In reply to Rodney.
Rodney,
In reading and watching his congressional testimony January 17th, I didn’t get the impression that Griffin “hated” Starship. Instead, what he disliked are decisions made by those no longer within NASA in an efforts to return to the Moon, HLS contractors who are promising a capability to land astronauts on the Moon knowing full well that the likelihood of meeting that challenge by promised dates is very low to zero, all of which means that there is a real non-zero chance that China could beat us to the Moon.
Let’s begin with one point Griffin challenged in his January testimony; NASA’s choice of a NRHO, which has a period of 6.5 days. As he testified,
“If a lunar crew encounters a problem on the surface that mandates a return to the comparative safety of the Gateway, then depending upon when that problem occurs, a multi-day wait may be required. It is possible in some scenarios to wait in low lunar orbit (LLO), but access to the Gateway is only possible at periodic intervals.”
What Griffin didn’t mention is that such a stay could last far longer in some cases, such as if the landing crew are forced to make a “touch-and-go” landing, as NASA puts it, and need to remain in a quiescent state.
Regarding NASA’s choice of lunar lander requirements (see NASA’s Appendix H: Human Landing System, Attachment F, HUMAN LANDING SYSTEM (HLS) REQUIREMENTS DOCUMENT, HLS-RQMT-001 Document Rev-R (SRD), (Document Number HLS_RQMT-001) Griffin testified,
“Tactically, the selected mission architectures pose significant concerns. SpaceX’s approach requires an impractically large number of orbital refueling operations for even a single lunar mission, while Blue Origin’s mission design depends on the development of one of the most difficult enabling technologies for long-duration space flight, zero-boiloff cryogenic fuel storage.
These architectures feature concepts – cryogenic propellant storage, likely in large depots with low, controllable boiloff – that are critical to long-term, sustainable human space exploration. But while important, their development is unlikely to be completed easily or quickly, and over the last half-century we have used up the time that could have been devoted to the evolution of Apollo-era systems to a more sustainable architecture. Like it or not, we are engaged in a
competition with others who do not wish us well; timeliness maters.”
What Griffin is pointing out are issues with the Artemis architecture. He points out that none of the HLS landers can go to the Moon without some exotic capability not available today nor likely soon, and that pursuing those capabilities isn’t as important as reaching the Moon before our adversaries do. That isn’t “hating” Starship so much as pointing out obvious downsides to the HLS portion of the Artemis architecture and faced by both SpaceX and Blue Origin.
Regarding Starship in his testimony, Griffin offers a frequentist approach in analyzing the probability of a Starship lunar landing for a given range of required refueling missions and probability of those being successful. As you might recall from probability, each refueling mission is ideally an independent event. The total probability is the product of the individual probabilities. So, if 10 refueling launches are needed and if each has a (unrealistically high) reliability of 99%, then the total probability of success of those 10 missions is 90%. But, if the reliability of each refueling mission drops even a smidge, to say 97%, the total probability of 10 refueling missions drops to 74%; a drop to 95% means a total of just under 60%. I don’t think even the most diehard SpaceX fan can look at those numbers and feel comfortable at the overall mission risk.
Perhaps I’ve evolved too thick a skin having written on space matters over the last 16 years, but Griffin’s testimony regarding Starship doesn’t sound like “hate”, as you write, but well argued, darn hard to refute concerns.
To your point that some in NASA and Blue will be happy when, not if, it becomes unavoidable that Starship will not be ready for Artemis III? With all due respect Rodney, I don’t think most outside of NASA and its contractors realize that there is a zero chance SpaceX will be ready for Artemis III. Or IV. Even Elon admitted last January that SpaceX wouldn’t be ready to land astronauts on the Moon until 2028, and given his record, that likely means sometime in the 2030’s.
The important point is that there is a non-zero chance that we’re going to have a crewed lunar capable lander by 2028 (Elon’s words, not mine) or later. The most important point isn’t whose lander, whether SpaceX or Blue Origin, gets us to the Moon. The most important point, as laid-out by those paying for the Artemis program – that would be Congress – is that we get back to the Moon before our adversaries do.
And to be clear, Griffin made the case in his testimony that between NASA’s lunar architecture, its HLS office’s HLS requirements, the lander contractors, the lunar spacesuit contractors, things are looking bad.
Nobody wants the day of reckoning when it becomes unavoidable for Congress not to notice that NASA’s NRHO choice, the HLS program office’s decision to forbid any use of SLS to launch lunar landers, and the contractors may very well prevent the US from reaching the Moon first. But that day is coming, and likely the pieces will start falling after Artemis II lifts off.
Lastly, as concerns your point about, “…knee jerk reaction can be modified for reusable launch vehicles. eg. if a vehicle fails on its 20th launch, do new or fairly new vehicles need to be stood down ? Or, if a new vehicle fails on its first launch, do proven vehicles need to be stood down ?” Having been a pilot, I know that even long legacy systems can surprise. So, no, that “knee-jerk reaction” won’t, hopefully, ever go away. As Hans Mark, a former NASA Deputy Administrator and professor of mine, once said, “Americans don’t like it when you kill their astronauts.”
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via World Space Info
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