The initial advocate for off-planet colonies now concedes that the additional difficulties associated with constructing a space colony would encourage the successful construction of terrestrial lifeboats before attempts are made to construct one on another body. The only reason to still countenance their construction at all is an issue which revealed itself to the advocate for terrestrial biospheres towards the end of the collaboration. A terrestrial lifeboat could end up being easily discontinued and abandoned if funding/political will failed, whereas a space colony would be very difficult to abandon due to the astronomical (pun intended) expense of transporting every colonist back. A return trip for even a relatively modest number of colonists would require billions of $ allocated over several years, by, most importantly, multiple sessions of a congress or parliament. This creates a paradigm where a terrestrial lifeboat, while being less expensive and in many ways more practical, could never be a long term guarantor of human survival do to its ease of decommissioning (as was seen in the Biosphere 2 incident). To be clear, the advocate for terrestrial lifeboats considers this single point sufficient to decide the debate in its entirety and concedes the debate without reservation.