Self-Bond on MISSE-17

Next step in demonstrating on-orbit on-demand bonding
Jacob Meyer

The next step in demonstrating ATSP as a reversible adhesive for in-space assembly is coming soon. Several coated coupons will be going up on (tentatively) March 2nd on SpaceX 27 (SpX-27) as part of the MISSE-17 mission on the International Space Station. Our high Tg reversible adhesives were previously demonstrated to both offer the highest strength (~65 MPa in pull-off), highest upper temperature limit (>300C), and highest count of bond and break cycles of any reversible or reworkable adhesive on the market (>50 cycles). ATSP’s Self-Bond line of products offers reversible bonding/rework without sag and with an indefinite open time. As part of our NASA-funded work, we found that this function persists when exposed to the equivalent of 10 years of LEO exposure in terms of their resistance to atomic oxygen and 2 MeV protons (targeting surface and through-coating damage mechanisms). We found no change to their reversible adhesive function or their bond exchange behavior (how its reversible adhesive character is mediated) following this exposure. We’ve used embedded heaters, IR, induction, Joule, and microwave heating to bonds these resins across substrates ranging from titanium to sapphire to composite with bonding times less than a minute and with high tolerance to dust build up. 
These reversible adhesives will aid in-space assembly and manufacturing by offering a simple and rapid adhesive option for bonding truss structures, debris remediation, or enabling attachment of future upgrades. This is without the adhesive action requiring the adherends to be a liquid or having a cure time. They reach maximum strength as soon as they cool.
Before handing these specimens off to Aegis Aerospace (who handles the MISSE platform for NASA), the reversible adhesives were assessed in terms of surface chemistry, thermomechanical properties, vacuum outgassing, and surface profilometry. When they come back down following the harsh environment including UV, atomic oxygen, solar protons, and other damaging species, we will again assess their chemistry, profilometry (to assess recession of the coating), thermomechanical properties, and reversible adhesive function. 
We would like to thank NASA - National Aeronautics and Space Administration, Aegis Aerospace Inc., the University of Illinois Urbana-Champaign, and Texas A&M University, and especially the memory of ATSP’s original inventor and ATSP Innovations co-founder James Economy, who left us in 2021.