Orion Pad Abort 1: Countdown and Flight Profile
NASA's Pad Abort 1 will be the first fully integrated flight test of the launch abort system being developed for the Orion crew vehicle. The test is part of an ongoing mission to develop safer vehicles for human spaceflight applications.
The information gathered through the test will be used to design and develop future systems that provide a safe escape for crews in the event of an emergency. It will be conducted at the Orion Abort Flight Test Launch Complex 32E at the U.S. Army's White Sands Missile Range (WSMR) near Las Cruces, N.M.
Launch is targeted for 9 a.m. EDT on May 6, 2010. NASA TV coverage of the test is scheduled to begin at 8:30 a.m.
› Pad Abort 1 Flight Sequence
- A day-of-launch briefing is conducted with the ground team
- PA-1 Test Director Don Reed receives a weather briefing from the missile range weather service
Systems being used for the test at WSMR are checked, including:
T-3 Hours, 30 Minutes
- Range communications.
- The telemetry bit error rate is checked to make sure the telemetry system can flow the proper amount of data expected during the test for monitoring and recording.
- Launch countdown clocks are synchronized.
- The range launch inhibit function is checked to verify the range will be able to remove the automatic launch restriction that is in place for safety until the actual launch.
- Video interface.
- Weather tower and balloon data.
- Radar and imagery tracking systems are calibrated.
- A weather balloon is released from WSMR. It is the first in a series to be released throughout the countdown to evaluate atmospheric conditions such as pressure, humidity, temperature and winds.
- The launch team members are called to their stations in NASA's mobile operations facility (MOF) and WSMR's Cox Range Control Center (CRCC).
- Communications systems are checked in the MOF.
- The launch team receives an update on weather conditions based on the first balloon released.
T-1 Hour, 50 Minutes
- The ground crew is released and the launch pad is evacuated. The evacuated area extends in a four-mile radius around the launch pad.
T-1 Hour, 30 Minutes
- Power up of the launch abort vehicle begins, including ground support systems, flight computers, inertial gyro system and instruments taking readings for the flight test.
- The parameters based on weather conditions are delivered to the vehicle to adjust the navigation.
T-1 Hour, 25 Minutes
- The appropriate road blocks are set in place onsite at WSMR.
Preparing the launch abort vehicle's systems continues, including:
- Powering on the operational and flight test telemetry transmitters and the attitude control motor.
- Commanding the navigation system into alignment mode, also known as gyro compass align.
- Checking the health and capacity of the main vehicle batteries.
- Commanding the built in test for the LAS to calibrate the attitude control motor thrust vectoring system.
- Checking the function of the LAS safe and arm device that provides a method of preventing the three LAS rocket motors from receiving signals which would cause them to ignite.
- Road blocks on the nearby public Hwy 70 are set in place for safety.
- Coverage of the flight test begins on NASA Television.
- Preparing the launch abort vehicle's systems continues, including:
- Flight data recorders are commanded to start recording
- Vehicle power is transferred to main vehicle batteries
- The pyro event controller, a device that sends signals to fire pyrotechnic events, is power enabled
- The LAS safe and arm devices are commanded to "Arm"
- The range is confirmed green and go for launch after sweeps along Hwy 70 are complete.
T-1 Minute, 50 Seconds
- The final countdown begins
- The "Abort Enable" command is sent.
- The vehicle is commanded into launch ready mode
- The "Abort Execute" command is sent.
- Liftoff and the vehicle begins a slight pitch over, which tilts its trajectory to the north
- The abort motor burns out and black smoke may still be seen from the motor for a few seconds after burnout.
- The attitude control motor begins the vehicle reorientation phase to set the proper vehicle orientation for LAS jettison, forward bay cover jettison and parachute deployment.
- The jettison motor separates the spent LAS. The attitude control motor is expected to continue to burn for a few seconds after jettison.
- Explosive bolts separate the forward bay cover from the crew module. Two small parachutes are deployed from this cover at release which continue its departure away from the crew module.
- Mortars fire to deploy two crew module drogue parachutes.
- Crew module drogues are cut-away and main chute pilot mortars fire to deploy three small pilot parachutes. The pilot chutes immediately extract the three main parachutes
- The three main parachutes reach initial "line-stretch" at 2.5% open condition
- The three main parachutes are dis-reefed to 10% open condition
- The spent LAS lands on the ground, approximately one-half to two-thirds of a mile northward of the launch pad.
- The three main parachutes are dis-reefed to full-open condition
L+1 Minute, 37 Seconds
- The main parachutes have opened all the way and the crew module falls at a slow, constant rate of 30 feet per second until touchdown.
- The crew module touches down about one mile away from the launch pad.
- The crew module and LAS recovery teams depart.
- The operational mission is complete.
- Flight test video replays on NASA Television.
- The safety road blocks are released.
- Post launch news conference on NASA TV.
- The Test Director is debriefed by the team.