From Garrett Reisman:

I think that Chris did a great job outlining the exciting things coming next in human spaceflight and I agree with him that the first orbital flight of Starship will be a huge milestone and a real game changer - if it works!

As far as space tourism goes - it's definitely here and here to stay. I know it can be frustrating for space fans out there in that the price is still so very high and unfortunately space tourists will continue to be billionaires or representatives of nations (or contest winners) for the near future. But remember, this was the case for commercial airlines at first too. In the early days of passenger air travel it was only millionaires and movie stars who got to fly. Even as recently as the 1960's air travel was for the elite 'jet set' and priced out of the reach of ordinary citizens. But today we have Spirit Airlines, Jet Blue and Southwest (well, most of the time) and air travel is affordable for most Americans.

This will be the case in space eventually too. The sooner the better!

From Garrett Reisman:

Hi Jude! The Shuttle was a bit bumpy during the first stage. During my first launch on Endeavour, I was seated on the middeck so I didn't have much to do during ascent. I did have a kneeboard though and I took a writing sample during the first stage and my handwriting was even worse than usual! It was much more legible during the 2nd stage. But I would say that the vibration wasn't really that bad even during the first stage. It was comparable to flying an airplane in light to moderate turbulence or being on a typical motion-simulator ride. Nothing too crazy.

As for SLS, I have no personal experience on that thing. :) Nor have I seen any analysis of the random vibe environment. But I don't think that the extra segment would make it worse, it would just make the SRB portion of the ascent last longer. Plus the additional mass of the SLS compared to the Shuttle would likely give you more inertia to reduce the amplitude of the vibration, so I think the ride would probably be quite nice. But again, I'm just speculating here!

From Garrett Reisman:

Well, I haven't asked him lately, but I hope he's not disillusioned at all. Making human life multiplanetary is the whole reason SpaceX exists and it's what motivates everyone working there on a daily basis. Nobody, especially Elon, thinks this will be easy but it's a noble goal! (As for me personally, I'm not going until there is decent pizza up there.)

From Garrett Reisman:

The biggest challenge is dealing with the radiation. We've gotten pretty good at spending up to a year in space on the ISS, but we fly under the Earth's magnetosphere and are still mostly protected from the nasty radiation outside of low earth orbit - solar particle events (SPEs) and Galactic Cosmic Radiation (GCRs). When we go back to the Moon or on to Mars we will not have that protection. A 2.5 year round-trip journey to Mars would result in a radiation dose equivalent of 1 Sievert which is 10 times as much as you would take on the ISS for 6 months and would be at about the NASA career limit for most astronauts.

The thing is, we know very well what kind of radiation is up there - how much flux density and particle energies to expect, but we have little knowledge of exactly what that type of radiation does to human tissue. So we are still learning, and there is a lot of uncertainty about how dangerous this will be for our Mars colonists.

From Christian Davenport:

As I stated above, Mars is a HUGE challenge. And Elon has acknowledged that. It's going to be extremely dangerous. As someone once told me, say you get to Mars and the mission went perfectly. You survive the entry, descent and landing and touch down softly and everything went exactly according to plan. Even then you'd be in almost constant state of emergency given how dangerous the place is. That said, people died crossing the oceans for the first time. There is a certain amount of sacrifice that goes into exploration. But in the long run, it'd be worth it to have humans on Mars. Imagines the discoveries they'd make! And as Garrett noted above, it does have a reasonable gravity and resources that could sustain a colony. Elon does enjoy a challenge and SpaceX has pulled off feats no one thought was possible.

From Garrett Reisman:

My experience was quite different from Mr. Shatner's and different from most astronauts, for that matter. I did not find the view of the Earth out the window to be in any way depressing. The Earth was beautiful - especially the Eastern part of Africa and all of Australia, both of which had magnificent red and brown hues that looked more like Mars to me than Earth.

But I did not really experience the 'overview effect' often described by astronauts as the realization that we are all one humanity sharing the same home and breathing the same atmosphere. That all the things that divide us: nationality, religion, race, gender, politics, etc. are so much less important than these things that we all have in common.

These observations are all true of course, but perhaps I wasn't suddenly struck by them because I knew this before I went to space. The fact that we are all created equal should be self-evident. You shouldn't have to strap yourself into a rocket to understand this.

From Christian Davenport:

I touched on the future of space in a previous post, but for space tourism, there's been ups and downs. Virgin Galactic flew its flight with Richard Branson ... and hasn't flown since. It's been refurbishing its vehicles and says it'll start commercial operations in the second quarter of this year. We'll see. Blue Origin had flown a series of flights and then had an engine failure and has been grounded while they investigate. They hope to resume flying this year. SpaceX has the Polaris program, funded by Jared Isaacman, which is really interesting. After flying the first all private-citizen crew for the Inspiration4 flight, he's set to do another mission this year that would feature a space walk. That's a big deal and requires a lot of training and is in preparation for the next flight, which could boost the orbit of the Hubble telescope, allowing it to remain in operation for years to come. I got a first-hand look at how the crew is preparing by flying in a fighter jet with Jared. It was pretty awesome. (And, no, I didn't throw up.) You can read about that here: https://www.washingtonpost.com/technology/2022/10/02/astronaut-training-fighter-jets/

In addition to the Polaris program, SpaceX is flying private astronauts for a company called Axiom Space, and expects another of those flights, to the ISS, this year as well.

From Garrett Reisman:

Thank you! I'm glad you enjoyed the little podcast that I did with Mike Massimino. We would definitely like to add a second season but we are on hiatus right now as we search for a sponsor so that we no longer have to fund the podcast ourselves. Hopefully we will be back at it again soon!

From Christian Davenport:

Can I second this? I love the podcast. Garrett and Mike Massimino ARE funny. Not just astronaut funny. But funny funny. Go listen.

From Garrett Reisman:

'Mission Specialist' was a designation we used during the Space Shuttle Program to refer to astronauts who were not either the Commander or Pilot. So Mission Specialists did not directly operate the flight controls on the Shuttle, but we did serve as flight engineers, robotics operators, payload operators and spacewalkers.

So 'Mission Specialist' was a bit of a misnomer since we were really generalists - trained to do all those things. Only once you were assigned to a specific flight did you specialize and train intensively on the tasks you were to perform on that mission.

Today NASA considers all astronauts to be simply 'Astronauts' and there is no longer a distinction between 'Pilot Astronauts' and 'Mission Specialist Astronauts' as there was back in the Shuttle days.

From Christian Davenport:

We get these sort of future prediction questions a lot...trying to look 20-30 years in the future. I like to narrow them a bit to see what's possible in 10 years, which seems a more reasonable timeframe. Within a decade, I think we will have people back on the moon, including the first woman and person of color as part of NASA's Artemis program. We'll see multiple companies working with NASA to escort astronauts to and from the surface and to supply them with supplies, as NASA seeks to build a permanent presence there, as I wrote about in our series. We will see low Earth orbit flooded with thousands of satellites used for the Internet as SpaceX's Starlink constellation continues to grow and others, such as Amazon's Kuiper constellation, get going. We should also see commercial space stations starting to proliferate and replace the International Space Station, which is expected to be deborbited in 2030. Not bad for a decade's work!

From Garrett Reisman:

No.

From Garrett Reisman:

Yes, for long-duration spaceflight in a microgravity environment, artificial gravity offers a lot of advantages to alleviate or eliminate various physiological issues associated with adaptation to microgravity. Also, there would be many practical advantages too, including:

• Locomotion (walking) becomes more natural

• Fluids separate (air-liquid) and there is natural convection

• Terrestrial tools and processes are easier to adapt

• Items remain where they are placed

But using rotation to create artificial gravity would require a combination of rotation rate and diameter that would present significant engineering challenges.

Consider this table which gives combinations of speeds and rotation rates to create an artificial gravity level equivalent to ours on Earth:

​

So either your spacecraft has to be huge or spin very fast. And spinning fast will cause you to run into problems associated with the limits of human physiological tolerance.

So it's not easy!

From Garrett Reisman:

Yes! I'm still the technical consultant for the show and we are just wrapping up the principal photography for season 4. Stay tuned!

From Christian Davenport:

I'm really looking forward to launch of SpaceX's Starship rocket. It has the potential to radically transform the industry (again). The vehicle is now fully stacked down in Boca Chica awaiting a wet dress rehearsal (basically a fueling test) and then a static fire of its 33 main engines. If those go well, we could see a launch at some point (pending the FAA approval of course). Elon has said it's possible it could come in early March, but there still some hurdles to clear first. There's also the first crewed flight of Boeing's Starliner spacecraft, robotic missions to the moon under NASA's CLPS program, progress toward the Artemis II mission. I outlined what's to come in space in the coming year here: https://www.washingtonpost.com/technology/2023/01/08/year-ahead-space-nasa-moon/

From Garrett Reisman:

Good question. You are right that the Moon is easier - much quicker to get to, and more importantly much quicker to get home in an emergency, and you can go pretty much anytime, you don't have to wait for a window to open up every 2 years. That means you can go for a few days, a few weeks, a few months or a few years which would let us get experience living for extended periods of time in partial gravity outside the Earth's magnetosphere in a safe and incremental manner. If you go to Mars, you pretty much have to commit for a round-trip duration of about 2.5 years.

But Mars is a much more suitable place for humans to live. It has an atmosphere, a gravity level of about twice that of the Moon, reasonable temperatures and lots of resources that can help support a human colony including oxygen for breathing, water for drinking and methane for fuel. Plus there is the promise of incredible scientific discoveries including, probably, proof of life existing outside of the Earth.

One day it might be possible for a human colony on Mars to be truly self-sustaining. That won't happen on the Moon without continual resupply from Earth.

From Christian Davenport:

I'm fascinated by the Space Force and remember hearing a top Pentagon official talk about the threats in space years ago. He recalled the general panic over Sputnik, in 1957, which was little more than a ball with a radio transmitter, and said that if the American public were paying attention to everything going on in space today--even the unclassified activity--there would be that level of concern. Now, the threats in space have come to the forefront, and we saw in late 2021 how Russia blew up a dead satellite creating a massive debris field. We've also seen in Ukraine, the rise of commercial satellite imagery playing a huge role and test the rules of warfare. I wrote a lengthy story about this. SpaceX's Starlink Internet constellation has also given Ukraine a big boost that has helped its military tremendously.

From Christian Davenport:

That was a tough blow for Virgin Orbit, which is really struggling. They needed that launch to go well. Like a lot of companies that went public via SPACs, they are now beholden to the public markets, which don't look kindly on failures even though that is a normal part of the rocket business, especially at first. A quick Google search shows their stock price down 83 percent in the last year. Richard Branson's Virgin group has continued to invest in the company but it is clearly going through a tough time at the moment.

From Christian Davenport: Living on Mars is like living on top of Mount Everest. No, it’s like living inside Chernobyl on the top of Mount Everest, given the high levels of radiation. Mars represents such an unfathomable challenge that writers such as Homer Hickam, the former NASA official and author of “Rocket Boys,” once wrote an essay titled, “A Myth Known as Mars (Psst, NASA’s not going there, pass it on.)” Even Elon Musk, who founded SpaceX with the purpose of getting to Mars, doesn't sugar coat the difficulties and once told me that "probably people will die "on the first trips to Mars. Which is why you're exactly right -- NASA wants to go to the moon first and learn how to live there before going all the way to Mars. Mars is the horizon goal that could come at some point. But NASA -- and SpaceX -- are set on going to the moon first.

Thank you so much for sharing this story! Here's a little preview of the article for you.

From reporter Robin George Andrews:

When the sinuous structures first came into view on the computer screen, John Wilding’s jaw dropped. “I was jumping around the office,” said the graduate student of geophysics from the California Institute of Technology. “I was thinking that it’s a part of the Earth that, in this moment, I was the only person on the planet who knew these things were there.”

Scientists had suspected that somewhere below Hawaii, a secret was entombed in stone — something that plays a leading role in influencing the island chain’s famous volcanism. Now, with the help of almost 200,000 earthquakes and a machine learning program, Wilding and his colleagues have finally unearthed it.

In a study published Thursday in the journal Science, the team has revealed a previously hidden collection of magma caches that may act like the beating heart of the volcanoes above. The discovery offers a possible solution to a long-standing mystery — how does magma from the deep mantle travel to the Hawaiian surface? The work gives scientists a valuable new window into the behavior of some of the most capricious, and hazardous, volcanoes on Earth.

The shallow magma reservoirs that feed Hawaii’s eruptions have been known about for some time. This is partly thanks to seismic waves, which are closely monitored in Hawaii by an ever-expanding network of sensors. The waves act like an ultrasound for Earth; changes in their speed and trajectory during their subterranean voyages tell scientists what sorts of matter they have been traveling through, providing clues to its temperature, density and composition.

But to truly understand what drives these volcanic powerhouses, scientists need to know what is happening at the interface of the squishy mantle and the solid crust. That is what the new study at last reveals in unexpected detail.

Read the full story here, free with email registration: https://www.washingtonpost.com/science/2022/12/22/hawaii-volcanoes-magma-chambers/?utm_source=reddit.com