Tag: Core stage

Green Run Update: Engines Igniting as Hot Fire Gets Underway 

The hot fire is underway for the Space Launch System (SLS) rocket core stage at NASA’s Stennis Space Center near Bay St. Louis, Mississippi.

Engine ignition began at approximately six tenths of a second before T-0, beginning with Engine 1, then Engines 3, 4, and 2 ignited in sequence a few hundredths of a second apart. The test is expected to last about 8 minutes and will include three different power levels for the engines, as well as two 30-second engine gimballing, or pivoting, movements to simulate flight steering commands. Depending on the rate propellant is burned the time is estimated to range from 485 to 493 seconds to simulate launch.

Learn more about Green Run, and check back at this blog for updates on the SLS core stage hot fire test.

Green Run Update: Terminal Countdown Sequence Started

The test conductor polled the team and has approved the decision to proceed with the terminal countdown that includes the final 10 minutes before the hot fire. During the terminal countdown, the team is executing the autonomous launch sequence that simulates the countdown for the Artemis I launch. The test transitions from ground control to on-board software control of the core stage and so the test is fully automated starting at T-30 seconds. 

Key milestones during the final count include starting the core stage auxiliary power units (CAPUs) for each engine to help operate and steer the engines during the test, purging the engines with nitrogen gas to ensure they are completely clean before flowing propellant, moving the engines into position for engine start, and switching the core stage from external test stand power to internal battery power. 

Below are the key milestones in the terminal countdown: 

  • T-4 minutes: Core Stage Auxiliary Power Unit CAPU Start 
  • T-3 minutes: Engine Purge Sequence Start 
  • T-2 minutes, 30 seconds: Pre-Ignition Gimbal Sequence Started 
  • T-1 minute, 30 seconds: Core Stage to Internal Power 
  • T-33 seconds: Automated Launch Sequence (ALS) Start 
  • T-6 seconds: Engine Start Commands 

The B-2 test stand flame deflector cooling water also will begin flowing to protect the deflector from superheated engine exhaust about a minute and a half before firing up the engines, and test stand acoustic suppression water flow will begin about 65 seconds before hot fire. 

Hear the test conductor in the final minutes before the countdown during live coverage underway on NASA Television and the agency’s website. 

Learn more about Green Run, and check back at this blog for updates on the SLS core stage hot fire test. 

Green Run Update: Hot Fire Test Targeted for within an Hour

The teams are now targeting a hot fire test for NASA’s Space Launch System (SLS) rocket core stage within an hour. The team has completed a successful pressurization demonstration and is evaluating the data to ensure they are ready to proceed.

Live coverage is underway on NASA Television and the agency’s website.

Teams began the countdown for the hot fire test earlier today. This is the eighth and final test in the Green Run testing series for the rocket’s core stage that will launch NASA’s Artemis I mission around the Moon. Learn more about Green Run, and check back at this blog for updates on the SLS core stage hot fire test.

Green Run Update: NASA TV Coverage Underway for Hot Fire Test 

Countdown is continuing for the hot fire test of the core stage for NASA’s Space Launch System (SLS) rocket. The test is targeted for as early as 4 p.m. EST and is expected to last about 8 minutes to simulate launch and ascent of the SLS to orbit.

NASA Television coverage has begun. Watch live: http://www.nasa.gov/live

Teams powered up the core stage’s avionics systems Thursday, Jan. 14, and began the countdown for the hot fire test earlier today. The team is continuing to closely monitor core stage and facility performance before proceeding into the final phase of the test: the terminal countdown leading to the hot fire.

During this test, the team has repeated many of the major milestones marked during the first wet dress rehearsal including chilling the main propulsion system and completely filling both propellant tanks. Coming up at 10 minutes before the test, the test conductor will poll the team who will give the final “go/no go” to proceed with the hot fire test.

Learn more about Green Run, and check back at this blog for updates on the SLS core stage hot fire test.

Green Run Update: Teams Running Ahead of Schedule, NASA TV begins at 3:20 p.m. EST

Teams are progressing through the countdown and running approximately an hour ahead of schedule. The test is targeted for as early as 4 p.m. EST. Live coverage will begin earlier at 3:20 p.m. on NASA Television and the agency’s website.

Learn more about Green Run, and check back at this blog for updates on the SLS core stage hot fire test.

Green Run Update: Tanking Complete for Hot Fire Test

Engineers have completed tanking for the hot fire test of NASA’s Space Launch System (SLS) rocket core stage at NASA’s Stennis Space Center, and the countdown is proceeding normally.

The liquid hydrogen tank holds 537,000 gallons of liquid hydrogen, cooled to minus 423 degrees Fahrenheit. The liquid oxygen tank holds 196,000 gallons of liquid oxygen, cooled to minus 297 degrees Fahrenheit. The cryogenic fuel and oxidizer in the tanks will be replenished, or “topped off,” as needed, because some of the fuel boils off due to temperature fluctuations as the propellant is loaded. The tanks were filled during an earlier wet dress rehearsal on Dec. 20. Today is only the second time that they have been completely loaded with propellant.

Learn more about Green Run, and check back at this blog for updates on the SLS core stage hot fire test.

This infographic explains more about the Green Run tests that have already occurred before this final hot fire test.This infographic explains more about the Green Run tests that have already occurred before this final hot fire test.

Green Run Update: Test Team Gives “Go” To Proceed with Tanking

The test team conducted a pre-test briefing in the Test Control Center at the B test complex at NASA’s Stennis Space Center near Bay St. Louis, Mississippi, and gave a “go” to proceed with testing and to fill the propellant tanks.

Over the next several hours, the teams will monitor the systems and load more than 700,000 gallons of cryogenic, or supercooled, liquid oxygen and liquid hydrogen that will be fed to the four RS-25 engines.

The hot fire will last up to 8 minutes and is scheduled to take place during a two-hour window that begins at 5 p.m. EST. Live coverage will begin at 4:20 p.m. EST on NASA Television and the agency’s website.

Learn more about Green Run, and check back at this blog for updates on the SLS core stage hot fire test.

SLS core stageThis infographic provides information on the core stage including its two large propellant tanks.

Green Run Update: Start of Avionics Power Up for Hot Fire Test

The countdown is underway for the hot fire test with the core stage of NASA’s Space Launch System (SLS) rocket, scheduled for Jan. 16. Engineers have initiated power up of the avionics for the Artemis I core stage.

On Saturday, Jan.16, the management team will provide approval to proceed into the test, followed by a briefing for the test team in the Test Control Center at the B test complex.

Six barges filled with liquid hydrogen and oxygen will supply the propellant to the B-2 test stand at NASA’s Stennis Space Center near Bay St. Louis, Mississippi, where the Green Run tests are taking place. The engines use cryogenic, or supercooled, liquid hydrogen as fuel and liquid oxygen as oxidizer to create combustion.

To fill each of the six barges, three for liquid oxygen and three for liquid hydrogen, it required 18 to 20 tanker trucks worth of propellant. The barges are towed by tug from a fuel depot at Stennis to the B-2 stand.

Learn more about Green Run, and check back at this blog for updates on the SLS core stage hot fire test.

In this video, SLS Stages Manager Julie Bassler, describes avionics and flight software testing conducted in the Systems Integration Laboratory at NASA’s Marshall Space Flight Center in Huntsville, Alabama, to support Green Run.