UP Aerospace, Inc. is a private spaceflight corporation headquartered in Denver, Colorado. UP Aerospace provides sub-orbital transportation for corporate, military and educational payloads, via their SpaceLoft XL sounding rocket launch vehicles.

UP Aerospace was started in 1998 by Jerry Larson, an aerospace engineer who had long been involved in the space program as an employee of Lockheed Martin. Larson was also a member of the Civilian Space eXploration Team (CSXT), which in 2004 became the first amateur organization to launch a (suborbital) rocket into space. The company was incorporated in 2004.

The first launch of the SpaceLoft XL occurred on September 25, 2006, from Spaceport America in Upham, New Mexico. The vehicle failed to go higher than 40,000 ft due to a malfunction attributed to faulty fin design and unexpected aerodynamic effects.

UP Aerospace conducted eight launches from Spaceport America during 2006–2009, including three in 2009. They plan to "double the number of customer launches from Spaceport America to six or more in 2010 as demand for the company's services increases."

As of November 2015 the company is developing an orbital small satellite launch vehicle known as Spyder, with support from NASA.

On July 31, 2018, UP Aerospace announced it had been awarded a 5-year IDIQ launch contract by NASA under Flight Opportunities Program. The contract calls for UP Aerospace to conduct suborbital rocket flights for NASA using its SpaceLoft XL rocket. This was the third contract of this type awarded to UP Aerospace by NASA. UP Aerospace had conducted, up to 31 July 2018, 7 launches for NASA under the Flight Opportunities program since 2012.

As of 23 November 2019, UP Aerospace has made 18 launches, including 13 with the SpaceLoft XL rocket. Most launches have been successful. All launches have been suborbital and all launches have taken place from Spaceport America.

Maiden launch of SpaceLoft XL took place on 25 September 2006.