NRC Report on NASA’s Meteoroid and Orbital Debris Programs

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Publication date: 
4 October 2011
Number: 
124

The recent reentry of the  Upper Atmosphere Research Satellite into the Pacific Ocean has focused new  attention on the problems created by orbital debris.  Posing an occasional threat to  Earth, orbital debris, and meteoroids, are a  significant problem to NASA’s spacecraft. 

A report by the National  Research Council reviews NASA’s programs to track orbital debris and  meteoroids.  A prepublication copy of  this 180-page report, “Limiting Future Collision Risk to Spacecraft: An  Assessment of NASA’s Meteoroid and Orbital Debris Programs” was released last  month).  The report was written by the 13-member  Committee for the Assessment of NASA’s Orbital Debris Programs, chaired by  Donald Kessler.  NASA sponsored this  project, which was performed under the Aeronautics and Space Engineering Board,  Division on Engineering and Physical Sciences, of the National Research Council  of the National Academies.

The committee started its  work in late 2010, having four meetings with NASA program managers and experts,  and individuals from the Office of Science and Technology Policy, the Office of  Management and Budget, the European Space Agency, and the Aerospace Corporation.  A preface in the report explains that the  committee was not charged with assessing the threat that debris and meteoroids  presented, or how to remove debris from space.   Rather, “the study’s primary task was to review NASA’s current efforts  with regard to meteoroids and orbital debris and provide recommendations as to  whether NASA should increase or decrease its efforts or pursue new directions.”  “In effect, this study is more a review of  NASA’s meteoroid and orbital debris programs than an attempt to solve the threat  posed by meteoroids and orbital debris,” the report explains.

Early in the report, the  committee describes the mounting threat posed by meteoroids and space debris:

“When a handful of reasonable  assumptions are used in NASA’s MMOD [meteoroid and orbital debris] models,  scenarios are uncovered that conclude that the current orbital debris  environment has already reached a ‘tipping point.’  That is, the amount of debris - in terms of  the population of large debris objects, as well as overall mass of debris in  orbit - currently in orbit has reached a threshold where it will continually  collide with itself, further increasing the population of orbital debris. This  increase will lead to corresponding increases in spacecraft failures, which  will only create more feedback into the system, increasing the debris  population growth rate. The increase thus far has been most rapid in low Earth  orbit (LEO), with geosynchronous Earth orbits (GEOs) potentially suffering the  same fate, but over a much longer time period. The exact timing and pace of  this exponential growth are uncertain, but the serious implications of such a  scenario require careful attention because of the strategic importance of U.S.  space operations.” 

The committee found uniform  praise for NASA’s Orbital Debris Program and described improvements that have  been made at the agency’s Meteoroid Environment Office.  To enhance these programs, the committee  offered a series of findings and recommendations which have been compiled into seven  pages in Chapter 14 of the report.  In the  concluding section entitled Preparing for the Future, the committee provided  the following three findings and two recommendations:

Findings:

“The long-lived problem of  growth in the orbital debris population as a result of debris self-collision  and propagation requires that NASA take a long-term perspective to safeguard  the space environment for future generations.”

“Although the meteoroid and  orbital debris environment may be manageable at present, debris avoidance,  mitigation, surveillance, tracking, and response all require money. At present,  these costs usually come in the form of additional spacecraft mass and fuel and  in the maintenance of debris surveillance systems. Such costs are usually  absorbed in the budgets for space mission design, operations, and, in the case  of commercial activities, insurance premiums. In the absence of appropriate  meteoroid and orbital debris management to deal with the issue, these costs may  grow over time. Although they can serve to highlight the importance of NASA’s  debris measurement and monitoring activities, at present these costs are not  routinely measured and reported.”

“The cost of replacing  spacecraft has been used as a measure of the economic harm of a catastrophic  debris impact but may underestimate the full cost of harm for two reasons: (1)  actual replacement may be difficult because of funding, launch window limitations,  or other constraints; and (2) replacement cost, insurance premiums, and other measures  of the cost incurred to protect a spacecraft understate the full cost to  society as a whole if that spacecraft, damaged by a meteoroid or orbital  debris, itself generates debris that then creates potential harm to other  spacecraft.”

Recommendations:

“NASA should lead public  discussion of the space debris problem to emphasize debris as a long-term concern  for society that must continue to be addressed today. Necessary steps include  improvements in long-term modeling, better measurements, more regular updates  of the debris environmental models, and other actions to better characterize  the long-term evolution of the debris environment.”

“NASA should join with other  agencies to develop and provide more explicit information about the costs of  debris avoidance, mitigation, surveillance, and response. These costs should be  inventoried and monitored over time to provide critical information for  measuring and monitoring the economic impact of the meteoroid and orbital  debris problem, signaling when mitigation guidelines may need revision, and  helping to evaluate investments in technology for active debris removal.”