Three groups are vying to lead the designs behind the Defense Advanced Research Projects Agency’s (DARPA’s) XS-1 Program, which aims to make a craft that can go to space and launch satellites 10 times in 10 days.

On Monday the agency set the deadline for July 22, at which point it will pick between the designs of three groups, Northrop Grumman, partnered with Virgin Galactic; Boeing, partnered with Blue Origin; and Masten Space Systems, partnered with XCOR Aerospace. The winner of the public-private partnership with be awarded $140 million in DARPA funding to build the submitted designs for the reusable rocket.

The designs of this craft must meet four goals laid out by DARPA.

Fly 10 times in a 10-day period (barring weather) to demonstrate aircraft-like access to space. Achieve flight velocity sufficiently high to enable use of a small (and therefore low-cost) expendable upper stage. Launch a 900- to 1,500-pound payload and demonstrate the ability to eventually launch 3,000+-pound payloads during future missions. Reduce the cost of flight to just $5 million per flight.

A DARPA concept video shows a concept XS-1 craft launching a satellite. YouTube

Jeff Bezos’ Blue Origin has been the company at the forefront of this sort of launch so far. The Amazon and Washington Post owner has already demonstrated that his space company’s crafts are capable of launching and landing the same craft three times in a row. While these launches are lower in altitude than similar events from Elon Musk’s SpaceX, it seems DARPA is only looking to launch satellites, not deliver payloads to the International Space Station. For those purposes, Blue Origin seems like the player to beat here, especially when assisted by the folks at Boeing.

Virgin Galactic hasn’t proven itself a major player in the commercial space flight game yet, but maybe Richard Branson can take this opportunity to prove himself in a major way. Veterans from the company recently started a new company called Vector Space Systems, which aims to do many of the same things.

The third partnership is by far the least well known, but could be a formidable underdog. Masten Space Systems focuses on entry, descent, and landing technologies (EDL) while XCOR Aerospace is developing some pretty cool looking reusable rockets. Maybe these two specialties combined can win out to beat the big dogs.