Antares Launch Postponed Due to Support Equipment Mishap

Antares’ second stage Umbilical Interface. The power line detached, probably because of high winds (Credits: NASA TV / Spaceflight 101).

The Antares rocket launch, scheduled on April 17 at 20:00 GMT from NASA’s Wallops Flight Facility, was cancelled due to a Ground Support Equipment issue during the countdown.

The clocks had to be stopped at T-12 minutes when a power umbilical line to the second stage came loose from the vehicle prematurely, forcing the team to scrub the launch.  Following the event, de-tanking started promptly, along with other safety tasks.

It appeared that the Umbilical Tower on the Transporter, Erector & Launch Device moved slightly away from the vehicle, probably because of high winds, causing the umbilical to become detached.  However, there is no official confirmation from Orbital Sciences as to that cause.  Antares was quickly put in a safe configuration, draining the 177,260 kg of LOX and 64,740 kg of RP-1 from the rocket’s first stage.  Only after the propellant was drained could the technicians enter the launch pad to inspect the second stage umbilical and the cause of the detachment.

The Orbital Science’s rocket had the green light for the launch with 20kts winds although the limit was previously set to 15kts.  According to Spaceflight 101, the second stage umbilical has not had as much testing experience as the first stage equipment since the previous on-pad testing campaign involved just the first stage.  The second stage’s Umbilical Mast was used only during the Wet Dress Rehearsal (WDH). WDH is a phase of the launch campaign when the rocket’s systems are tested before the actual launch with the rocket fully loaded with the liquid components.

A new launch attempt can come as early as April 19 or 20 depending on how repairs progress and on weather conditions at the spaceport.

Below, the launch abort from NASA TV: