Critics have mocked President Donald Trump's recent call for the U.S. military to create a "space force," but Morgan Stanley says the proposal could help create what the firm thinks will become the world's next trillion-dollar industry -- the business of outer space.

"Many investors would rather think about nearer-term themes that are actionable and can impact their portfolios in 2018. However, our conversations with various actors (current and retired) in the U.S. government, military and intelligence communities overwhelmingly indicate that space is an area where we will see significant development," Morgan Stanley analysts wrote Friday in a research note.

Trump raised eyebrows this month when he called for Pentagon officials to create a sixth branch of the military that would protect U.S. interests in space. But Morgan Stanley said in its note that his idea has some credence to it, as a space force would shore up the country's national security and get the military to "focus and accelerate investment in key technologies and capabilities."

The investment bank added that it views the space industry as a "highly relevant investment domain" for the future. For example, the firm estimates that when not running Tesla (TSLA - Get Report) , Elon Musk could see his privately held space-travel company SpaceX reach as high as a $120 billion valuation vs. the $28 billion that a recent fund-raising round valued the company at. Morgan Stanley also noted that CEO Jeff Bezos of Amazon AMZN personally contributes an estimated $1 billion a year to fund Blue Origin, his own privately owned space venture. 

Morgan Stanley said that while investor interest in space is currently low, that could bode well for those willing to pounce early. The firm compared current investor interest in space exploration to where interest in self-driving cars was in 2013. Investor sentiment was low around that sector at the time, but now companies like Tesla and Waymo (a unit of Alphabet (GOOG - Get Report) , (GOOGL - Get Report) ) have rolled out prototypes or plans for autonomous vehicles.