Commercial crew providers aplenty (part 2)
by Anthony Young
|The choice for a CST-100 launcher was really down to two venerable and reliable launch vehicles: either the Delta IV or Delta IV Heavy, or the Atlas V, which was ultimately chosen.|
In September 2009, The Boeing Company submitted a proposal to NASA for its commercial Crew Transport System (CTS) as part of the agency’s Commercial Crew Development (CCDev) Phase 1 initiative. Interestingly, Boeing was also working with Bigelow Aerospace, which has been developing its own commercial space station. From the beginning, Boeing’s crew capsule, designated the CST-100, would be designed to dock with both the International Space Station and Bigelow’s commercial facilities. In February 2010, Boeing signed a funded Space Act Agreement with NASA, using earmarked funds from the American Recovery and Reinvestment Act of 2009. While some proven aspects of the Apollo-era capsule were chosen by Boeing, like the upper conical angle and parachute system, the CST-100 was considerably larger, measuring 4.56 meters in diameter. Crew configurations could ultimately include up to seven astronauts. It also has an integrated service module, though much shorter than the one from the Apollo program.
Other differences were immediately apparent with Boeing’s capsule. Absent was the familiar launch escape tower to pull the capsule free of the launch vehicle in the event of a catastrophic failure during the boost phase. The CST-100 employs an alternative approach, called the Pusher Launch Abort System. This uses four high-thrust hypergolic bi-propellant “Bantam” engines manufactured by Pratt & Whitney Rocketdyne. The exterior surface of the capsule and service module is a weldless pressurized structure that is intricately machined to increase its strength while reducing its weight, over which exterior panels will be installed. Other departures from the Apollo capsule include an airbag landing system to allow the spacecraft to touch down on ground instead of water, thus eliminating traditional ocean recovery operations.
Boeing conducted numerous risk reduction demonstrations during 2011 as part of its follow-on CCDev-2 award. These included operation of the abort engine system, which will also be used for on-orbit operations; airbag drop demonstration; wind tunnel tests; demonstration of the parachute system; and other tests. There was some speculation as to which launch vehicle Boeing would select to launch the CST-100, as Boeing indicated the spacecraft would be compatible with a wide range of launch vehicles. The choice, though, was really down to two venerable and reliable launch vehicles: either the Delta IV or Delta IV Heavy, or the Atlas V. In August 2011, Boeing announced it had selected the Atlas V built by United Launch Alliance (ULA).
In March of this year, Boeing completed a rigorous Preliminary Design Review of the CST-100 that included representatives from NASA, the FAA, and numerous consultants. In April, ULA announced the formation of its Human Launch Services that would support NASA and its contractors during missions with the CST. That same month, Boeing signed another agreement with NASA’s Missions Operations Directorate at Johnson Space Center to collaborate on mission planning, training and flight operations of the CST-100—yet another display of the trend in commercial operations NASA is fostering.
The CST-100 should not be confused with the Orion capsule, built by Lockheed Martin. This capsule is designed for missions beyond low Earth orbit. The first Orion flight test article was delivered to Kennedy Space Center in July, to complete its assembly in the Operations and Checkout Building and begin preparations for launch aboard a Delta IV Heavy in 2014.
Two lesser-known participants in CCDev-2 include Blue Origin and Sierra Nevada Corporation. Blue Origin was founded by Amazon.com founder Jeff Bezos and is based in Kent, Washington. Readers of The Space Review are probably most familiar with the company’s powered ascent and descent suborbital test vehicles (see “Blue is a little less black”, The Space Review, February 22, 2010). However it is the company’s appropriately named Space Vehicle as part of its efforts under the CCDev program that is of the most interest to NASA. The design of its Space Vehicle is asymmetrical, which the company calls “biconic.” Blue Origin proposed to place that vehicle atop an Atlas V initially for crewed missions, but has suggested it eventually plans to develop its own reusable launch vehicle.
In April, the company delivered its BE-3 engine thrust chamber assembly to NASA’s Stennis Space Center for testing there. A scaled test model recently underwent aerodynamic testing at Lockheed Martin’s High Speed Wind Tunnel in Dallas, Texas. In May, Blue Origin successfully completed a System Requirements Review of its Space Vehicle with representatives from NASA and the FAA.
|The commercial efforts by SpaceX, ATK, Boeing, Blue Origin, and Sierra Nevada will see to it those astronauts will soon be launched from American soil.|
Sierra Nevada was founded in 1963 and today is a prime integrator of aircraft electronics, avionics, and communication systems. Its Space Systems division, located in Louisville, Colorado, has been actively involved in small satellite development and manufacture, spacecraft propulsion systems, and, most recently, the design and development of its Dream Chaser crew vehicle as part of the CCDev and CCDev-2 initiatives. The Dream Chaser is a classic lifting body design based on NASA’s HL-20. It will be capable of carrying up to seven astronauts to the ISS aboard an Atlas V launch vehicle. In February, Sierra Nevada delivered the first Flight Test Vehicle to NASA, a pivotal milestone in the program. It has undergone captive carry tests in preparation for approach and landing tests at Edwards Air Force Base later this year.
NASA’s commercial crew program is a crucial element of America’s human spaceflight efforts. It has rankled more than a few prominent aerospace historians—and Apollo astronauts themselves—that this country must rely on Russia to get its astronauts to the ISS. The commercial efforts by SpaceX, ATK, Boeing, Blue Origin, and Sierra Nevada will see to it those astronauts will soon be launched from American soil.