European Space Sector concerns about transport of UN 2029 Hydrazine Anhydrous
Hydrazine is a fuel commonly used for the propulsion of space systems, mainly in orbit, but also, marginally, in their launch phase. Hydrazine is a highly toxic and explosive substance. Its use by the space sector is therefore accompanied by numerous safety measures aimed at protecting both workers and the environment from exposure and/or accidental detonation.
The United Nations ECOSOC subcommittee proposes to regulate the transport of hydrazine, in particular by lowering the pressure thresholds to which hydrazine would be subjected in its transport phases. This measure would aim to reduce the risk of explosion.
The space sector believes that this measure would make the transport of hydrazine impractical under the conditions of concentration, purification and pressurisation that are required to make this substance suitable for powering space propulsion systems.
Currently, space industry players use stainless steel pressure vessels for the packaging and transportation of hydrazine. The tanks have a minimum wall thickness of 6.9 mm and are certified for a pressure of 35 bar, making them extremely durable and safe for transport phases. Furthermore, these pressure vessels have a long technical heritage and are proven to be safe, causing no accidents in the EU over several decades.
Packaging hydrazine in a less stable container (as in the ECOSOC PP5 recommendation) would considerably increase the risk in the event of accidents during handling and transport, this risk being all the greater the higher the outside temperature (as is the case at the Kourou space base for example) which would increase the internal pressure and could cause a rupture. The addition of ventilation or overpressure devices could further increase the risk of overpressure and rupture.
In conclusion, the European space sector considers that the current transport solution presents a low level of risk, and could be retained, at least for the uses of hydrazine in space systems.
Further information about expected impacts from PP5 addition to UN 2029 and substitution constraints is available in our detailed impact assessment of 12 June 2024 (ref. MPTB-ES-PO-0150), available HERE.
This is a joint paper of the European Space Industry, represented by ASD-EUROSPACE – with the support of European Space Agency (ESA), Deutsches Zentrum für Luft- und Raumfahrt (DLR), Centre National d’Etudes Spatiales (CNES) and the European Defence Agency (EDA) as observer with regards to an agreement of the UN Sub-Committee of Experts on the Transport of Dangerous Goods (SCETDG) at its 63rd session on 27 November – 6 December 2023. This paper is also supported by the Aerospace, Security and Defence Industries Association of Europe (ASD). This paper is also strongly supported by the Defense Logistics Agency Aerospace Energy of US and the Aerospace Industries Association of America, Inc. (AIA).
The United Nations ECOSOC subcommittee proposes to regulate the transport of hydrazine, in particular by lowering the pressure thresholds to which hydrazine would be subjected in its transport phases. This measure would aim to reduce the risk of explosion.
The space sector believes that this measure would make the transport of hydrazine impractical under the conditions of concentration, purification and pressurisation that are required to make this substance suitable for powering space propulsion systems.
Currently, space industry players use stainless steel pressure vessels for the packaging and transportation of hydrazine. The tanks have a minimum wall thickness of 6.9 mm and are certified for a pressure of 35 bar, making them extremely durable and safe for transport phases. Furthermore, these pressure vessels have a long technical heritage and are proven to be safe, causing no accidents in the EU over several decades.
Packaging hydrazine in a less stable container (as in the ECOSOC PP5 recommendation) would considerably increase the risk in the event of accidents during handling and transport, this risk being all the greater the higher the outside temperature (as is the case at the Kourou space base for example) which would increase the internal pressure and could cause a rupture. The addition of ventilation or overpressure devices could further increase the risk of overpressure and rupture.
In conclusion, the European space sector considers that the current transport solution presents a low level of risk, and could be retained, at least for the uses of hydrazine in space systems.
Further information about expected impacts from PP5 addition to UN 2029 and substitution constraints is available in our detailed impact assessment of 12 June 2024 (ref. MPTB-ES-PO-0150), available HERE.
This is a joint paper of the European Space Industry, represented by ASD-EUROSPACE – with the support of European Space Agency (ESA), Deutsches Zentrum für Luft- und Raumfahrt (DLR), Centre National d’Etudes Spatiales (CNES) and the European Defence Agency (EDA) as observer with regards to an agreement of the UN Sub-Committee of Experts on the Transport of Dangerous Goods (SCETDG) at its 63rd session on 27 November – 6 December 2023. This paper is also supported by the Aerospace, Security and Defence Industries Association of Europe (ASD). This paper is also strongly supported by the Defense Logistics Agency Aerospace Energy of US and the Aerospace Industries Association of America, Inc. (AIA).