Biosphere 2 bears more explanation. That project locked MacCallum, Poynter, six other individuals and dozens of animals into an airtight dome housing a simulated ocean, rain forest, desert and other natural components of an Earthlike environment, with the sun supposedly as the only outside influence. They wound up enduring prolonged semi-starvation, problems related to the balance of oxygen and carbon dioxide and psychological issues related to their confinement.
The science behind the Biosphere project was questioned from the beginning, and the data collected was of dubious value. Egos got in the way at every step. In particular, there seemed to be a reluctance on the part of those involved in the project to admit the mission had been compromised, even when they were accused of smuggling in food or forced to pump oxygen into the dome.
The Vanity Express
Tito is able to fund the initial phase of this Mars project through his own private fortune, just like he did with the space-tourist stint.
Likewise Biosphere 2 was funded entirely by billionaire Ed Bass. The lack of outside funding allowed it to rely on a small, close-knit group of people, compounding suspicions in the public and the scientific community of a conspiratorial hoax.
Instead of bringing funding onboard from a variety of respected sources as a way to build credibility, both of these projects decided they could use wealth to buy trust at a discount.
At this point, Inspiration Mars has no significant partnerships, from NASA or SpaceX, for example, or others in the commercial space industry. SpaceX offered its Dragon capsule and designs for the Falcon Heavy but has made no serious commitment or endorsement; NASA offered to help develop certain systems if funding for the work came from Inspiration Mars but has said specifically it is not endorsing the Mars mission.
No outside funding commitments, no professional partnerships, yet the team announced anyway. Why? Because the four of them thought this was a good idea? What are they, a rock band? Is this
Bill and Ted's Excellent Adventure to Mars
Vanity. It has a way of alienating people from the very cause you seek to promote.