[Space] Space Launch System, SLS - Page 12

Publicly NASA is still holding onto the possibility of a 2021 launch date for the debut flight of its Space Launch System rocket. This week, an agency spokesperson told Ars that "NASA is working toward a launch for the Artemis I mission by the end of this year."

However, a source said the best-case scenario for launching the Artemis 1 mission is spring of next year, with summer the more realistic target for a test flight of the heavy lift rocket and Orion spacecraft. The space agency is already running about two months behind internal targets for testing and integrating the rocket at Kennedy Space Center, and the critical pre-flight tests remain ahead.

NASA's Kathryn Hambleton acknowledged that the space agency has seen schedule slips. "The agency continues to monitor the rise of COVID cases in the Kennedy area, which combined with other factors such as weather and first time operations, is impacting our schedule of operations," she said. "Moving step by step, we are progressing toward launch while keeping our team as safe as possible."

Earlier this summer technicians and engineers in Florida completed stacking the SLS rocket, along with its side boosters. A "mass simulator" for Orion was then placed atop the rocket. At present NASA and its contractors are working on vibration tests of the assembled rocket, with the goal of better understanding the difference between the natural vibrations of the full stack versus those caused by external forces. This information will be fed into flight software.

NASA originally hoped to complete this work in July, but Hambleton confirmed to Ars that this vibration, or "modal" testing, is ongoing in the Vehicle Assembly Building at Kennedy Space Center.

Following this testing, the mass simulator will be removed, and the Orion spacecraft with its launch abort system will be stacked carefully on top of the rocket. This process may take a few weeks. Following this assembly and further tests, the SLS stack will be rolled to Launch Pad 39B for a "wet dress rehearsal," during which the vehicle will be fueled and much of an actual countdown simulated. However, the vehicle's engines will not be fired. A source said this wet-dress test will likely take place in November or December.

Following this test, the vehicle will be rolled back into the Vehicle Assembly Building for final checks and closeouts. Assuming the wet dress rehearsal proceeds nominally and other activities continue on schedule, the SLS rocket could launch next spring. However if there are further delays, or if the wet dress rehearsal identifies new issues, the launch would more likely slip to next summer.

Hambleton said NASA plans to soon offer an update on launch dates. After modal testing and stacking of Orion on top of the rocket, she said the agency will release a projected date for the wet dress rehearsal and the launch of the rocket itself. "As always, we will fly only when we are ready," she said.

Although years late and many billions of dollars over budget, the launch of this rocket will in some ways be a minor miracle. For a large bureaucracy like NASA, completing complex human spaceflight tasks is difficult. And the SLS rocket is complex both technically and politically.

Concerned about job losses after the space shuttle retired, Congress imposed this rocket on the space agency, down to dictating its various components to ensure that space shuttle contractors such as Boeing, Lockheed Martin, Northrop Grumman, and Aerojet Rocketdyne continued to receive substantial space program funding. Each contractor was given a "cost plus" contract that ensured funding but provided little incentive for on-time delivery.

The legislation creating the Space Launch System was passed in October 2010, at which time the rocket was expected to be ready for operations in 2016. One of the key legislators behind the rocket's creation was then Florida-Senator Bill Nelson. He relentlessly fought against the Obama administration's effort to see if private companies, such as United Launch Alliance and SpaceX, could more efficiently build a large rocket for NASA. The space agency and its traditional contractors could do the job better than anyone, he said.

"This rocket is coming in at the cost of what not only what we estimated in the NASA Authorization act, but less,” Nelson said at the time. “The cost of the rocket over a five- to six-year period in the NASA authorization bill was to be no more than $11.5 billion.” Later, he went further, saying, "If we can't do a rocket for $11.5 billion, we ought to close up shop."

More than a decade later, NASA has spent more than $20 billion to reach the launch pad. And Nelson is no longer a US Senator, he is the administrator of the space agency. The shop remains open.

NASA has asked the US aerospace industry how it would go about "maximizing the long-term efficiency and sustainability" of the Space Launch System rocket and its associated ground systems.

The request comes as NASA and its chief contractor for the rocket, Boeing, are nearing the launch pad after a long, arduous, and expensive development process that has lasted more than a decade. The heavy lift SLS rocket, carrying an Orion space capsule, should finally make its debut during the first half of 2022.

In its request NASA says it would like to fly the SLS rocket for "30 years or more" as a national capability. Moreover, the agency wants the rocket to become a "sustainable and affordable system for moving humans and large cargo payloads to cislunar and deep-space destinations."

NASA sees itself as the "anchor tenant" of the launch system and procuring one crewed flight per year for the next decade or longer. Where appropriate, the agency said, industry will "market" the large launch vehicle to other customers, including the science community and other government and non-government entities.

NASA plans to replace an engine controller aboard its massive SLS rocket after finding a communications glitch with the system’s avionics during pre-flight testing, the latest setback in a program for which Boeing Co. is the main contractor and that has been plagued by years of delays and billions of dollars in costs beyond its initial budget.

The National Aeronautics and Space Administration also said Friday it will explore launch dates for a test flight in March and April.

The rocket, which Congress authorized and began funding in 2010, was supposed to fly in late 2016. In October, NASA solicited ideas from the aerospace industry about ways to lower the costs associated with the Space Launch System.

Replacing the unit on one of the SLS’s four RS-25 engines is “the best course of action,” the agency said. The update comes after engineers preparing the rocket for flight detected a communications problem last month between the rocket’s avionics system and the No. 4 engine, and began troubleshooting the issue.

NASA plans to use the Space Launch System rocket and Orion crew capsule to return astronauts to the moon later this decade. It had set a tentative launch date of Feb. 12 for the SLS-Orion system’s initial uncrewed Artemis 1 test flight around the moon.

Boeing is the rocket’s prime contractor and the RS-25 engines, which date to the Space Shuttle program, are supplied by Aerojet Rocketdyne Holdings Inc. The main contractor for the Orion crew capsule, which is designed to take astronauts to deep space, is Lockheed Martin Corp.

For its initial four Artemis flights, NASA will likely spend $4.1 billion per launch for SLS and the Orion capsule, totaling $16.4 billion, according to a Nov. 15 NASA Inspector General report. The agency has spent more than $11 billion to date on the rocket. That document also predicted the first Artemis flight won’t be ready to launch before the summer of 2022.