Tag: Space Launch System

NASA will roll the Space Launch System rocket and Orion spacecraft for the Artemis I mission from launch pad 39B to the Vehicle Assembly Building (VAB) at the agency’s Kennedy Space Center in Florida beginning Thursday, June 30. 

First motion for the rocket and spacecraft atop the mobile launcher is expected to occur at 8 p.m. EDT today. The 4-mile trek atop the crawler transporter from the launch pad to the VAB will take approximately 8-12 hours. The journey previously was expected to begin just after midnight on July 1 but was moved up by several hours due to forecasted weather in the area. Teams will continue monitoring weather in the area and the start of the roll is subject to change. 

Teams completed the wet dress rehearsal test campaign for Artemis I on June 20 and have configured the rocket and spacecraft for return to the VAB. Once there, teams will replace a seal on the quick disconnect of the tail service mast umbilical to address a liquid hydrogen leak detected during the rehearsal along with final servicing and checkouts. NASA plans to return the mega Moon rocket to the pad for launch in late August and will set a specific target launch date after replacing hardware associated with the leak. 

A live feed of the rocket’s arrival to the VAB will be available on the KSC Newsroom YouTube Channel. 

Over the weekend, teams successfully conducted a test of the thrust vector control system on each of the twin solid rocket boosters of the Space Launch System for Artemis I while the rocket remains at Launch Pad 39B. The test was a follow-on to the wet dress rehearsal test campaign, which was completed last week.

During the test, engineers activated the booster hydraulic power units (HPU), which are hydrazine-powered turbines attached to hydraulic pumps that provide pressure to move the hydraulic actuators that gimbal the booster nozzles. The test verified the normal startup, operations, and shutdown of a fully integrated thrust vector control system, which controls the movement of the nozzles on each of the boosters during ascent. It also verified the rocket’s avionics system using both flight and ground software for the first time. The boosters were not ignited during the test.

The test was part of the objectives that were not completed during the wet dress rehearsal demonstration, as the rehearsal test ended at T-29 seconds during the terminal countdown. During launch, the automated launch sequencer gives the command to activate the HPUs at T-28 seconds.

Teams will drain the hydrazine from the boosters and are in the process of configuring the rocket and Orion spacecraft for their return to the Vehicle Assembly Building (VAB) at the end of the week. Once there, teams will replace a seal on the quick disconnect of the tail service mast umbilical to address a liquid hydrogen leak detected during the rehearsal. NASA plans to return the mega Moon rocket to the pad for launch in late August and will set a specific target launch date after replacing hardware associated with the leak.

A live feed of the rocket departing the launch pad and arrival at VAB will be available on the KSC Newsroom YouTube Channel.

The Artemis I wet dress rehearsal ended today at 7:37 p.m. EDT at T-29 seconds in the countdown. Today’s test marked the first time the team fully loaded all the Space Launch System rocket’s propellant tanks and proceeded into the terminal launch countdown, when many critical activities occur in rapid succession.

During propellant loading operations earlier in the day, launch controllers encountered a hydrogen leak in the quick disconnect that attaches an umbilical from the tail service mast on the mobile launcher to the rocket’s core stage. The team attempted to fix the leak by warming the quick disconnect and then chilling it back down to realign a seal, but their efforts did not fix the issue.

Launch controllers then developed a plan to mask data associated with the leak that would trigger a hold by the ground launch sequencer, or launch computer, in a real launch day scenario, to allow them to get as far into the countdown as possible. The time required to develop the plan required extended hold time during the countdown activities, but they were able to resume with the final 10 minutes of the countdown, called terminal count. During the terminal count, the teams performed several critical operations  that must be accomplished for launch including switching control from the ground launch sequencer to the automated launch sequencer controlled by the rocket’s flight software, and important step that the team wanted to accomplish.

NASA will hold a media teleconference about the test Tuesday, June 21 at 11 a.m., which will stream on the agency’s website. A live feed of the rocket at launch pad continues to be available.

 

The launch control team is filling the Space Launch System’s interim cryogenic propulsion stage (ICPS) with liquid hydrogen (LH2) followed by liquid oxygen (LOX) loading. The core stage LH2 and LOX tanks, meanwhile, are being replenished as some of the supercool propellant boils off, meaning the propellant tank will be full through the rest of the countdown.

For the wet dress rehearsal, teams will conduct a test to demonstrate the capability to stop loading the core stage LH2 flow and will then resume with replenishment.

At L-40 minutes, the launch control team will conduct a planned 30-minute hold around 3:58 p.m. EDT prior to the start of the terminal count portion of the test. Mission managers will conduct a final poll on whether to proceed with terminal count at that time.

NASA is streaming live video and live commentary of the test on the agency’s website. Venting on the rocket is visible during these tanking operations.

The launch control team has begun chill down operations and resumed the countdown clock ahead of flowing super cold liquid oxygen (LOX) into the core stage tank. The T-0 time for today’s test is now 4:38 p.m. EDT for the first of the two terminal count runs for the wet dress rehearsal.

The process for filling the core stage tank begins with the chill down, or cooling, of the propellant lines to load the liquid oxygen and liquid hydrogen in preparation for tanking. The team will slowly fill liquid oxygen into the core stage tank with the fast fill beginning soon after. Teams will then proceed to slowly fill the core stage’s liquid hydrogen tank followed by fast fill.

The next blog update will be provided when propellant loading of the interim cryogenic propulsion stage begins.

NASA is streaming live video and live commentary of the test on the agency’s website. Venting may be visible during tanking operations.

The launch director gave the “go” to start tanking operations. The countdown will resume at 9:20 a.m. EDT at T-6 hours, 40 minutes.

Tanking begins with chilling down, or cooling, the liquid oxygen propellant lines for the core stage. In sequential fashion, liquid oxygen (LOX) and liquid hydrogen (LH2) will flow into the rocket’s core stage and interim cryogenic propulsion stage tanks and be topped off and replenished as some of cryogenic propellant boils off. The team also will conduct leak checks to ensure propellant loading is proceeding as expected.

The core stage’s liquid oxygen tank holds 196,000 gallons of the propellant, cooled to minus 297 degrees Fahrenheit. Teams will fill the tank slowly at first and then will begin filling it more quickly. The liquid hydrogen tank holds 537,000 gallons. As the super cold liquid oxygen fills the core stage tank, some venting may be visible.

NASA is streaming live video and live commentary of the test on the agency’s website. Venting may be visible during tanking operations.

The mission management team chair has given a “go” to proceed with tanking the Space Launch System rocket for the Artemis I wet dress rehearsal test. As the countdown continues, the launch director will be responsible for giving the “go” to officially begin the tanking process. Meteorologists with Space Launch Delta 45 said that weather remains favorable for the test.

Tanking begins with chilling down the liquid oxygen lines for the core stage. In sequential fashion, liquid oxygen and liquid hydrogen will flow into the into the rocket’s core stage and interim cryogenic propulsion stage tanks and be topped off and replenished as some of cryogenic propellant boils off. The team also will conduct leak checks to ensure propellant loading is proceeding as expected.

NASA is streaming live video of the rocket and spacecraft at Launch Pad 39B and providing live commentary on the agency’s website. Venting may be visible during tanking operations.

The mission management team for Artemis I met this afternoon to review the status of operations and continues to press ahead toward terminal countdown for the wet dress rehearsal test. Meteorologists with the U.S. Space Force Space Launch Delta 45 currently predict favorable weather conditions for tanking operations on Monday, June 20. Weather constraints stipulate there must be less than a 20% chance lightning within 5 nautical miles of the pad during the first hour of tanking. Winds must not be above 37.5 knots and the temperature cannot be below 41 degrees Fahrenheit.

Teams are performing a pre-launch walkdown of the rocket to ensure the Space Launch System is prepared for the upcoming propellant loading operations. Later today, they will configure mobile launcher and pad facility systems and structures, and power up the interim cryogenic propulsion stage.

The mission management team will meet again Monday morning at 6 a.m. EDT or L-8 hours, 40 minutes in the countdown at the beginning of a planned 90 minute built in hold to assess operations and determine whether to proceed with tanking operations.

A summary of the schedule for the wet dress rehearsal test is available here.

NASA is streaming live video of the rocket and spacecraft at Launch Pad 39B and will provide live commentary on the agency’s website beginning with tanking operations scheduled to begin at approximately 7 a.m. EDT on June 20.