NASA makes right decision and delays Artemis-2 launch to do a 2nd dress rehearsal countdown
NASA management announced today that it has decided to postpone the launch of the manned Artemis-2 mission around the Moon until March in order to give it time to do a second wet dress rehearsal countdown of the rocket and fix the hydrogen fuel leaks that occurred in yesterday’s rehearsal.
Engineers pushed through several challenges during the two-day test and met many of the planned objectives. To allow teams to review data and conduct a second wet dress rehearsal, NASA now will target March as the earliest possible launch opportunity for the flight test.
Moving off a February launch window also means the Artemis II astronauts will be released from quarantine, which they entered in Houston on Jan. 21. As a result, they will not travel to NASA’s Kennedy Space Center in Florida Tuesday as tentatively planned. Crew will enter quarantine again about two weeks out from the next targeted launch opportunity.
It should be understood that these hydrogen leaks have been systemic to SLS’s core stage rocket engines, which come from the shuttle era. Shuttle launches were routinely delayed due to similar leaks. This was partly because hydrogen is extremely difficult to control, as its atom is so small and light, and partly because of the engine design. This was the first rocket system ever to use hydrogen as fuel, and was thus cutting edge, in the 1970s. We should not be surprised by such issues.
Newer hydrogen-fueled designs have apparently overcome the problem. For example, Blue Origin uses hydrogen as a fuel in the upper stage of its New Glenn rocket, and though it has only launched twice, it has not had such issues on either launch.
In its announcement NASA also noted a bunch of other issues that occurred during this first rehearsal, all of which suggest that a delay is called for. There was a valve issue in the Orion capsule, some audio communication channels kept dropping out, and the cold weather affected some equipment. Waiting until warmer weather will help alleviate some of this.
On Christmas Eve 1968 three Americans became the first humans to visit another world. What they did to celebrate was unexpected and profound, and will be remembered throughout all human history. Genesis: the Story of Apollo 8, Robert Zimmerman's classic history of humanity's first journey to another world, tells that story, and it is now available as both an ebook and an audiobook, both with a foreword by Valerie Anders and a new introduction by Robert Zimmerman.
The print edition can be purchased at Amazon or from any other book seller. If you want an autographed copy the price is $60 for the hardback and $45 for the paperback, plus $8 shipping for each. Go here for purchasing details. The ebook is available everywhere for $5.99 (before discount) at amazon, or direct from my ebook publisher, ebookit. If you buy it from ebookit you don't support the big tech companies and the author gets a bigger cut much sooner.
The audiobook is also available at all these vendors, and is also free with a 30-day trial membership to Audible.
"Not simply about one mission, [Genesis] is also the history of America's quest for the moon... Zimmerman has done a masterful job of tying disparate events together into a solid account of one of America's greatest human triumphs."--San Antonio Express-News
NASA management announced today that it has decided to postpone the launch of the manned Artemis-2 mission around the Moon until March in order to give it time to do a second wet dress rehearsal countdown of the rocket and fix the hydrogen fuel leaks that occurred in yesterday’s rehearsal.
Engineers pushed through several challenges during the two-day test and met many of the planned objectives. To allow teams to review data and conduct a second wet dress rehearsal, NASA now will target March as the earliest possible launch opportunity for the flight test.
Moving off a February launch window also means the Artemis II astronauts will be released from quarantine, which they entered in Houston on Jan. 21. As a result, they will not travel to NASA’s Kennedy Space Center in Florida Tuesday as tentatively planned. Crew will enter quarantine again about two weeks out from the next targeted launch opportunity.
It should be understood that these hydrogen leaks have been systemic to SLS’s core stage rocket engines, which come from the shuttle era. Shuttle launches were routinely delayed due to similar leaks. This was partly because hydrogen is extremely difficult to control, as its atom is so small and light, and partly because of the engine design. This was the first rocket system ever to use hydrogen as fuel, and was thus cutting edge, in the 1970s. We should not be surprised by such issues.
Newer hydrogen-fueled designs have apparently overcome the problem. For example, Blue Origin uses hydrogen as a fuel in the upper stage of its New Glenn rocket, and though it has only launched twice, it has not had such issues on either launch.
In its announcement NASA also noted a bunch of other issues that occurred during this first rehearsal, all of which suggest that a delay is called for. There was a valve issue in the Orion capsule, some audio communication channels kept dropping out, and the cold weather affected some equipment. Waiting until warmer weather will help alleviate some of this.
On Christmas Eve 1968 three Americans became the first humans to visit another world. What they did to celebrate was unexpected and profound, and will be remembered throughout all human history. Genesis: the Story of Apollo 8, Robert Zimmerman's classic history of humanity's first journey to another world, tells that story, and it is now available as both an ebook and an audiobook, both with a foreword by Valerie Anders and a new introduction by Robert Zimmerman.
The print edition can be purchased at Amazon or from any other book seller. If you want an autographed copy the price is $60 for the hardback and $45 for the paperback, plus $8 shipping for each. Go here for purchasing details. The ebook is available everywhere for $5.99 (before discount) at amazon, or direct from my ebook publisher, ebookit. If you buy it from ebookit you don't support the big tech companies and the author gets a bigger cut much sooner.
The audiobook is also available at all these vendors, and is also free with a 30-day trial membership to Audible.
"Not simply about one mission, [Genesis] is also the history of America's quest for the moon... Zimmerman has done a masterful job of tying disparate events together into a solid account of one of America's greatest human triumphs."--San Antonio Express-News
Small nit, RS-10 used hydrogen in the early 60s. More accurate to say the SSME/RS-25 was the first *booster stage* engine using hydrogen.
What’s even more depressing is that the leaks that delayed Artemis I’s launch occurred in the same place as these in the Tail Service Mast Umbilicals. The fix last time was mostly procedural; which is to say, the solution was to work around the design weakness. Redesigning the core stage plumbing or the ground systems would have taken far too much time and money, time and money NASA simply did not have.
In the absence of specific evidence to the contrary emerging, I don’t blame the ground crews, who I don’t doubt worked their tails off to make this WDR work. The problems of SLS are just far more fundamental than that, as most of us here know.
Similar to Mr Underwood’s comment the second and third stages of Saturn V used the J2 engines which were H2/O2 fueled. It looks like the RS-25/SSME is derived from a never built descendant of the J-2 called the HG-3 (per wikipedia for what that’s worth). So it looks like the RS-25 is early 70’s tech which makes immense sense given the shuttle starts in development as Apollo winds down. Darned if I can find anything about whether the J-2’s had Hydrogen leaks, but it wouldn’t surprise me, Liquid H2 is annoying stuff to handle and store.
The really annoying thing is that this was a known issue with Artemis I and whatever they did to fix it didn’t help. Doesn’t make me comfortable putting a crew on where most of their value seems to be showing the flag.
Meanwhile, Falcon 9 launches are suspended oven an upper stage anomaly. At least the payloads seem fine.
When was the last time two SLS cores split wide open?
There *was* leakage, of course, though to exactly what degree . . . part of the problem is that a) NASA in the late 1960’s only had access to less capable sensors to characterize those leaks, and b) NASA had a greater risk tolerance, a tolerance it does not have today. Also, bluntly, the higher flight rate of Apollo (5 launches over 10 months at its peak) meant the hardware and processes matured faster.
The J-2, RL-10, and RS-68 are all vastly simpler engines than the Shuttle/SLS RS-25. Vastly fewer seals, valves, etc. I’m pretty sure that’s the case for the various other Hydrolox engines out there like those on the Ariane, New Glenn, etc.
When people talk about why SpaceX chose Methane instead of Hydrogen for the Raptor, the availability of Methane on Mars is always brought up as the key reason. But the leak issue with Hydrogen was brought up frequently. SpaceX simply can’t tolerate the frequency of launch delays and aborts that the Shuttle experienced.