Sunday, November 26, 2017

U.S. Space Taxi Services Struggle to Meet NASA Safety Rules: Experts warn new manned capsules built by Boeing and SpaceX likely will need added protections to meet safety standards

Portions of Boeing’s manned CST-100 Starliner capsule undergo tests at NASA’s Kennedy Space Center.

The Wall Street Journal 
By Andy Pasztor
Nov. 25, 2017 7:00 a.m. ET

Can NASA send astronauts into space as safely as it promised?

The space agency is scrutinizing that question as both Boeing Co. and Elon Musk’s SpaceX work on new spacecraft that NASA would begin using as early as next year to fly astronauts to the international space station.

But these commercial efforts face formidable obstacles in meeting safety requirements set by the National Aeronautics and Space Administration, posing policy and public-relations dilemmas for the agency’s chiefs.

Experts say NASA likely will require inspections in space to reduce the threat of catastrophic accidents, a last-ditch safeguard that it had hoped to avoid when approving the plan three years ago. Still, it is unclear is whether such on-orbit checks by NASA would alleviate dangers from space debris and tiny meteor fragments, say experts inside and outside the agency.

For months, these experts have warned that without new protections neither Boeing’s nor SpaceX’s vehicles appear likely to comply with safety levels. Minutes of NASA’s Aerospace Safety Advisory Panel, composed of six independent safety watchdogs, are rife with concerns of danger.

The stakes are high both for NASA and the companies. After fatal explosions of two space shuttles in 1986 and 2003, NASA committed to making future spacecraft substantially safer. Falling short of the safety benchmark could further delay the goal of ending American reliance on Russian spacecraft to ferry U.S. astronauts to and from the international space station, a 250-mile-high orbiting laboratory. NASA’s ultimate sign off also is likely to prompt congressional scrutiny.

Boeing recently said company engineering models show its CST-100 Starliner “is a safe, robust vehicle” that will meet all mandatory safety numbers. “NASA will review that analysis” next month, according to a Boeing spokeswoman, and “we will not speculate on their findings prior to the meeting.”

Space Exploration Technologies Corp., the official name of Mr. Musk’s space-transportation company, recently said it and NASA are “working closely to ensure all safety requirements are met” for its new, manned Dragon spacecraft. It said the company was evaluating a number of options, including space inspections. Government and company experts “have jointly made significant progress in defining” orbital debris risks, SpaceX said.

NASA’s requirements now call for a statistical limit of no more than one possible fatal accident per 270 flights. By contrast, scheduled airlines experience roughly one accident per one million departures globally. Although even the new standard seems perilous, it is a reflection of the mission’s technical difficulties. The standard is still more than four times safer than the space shuttle fleet that was retired in 2011 under budgetary strains and safety concerns.

The commercial designers are seeking to alleviate other risks. They are concerned that extra shielding to better safeguard equipment and crews from collisions with debris could make spacecraft too heavy. They also are examining risks associated with vibrations during launch, explosives that deploy parachutes, vulnerabilities of heat shields and other issues.

But their biggest safety challenge stems from the thousands of tiny meteors or space particles now prevalent in space that can damage or penetrate the space capsules. Traveling at approximately 17,000 miles an hour, even a paint chip can spark disaster. Boeing partly addressed this by changing its design to install Kevlar backing. SpaceX is relying on other features.

The international space station also faces risks from such orbital debris, but its design minimizes hazards and it can maneuver to avoid collisions.

A comprehensive review of capsule safety is slated for early next month, which is expected to provide NASA’s preliminary conclusions about assessments submitted by each of the contractors. So far the agency has committed roughly $4 billion overall on the two systems, with a total of 16 flights expected through the mid 2020s.

A NASA spokeswoman said the agency plans to “work with the contractors [Boeing and SpaceX] through their final certification” and neither company “has requested a formal waiver from NASA” not to comply with required safety metrics. The agency “is still evaluating the use of inspection” for their vehicles, she said.

Aerospace industry consultant Doug Cooke, a former senior NASA official, said he wasn’t surprised by difficulties complying with safety standards related to orbital debris. “It’s always been a difficult requirement to meet,” Mr. Cooke said in an interview. “NASA has to make a judgment on where the overall risk stands,” a decision that is “always done with a lot of data and a lot of hand-wringing,” he said.

Today, only Russian rockets and spacecraft transport astronauts into orbit. But Moscow’s safety record for unmanned missions is worse than that of the U.S., and Washington is eager to take back that responsibility.

Original article can be found here ➤

No comments: