[ad_1]
NASA has unleashed the main stage of its massive new rocket – the Space launch system (SLS) – Saturday, January 16, during a critical test that appeared to end prematurely when the booster motors shut down earlier than expected.
Smoke and flames erupted from the four RS-25 engines that power the giant rocket’s base booster, a centerpiece of NASA’s Artemis lunar program, as it roared atop a test bed of The NASA. Stennis Space Center near Bay St. Louis, Mississippi. Ignition occurred at 5:27 p.m. (22:27 GMT), with 700,000 gallons (2.6 million liters) of cryogenic fuel flowing through the engines as they roared for just over a minute , much earlier than expected.
The test was to last 485 seconds (or just over 8 minutes), or the length of time the engines will burn during flight. After the engine was fired, the four RS-25 engines appeared to fire for about 1 minute, 17 seconds before they were shut down, although NASA will likely have the final numbers later today. A press conference was due to start two hours after the test.
“Obviously our engines were shut down before the 8-minute deadline,” NASA’s senior stage engineer Alex Cagnola said on a NASA TV show. “But we have a lot of good data to look at and hopefully we can move on.”
Video: How NASA’s megarocket SLS engine test works
At a press conference on Tuesday, Jan.12, John Shannon, vice president and SLS program manager at Boeing, said the engines had to run for a period of time to get the data they needed. “If we had an early stop, for whatever reason, we get all the technical data we need to have great confidence in the vehicle at around 250 seconds,” Shannon said.
Since the test was stopped in less than 250 seconds, and before the teams were able to swallow (or move) the engines, the exact amount of data and the confidence of the teams in the vehicle remains to be determined. .
Saturday’s test was initially moved one hour to 4 p.m. EST (19:00 GMT) as preparations for the test were ahead of schedule. However, during the countdown, engineers paused the countdown to perform water deflection system checks and other tests on the engine test bench. The teams were able to resolve the issues and resume the count in time to complete the test on Saturday, despite the short turnaround time.
Exercise, known as a hot fire test, tested the main components of the space launch system’s thruster – the four RS-25 main engines, fuel tanks and computers, and rocket avionics. The test simulated a launch while holding the rocket firmly in place, secured to a test bench. (The same test bench was used to test the engines of both NASA Saturn V rocket and the space shuttle orbiters.)
“The SLS rocket is the most powerful rocket ever built in human history,” NASA administrator Jim Bridenstine told NASA TV shortly before the test. “This is the same rocket that, by the end of this year, will launch an Orion crew capsule around the moon.”
Anatomy of the Space Launch System
NASA’s space launch system was first designed in 2011 and is finally coming together for an unmanned trip around the moon later this year.
Each SLS rocket will use four RS-25 rocket motors to launch its 212-foot (65-meter) center stage. The rocket will also rely on two solid rocket boosters and an upper stage to launch NASA’s Orion crew capsule beyond low Earth orbit.
Together, SLS and Orion are the two main components of NASA Artemis Moon Program who seeks to bring astronauts back to the moon in 2024.
The agency currently has 16 RS-25 engines on hand, which were salvaged from the now retired agency space shuttle program. These engines will be used on the first four SLS rocket launches for Artemis missions 1 through 4. (These flights include the program’s first crewed moon landing, Artemis 3, and a follow-up flight.)
Space launch system: NASA’s giant rocket for moon missions Artemis explained
Since the engines from these early missions are shuttle scraps, they have been overhauled with new computer controllers as well as upgrades that ensure they can handle the higher performance demands of an SLS launch, have NASA officials said.
This is not the only recycled part of past programs. Like engines, solid rocket boosters have also been used to propel NASA’s fleet of space shuttles into orbit. They, too, have been modified to work with SLS. But they will not be used forever. As technology evolves, side boosters will be replaced with advanced boosters.
The SLS will contain a pair of these boosters attached to the side of the center stage. It consists of four RS-25 engines at the base of the vehicle, and stacked on top will be the rocket components with an Orion capsule and a service module perched on top.
The entire vehicle will be capped with a launch orbit system designed to move the capsule away from the rocket in the event of a problem during a launch.
Road to the test bench
NASA has systematically tested the various components of the SLS rocket over the past few years.
The agency tested each of the main engines separately to ensure they started as expected. And to make sure the flight hardware meets design expectations, NASA has started what it calls a “Green Run” test which included the craft’s avionics test, launch countdown and schedule, refueling procedures and more.
The tests went well, but not without problems. A global pandemic coupled with an unprecedented number of tropical storms and hurricanes impacting test sites are adding to the delays caused by hardware problems.
NASA conducted two separate “wet dress rehearsals,” in which fuel was loaded into the engines and then drained. During one of these exercises, which took place on December 20, the test ended early unexpectedly, which delayed today’s hot shot test from December, according to a statement from NASA. Another attempt to refuel earlier in December was blocked due to temperature issues.
Saturday’s engine test race also saw a streak delays due to the ongoing coronavirus pandemicNASA officials said. The social distancing restrictions meant that many NASA officials, engineers and other members of the SLS team (as well as the media) could not be present in person to witness the rocket pivot test. Many of the team sent in videos to participate virtually.
Testing is the key
The aim of the test is to ensure that the rocket can carry an unequipped Orion spacecraft on a trip around the moon later this year.
With the firing of all four RS-25 engines, it closed a critical period of pre-flight testing for the rocket that NASA called its “green race”. This series of tests began with stress tests on the physical structure of the rocket and ended with today’s hot shot test.
The purpose of the test was to perform launch day procedures and ignite all four engines, allowing them to burn for just over 8 minutes – just below the amount of time they will burn during actual flight.
As expected, the engines came to life, producing 1.6 million pounds of thrust as they burned for 485 seconds. The full duration test will provide engineers with massive amounts of data on the performance of the main stage.
It will take several days for teams to review the data before taking the major step of its next task: the renovation and eventual transport to the Kennedy Space Center launch site in Florida.
Once arrived, it will be integrated with the rest of the vehicle already on site. This includes its two solid rocket boosters, which are currently stacked in the vehicle assembly building at the Kennedy Space Center.
The boosters have already been tested before being shipped in segments to Florida. Each booster consists of five segments stacked on top of each other.
The Orion spacecraft is finished and almost ready to be attached to the top of the SLS once the rocket is fully assembled.
Editor’s Note: NASA will hold a press conference on NASA TV later this evening to update the media and the public on the results of the Space Launch System hot-fire test. You can watch it live here. It was expected about 2 hours after the test, or about 7:30 pm EST (0030 GMT). This story will be updated as more details become available.
Follow Amy Thompson on Twitter @astrogingersnap. Follow us on Twitter @Spacedotcom or Facebook.
[ad_2]
Source link