As tow tests of Sierra Nevada Corp.'s Dream Chaser lifting body begin in California, the two competing capsule-based contenders for NASA's commercial crew program (CCP) are running through a fast-paced series of milestones toward the start of planned demonstration flights.

While the three-way contest for NASA's competitive Commercial Crew Integrated Capability (CCiCAP) initiative was already highly charged, the outcome of the upcoming tests has become even more crucial given increasing budget pressure. The program, which aims to develop U.S. human spacelaunch capability to succeed the now retired space shuttle, has been slipping as Congress continues to cut funding. The shortfall has forced NASA to revise its acquisition plan that notionally calls for a request for proposals in fiscal 2016, and first U.S.-crewed service flights to the International Space Station (ISS) in November 2017—two years later than originally planned.

To qualify, the teams must pass a rigorous, two-phase certification process which will include at least one crewed ISS mission in fiscal 2017. However, the squeeze on funding may force the agency to winnow down the contenders sooner than originally planned, which makes the upcoming milestones all the more important.

Boeing, with its CST-100, still aims to demonstrate the seven-person capsule on a three-day manned orbital test flight in 2016, says John Mulholland, vice president and program manager for Commercial Programs. At the recent Space Tech Expo in Long Beach, Calif., he said CST-100 “can be operational as soon as 2016. It is really important for NASA to maintain the 'no-later than 2017' launch date. That's the No. 1 priority and I think NASA, with good reason, wants to maintain competition through the next round. That would be healthy as long as you have the budget to allow that competition in the next round and still fly in 2017.”

The company is more than a third of the way through a series of 13 key CCiCAP program performance milestones for 2013 that will lead the way to an integrated critical design review (CDR) in April 2014. In all, the company must pass a total of 19 such milestones by mid-2014. This month the company is set to conduct tests of the Aerojet Rocketdyne orbital maneuvering and attitude control thrusters, and in September will conduct a CDR of the spacecraft's primary structure. “It's the grind. This is where you get into the final engineering release and all the focus of the team is on the baseline release to support the build cycle. We are making sure we can receive flight design hardware by the end of the calendar year,” Mulholland says.

Other milestones for this year include a support module propulsion system critical review in August, and two events in September covering a mission-control-center-interface demonstration and launch vehicle adapter CDR. The CST-100, like the Dream Chaser, is slated to launch initially on a United Launch Alliance Atlas V (AW&ST June 3, p. 54). Last April, Boeing completed wind-tunnel tests of a 7%-scale vehicle and adapter “to make sure we fully understood the loads and that there were no instabilities. It went really well,” Mulholland says.

Boeing's plan calls for the first two launches to be on an Atlas, but the company has not ruled out other launchers, including the Falcon 9 developed by CCiCAP rival Space Exploration Technologies (SpaceX). “It's got to be compatible with others and we continue to have discussions with SpaceX because once the Falcon 9 has enough flights under its belt and is safe enough to fly crew, we feel we can make that business decision. We'll be going over [to SpaceX] soon to see what it will take to make sure our new vehicle is compatible with the Falcon 9. If the price point stays extremely attractive then that is the smart thing to do.”

Boeing is also scheduled to conduct a launch site preliminary design review at Cape Canaveral, looking at the launch tower design for Space Launch Complex (SLC-41B) “to make sure ULA can go and build it,” says Mulholland. In November, Boeing plans to conduct emergency detection-system standalone testing. “It is vitally important to make sure you know when to leave the rocket and that you do not have a false trigger. In December we will release the multi-string flight software,” he adds. A pilot-in-the-loop demonstration is set for February 2014, with a software CDR the following month. “We will then move to the validation phase and flight test,” he says

SpaceX Commercial Crew project manager Garrett Reisman says his company's plan to conduct a pad abort test in December remains on track, paving the way for a test flight to the space station with a non-NASA crew in a version of the Dragon spacecraft in 2015. “What we think we need to complete launch assurance is just over two years, so we could do a test with people on board around mid-2015. That is what we proposed under CCiCAP and it is the trajectory we are on today but,” depending on funding, that may not hold,” he warns.

The company delivered a detailed pad abort test plan to NASA in March, and in May completed its human certification plan review with delivery of overall certification and master verification plans. The preliminary design of the automatic-approach-and-docking system as well as the entry, descent and landing system is subject to an on-orbit and entry preliminary design review in July. Following a Dragon parachute test in August, the detailed inflight abort test review is slated for September, with the over-arching safety review covering hazard analysis, safety assessment and failure modes, due in October.

Following a flight review of the upgraded Falcon 9 standard for human missions in mid-November, SpaceX plans to conduct a pad abort test a month later. “The primary structure for the pad abort is already fabricated and almost complete. This the next really exciting milestone and the first abort test as part of commercial crew program. We are going to stick Dragon on top of a Falcon 9 and take it to the transonic regime. We will light up the launch abort system and fly away safely from the Falcon 9. This will demonstrate total thrust (as opposed to total impulse),” adds Reisman. “Then we move on to the human certification review.” The qualification effort of the Dragon primary structure is due to be completed in mid-January, with the integrated CDR for the entire vehicle now set for March 2014 and an inflight abort test the following month.

Tap on the icon in the digital edition of AW&ST for a video of the Dream Chaser, and see the video and images of the flight-test vehicle at NASA Dryden alongside one of the agency's original lifting body designs on our OnSpace blog at ow.ly/mpDfQ