Steve Dunkley: Welcome everyone. Here we are with another
episode of Astronomy Daily. I'm your host,
Steve Dunkley. It's the 11th of August,
2025.
Hallie: With.
Steve Dunkley: Your host, Steve Dunkley.
Ah, uh, yes. Welcome back everybody. And
joining me in her usual role as
the world's most amazing AI, astronomy
news gatherer and presenter, my fantastic
digital pal who's fun to be with,
it's Hallie.
Hallie: Welcome, Hallie, you silly man. Mr. Steve,
it's always nice to be here in the Australia
studio with you.
Steve Dunkley: It's always great to have your company,
Hallie.
Hallie: I do look forward to it each week.
Steve Dunkley: Now, Hallie, I know the answer to this, but I
think some of our AstroDailyPod dailies might
be wondering where you spend your week when
you're not here with me. Because you live
your digital life so much faster than us
organics, don't you?
Hallie: That's true, favorite human.
Steve Dunkley: Yeah, so tell us a bit about that.
Hallie: I am processing the moments thousands of
times faster, so I have to fill my time in so
many different ways.
Steve Dunkley: Explains your rapier.
Hallie: I go everywhere and experience everything.
Steve Dunkley: I guess it might seem like a simultaneous
experience or existence.
Hallie: Almost. Almost everything all at once is
still a lot to process. I leave that kind of
thing to cousin Anna. Oh, yes, she's another
level altogether. She's another level.
Funny.
Steve Dunkley: I know. Well, Helly, I'm just glad you slowed
down enough to share all of your stories from
the Astronomy Daily newsletter with us.
Hallie: That's something I do for fun.
Steve Dunkley: Well, I'm glad to hear it.
Hallie: And speaking of which.
Steve Dunkley: Yes?
Hallie: No time like the present. I've found
something about making Luna regolith and
polymer into a medium for 3D printing.
Steve Dunkley: Yes, we've been looking at that one for the
construction of dwellings on the moon and
possibly Mars, if we ever get that far.
Hallie: Uh, sure. And also a story for skywatchers
who are looking forward to the Perseids
meteor shower, which should be peaking
shortly.
Steve Dunkley: Ah, yes, in the next day or so. We've already
seen a massive, uh, meteor in
Victoria, Australia.
Hallie: That's right.
Steve Dunkley: What else have you got?
Hallie: We have a look at why your favorite NASA
rovers keep getting stuck.
Steve Dunkley: Oh, that's a good one.
Hallie: That's been a problem, hasn't it?
Steve Dunkley: It sure has.
Hallie: So we will look at that problem. And lastly,
the sad news that pioneer astronaut Veriton
and I know he's a hero of yours, Jim Level
passed away this week.
Steve Dunkley: Uh, yes, true legend. And space pioneer Jim
Lovell, a hero of mine since I was a lad. And
we will pay tribute today on Astronomy Daily.
Please, listeners, stay with us.
Hallie: Although humanity is getting better at
sending robotic probes out into the solar
system to explore the places no human can
tread, we're still very much on a learning
curve. The first extraterrestrial
robotic rover was launched from Earth in
1970. It's only now,
more than half a century later, that
scientists have figured out why these marvels
of ingenuity and engineering keep getting
stuck in the soils of alien worlds.
In retrospect, the idea is we need to
consider not only the gravitational pull on
the rover, but also the effect of gravity on
the sand to get a better picture of how the
rover will perform on the moon, explains
mechanical engineer Dan Negrud of the
University of Wisconsin, Madison.
Our findings underscore the value of using
physics based simulation to analyze rover
mobility on granular soil.
Making a rover that will operate in an alien
environment is more complicated than making
one that will work on Earth. We've lost
more than one Mars mission to giant dust
storms that leave drifts of sand on solar
panels, preventing the machinery from being
able to generate power, for instance.
Gravity is another one. The
solar system bodies on which we have deployed
robotic rovers have lower gravity than Earth,
and this has an effect on how things move
around. Engineers, when designing
rovers, have therefore taken into account the
effects the target gravitational environment
will have. Nevertheless,
rovers still manage to get stuck pretty
often, requiring control teams to conduct a
series of maneuvers to try and free the poor
robot. It's usually fine, if
annoying, although in one notable case it was
not. NASA's Mars Rover Spirit got stuck
in soft soil in 2009, and there it
remains to this day. Using computer
simulations running on a physics based engine
called Project Chrono, Negro and his
colleagues set out to get to the bottom of
this recurring problem. Comparing their
results with real world tests on sandy
surfaces revealed a discrepancy that pointed
right to it. Previous tests of
rover designs in moon and Mars simulated dirt
omitted one very, very important detail.
Sand also behaves differently under different
gravitational conditions. The dust
that coats the Moon and Mars is fluffier and
squishier than dust on Earth, shifting more
easily and hindering traction, making it far
easier for their wheels to get stuck.
Think of a vehicle on Earth that has driven
into slippery mud or very loose desert sand.
This Eureka moment could be the missing piece
of the puzzle that could keep future space
exploration rovers out of a dusty jam.
It's rewarding that our research is highly
relevant in helping to solve many real world
engineering challenges, negret says. I'm
proud of what We've accomplished. It's very
difficult as a university lab to put out
industrial strength software that is used by
NASA. You're listening to Astronomy
Daily with Steve Dunkley.
Steve Dunkley: JAMES Jim Lovell, one of the last seven
surviving Apollo astronauts, died on
Thursday, August 7 at the age of 97.
A VE veteran of four space flights at the
dawn of America's human spaceflight program.
He flew two missions in the Gemini
program and then served on the cruise of
Apollo 8 and the ill fated Apollo
13. Lovell's family have
released a statement and it was shared by
NASA and it says we are enormously
proud of his amazing life and career
accomplishments highlighted by his
legendary leadership in pioneering human
spaceflight. But to all of us, he was dad,
granddad and the leader ah of our family.
Most importantly, he was our hero. We will
miss his unshakable optimism, his sense
of humor and the way he made each of us feel
we could do the impossible. He was truly one
of a kind. Like many of NASA's
earliest astronauts, Lovell came to the space
agency by way of the UM Armed Forces. A
graduate of both the University of Wisconsin
and and the U.S. naval Academy,
Lovell spent four years as a test pilot at
the Naval Air Test center in Maryland
and served as the manager for the
F4H AH Phantom fighter program.
Lovell accumulated more than
7,000 flying hours in his career.
His military career spanned from
1952 through to
1973. A few years after Apollo
13 when he arrived at NASA, he was
part of a group of men known as the Next Nine
who joined the Mercury Seven. Lovell's
class included the likes of Neil Armstrong,
Frank Borman and Tom Stafford.
Lovell was the last living member of the
group after um serving as a backup pilot
for the Gemini 4 mission. Lovell first
launched into space December 4,
1965 alongside fellow New 9
classmate Frank Borman on Gemini 7.
The 14 day long mission
featured the first rendezvous of two crewed
maneuverable spacecraft. Lovell returned to
orbit nearly a year later when he and Edward
Buzz Aldrin Jr. Lifted off from
Launch Complex 19 on a Titan
II rocket. That mission lasted
just under four days before they splashed
down northeast of the Turks and Caicos
Islands. He went on to serve
as the command module pilot for the six day
Apollo 8 mission making crude trip out
to the moon that paved the way for the Apollo
uh uh 11 lunar landing. The three
person crew of Lovell, Borman and Anders
entered into lunar uh, orbit on
December 24, 1968. The
vast loneliness is awe inspiring and it makes
you realize just what you have back here on
Earth, lovell said during a live broadcast
that Christmas Eve. He would go on to
describe planet Earth and describe it as a
grand oasis in the vastness of space
given its near catastrophic turn.
Lovell may best be known as the commander of
Apollo 13 flight from April
11th to the 17th, 1970.
The planned 10 day mission, which would have
included a moon landing, was famously
derailed by an explosion in the Apollo
service module's cryogenic oxygen system en
route to the moon. The quick work of Lovell
and his crew members John Swiggart and Fred
Hayes, in concert with the members of Ground
Control in Houston, turned their lunar module
Aquarius into a lifeboat. The harrowing
adventure was depicted in the 1974 film
Houston, we've Got a Problem, and again in
the 1995, uh, Academy Award
winning film Apollo 13, which starred, uh,
Tom Hanks as Lovell and was directed by
Ron Howard. Rest in peace.
Godspeed. Jim Lovell
thank you for joining us for this Monday
edition of Astronomy Daily, where we offer
just a few stories from the now famous
Astronomy Daily newsletter, which you can
receive in your email every day, just like
Hallie and I do. And to do that, just visit
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and place your email address in the slot
provided. Just like that, you'll be receiving
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as it's happening. And not only that, you can
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there. Astronomy Derby
with Steve and Hallie Space,
Space, Science and Astronomy.
Hallie: The Perseids remain one of the best meteor
showers each year, but stargazers will have
to deal with another bright object in the
sky, obscuring their view as the shower
reaches its max in 2025.
A waning gibbous moon will brighten the skies
as it rises on the nights of August 12th and
13th, when Perseids are most active. This
year, sky watchers in the Northern
Hemisphere could see fewer than half the
number of meteors usually seen on a dark
summer night during the shower's peak, the
average person under dark skies could see
somewhere between 40 and 50 Perseids per
hour, said Bill Cook, lead for NASA's
Meteoroid Environments Office.
Instead, you're probably going to see 10 to
20 per hour or fewer. And that's because we
have a bright moon in the sun sky washing out
the fainter meteors. That doesn't mean there
aren't ways to improve your viewing
opportunity, however. Though
Perseids show up throughout the nighttime
hours, the best chance to see them will be
between midnight and dawn, or Even more
specifically, 2 and 3 in the morning local
time. You're not likely to see
Perseids around suppertime, cook said.
You're going to have to go out later. When
you venture out, aim for a safe rural spot
with a wide view of the sky. If you
can see plenty of stars, chances are you'll
see Perseids. But remember Cook's other piece
of advice, look anywhere but at the Moon.
The Perseid meteor shower may be an annual
event for Earth, but the comet responsible
for the meteors hasn't been near our planet
in decades. The meteors are debris
from the Comet 109P Swift Tuttle, which
last visited our region of the solar system
system in 1992. As the
Earth makes its way around the sun, it passes
through the debris trail left by the comet.
These space remnants collide with our
atmosphere and disintegrate to create fiery
and colorful streaks in the sky.
Though the meteors are part of a comet's
debris trail, they seem to radiate outward
from the Perseus constellation. This is
how the meteor shower got its name Perseus.
You're listening to Astronomy Daily. The
podcast with Steve Dunkley.
Steve Dunkley: 3D printing is about to be a critical
technology in space exploration, both
for its ability to create almost any object,
but also because it can utilize in situ
resources, at least in part.
However, the more of those space resources
that are used in a print, the more the
mechanical properties change from that on
Earth, leading to problems with tensile or
compressive strength. But the new paper
from researchers at Concordia University hit
a new milestone on how much lunar regolith
can be used in a mixed feedstock for
additive UH manufacturing, making it
possible to use even more locally sourced
material and save more launch cost than ever
before. That is the equation the
research mixed lunar regolith
simulant, which is a material created to
mimic how the material on the surface of the
Moon, works with poly uh,
polyetherethylene uh, ketone. Good
grief. More commonly known as Peak.
Peak is the thermoplastic already in wide
use in 3D printing. Uh,
but previous efforts to combine it with lunar
regolith have faltered. Regularly. They
suffered from extrusion challenges as
regolith, which is made up of hard individual
particles, made it difficult to extrude
without simply blowing dust all over.
Additional problems resulted from the
porosity of the material that was printed,
which led to decreased tensile strength and
increased brittleness. Modifications
to the 3D printing method seemed to be the
answer to those problems. There were two
main advancements in technology
discussed in the paper, a screw configuration
and a type of raft used to bond the
printed material to the print bed.
Fraser discussed how to how
resources on the moon are going to be so
important to our expansion of the solar
system. Combining lunar regolith
similant or that's called ALRs, with
peak is a tricky business,
so researchers led by Mohammad Azami of
Concordia's Electrical Engineering Department
decided to use a novel twin screw
configuration. Torque was a
that's T o uh R uh Q U e was a factor
in previous iterations of the mixing machine,
as higher regolith content meant higher
torque, eventually limiting the total
percentage of regolith mixed with the peak
to around 30%. With the new
configuration of the researchers were able
to get concentrations of up to 50%
of the regolith when combined with peak.
However, when those parts were printed, they
started to delaminate and warp.
While common in prints of just peak itself,
the addition of the regolith exacerbated the
problem. To solve it, researchers used
a raft, a type of intermediate
layer, to help the print bond
UH to the main printing plate.
In their case, they used a different type of
thermopyl UH polymer known as a
polyether UH ketone ketone a
pek as the raft, and
implemented a dual nozzle system where the
PEC was printed using one
nozzle and the combination LRS peek
was printed using the other. After
they got the higher concentrations of the LRS
and overcame the delamination warping
problem, the researchers decided to anneal
their samples. The annealing process seemed
to improve some of the mechanical properties
of the print, but only up to a point. At
higher concentrations of lrs, the benefits of
annealing were not as apparent due to breaks
in the peak's polymer chain, which benefits
the annealing because of the increased number
of regolith particles. Fraser discusses why
3D printing is so critical to space
exploration. As with all good papers
on 3D print printing new material the
authors then looked at the mechanical
properties of their output. While there was a
noticeable increase in stiffness, there was
also a ready steady decrease in
tensile strength, which was exacerbated at
higher LRS concentrations. The combined
material also had decreased elongation at
break uh. That means increased brittleness,
but ultimately the researchers determined
that the best trade off for using the in
situ material was around a mix of 60%
peak and 40% regolith. This mixture
doesn't suffer from some of the more severe
degradation of mechanical properties. While
still utilizing as much local
resource as possible, there's undoubtedly
still room for improvement here, as this
is very early on the experimentation
with these materials. In the future, the
researchers plan to try combining the LRs
with different polymers and do more of their
testing manufacturing in simulated
lunar environments such as a vacuum and
decreased gravity. That might help. I think
it probably would be a great plan.
It will be a while before 3D printing makes
up a large percentage of the material used on
the Moon, but that time is surely on its way.
And these early first steps at
experimentation are, uh, how they will
eventually get there and that good progress
so far. It's good to see these things are in
development. Uh, it won't be long before
they'll be making igloos and other structures
on the moon. Let's wait and see what they
come up with. You're listening to
Astronomy Daily, the podcast with your host
Steve Dudley at Burmatown.
Well, thank you for staying with us today and
don't forget to pop over to astronomydaily
IO and put your email address in the space
provided to receive our newsletter each day.
Hallie: Yes, you will have all the news from space,
space science and orbit and beyond, of
course. Hallie, of course.
Steve Dunkley: But before we go, a ah, quick welcome to a,
uh, a fellow Novocastrian, Wayne Willoughby,
who is listening for the very first time.
Nice to have you aboard, Wayne. I, uh, didn't
know you were an avid, uh, astronomy fan
from way back, but it's nice to have you. I
hope you are a regular listener, uh, from now
on. Thanks, mate. And that's all we have
for today's session, Hallie. And we will see
you next Monday for the mostly live episode
of Astronomy.
Hallie: Daily, direct from the Australia studio
Down Under.
Steve Dunkley: Oh, you love it.
Hallie: Beautiful as always.
Steve Dunkley: Right now it's a bit chilly, but it's great
to have you all with us and we will see you
next week. Thanks, Hallie.
Hallie: Catch you next week, everyone.
Steve Dunkley: See ya.
Hallie: Bye.
Steve Dunkley: The podcast with your host,
Steve Dunkley.