Category Archives: Mathematics


wonders why NASA is considering crewing the first flight of SLS/Orion:

In a statement at the beginning of the Feb. 23 meeting of the Aerospace Safety Advisory Panel (ASAP), chairwoman Patricia Sanders said that if NASA decides to put a crew on the first SLS/Orion launch, Exploration Mission 1 (EM-1), it must demonstrate that there is a good reason to accept the higher risks associated with doing so.

“We strongly advise that NASA carefully and cautiously weigh the value proposition for flying crew on EM-1,” she said. “NASA should provide a compelling rationale in terms of benefits gained for accepting additional risk, and fully and transparently acknowledge the tradeoffs being made before deviating from the approach for certifying the Orion/SLS vehicle for manned spaceflight.”

“If the benefits warrant the assumption of additional risk,” she added, “we expect NASA to clearly and openly articulate their decision-making process and rationale.”

The point of my book was not that NASA should simply be more accepting of risk, or be reckless, but balance the risk against the reward. In my opinion, accelerating commercial crew would be worth the risk, to end our dependence on Russia, and increase the productivity of the ISS. Redoing Apollo 8 half a century after the original as a political stunt would not.

[Update a little before 1 PM EST]

NASA is about to have a news conference, probably in response.

[Update post conference]

It was the Bills Gerstenmaier and Hill. Gerst is always deadpan, but one had the impression that he’s not enthusiastic. They’re doing a feasibility study because the White House asked, and won’t be making any recommendations, just describing would it would take in terms of changes in schedule and budget. They just want to see “if they can fly crew sooner.” They expect to have some answers in a month or so (presumably as part of the input for FY2018 budget request). I wish the White House would ask them if they could fly crew sooner on Dragon and Starliner. That would be worth doing.

I can’t believe I just typed the words “FY 2018 budget request.” Makes me feel old.

[Update a few minutes later]

[Update a few minutes later]

Here‘s Keith Cowing’s story.

[Early afternoon update]

And here‘s Eric Berger’s take.

[Update a while later]

And Joel Achenbach’s.

I’d note that the reason they would only have two crew is probably a) to reduce the number of losses if it doesn’t go well and b) more margin in the (primitive?) life support.

Climate Models

are flawed. That’s putting it mildly:

Professor Curry said: “It’s not just the fact that climate simulations are tuned that is problematic. It may well be that it is impossible to make long-term predictions about the climate – it’s a chaotic system after all. If that’s the case, then we are probably trying to redesign the global economy for nothing”.

I’ve been saying that’s likely the case for years. I’ll look forward to reading her paper.

A Taxonomy Of Uncertainty

Climate science is currently somewhere between levels 4 and 5, but many (particularly ignorant adherents of the climate religion) think that it’s at 2 or 1.

Risk In Human Spaceflight

I didn’t make it to the conference in time to hear him, but I was told a couple weeks ago that Bill Gerstenmeier would be talking about many of the themes of my book. He apparently did. I would note though, that “loss of crew” isn’t just probability of killing crew; it also includes causing a career-ending injury.

[Update a few minutes later]

Related: With new types of launch systems, we’re discovering new causes of launch failure, even after almost sixty years of orbital spaceflight.

Progress On Aging

…and the resistance to it. I think he’s right that it’s not based on science or logic, but philosophy. Some people (including Isaac Asimov) think that death is necessary, almost to the point of ultimately worshiping it. Of course, some of it could be a recognition, conscious or otherwise, of the supreme disruption to many accepted institutions that it would entail, including pensions, life-time appointments, death taxes, etc.

And I hate when they use the word “immortality.” I think an eternal life would be far worse than death, but that’s not the goal; it’s simply living as long as we want to continue to live.

Update a couple minutes later]

Sort of related: GM Salmonella cures cancer. Cool. But the anti-science left will oppose it because GM.