This week, Sierra Nevada Corporation Space Systems (SNC), one of three private companies currently developing spacecraft with NASA funds to ferry crews to and from the International Space Station, successfully completed Milestone-9 in the development of their Dream Chaser under the company’s Commercial Crew Integrated Capability agreement (known as CCiCap) with the space agency.
The major comprehensive review, known as the Risk Reduction and Technology Readiness Level (TRL) Advancement Testing milestone, subjected five specific Dream Chaser systems to the extensive testing.
The comprehensive Milestone 9 systems tests that were conducted included:
- Thermal Protection System: Extensive design qualification testing was conducted at NASA’s Ames Research Center in California and NASA’s Langley Research Center in Virginia through existing Space Act Agreements to validate TPS design performance. This effort included over 350 tests that allowed SNC to select the optimal TPS architecture for Dream Chaser to safely fly through the high-heat-load atmospheric environment during nominal return to Earth as well as during high altitude ascent aborts.
- Structures: Numerous tests were conducted in collaboration with SNC Dream Team member Lockheed Martin at NASA’s Michoud Assembly Facility in Louisiana. More than 1,500 stress tests were executed on the primary structure to fully validate the strength and reliability of the Dream Chaser advanced composite structure.
- Crew Systems: Multiple tests were performed at SNC’s Space Systems headquarters in Louisville, Colorado. These crew-related assessments included reach and visibility, as well as crew ingress and egress testing in the horizontal and vertical positions, all in the new full-scale Dream Chaser crew cabin mockup. Over 25 tests were conducted totaling more than 90 hours of data.
- Environmental Control and Life Support Systems: Human-in-the-loop tests were performed to analyze temperatures and metabolic rates for crew as part of an in-orbit simulation at Orbital Technologies Corporation (ORBITEC) of Wisconsin in conjunction with their teammate UTC Aerospace in Connecticut.
- Thermal Control System: Both internal and external active thermal control of the spacecraft was successfully demonstrated through rigorous testing by Orbitec at their facilities.
The completion of Milestone-9 marks the second CCiCap milestone SNC has completed in less than a month, as just a couple weeks ago the company completed Milestone-9a, which subjected Dream Chaser’s Main Propulsion System and Reaction Control System to similar Risk Reduction and TRL advancement tests. Over 3,500 tests have been conducted over the course of the last year during both Milestones 9 and 9a, and with this week’s completion of Milestone-9, SNC has now received 92 percent of the total award value of the CCiCap agreement.
“By thoroughly assessing and mitigating each of the previously identified design risks, SNC is continuing to prove that Dream Chaser is a safe, robust, and reliable spacecraft,” said Mark Sirangelo, corporate vice president of SNC’s Space Systems. “These crucial validations are vital steps in our Critical Design Review and in showing that we have a very advanced and capable spacecraft. This will allow us to quickly and confidently move forward in restoring cutting-edge transportation to low-Earth orbit from the U.S.”
The Dream Chaser’s potential as a reusable lifting-body (winged glider) spacecraft is unique—no other company is developing anything similar. Dream Chaser will have no abort blackout zones and a 3.5-day free-flight capability—with the added benefit of deorbiting at any time (since Dream Chaser can land on any conventional runway, not just the SLF). The spacecraft will also be able to stay at the International Space Station (ISS) for up to seven months at a time, if needed, before having to return to Earth, and an expected 1.5 G nominal reentry will provide ideal conditions for returning fragile cargo and science experiments, in addition to making the return to gravity easier on the crew (SNC expects immediate access to crew and cargo upon landing). A quick turnaround and an almost entirely reusable vehicle put Dream Chaser in a class all its own.
That is, of course, assuming SNC advances to the second phase of NASA’s Commercial Crew Program (CCP) later this year, when the space agency is expected to award at least one of the three companies hoping to return U.S. astronauts to the ISS from American soil a Commercial Crew Transportation Capability (CCtCap) agreement.
The company, assuming again that they advance with NASA’s CCP and earn a CCtCap award, hopes to launch their first autonomous orbital spaceflight in 2016 atop a United Launch Alliance (ULA) Atlas-V 402 rocket, with the first crewed mission to launch in the third quarter of 2017. The company expects to eventually base a fleet of dream Chaser’s, each with unique capabilities, out of Florida’s historic launch sites at Kennedy Space Center and Cape Canaveral Air Force Station.
“Our partners are making great progress as they refine their systems for safe, reliable and cost-effective spaceflight,” said Kathy Lueders, manager of NASA’s Commercial Crew Program. “It is extremely impressive to hear and see the interchange between the company and NASA engineering teams as they delve into the very details of the systems that help assure the safety of passengers.”
Dream Chaser has flown once so far, an autonomous free flight test over Edwards Air Force Base. A second autonomous free-flight test, known as ALT-2, is planned to take place at Edwards again later this year before the company conducts its first piloted Dream Chaser free flight test. No specific date(s) have been announced by SNC for those flights yet.