers could vent the fuel into outer space, but that would presuppose that ground controllers have two-way communication with the spacecraft, and that it has the capability to dump its fuel.

9 “US spy satellite plan a cover”, BBC News, February 17, 2008.

10 For an excellent analysis of Article IX and its applicability to the FY-1C and USA-193 intercepts, see Michael Mineriro, “FY-1C and USA-193 ASAT Intercepts: An Assessment of Legal Obligations Under Article IX of the Outer Space Treaty,” Journal of Space Law, Volume 34, p.321.

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