I will be hosting live commentary over Zoom during the Splashdown of Crew Dragon (the return to Earth of NASA’s #LaunchAmerica: the first launch of crew to orbit in a commercial spacecraft).

When: Sunday, August 2, 2020 11:15am Pacific Time

Where: Register in advance for this meeting (because it is public): https://zoom.us/meeting/register/tJYkfuqvrz8tHtF1InWLMWB77rwAopWZc8cl

I will probably be livestreaming the splashdown via https://www.nasa.gov/live within the commentary. I will be commentating directly with you, and will attempt not to be talking over the NASA and SpaceX official commentators, but explaining some terms they use and answering your direct questions.

To watch the livestream of the launch on your own go to https://www.nasa.gov/live to get the best links from NASA.

Here’s my Twitter summary of why the launch was historic, and hence the return-to-Earth as well:

This is going to be a very big step. If I’m checking my history correctly, this will be the first crewed orbital flight of a truly-new design of spacecraft since the Space Shuttles first orbited in ~1981. I’m not dismissing SpaceShipTwo’s accomplishment of suborbital human spaceflight in 2018, but orbital is definitely different.

I am also not dismissing 神舟(Shenzhou) in 2003, though you have to admit that 神舟 is very, very, very similar to Сою́з(Soyuz). In trying to capture the significance of this upcoming crewed Dragon launch, the technology of 神舟 didn’t *feel* as new.

I guess I’m trying to say this *feels very different and very new. As we’re living in a time of heightened anxiety with the pandemic, things that *feel like risky new technology can *feel even newer or riskier. Let us not mistake *feelings for quantitative and scientifically-conducted risk assessment in any of our scientific endeavors right now, be they human spaceflight, quarantine advice, or the accelerated development of massive SARS-Cov-2 testing and vaccines.

See you in the morning!

-Alice

I will be hosting live commentary over Zoom during NASA’s #LaunchAmerica: the first launch of crew to orbit in a commercial spacecraft. The launch is currently targeted for Wednesday, May 27, at 1:33pm Pacific time. I will start my commentary at 1:00pm Pacific Time. This will all be rescheduled if the launch gets rescheduled.

When: Wednesday, May 27, 1:00pm Pacific Time

Where: Register in advance for this meeting (because it is public):
https://zoom.us/meeting/register/tJ0rdu6rqTwiGtThxCfYc7rK-UgGcvDTj6qY

I will probably not be livestreaming the launch within the commentary. It’ll be better quality if you open the Zoom link up in one tab, and the launch livestream in another. I will be commentating directly with you, and will attempt not to be talking over the NASA official commentators, but explaining some terms they use and answering your direct questions. If it does seem to work better, then I will try livestreaming the launch also. We’ll see. Technology, yo.

To watch the livestream of the launch go to https://www.nasa.gov/beourguest and register to get the best links from NASA. I will also post more links here and in the Zoom chat once we’re rolling tomorrow.

Here’s my Twitter summary of why this is historic:

This is going to be a very big step. If I’m checking my history correctly, this will be the first crewed orbital flight of a truly-new design of spacecraft since the Space Shuttles first orbited in ~1981. I’m not dismissing SpaceShipTwo’s accomplishment of suborbital human spaceflight in 2018, but orbital is definitely different.

I am also not dismissing 神舟(Shenzhou) in 2003, though you have to admit that 神舟 is very, very, very similar to Сою́з(Soyuz). In trying to capture the significance of this upcoming crewed Dragon launch, the technology of 神舟 didn’t *feel* as new.

I guess I’m trying to say this *feels very different and very new. As we’re living in a time of heightened anxiety with the pandemic, things that *feel like risky new technology can *feel even newer or riskier. Let us not mistake *feelings for quantitative and scientifically-conducted risk assessment in any of our scientific endeavors right now, be they human spaceflight, quarantine advice, or the accelerated development of massive SARS-Cov-2 testing and vaccines.

See you tomorrow!

I was alerted last week to the possibility that people might be asking questions about the scientific possibilities suggested in the movie Oblivion, released today. May I point out that ripping apart the science in movies like this is a form of entertainment for me? If you aren’t interested, go read someone else’s blog.

Shameless plug: You should go see Oblivion at Pacific Science Center in IMAX.

In order to address these issues, I have to talk about the movie, but I’m going to do my best not to spoil the whole thing since you might want to see it.

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In Oblivion the year is 2077, and the Moon has been destroyed by robot aliens. This caused widespread destruction due to earthquakes and tsunamis. The tectonic activity has stabilized, but humanity has migrated to Titan. A few people are still on earth guarding the Hydro Rigs that convert seawater into energy for the Titan colony. The Moon is depicted as being half there, half a debris ring around the Earth.

Meteorites

Yes, and the movies doesn’t have any.

The method of the Moon’s destruction isn’t dwelled upon in the movie, but I get the impression it was a nuclear war. Let’s just assume the alien race has enough power to blow up the Moon, and they do so.

The first effect is going to be a huge number of meteorites slamming into the Earth. These aren’t going to be just a few that make some pretty craters, that’s a lot of mass up there in the Moon and a lot of it is going to come raining down on the Earth. I think this is going to be the most devastating effect. I’ll have to run some hypothetical math (or maybe Phil Plait or XKCD What-If will do it before me), but it seems like this rain of debris would be significantly more destructive than the meteor that probably killed off the dinosaurs. There will be more mass than that single meteor (a LOT more mass), and it will rain down over more of the planet. I suspect it will be moving more slowly though, so that may mitigate the effect a bit.

Last I heard the dinos died out either because of the ensuing nuclear winter (too much ash and dust in the atmosphere, cooling the climate) or a nearly instantaneous ignition/superheating of most of our atmosphere, which would have broiled everything aboveground leaving burrowing animals and sea-life alone. Whoo-ee. Someone check my references on that. (Jonas? Jonas? Why are you in New Zealand when I need you?). So, the Moon debris falling down would be very bad.

But somehow no meteorites from the lunar explosion.

Earthquakes

Sure. There could be earthquakes if the Moon blew up. Mostly due to IMPACTS FROM METEORITES. Barring those I’m having trouble envisioning why we would get earthquakes from the Moon breaking up in orbit. So my answer is:

Not the way they are in the movie.

The Moon does pull tidally on the Earth’s crust a little bit, but the effects are not the kind that we generally notice over the span of human lifetimes. Even by spreading out the mass of the Moon into more of a ring, you’ll also lose that tidal flex. I would expect that to make fewer earthquakes, not more. In the process of the Earth settling from a shape influenced by the Moon into a shape influenced by the debris ring we will have some earthquakes, but not ones that destroy cities.

If we were Jupiter’s moon Io, and it was Jupiter that was destroyed then yes, we would feel significant tectonic stress. But we’re not.

The Moon’s tidal forces do assist in keeping the Earth’s crust heated, and possibly impact the fact that we have moving tectonic plates in the first place. Now that tectonic plates have formed though, it will take a bajillion years to slow them down and stop them.

Tsunamis

Let’s say yes.

We all know the Moon is the major influencer on our tides here on Earth. The Moon and the Sun share the duties of causing the Earth’s tides, but the Moon does 2/3 of the work, and the Sun only does the leftover 1/3. So there’s a lot of water caught up in the tidal oval at any given time. The Earth rotates through that oval of influence, giving us two high tides per day.

Here’s a diagram of the tidal oval. It’s exaggerated a lot:

From: http://hyperphysics.phy-astr.gsu.edu/hbase/tide.html#stid

That’s a LOT of water to displace, and most of it is at the equator. So if the Moon suddenly disappears, that peak will slosh back down and (after sloshing back and forth a lot) will settle into a more even distribution. With half the Moon still in place, we’ll only be redistributing about 1/3 of that water. Also, since the Moon’s debris is staying in orbit (forming a ring), we won’t need to displace the water towards the poles, it can stay concentrated near the equator. Even though that is a significant reduction, it’s still a lot of moving water, suddenly. That’s a tsunami: a LOT of ocean water being displaced suddenly.

A caveat: it looks in the movie as if those tsunamis carried a lot of sediment with them, enough to cover all but the very top of the Empire State Building. Tsunamis from the destruction of the Moon would have no reason to dredge up sediment from the bottom of the ocean, so I don’t know where it is implied that material came from. I have no problem with the water washing that high in a significant Moon event, but not mud or sand.

A Ring around the Earth

When you first see the movie you’ll say “Alice! That ring is around the Moon, not the Earth.” Just wait, later on it becomes visible as a ring around the Earth.

Yes and no.

I guess that’s my answer for all of these. This is the case where I need to pull out my solar system dynamics textbooks and run through some equations first though.

Yes: soon after the destruction of the Moon, any debris will end up in orbit, and a lot of that will be leading or following the Moon’s own orbit, since that’s where it originated. This will give us a lumpy ring. It won’t be as bright as in the movie, because it will be mostly dust and boulders. Saturn’s ring is very visible because it is mostly very reflective ice. Dust is darker.

Over 60 years (from the Moon’s destruction around 2017 or later until the time of the movie in 2077), some of that debris will have reentered the Earth’s atmosphere, and the rest will also still be orbiting in that ring.

Over a more extended period of time I don’t think the distance of the Moon’s orbit is a stable place for a ring system. The dust will either recoalesce into one or a few Moons, drift to a different orbit, or fall down to the Earth.

I haven’t had time to sit down and calculate any of this out, but these are my reasonably-well-educated guesses.

References

If We Had No Moon, Bernard Foing http://www.astrobio.net/index.php?option=com_retrospection&task=detail&id=2507

Sun’s Tidal Effect http://hyperphysics.phy-astr.gsu.edu/hbase/tide.html#stid

365 Days of Astronomy http://cosmoquest.org/blog/365daysofastronomy/2009/03/28/march-28th/

NASA http://helios.gsfc.nasa.gov/qa_earth.html#quake

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~ A l i c e !

Which missions do you wish people wouldn’t forget about? Here are some of mine:

• Apollo 11. Humans first walked on the Moon. 2 American men: Neil Armstrong and Buzz Aldrin. Michael Collins piloted.
• Sputnik. First man-made object in orbit – a beeping satellite from the USSR.
• The Vostok Program: Yuri Gagarin – first human in space, first human to orbit the Earth. USSR.
• Mercury (specifically “Freedom 7”): Alan Shephard – first American in space.
• STS “Space Transport System” – the official name of the Space Shuttle program. Many important occurrences.
• Pioneers 10 & 11, Voyagers 1 & 2 – Our first “close” views of the other planets.
• Hubble – Hubble’s photos changed the average person’s view of astronomy, and advanced the science immensely.
• Skylab, MIR, and ISS – these are some of our space stations, we had them serially not simultaneously. ISS is the only one now.
• SpaceShip One: Burt Rutan flew the 1st commercial (non-government/non-military) flight into space on a reusable craft.
• Last but not least, keep these in your heart: X-15, Soyuz 1, Soyuz 11, Apollo 1, Challenger, Columbia.
• Just a couple inspiring names: Sally Ride, Valentina Tereshkova, John Glenn, Shenzhou

Links

• Want more?
• Disaster Details
• If that link doesn’t work – use this one. Or the source.

~ A l i c e !

I went to see the press preview of  Hubble 3D at Pacific Science Center’s Boeing IMAX Theater. It’s opening on March 19th (2010) – tickets here. Full disclosure, in case you were unaware, I am employed by Pacific Science Center but my comments here are my own.

I have been looking forward to this film for months, and I was struck by the similarity to some of what I do. So, if you will excuse the conceit, I would like to share a double story with you.

Hubble

Hubble 3D is partially just plain fun: fly-throughs of actual beautiful Hubble images, three-dimensionalized by some very talented folks who worked with some very intelligent astronomers to be as accurate as possible. As much as I love Hubble images, the other part of the movie is what I enjoyed most. The story of how to fix an ailing telescope, 350 miles above the Earth’s surface. I’ll give you some hints – but go see the movie for yourself to get the full story of the repairs to Hubble.

A Day in the Life

Then there’s what I do. In November, the planetarium projector also chose to show its age. On its way down the elevator shaft it slipped the last six inches and refused to budge. This was extremely scary for all of us, and after several calls to the techs in Pennsylvania we decided we needed to winch it up.

Here’s where it gets similar to the Hubble mission. Compare these two pictures:

That’s Astronaut Mike Massimino in the center, with his head stuck up in the bowels of Hubble. Astronaut Mike Good’s  hands are in the lower right, holding a tool that looks like a drill with a long bit.	And this is me. Five feet down an elevator shaft that’s about  three-and-a-half or four feet in diameter, trying to reach down another two and a half feet to unhook a chain.

The astronauts on STS-125 had quite a lot more to contend with, they were wearing space suits, the stakes were higher, their equipment larger and more expensive, but we both succeeded through teamwork, specialized tools, perseverance, and time.

Nemeses

Ah, and then the equipment just seemed to fight back:

This is not the handrail that Astronaut Mike Massimino had to break off, but it looks very similar and I can’t find a photo online of the broken one.	This chain and sprocket caused a day and a half of work for several people. Arrrgh! But, we succeeded!

Specialized Tools

In order to safely remove small screws in space, and be able to manipulate power tools while wearing gloves, they developed some very specialized tools for the Hubble repair missions.	Well, we were inspired by this – but  Mark made a tool very similar, but with a slightly pointier point. Unfortunately, that tool is at the bottom of the elevator shaft now, so I can’t show you a real picture. (Coat Hanger credit: Demion on Flickr)

Teamwork

This is the team, and this is their poster: I love it.	Well, we may not have a movie poster, but we couldn’t have lifted the projector without the work of a large number of people, not the least of whom were Mark Rogers, Kim Chinn, Sarah Huschle, Chuck Hanna-Myrick, and the planetarians! Gary Kezele made the commemorative sketch.

Want More?

Hubble

STS-125 (the repair mission)

Hubble 3D in IMAX – the newest IMAX space movie.

See it in Seattle (Use this link until March 19th) (Use this link after March 19th)

~ A l i c e !

P.S. All astronaut photos are from NASA. As you might expect.

How long does it take to get to Mars? Well, that depends. As per usual I’ll give you the short answer first: 5-7-ish months.

Depending On …

• Energy

  • The faster you go, the more energy you must expend to get there. Energy is expensive.

• When You Leave

  • You could leave any time you wanted to, but if you don’t leave at the right time you’ll just end up chasing after Mars, or doodling around the orbit waiting for Mars to catch back up to you. It’s like catching a bus – you don’t want to wait around at the bus stop too long, but you also don’t want to miss the bus.

• Length of Stay

  • If you’re going to all the trouble of going to Mars, I would think you’d want to spend a little time there. Then, your return journey has to be timed just right

Some Choices

A Hohmann transfer orbit is one of the most common ways to move between orbits. It is energy-efficient without being incredibly slow.

The Classic Choice:

Hohmann Transfer - Image Credit: Gary Kezele

So, if you do a couple of plain Hohmann transfer orbits – one on your way to Mars, one on your way back, you end up with about 7.5 months each direction with a nice long stay of over a year on Mars.

Speed It Up:

Get There Quick - Image Credit: Gary Kezele

Well, why waste all that time en route? If you up your energy consumption you can move between orbits a little faster. This is very similar to a Hohmann transfer orbit, but significantly quicker. Travel time is more like 5 months each direction, and you still get to spend almost two years on Mars.

Early-Return

Early-Return Mission - Image Credit: Gary Kezele

What if you get there and need to come back? What if you’re just not sure what might happen and don’t want to invest a lot in spending time there? If your goal is more to prove that it is possible to go there than to spend time there, you might prefer an early-return mission. You sacrifice a lot on the return mission: it takes almost 10 months to get home. For a “footprints on Mars” mission (similar to our first Moon missions) this gets you just under a month of study-time on Mars. Also, if things start to go wrong early on in a longer mission, you could abandon the remaining mission and return early using this path. Plus you might get to swing by Venus!

Ultra-Slow

There are two more quick options I’d like to mention. The ultra-slow route – spiraling out from Earth’s orbit, eventually reaching the orbit of Mars. The Dawn spacecraft is using an orbit like this and a low-energy ion engine to reach the asteroid belt over the course of six years.

Don’t Come Back

It sure takes months off your travel time if you just go and don’t return. Like the settlers of the American West and all over the world – the people who make a new world their own are the people who set out with that in mind. This is a much cheaper mission – and there are some fascinating arguments for it.

Want More?

http://nssdc.gsfc.nasa.gov/planetary/mars/marsprof.html
http://image.gsfc.nasa.gov/poetry/venus/q2811.html
http://dawn.jpl.nasa.gov/mission/trajectory.asp

~ A l i c e !

As you may or may not have figured out, one of my other interests is baking, as well as eating yummy food.

What better for the holidays than a post all about cooking in space? Turns out, although most astronauts rehydrate and reheat the packages of food, one astronaut at least experimented with combining those foods and ways of cooking in space. Check out Nancy’s story about Astronaut Sandy Magnus and her adventures in preparing holiday food – over at Universe Today.

You can also look into Sandy’s journal about cooking in space, or stop by my collection of recipes (none of which were ever prepared in space, sadly).

Happy Newtonmas and Merry Christmas!

~ A l i c e !

Thanksgiving is upon us, here in the United States. By now your in-laws, friends, acquaintances, and family have probably learned that you think Astronomy is cool. Which means you’re the expert. Awesome!

Wait, did that worry you a bit? Being called an expert in astronomy? I sure get worried when I’m called an expert. So, just for you, an astronomy cheat sheet for Thanksgiving dinner-table conversation! So, if you want to steer the conversation away from politics and religion, here are a few ideas – in no particular order.

Topics You May Be Asked About

Water on the Moon

Question: So I hear they discovered water on the Moon! Or, what was that a couple weeks ago about NASA crashing something into the Moon?

Answer: Yup! There have actually been a couple of discoveries recently, but when NASA’s LCROSS mission slammed into a crater at the Moon’s south pole, it kicked up a cloud of material (which is what they were hoping for), and they discovered water and a lot of other interesting molecules in that cloud. Is it enough to use? Yeah, but we’d have to clean out those other chemicals first which might be difficult.

More info about Water on the Moon.

2012

Question: I hear the world is going to end in 2012, what’s up with that?

Answer: No. The 2012 hoax is based on a bunch of misinformation and misinterpretations. The planets won’t be aligned, the poles won’t flip, and neutrinos from the Sun won’t boil the Earth’s interior. Intriguingly, we will have a solar maximum in 2013, so 2012 promises to have some nice sunspots, flares, prominences, and other Sun activity.

More info about 2012.

Mars

Question: These questions have a wide range: from “Is there life on Mars?” to “How are those Mars missions doing anyway?”

Answer: Yes, we’ve found water on Mars, though not a lot. We’ve found that water many times. The most recent surface expeditions to Mars were Phoenix (at one of the poles, currently probably under a layer of ice), Spirit and Opportunity (which both had rovers). Phoenix is now defunct, as there is no sunlight from which it can draw power. Even when the Martian winter recedes and the Sun shows up again in spring don’t expect Phoenix to turn back on. Spirit and Opportunity have been going for almost 6 years now – and their original mission was slated for 90 “sols” (days on Mars). Their 6-year anniversary is January of 2010. At this moment Spirit is stuck in a sand trap, and the NASA JPL techs are working hard to extricate her.

And no, we haven’t found life there yet and the chances are getting slimmer.

More info about water on Mars, life on Mars, Phoenix, and the rovers.

Hey, What’s That?

Question: Hey, what’s that?

Answer: Jupiter.

Well, it is possible that it is Sirius or Mars, but you’d have to be up fairly late with your family for that to be the answer. If you’re out for a post-dinner walk, and you notice something bright in the sky, it is probably Jupiter. To double-check yourself, Jupiter is low in the southwestern sky before sunset here in the United States.

More info on what’s in tonight’s sky.

CERN

Question: I hear they turned on that world-destroying black hole maker again.

Answer: Yup! I mean, no … it isn’t a world-destroying black hole maker, but they (CERN) did turn on the “LHC” (Large Hadron Supercollider) in Switzerland. They’ve turned it on, spun it up, and even gotten collisions of particles! Yay! Now, it will still be a bit until they discover that strange particle they’re looking for. And maybe a little longer until they prove that dark matter is real.

By the way, did you know that CERN stands for European Organization for Nuclear Research? How does that make sense? (Well, okay, I get the “RN” instead of “NR” part, but … I don’t get the “CE” instead of “EO”)

More info on CERN.

Topics You Might Like to Bring Up

Free Spirit

Pitch: We have a remote-control car stuck in a sand trap on Mars.

Details: Well, it’s actually a lot cooler, more difficult, and more emotionally wrought for many folks than just a remote control car and a sand trap. Spirit, one of our two rovers on Mars has gotten hung up in some soft soil. It has been trapped for weeks – the soil is softer than they expected, and there may be some loose rocks hidden by the sand which make plotting a course almost impossible. Every movement is like sinking into quicksand – it causes the rover to slip deeper into the soil. Also, there are some indents on the bottom of the rover that could easily get hung up on some sharp rocks underneath Spirit’s belly if the rover sinks too far. The rescue operation is continuing.

More information on Free Spirit.

Galileoscope

Pitch: The only decent cheap telescope on the market.

Details: For the International Year of Astronomy a working group was put together to design a cheap, decent telescope kit, that any kid could use to see the rings of Saturn. This telescope is amazing for the price – and you get to learn how the optics work while putting it together. It also only takes about 10 minutes to assemble and no tools are required. This is a good beginner scope, but you should complement it with a tripod to get any use out of it at all. I highly recommend the give-one-get-one option, because they’ll send Galileoscopes to kids in underserved countries with these donations.

More information on the Galileoscope.

Shuttle Missions

Okay, watch out because this one could turn into a political conversation.

Pitch: There are only 5 shuttle missions left until the Space Shuttles are all retired.

Details: It’s about time we created a new ground-to-orbit technology. The Shuttles were launched in the 80’s (raise your hand if you’re still driving a car that was built in the 80’s. I thought so – not that many of you). Besides, if your clunker breaks down you’re stuck on the highway and you call AAA for a tow. If your shuttle breaks down … well, we’ve seen that twice and it is heartbreaking. I remember both vividly, and I’m actually just barely old enough to be able to remember the first one.

More info on the shuttle retirement, and the replacement.

Enceladus

Pitch: Yowsers watch out for those geysers!

Details: Cassini, which has been in orbit of Saturn for some years now, has just done a couple of screamingly-close flybys of Saturn’s moon Enceladus. Why do you care? Because Enceladus is on the short list of places in our solar system we rate as likely for finding life. In fact, one scientist has ranked it as “more habitable” than Earth, based on a set of seemingly-reasonable characteristics.  You also care because, well, why are there geysers on this moon? What are they made of? What do they mean? We don’t know all those answers yet, but Cassini will help us figure it out.

More images from Enceladus.

My favorite (click and look closely at the dark side …):

One of Cassini's images of geysers on Enceladus.

I wish you a wonderful Thanksgiving, if you celebrate it, and a wonderful Thursday, Friday, and weekend if you don’t.

~ A l i c e !

Question: As you probably know, several of us from Pacific Science Center, went to a NASA Forum at the Museum of Flight on January 25, 2008. NASA officials talked about a very complicated plan for a manned-Mars mission sometime this century, using a permanent Moon base as a starting point. Have you heard anything more about this possible reality?

The Constellation Program

The program you’re asking about is called “Constellation” and the first goal is to put people back on the Moon by 2020. Indeed, the program is up and running and NASA is making progress as each day passes. The Constellation Program has three basic components. Let me look into the status of each.

The Orion Crew Vehicle:

Status: design and component mock-up

Currently NASA has a mock-up of the Launch Abort System being driven across the country to the White Sands test range. (Trust me, you want the launch abort system to work.). Actually, by the time you read this the LAS has probably already arrive at the facility for testing. NASA hopes to have finished testing and begin building by 2012.

The Ares Launch Vehicle:

Status: components built, in preliminary testing

As you can see from the picture here, the Ares 1 rocket fires just fine. Now the question becomes – is that firing under control? Is it exactly the thrust needed? Do the scientists and engineers have the control over it that they expected to have? NASA hopes to have finished testing and begin building by 2012.

Ares Rocket Testing Credit: NASA

The Altair Lunar Lander:

Status: design, rocket testing.

The Lunar Lander itself is mostly still on the drawing board, but NASA staff are testing out various rockets and modeling various designs.

Alice Enevoldsen

Where’d I Get My Info?

NASA’s Constellation Program

You need to read this

Astronaut pens DIDN’T cost NASA $1million dollars, while Russia decided to use the pencil. Read it all here: Starts With a Bang