This is part of IEEE Spectrum's Special Report: Why Mars? Why Now?

As cofounder of Space Angels Network, I evaluate dozens of space, aviation, clean-tech, and information-technology start-ups each year as potential investments for our members. My colleagues and I also work closely with investors who are interested in supporting nascent aerospace-related ventures.

We do so not only because we believe there’s money to be made in space; we also want to support an industry that has been dominated for far too long by government and large defense corporations. Besides, it’s just cool to play with rocket engines and satellites and brag to your friends that you own a piece of the space business.

We’re not alone, by any means. ”Super angel” investors are those who have put US $50 million or more of their personal or corporate assets into space—people like Jeff Bezos, Richard Branson, and Elon Musk. Clearly, they think it’s a sound business strategy and that entrepreneurs have a vital role to play in space, but they don’t expect to turn a profit for a decade or more. Venture capital firms, by contrast, target space investments that could pay off in five to seven years, at which point they would expect the company to be sold or go public. And angel investors look for returns within three to ten years.

Lately, with the world economy down and concern over carbon emissions and global warming up, my partners and I are frequently asked whether space is still a good investment. My answer, unequivocally, is yes. Here’s why.

The consensus in Silicon Valley, where I live and work, is that this recession, severe as it is, offers unprecedented opportunities to address our planet’s energy and environmental problems. Tom Siebel, the founder of Siebel Systems, which recently merged with Oracle Corp., speaks of the convergence of ET (energy and environment technologies) and IT (information technology) as an area ripe for investment. Our investors take a broader view by including ST (space technologies) in this equation.

For example, the global shift to carbon-free economies will require new infrastructure for monitoring emissions, and I expect terrestrial-, aerial- and space-based sensor networks to expand significantly in the next decade or two to support this effort. To improve energy efficiency, data collected by space-based sensors will be fused with accurate environmental and climate models and with smart energy management systems. Some of the key space technologies that will make this scenario possible include telecommunication satellites, GPS-based navigation and location services, and Earth imaging, observation, and sensing systems.