[Image above] Brown University graduate Marco Cross holds the SBUDNIC satellite, which he led development on. This satellite is designed to reenter Earth’s atmosphere more quickly than normal, thus helping reduce space debris. Credit: Marco Cross, Brown University
Looking up at the nighttime sky, it can be easy to forget that the peaceful, twinkling stars belie the harsh environment existing beyond our atmosphere. In addition to extreme temperatures that run hundreds of degrees below and above zero, high-energy radiation and ultrahigh vacuum make space a difficult place to safely visit.
For this reason, spacecraft typically consist of materials that can withstand the harsh environment, such as ceramics and glass. Unfortunately, designing all equipment to be this sturdy has led to a new hazard—space debris.
In our 60+ years of space activities, the European Space Agency reports that more than 6,050 launches have resulted in some 56,450 tracked objects in orbit, of which about 28,160 remain in space and are large enough to be cataloged. When accounting for miniscule pieces—such as lens covers, peeling insulation, and fragments produced from colliding objects—that number rises to the millions.
Considering that a piece of space debris the size of a blueberry can create the impact of a falling anvil, it is important for spacecraft to avoid colliding with this junk. But steering clear of debris is becoming increasingly challenging as private space entrepreneurs add to the rubbish cloud by launching unprecedented numbers of new satellites into orbit.
The problem of space debris has been a topic of discussion since the late 1970s, but it is only recently that governments have expanded from funding programs that simply track the junk to actively supporting initiatives that remove or prevent it.
For example, in 2014, the European Space Agency (ESA) announced the Clean Space program, which aims to safeguard the terrestrial and orbital environments from space debris. As explained in the launch video (below), the problem of space debris will be tackled through several pathways, including by designing satellites to have less than a 1 in 10,000 chance of surviving reentry to Earth’s atmosphere.
This “Design for Demise” approach to satellite construction has led to several innovations. For instance, as explained in a SpaceNews article, engineers from Portuguese space technology company LusoSpace worked with the ESA Clean Space team to test a new magnetorquer design. They purposefully exposed a portion of the device’s core, which allowed it to burn up completely when separated from the spacecraft. In contrast, previous magnetorquer models had only a 60% chance of burning up when released.
Besides ESA, several university research groups have successfully applied “Design for Demise” principles. For example, in the past year,
- Brown University: In March 2023, the university reported on the success of a 3D-printed drag sail created by students to bring satellites out of orbit much more quickly than usual.
- Boston University: In May 2024, the university reported that several students won first place in the second annual Collegiate Space Competition. They proposed using nanosatellites to move space debris into position for reentry. Doing so would allow satellites to use all the fuel on board rather than saving some for reentry, thus extending their lifecycle and reducing the number of new satellites sent to space each year.
- Kyoto University: In June 2024, Nature magazine reported on a satellite created by researchers at Kyoto University and Tokyo-based logging company Sumitomo Forestry. Called LignoSat, the satellite is made of magnolia-wood panels and an aluminum frame, which should allow it to incinerate easily upon reentry.
Despite the benefits of adopting a “Design for Demise” mentality, space agencies around the world have typically applied the approach in an ad hoc manner. But that may change with the new Zero Debris Charter.
Facilitated by ESA, the Zero Debris Charter is a community-driven and community-building document and initiative for the global space community. It contains both high-level guiding principles and specific, jointly defined targets to get to zero space debris by 2030.
The charter was finalized in spring 2023 and unveiled at the ESA Space Summit in November. In May 2024, ESA and 12 countries signed the charter. More than 100 organizations, including industrial and academic institutions, promised to sign the community-led endeavor in the coming months. Organizations can register their intent to sign the charter at this link.
