ARTEMIS SRBs: THE POWER AND HISTORY

 

By Wes Oleszewski; Aero-News Network Spaceflight Analyst

Propelling the Artemis II launch vehicle will be two types of rockets. At its core the Space Launch System (SLS) booster has four liquid fuel RS-25 engines. But most prominent are the two Solid Rocket Boosters (SRB) strapped to each side of the core. When the Artemis II launches toward the Moon, it will do so by way of these incredibly powerful and fairly historic SRBs.

Developed for the Space Shuttle program the Artemis SRBs are longer. Each stands 177 feet tall and weighs in at 1.6 million pounds. Burning a polybutadiene acrylonitrile (PBAN) propellant, the combination of the two SRBs produces 7.2 million pounds of thrust at liftoff. To put that in historic perspective, the Apollo 17 Saturn V that sent the last crew to the Moon produced 7.7 million pounds of thrust at liftoff. So, when combined with the Artemis II core stage of the SLS booster lifts off with 8.8 million pounds of thrust. The total burn time is just two minutes and six seconds before the SRBs are jettisoned into the Atlantic Ocean. Unlike the Space Shuttle, the Artemis SRBs are not recovered for reuse.

Additionally, the unusually cold weather in Florida this week has drawn a number of myopic and uninformed questions as well as countless social media posts citing the Challenger disaster and comparing that to now. Challenger was destroyed by one factor. Engineers were ordered by managers to “Take off their engineer’s hat and put on their management hats” in order to push for the launch to take place outside of the test data temperature envelope. That caused the burn through of the SRB segment joints which triggered the disaster. Artemis is NOT Challenger. The current SRBs have been specifically re-engineered to assure such will not happen again.

A foundational element of the SLS booster is that it was developed to leverage Space Shuttle technology. In its earliest concepts the Shuttle did not have SRBs but instead was composed of two huge airplane-like vehicles. By the end of 1971 there was only one aircraft in the system which was boosted by two SRBs and three liquid propellant orbiter engines fueled by an external tank. This configuration was first shown in model form to President Richard Nixon on January 3, 1972. Nixon was fascinated by the model and two days later released a statement where he gave it, not only his approval, but also the name “Space Shuttle.”

Large Solid Rocket Motors (SRM) were nothing new in 1972. Because on June 8, 1965, the largest SRMs in the world boosted the first Titan IIIC from Cape Canaveral Launch Complex 40 for the U.S. Air Force. Those 120-inch diameter, five segment boosters combined to produce 2.647 million pounds of thrust making the Titan IIIC the most powerful launch vehicle in the world at that time. Thus, in the early 1970s NASA elected to use two SEBs consisting of four segment each to boost the Shuttle. Those SRBs were 147 inches in diameter and the combination of the two produced 5.6 million pounds of thrust at liftoff. Over 135 launches only one of those boosters failed and that was due to it being fired at temperatures outside of its published performance limitation. Most of the other SRBs were recovered and reused.

Thus, Artemis SRBs are assembled from former Shuttle SRBs. One adaptation is the SLS will fly on five segment SRBs rather than the Shuttle’s four segment boosters. As a result of all this, Artemis II SRBs are composed of an assortment of sections with an amazing Space Shuttle history. As an example, a combined 84 different Shuttle missions total will fly on Artemis II. The left SRB has portions with a history of being used in nine ground test firings and 47 Shuttle missions. As an example, that SRB’s forward skirt has flow 14 times. Meanwhile, the right-hand booster has also been used on nine ground test firings, and its forward skirt has also been flown on 14 missions. But that SRB has an accumulated record of an amazing 64 missions overall. Additionally, the same SRB’s upper most segment, cylinder 86, is the oldest of the segments on Artemis II and dates all the way back to STS-5 when it boosted the orbiter Columbia on November 11, 1982.

In the Artemis program the SRBs are no longer recovered for re-use. This is because the cost of recovering, refurbishing, transporting and reloading a single SRBs has, over the history of their use, added up to a good bit more than simply making a new SRB. The same rule applies to the RS-25 engines on the SLS core stage.

Yet, when you see Artemis II launch, you now know the both the power and the history.

ARTEMIS- ABOUT THAT B.W.M.

 

By Wes Oleszewski- Aero-News Network Spaceflight Analyst

We were riding aboard the NASA press-bus headed out on Wednesday, December 8, 2010, to witness SpaceX launch their Falcon 9 and Dragon combination for the first demonstration mission under NASA’s Commercial Orbital Transportation Services program (COTS 1) from Space Launch Complex 40 (SLC-40) at Cape Canaveral Space Force Station in Florida. The press had a special area on the causeway for launch coverage. As we left the main press site near the huge Vehicle Assembly Building (VAB) we got a clear view of the parking site where the Space Shuttle Crawler/Transporters were standing idle. Located nearby them was the mobile launcher for the Ares I. It was in the advanced stages of its construction which had now been halted due to Obama defunding its parent program called Constellation.

At that moment, a well-known spaceflight reporter elbowed me.

“So, what do you think about that B.W.M.?” he asked as he thumbed toward the huge gray launch tower.

“Pardon me?” I replied, having no idea what he meant.

“That B.W.M.,” he retorted with a sneer, “Big Waste of Money.”

The launch tower was a key part of a NASA’s Constellation program. That program, had been ordered by President George W. Bush in 2004. It was intended to be a replacement for the Space Shuttle and included a return of astronauts to the Moon. By 2010, however, President Obama was in office and he simply de-funded Constellation. That action myopically ignored the fact that NASA had already invested more than $11 Billion in the program. Thus, it was a fairly dark time, as humanity’s return to the lunar surface had been deleted by nothing more than political hubris. That launch tower appeared to have no future other than scrapping.

After taking a good look at the incomplete launch tower, I turned to the reporter and said,

“It’s not a waste until they break out the scraper’s torches.”

He simply snickered and shook his head.

For more than a half dozen years that reporter’s “BWM” resided quietly in place with work slowly continuing as pro-spaceflight members of congress pushed back against Obama in the effort to preserve NASA’s human spaceflight. All the while his administration and their comrades in congress did their best to drag their feet when it came to the heavy lift launch vehicle that their opposition on Capitol Hill had approved and funded. That launch vehicle became the Space Launch System (SLS). At the end of the Obama’s rein President Trump ordered the effort to return to the Moon fully restored. The program was now called Artemis and its heavy lift booster, the SLS would use the former Ares I launch tower.

On January 17, 2026 we all watched as the SLS rolled out of the VAB for its second trip to the Moon. Unlike its first un-crewed flight, this time it will carry a crew of four astronauts. The scrapper’s torches never got to it, and thus that “BWM,” wasn’t a “big waste of money." In fact all Obama accomplished was a BTW... Big Waste of Time.

 

ARTEMIS II; THE MISSION

 

By Wes Oleszewski- Aero-News Network spaceflight analyst

Not long from now NASA will launch a mission to the Moon called Artemis II. Yet, there seems to be some lack of general understanding as to what that mission is all about. Here, I will do my best to make that clear.

First off, although it is flying to the moon, Artemis II is not a mission of exploration. Instead, it is a mission of flight test. The purpose is to test critical hardware of all sorts; everything from life support systems to the onboard toilet. It all needs to function perfectly for 10 days and at lunar distance.

Additionally, the mission is equipped with computers and software that is tens of thousands of times more powerful and complex than anything used in Apollo. Often you hear the reasoning that Apollo went to the moon with computer equipment that had less capability than a modern-day kid’s toy calculator. Thus, your own home office may have more computing power than that used during an entire Apollo lunar mission. Yet, a single lightning strike across the street from your home can knock that office of yours off-line. The point is that NASA must be able to test this modern technology and computing power in deep space. And that is where assorted cosmic interference can do nasty things.

Another issue is the systems have to be exercised in flight. Just sending an uncrewed Orion to the moon and back only demonstrates reliability to a certain point. In a 10-day mission the four astronauts will be living, working and generally bumping around inside the vehicle. That level of human factors alone will generate a laundry list of changes in procedures and hardware use.

Both the Orion crew module and its service module need to operate without question. An example of that not happening, recently took place with the Boeing CST-100 Starliner spacecraft. That vehicle while flying up to dock with the International Space Station (ISS) suffered a series of cascading thruster failures. Due to that, NASA decided to hold the crew aboard the ISS and have them return aboard a Dragon spacecraft.

The one thing which must be the same as Apollo is dependability. The Block II Apollo Command Modules never let their crews down. If there is anything in the Artemis program that must be the same as Apollo, it is that level of dependability. The crew of Artemis II are ready to ring out their vehicle in a deep space test flight.

So, when you see Artemis II flying, think more of test piloting rather than a grand exploration. They will be proving the hardware and software which will make a foundation for the explorers who will follow them.