Aviation Week & Space Technology - 3 November 2014

26 AVIATION WEEK & SPACE TECHNOLOGY/NOVEMBER 3/10, 2014 AviationWeek.com/awst

C

ontingency planning and the multi-vehicle approach to sup-

plying the International Space Station will mitigate the ef-

fects of the worst accident to hit human spaceflight since

the Columbia disaster, but not without some belt-tightening and

lesson-learning in the months ahead.

No one was hurt in the Oct. 28 failure

of the fourth Orbital Sciences Corp. An-

tares launch vehicle carrying ISS cargo

shortly after it cleared the tower at its

launch facility at Wallops Island, Vir-

gina. The launch was delayed by a day

because a sailboat was in the of-shore

keep-out zone on Oct. 27. The vehicle

failed shortly after liftoff and fell al-

most straight back to Earth, erupting

in a massive fireball in the vicinity of its

state-owned launch pad.

Damage assessment was hampered

at first by burning solid propellant from

the vehicle’s upper stage and potential

danger from the toxic hypergolic pro-

pellants on board. Based on a “cursory

look” by the incident response team at

NASA’s Wallops Flight Facility and vid-

eo shot the morning after the sundown

launch attempt, the most serious dam-

age afecting future flight probably fell

on the transporter erector that raises

the vehicle from horizontal to vertical,

and the pad’s lighting suppression rods.

“[I]t will take many more weeks to

further understand and analyze the

full extent of the efects of the event,”

NASA stated. “A number of support

buildings in the immediate area have

broken windows and imploded doors.

A sounding rocket launcher adjacent to

the pad, and buildings nearest the pad,

sufered the most severe damage.”

“It looks fairly okay,” says William Ger-

stenmaier, associate administrator for

human exploration and operations. “The

details are going to come out later, and

we’ll figure out what needs to be done.”

Ofcials from NASA and Orbital, one

of two companies hired to deliver food,

hardware and scientific experiments

to the ISS, say the complex systems of

tanks and plumbing that deliver liquid

oxygen and kerosene to the vehicle on

the nearby pad during fueling were

holding pressure the day after the fail-

ure, but burning solid propellant appar-

ently damaged plumbing and wiring on

the structure itself.

Frank Morring, Jr. Huntsville, Alabama, Amy Svitak Paris,

Mark Carreau Houston and Guy Norris Los Angeles

Antares

Setback

Launch failure strains NASA’s new ISS

resupply approach—without breaking it

SPACE

An Orbital failure-review team—with

NASA participants—will replay telem-

etry and study the debris in an efort to

learn the cause of the failure and plan a

fix. Testing the fix will be hampered by

the pad damage, since Orbital uses the

pad itself instead of a separate stand for

static tests of the Antares.

The company also runs hot-fire ac-

ceptance tests of its Russian-built AJ-26

engines it flies in pairs on the Antares

at Stennis Space Center, Mississippi.

In May one of the refurbished surplus

engines, some of them 40 years old, suf-

fered “significant damage” in a failure

at Stennis. Gerstenmaier says a review

found that engine “essentially explod-

ed” after a “high-temperature event”

in the oxygen turbine section, but he

stressed on Oct. 29 that it was much

too soon to implicate the engines in the

previous day’s launch failure.

“It’s an extensively tested engine,” said

Frank Culbertson, executive vice presi-

dent and general manager of advanced

programs at Orbital, in a press confer-

ence the night of the failure. “It is very

robust and rugged, and it goes through

extensive testing by a team at Stennis

Space Center before it’s ever installed

on the rocket. These engines were taken

through the normal acceptance testing,

and pressure testing, et cetera, both at

Stennis and here at Wallops prior to the

launch, so we didn’t see any anomalies or

anything that would indicate there were

problems with the engine.”

The failed launch also was the first

with an upper stage based on the sol-

id-fuel ATK Castor 30XL, an upgrade

from the original Castor 30 designed

to increase vehicle performance for an

expanded Cygnus cargo carrier.

With a dwindling supply of the

engines, Orbital has been seeking a

replacement for the core stage of An-

tares, which, along with the Cygnus, is

圀漀爀氀搀䴀愀最猀⸀渀攀琀圀漀爀氀搀䴀愀最猀⸀渀攀琀

圀漀爀氀搀䴀愀最猀⸀渀攀琀