As has already been remarked, the role of media and communication technology is important in No Horizon in a way we didn't see in either Annapurna narratives or the short stories of Krakauer and Stempf. The trek across Antarctica is physically accomplished by two women, but the level of oversight, the safety nets, provide the assurance that they are not alone. In Chapter 4, the strength of those safety nets is made quite clear as the team at home prepares to send a rescue plane upon reception of an emergency transmission.
Herzog sent his telegrams back to France, but he had only his immediate team to get him back down the mountain. They did so successfully, of course, but even if their contacts in France had known of illnesses of the Herzog and Lachenal, they would have had no way to send aid. I think that this is important because it is one of the aspects that creates the sense that the expedition of No Horizon is such a community effort. With only each other to rely on during the actual physical part of the trek, Arnesen and Bancroft have the advantage of fewer supplies and speed, but the less immediate help in the case of an emergency. But the people who can interact with the expedition from afar give the women a layer of both security and inspiration that is both external and internal to the mission.