Boeing’s CST-100 Starliner has separated from the Atlas V Centaur and is flying on its own, embarking on its flight to the International Space Station. After a series of orbital adjustments, Starliner will be on course for rendezvous and docking with the space station at 7:10 p.m. on Friday, May 20.
Booster ignition and liftoff of the United Launch Alliance Atlas V rocket carrying Boeing’s CST-100 Starliner spacecraft on NASA’s Orbital Flight Test-2 to the International Space Station. Launch occurred at 6:54 p.m. EDT from Space Launch Complex-41 on Cape Canaveral Space Force Station in Florida.
About one minute after launch, the Atlas V rocket achieved Mach 1. About two-and-a-half minutes into flight, a series of key events will begin to occur over the next few minutes. The Atlas V solid rocket boosters will fall away. The Atlas first-stage booster engine will cut off, followed by separation from the dual-engine Centaur second stage. The Centaur first main engine will start, followed by aeroskirt jettison. A few minutes later the Centaur engine will cut off.
Launch conductors have completed their polls of the launch teams. The T-4 minute built-in hold has been released and the countdown has resumed. The Starliner spacecraft has been configured for terminal count. Three seconds before launch, the Atlas V booster’s RD-180 engine will ignite.
Starliner has been switched to internal power and configured for launch. The crew access arm has been stowed for launch. Weather still looking good.
The Boeing launch conductor is polling the launch team to determine a “Go” for launch of the Boeing’s CST-100 Starliner. The launch team is monitoring data feeds, looking for any anomalies.
The launch conductor has started a terminal count briefing with the launch team. There are three control rooms: the United Launch Alliance’s Atlas Spaceflight Operations Center on the Cape Canaveral Space Force Station; the Boeing Mission Control Center at Kennedy Space Center; and the Space Station Control Room at Johnson Space Center in Houston. NASA’s Emergency Operations Center also is activated, and United Launch Alliance has teams in Denver who will monitor ascent of the rocket.
Though no crew will be onboard the spacecraft for NASA’s Boeing Orbital Flight Test-2, the Starliner commander’s seat will be occupied by Rosie the Rocketeer, Boeing’s anthropometric test device. During OFT-1, Rosie was outfitted with 15 sensors to collect data on what astronauts will experience during flights on Starliner. For OFT-2, spacecraft data capture ports previously connected to Rosie’s 15 sensors will be used to collect data from sensors placed along the seat pallet, which is the infrastructure that holds all the crew seats in place.
The combined White Room Crew of Boeing and United Launch Alliance have closed and secured the white room, performed cabin leak checks of the CST-100 Starliner and cleared the white room. The team has cleared the crew access tower and driven to a safe distance from the launch pad.
Meteorologists with the U.S. Air Force 45th Weather Squadron now predict a 90% chance of favorable weather for launch this afternoon.
United Launch Alliance’s Atlas V rocket that will launch Boeing’s CST-100 Starliner to the International Space Station for NASA’s Commercial Crew Program was modified specifically for the agency’s Orbital Flight Test-2. This rocket configuration does not include a payload fairing. Instead, the Starliner’s own protective surfaces will take the place of the fairing to protect the uncrewed spacecraft during launch and ascent. The rocket has two solid rocket boosters (SRBs) and a dual-engine Centaur upper stage. Starliner is attached to the Atlas V using a launch vehicle adapter, which includes an aeroskirt to reduce the aerodynamic loads on the vehicle.
The Atlas V booster is 12.5 feet in diameter and 106.5 feet in length. The booster’s propulsion is provided by the RD-180 engine system, which delivers 860,200 pounds of thrust at sea level. The SRBs generate the additional power required at liftoff, with each providing 348,500 pounds of thrust.
The Centaur second stage is 10 feet in diameter and 41.5 feet in length. For this configuration, the Centaur is configured with dual RL10A-4-2 engines, each producing 22,600 pounds of thrust. The cryogenic tanks are insulated with a combination of helium-purge blankets, radiation shields, and spray-on foam insulation. The Centaur includes an Emergency Detection System that monitors for critical hazards. This system will provide critical in-flight data which supports jettison of the ascent cover and initiates CST-100 spacecraft separation.
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