NASA requires Boeing and SpaceX to demonstrate that there’s no more than a one in 270 chance for a fatal accident during a flight. The Space Shuttle program lost two shuttles in 135 launches.
John Mulholland, vice president and program manager for the commercial crew program at Boeing assessed three separate requirements, including the overall loss of crew as well as ascent and entry risks and loss of mission.
SpaceX and Boeing increased micrometeoroid and orbital debris protection.
Visually one of the biggest changes to the SpaceX Crewed Dragon is changing from solar panels on wings to having solar panels directly on the lower body of the spacecraft.
Long-road for NASA,Boeing and SpaceX to Safer Manned Flight
In September 2014, NASA awarded firm-fixed-price contracts to Boeing and SpaceX, valued at up to $4.2 billion and $2.6 billion, respectively, for the Commercial Crew Transportation Capability phase.
About a month away from the first orbital test flight of crew Dragon https://t.co/U01Oxu3M7E
— Elon Musk (@elonmusk) January 5, 2019
Yes, will be extremely intense. Early flights are especially dangerous, as there’s a lot of new hardware.
— Elon Musk (@elonmusk) January 6, 2019
NASA, Boeing and SpaceX Report on Safety
Boeing’s spacecraft—CST-100 Starliner—is composed of a crew module and a service module.
· The crew module will carry the crew and cargo. It also includes communication systems, docking mechanisms, and return systems for Earth landing.
· The service module provides propulsion on-orbit and in abort scenarios as well as radiators for thermal control.
In 2018, the Commercial Crew Program’s top programmatic risks identified for Boeing include challenges related to its abort system performance, parachutes, and launch vehicle.
SpaceX’s spacecraft—Dragon 2—is composed of a capsule, which we refer to as the crew module, and a trunk, which we refer to as the support module.
· The crew module is composed of a pressure section and a service section. This module will carry the crew and cargo. It also includes avionics, docking mechanisms, and return systems for a water landing.
· The support module includes solar arrays for on-orbit power and guidance fins for escape abort scenarios.
In 2018, the Commercial Crew Program’s top programmatic risks identified for SpaceX are in part related to ongoing design and development efforts related to its launch vehicle design, the Falcon 9 Block 5.
· Composite Overwrap Pressure Vessel: This Block 5 design includes SpaceX’s redesign of the composite overwrap pressure vessel, which is intended to contain a gas under high pressure. SpaceX officials stated the newly designed vessel aims to eliminate risks identified in the older design, which was involved in an anomaly that caused a mishap in September 2016. SpaceX plans to qualify the updated design for flight prior to the uncrewed flight test design certification review.
· Engine Turbine Cracking: The Block 5 design also includes design changes to address cracks in the turbine of its engine identified during development testing. NASA program officials told us that they had informed SpaceX that the cracks were an unacceptable risk for human spaceflight. SpaceX officials told us that they have made design changes to this Block 5 upgrade that did not result in any cracking during initial testing. However, this risk will not be closed until SpaceX successfully completes qualification testing in accordance with NASA’s standards without any cracks. As of March 2018, SpaceX had not yet completed this testing.
· Propellant Loading Procedures: Both the program and a NASA advisory group have raised SpaceX’s plan to fuel the launch vehicle after the astronauts are on board the spacecraft to be a potential safety risk.