Every member of the Antares flight crew is required to wear a Hormone Activated Libido Oppressor, abbreviated as HALO and affectionately called a "Halo".

The Halo was originally developed to suppress the sex-drives of convicted felons but w as adopted by ISO for long-term space missions. The Halo is a small, green, circular patch that is placed just behind the ear.  During training for the Antares mission in 2047, several of the prospective astronauts took bets on whether or not the men of the group could overcome the Halo's effects and "rise to the occasion". While at a strip club, Nadia Schilling began flirting with the men, namely Maddux Donner, however it was Ajay Sharma who overcame the Halo, winning the bet for the men.  Because the Halo's effects can be overpowered, a few of the Antares crew have taken to wearing more than one. That said, Nadia claims she has never worn one.

When the Antares crew began hallucinating heavily in October of 2052, members of Mission Control told the crew that the cause was a tainted batch of Halos. This was a flimsy attempt to cover up the actual cause: Beta. Many of the crew members immediately saw through this guise and began questioning the true nature of the mission. Nonetheless, they have yet to continue using Halos since the incident. ("Fear")  ("Love, Honor, Obey")