It’s the beginning of November!
And that means that SciShow Space is supported
by the November pin of the month!
To reserve your pin, go to or click the link in the description down below.
[♪ INTRO]
These days, space missions often cost billions of dollars
and take decades to develop.
And these massive efforts have stunning results,
making it well worth the effort and the wait.
Even if it is a very long wait in some cases.
But 25 years ago, scientists on shoestring budgets were sending
much simpler spacecraft out into the solar system.
And many of those achieved incredible things too.
In fact, some of these simpler probes truly outdid themselves,
perhaps none more so than the asteroid mission NEAR Shoemaker.
The mission was part of NASA’s Discovery Program, launched in the 1990s.
Unlike many modern spacecraft that are built to accomplish lots of things,
the Discovery missions were often designed to go after a single scientific question
about a single body, like a comet, the Moon, or an asteroid.
And they were meant to cost less than $150 million
and take under 36 months to develop.
That’s not a lot of money or time to develop a space mission,
but the NEAR Shoemaker easily met those requirements.
It was a basic spacecraft about the size of a car, with minimal moving parts.
It had just six instruments that were fixed in place,
letting it do things like capture images, analyze X-rays
and gamma rays, and detect magnetic fields.
And the whole thing was powered by solar panels.
Thanks to this relatively simple design, not only did the spacecraft
come in under budget, but it was ready for launch after just 26 months.
In 1996, NEAR Shoemaker became the first Discovery mission to make it to space.
The goal was to put it into orbit around the asteroid Eros, a large rock in the inner
asteroid belt that mostly hangs out between the orbits of Earth and Mars.
Astronomers hoped to learn about its formation, physical properties,
and other qualities… and to do that, they needed to get up close and personal.
But NEAR Shoemaker didn’t just make a beeline for the asteroid.
Along the way, mission scientists found a way to get a lot more bang for their buck.
First, in June 1997, the spacecraft flew past a different asteroid,
called 253 Mathilde.
This was NASA’s first encounter with a so-called C-class asteroid,
a type of dark-colored asteroid containing a lot of carbon.
And even though the camera on NEAR Shoemaker wasn’t designed to
take pictures while it was traveling that fast, it did it anyway,
and they came out much better than anyone expected.
Thanks to this data, scientists were able to estimate the mass of an asteroid for the
very first time, and they discovered that it was a lot less dense than they expected.
Three months later, the spacecraft’s gamma ray detector
was reconfigured in-flight, in preparation for its arrival at Eros.
It was meant to measure gamma radiation from minerals on Eros’ surface,
but to everyone's surprise, it picked up a powerful
gamma ray burst before it even got there.
Astronomers at the time still weren’t sure exactly what caused bursts like this one,
but they were thought to come from intense explosions in distant galaxies.
So while it was en route to Eros, NEAR Shoemaker casually joined a network of
other spacecraft detecting more of these signals and helping pinpoint their origins.
The spacecraft was crushing it even before it got to its destination.
But then it almost didn’t make it.
An engine misfire in December of 1998 could have destroyed the craft, but luckily,
ground control acted fast and got it back on track.
A year behind schedule, but still going.
Finally, on Valentine’s Day of the year 2000, NEAR Shoemaker reached Eros,
which just so happens to be named after the Greek god of love.
It was like this was meant to be!
Here, the spacecraft finally got to its main mission: It orbited the asteroid for
a whole year and took thousands of photographs and measurements.
Astronomers studied this data for signs of a magnetic field,
and they used the gamma ray detector to scan for radioactive minerals,
so they could work out the asteroid’s composition.
They found that it was a lot like stony meteorites we find on Earth,
and that it had likely broken off of a bigger asteroid or planet.
But…
there was more.
In January 2001, as the spacecraft was running out of fuel,
the mission planners decided to try one last thing.
They wanted to make a controlled descent to the
asteroid surface to get the best, closest pictures they could.
Now, NEAR Shoemaker didn’t have any landing gear, or even legs,
so they didn’t expect it to survive the landing.
They just wanted to make the most of the spacecraft’s last moments.
So as the spacecraft circled the asteroid,
they performed engine burns to drop the speed to just 6.4 kilometers per hour.
The team managed to get pictures from as low as 120 meters,
showing features as small as 1 centimeter across!
And then it crashed into the surface.
But… to everyone’s surprise, NEAR Shoemaker survived its landing.
It ended up perched on two solar panels and one edge of its body.
It was even oriented just right so that the solar panels could keep supplying power.
This made it the first spacecraft to orbit and land on an asteroid,
despite never being designed to do so.
Not only that, but it was able to keep collecting data for two more weeks.
There are not any pictures from the surface, but the gamma ray data collected
during those two weeks was some of the best of the whole mission.
From just 10 centimeters above the ground, the detector had a perfect view
of the surface, and could get much stronger signals than from orbit.
So even though NEAR Shoemaker definitely had its limitations and setbacks,
it was still able to produce good science, bonus science, and surprise science.
It not only showed what could be achieved on a shoestring budget,
but it also paved the way for the more
advanced missions exploring asteroids today!
And for a much smaller budget than even the NEAR Shoemaker was working with,
you can take home a beautiful commemorative pin
with the NEAR Shoemaker on it.
It’s the November pin of the month!
And it will only be made right now.
Once December comes, pre-orders will close and
we’ll never have another NEAR Shoemaker pin again.
So to get yours before they’re gone, so that people can say
“Hey, what’s that” and you can tell them the amazing story of NEAR Shoemaker,
you can find the pin at DFTBA.com/SciShow
or in the link in the description down below.
Then, you wait in anticipation for the next pin coming in December.
Thanks for your enthusiastic support!
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