Posted inOpinion

Letter | 25-year Orbit Disposal Guideline Poorly Cast

Debris in low Earth orbit
Debris in low Earth orbit. Credit: European Space Agency

Regarding the recent article on guidelines for the disposal of cubesats [“1 in 5 Cubesats Violates International Orbit Disposal Guidelines”] almost no codes of conduct, guidelines, regulations or laws are stated in a manner that is measurable, verifiable, or enforceable. A guideline is a not a law or regulation. No operator can violate a guideline.

Inter-Agency Space Debris Coordination Committee (IADC) guidelines are not stated in a manner that can be enforced. The frequently misunderstood guideline that post-mission orbit lifetime be no longer than 25 years is inapplicable until it is too late to act. If it is violated, there is no action that would change the threatening environment.

No law or regulation can reasonably require any specific lifetime. The operation of a satellite would have to be monitored continuously throughout its life, and the near-Earth space environment would have to be characterized regularly to assure satellite disposal. International Organization for Standardization (ISO) 24113, Space Debris Mitigation, which attempts to make IADC guidelines normative, violates the fundamental principles and rules of standardization, that requirements be measurable and verifiable.

Authorities and customers must confine requirements to what can be acted on and observed in time to invoke actions that could mitigate consequences. We can require only verifiable and correct analyses and tests that support estimates of lifetime, potential fragmentation,and collision avoidance throughout a satellite’s life.

These should employ reasonable and rational projections of the space environment. All of this is uncertain. The uncertainty increases with time in orbit. No authority or expert can guarantee that lifetime will be 25 years. Given the same starting data, diverse and equally credible orbit lifetime estimates vary by years.

Requiring all to adopt any institutionally unique or proprietary technique is restraint of trade. All stakeholders might not be capable of doing it that way. The U.S. Federal Communications Commission requires an end-of-life disposal plan that demonstrates intent and ability to remove a satellite within 25 years. It does not require a 25-year lifetime. The only verifiable element of ISO 24113 is a debris mitigation plan. A 25-year post-mission lifetime cannot absolutely be required a priori.

Each agency or authority should judge the veracity of analyses presented to gain launch and operational licenses. They might individually accept different levels of risk. If they were overly optimistic and there were incidents, they must bear the consequences. But all would be at risk, and none has the prerogative to decide what risk is acceptable to others.

We must not forget that the goal is to minimize debris and avoid collisions, no matter how long a satellite might remain in orbit. The 25-year guideline is poorly cast and unenforceable.

Dave Finkleman
Colorado Springs, Colorado