Nov 19 (Reuters) - Sierra Space said on Friday it was valued at $4.5 billion in fresh capital from investors led by venture firms General Atlantic, Coatue and Moore Strategic, in what was one of the biggest funding rounds for a company in the aerospace sector. Funds and accounts managed by BlackRock Private Equity Partners, AE Industrial Partners and others also participated in the round, which brought in $1.4 billion for Sierra Space.The commercial spaceflight wing of defense contractor Sierra Nevada Corp, Sierra Space aims to make space transportation affordable in the near future. The company is also developing what it calls a Dream Chaser Spaceplane, which is under a NASA contract to perform cargo resupply missions to the International Space Station.The idea of commercial space travel has been soaring in popularity, with high-flying companies like Richard Branson"s Virgin Galactic Holdings Inc (SPCE.N) and Jeff Bezos"s Blue Origin potentially vying for wealthy customers to pay a small fortune to experience the exhilaration of space travel. Both billionaires went on suborbital joyrides earlier this year. Morgan Stanley estimates that the space economy could be worth $1 trillion by 2040. Sierra Space said it intends to use the funds to speed up development of its Dream Chaser Spaceplane. It has also forged a partnership with Blue Origin to develop and operate a commercial space station in low earth orbit. Backers for the orbital reef project include Boeing (BA.N) and Redwire Space.