As the debate over what to do with the International Space Station heats up, with a new NASA report casting doubt over the plans to commercialize it by 2025, the ultimate outcome could be its intentional crash landing into the Earth. But even that contingency is lacking, l.
“At some future date NASA will need to decommission and deorbit the ISS either in response to an emergency or at the end of its useful life,” the report says. “However, the Agency currently does not have the capability to ensure the ISS will reenter the Earth’s atmosphere and land in a targeted location in the South Pacific Ocean.”
NASA, to its credit, has started the work. However, even the most preliminary steps are snarled up in diplomacy with the Russian space agency. The Inspector General says that in January 2017, NASA completed a draft plan but “this plan has not been finalized and is pending review by Roscosmos.”
And even that draft is hardly complete, with critical, unanswered questions, including how much propellant would be needed and the survivability of the systems and sensors required to deorbit the station in a controlled way.
It takes time and money to bring down a space station safely. “NASA estimates a controlled reentry or nominal deorbit of the ISS will take up to two years to execute and cost approximately $950 million,” the IG report says.
The cost is so high is due to the extra propellant needed to push the station into the perfect position, allowing it to smash down at “Point Nemo” in the deep Pacific. This is the most remote spot on the planet and, for that reason, the location of an underwater spacecraft graveyard.
And aiming is crucial. NASA estimates that 16 percent of the ISS would likely survive the burn and stresses of reentry, between 53,500 and 173,250 pounds falling to earth. Control-Moscow would direct the operation from the ground.
“Environmental impacts are projected to be small as any toxic liquids or materials are expected to burn up during the reentry process,” the report says. “Some fragments of the returning vehicle, however, could have sufficient kinetic energy to cause damage to people and structures, including ships.”
What if it was an emergency malfunction and ISS didn’t have two years to slowly come down? This kind of thinking is morbid but necessary. The Inspector General sets the odds of a meteoroid strike on ISS that does enough damage to cause depressurization at 1 in 120. In an emergency scenario, there would be about six months to crash the station safely into an empty part of Earth.
Should it happen, we’d be in trouble because world space community doesn’t have an emergency plan. The software that would enable simultaneous ignition of multiple Progress and Service Module engines needed for the emergency deorbit burn isn’t even loaded on board.
Another thing that’s lacking is enough fuel to steer the facility to a safe crash zone. The IG report points to the commercial space industry, which would have a surplus if fuel if needed in an emergency situation. The report says the agency should “develop options for obtaining supplemental emergency deorbit propellant support from U.S. commercial vehicles.”
The ISS, like any piece of machinery, is doomed to one day fail. And the wear and tear of spaceflight is taking its toll. The IG’s report notes somberly that “U.S. and Russian structural and technical feasibility assessments have also pointed to the risk of equipment failure with continued ISS operations beyond 2024.”
In the meantime, it’s more and more expensive to maintain. “Component degradation, manufacturers no longer in business, and changes in technologies over the past 20 years on a one-of-a-kind on-orbit spacecraft like the ISS also present the risk of hardware becoming technologically obsolete,” the report says.
The end of the ISS must be considered more urgently now that its funding future is in doubt. The IG report threw shade on NASA’s plan to transition the space station to commercial operators by 2025. “Transitioning the ISS to private operation under the timetable currently envisioned presents significant challenges in stimulating private sector interest to take on an extremely costly and complex enterprise,” the report says. “Based on our audit work, we question the viability of NASA’s current plans, particularly with regard to the feasibility of fostering increased commercial activity in low Earth orbit on the timetable proposed.”
The report accused NASA officials of planning ISS policy based on the rosy outlook for space industrialization. “In its ISS Transition Report, NASA includes several overly optimistic assumptions related to revenues and costs of operating a future private low Earth orbit platform that calls into question the validity of the analysis,” the IG report says.
Either way, the question of how it will come down if it has to is vital to answer. And quickly.
First published on Popular Mechanics USA