- [Speaker] Ignition.
(missile blasting)
- [Narrator] This intercontinental ballistic missile
or ICBM is a major part
of the US' nuclear defense strategy, but there's a problem.
These minutemen missiles were supposed to last 10 years,
but that's turned into almost 60.
The air force is spending over $100 billion to replace them
with a new modern iteration, the sentinel missiles.
But there are concerns about the process
of replacing them, even from the head of the air force.
- Sentinel, I think,
is quite honestly struggling a little bit.
- [Narrator] Here's how ICBMs fit
into the US' nuclear strategy,
how they work and why the challenges
of replacing them are mounting
(upbeat music)
ICBMs make up the land leg
of the US' nuclear defense strategy
called the nuclear triad.
The other two legs are submarines in the sea
and bombers in the air.
- The submarines are gonna have
that greater stealthy quality.
Bombers have the greatest flexibility in terms
of taking different routes, flexibility in terms
of recalling and not firing.
The benefit of ICBMs is not their location necessarily,
but the fact that they're distributed.
- [Narrator] That is, they're distributed in silos
across five states and about 40,000 square miles.
- By having 450 silos spread out
over a number of states in the American west,
that creates a massive targeting problem for the other side.
To kill 450 silos, you would have to devote 800
or 900 weapons round numbers.
- [Narrator] The air force says that a minutemen missile
can travel about 5,000 miles in under 30 minutes.
To do that, the missiles are designed with four main parts.
The first is this large rocket.
The second and third are smaller,
yet still powerful rockets.
And the fourth is the nuclear warhead covered
with a protective shroud.
The first large rocket allows the missile
to pull away from Earth's gravity
and the warhead jettisons its shroud.
The second and then third motors push it through the top
of Earth's atmosphere.
Then the nuclear warhead can reenter the atmosphere
to reach its detonation site.
(missile exploding)
But some of these minutemen missiles,
although continuously upgraded, are now over 50 years old
and losing reliability.
- The solid rocket motors that are in them tend to crack
and have other problems when they've been sitting
in a cold silo, say for decades on end.
- [Narrator] The sentinel ICBMs set
to replace them work like the minutemen missiles,
but the new outer bodies will be made
of carbon composites instead of heavier steel,
potentially allowing for more nuclear warheads.
Changes like these may allow for the sentinels
to be upgraded more easily
during their estimated 50 year lifespan.
- As opposed to opening up the silo door and going down
and plugging things in from the side of the missile,
the facilities are gonna permit a much better
and more efficient way of updating the system.
- [Narrator] But these updated missiles
and facilities aren't cheap
(fire blasting)
and updating the silos has been more complex
than anticipated.
That's a problem for the air force.
The sentinel program was once projected to cost $96 billion,
but now the air force says it's on track
to spend 130 billion.
You can see why on this map of one of the three silo fields,
these are the launch silos
and this is the copper communication wire connecting them.
Much of this land is privately owned.
The air force has to buy some areas in order
to rebuild the silos with modern technology
and replace the wiring.
- It's probably the biggest thing in some ways
that the air force has ever taken on
because it's a vast real estate development.
- What the air force
and the pentagon broadly is fighting is
that perhaps they didn't take into account some
of the enormous efforts that would be required.
- [Narrator] Another weakness,
the sentinels tech could potentially be easier
to hack than a minutemen missiles according to one analyst.
- As compared to an ICBM that was first deployed in 1971
and that until five years ago was still using some form
of large floppy disc.
The sentinel is gonna be a 21st century missile
in every respect.
- [Narrator] To hack a minutemen missile,
an enemy would have
to dig up the copper communication wire
and manually splice it to get it to launch.
- There's actually a kind of a benefit to that.
There's a beauty and simplicity to that
because it's really hard
to hack an analog system from the 1970s.
- [Narrator] Since the sentinels will have
significantly more software than the minutemen missiles,
officials are taking precautions
like upping boundary security.
- I would say there is an enormous amount
of attention being paid to looking
for potential vulnerabilities
in our nuclear command and control.
And in terms of the sentinel, they're going to make sure
that it is resilient against all that kind of thing.
- [Narrator] But increasing security
and vast real estate acquisitions have led
to the project going 37% over budget, which means it has
to be reviewed by the Department of Defense and Congress.
It's called a Nunn-McCurdy breach.
- DOD has hundreds of programs going on at any given time.
Since 2007, Nunn-McCurdy has had a couple dozen
of these breaches.
- [Narrator] Since these breaches are significant,
the review will be incredibly detailed
as they decide whether the sentinel project should continue
and some lawmakers are arguing it's too expensive.
- The estimates are well over $150 billion.
For what purpose, to make us safer?
No, won't make us safer at all.
- [Narrator] The air force and the office
of the Secretary of Defense say that having all three legs
of the triad is essential to American nuclear defense.
The pentagon review is due in summer 2024,
but military experts say it's unlikely to be halted.
- Every presidential administration since the end
of the cold war has taken a look
and kind of scratched their heads
and says, "Hey, do we really need
three different legs of a triad?"
And as it turns out, every single administration,
after looking at that, comes back
and says, "Well, actually, yes."
(dramatic music)