Engineers behind the Death Star infamously slapped a series of “thermal exhaust ports”—glorified holes—across the surface of their fictitious spacecraft. The holes were purportedly for ventilation, so when Luke Skywalker was able to exploit them so catastrophically in the original “Star Wars,” fans speculated: Was there not a better way? A University of Arizona space systems engineer explains the issue with the Death Star design—and it’s more complicated than you think.

1. Death Star Design
The Death Star’s thermal design was “costly,”
“inefficient,” and “terrible”
– Roberto Furfaro, director of University of Arizona’s Space Systems
Engineering Lab

2. What’s the University of
Arizona doing in space?
• Leading NASA’s OSIRIS-REx mission
to an asteroid
• Leading or partnering in running over
20 telescopes around the world
• Partnering with NASA to discover flowing
water on Mars
• According to the more recent NSF report,
the University of Arizona is ranked the
#1 public research university in aerospace

3. Meet Our Expert
• Roberto Furfaro is an assistant professor
in the UA’s College of Engineering
• Director of the Space Systems
Engineering Lab
• Currently works as a systems engineer
on NASA’s New Frontiers mission:
OSIRIS-REx

4. Furfaro’s Review
• According to Furfaro, the energy
requirements of a spacecraft the size
of the moon would be huge.
• The original Death Star runs on a
“hypermatter” reactor, a fictional power
source that functions something like
fusion.

5. Hypermatter power would
provide lots of energy,
but create too much heat,
he explains.

6. How the engineers of the
Death Star chose to deal
with that excess heat was
lazy design,
according to Furfaro.

8. 1 2 3 4 5Minimal Minor Moderate Signif cant Severe
5
4
3
2
1
Near Certainty
(~90%)
Highly Likely
(~70%)
Likely
(~50%)
Low Likelihood
(~30%)
Not Likely
(~10%)
Likelihood
Consequences
The small ventilation
holes are a tough target
to hit, putting it in the
“not likely” category in
the risk matrix, but one
highly unlikely shot (with
a little help from the
force) can destroy the
power core and rip the
ship to shreds, landing it
the “severe” category.
Death Star Thermal Exhaust
Risk Report Matrix

9. Furfaro suggests that the engineers should
have used radiators
that could dissipate or use heat
economically, depending on the
thermal environment. That’s how
temperatures get stabilized
on a spacecraft.

10. Heat dissipates as the liquid
moves through the radiator
At the surface of the ship
Cool liquid rotating from
radiator

11. Because the majority of the
ship’s surface area would be
covered with radiator
temperature control, any hit
from a rebel ship would
impact the radiator, giving the
radiator design a “near
certainty” rating on the risk
report matrix. A “Venetian
blind” type of control built into
the radiator system could
reroute cool liquid to keep
the Death Star functional,
meaning damage from an
attack could be minor.
Death Star Radiator Suggestion
Risk Report Matrix

12. External Power Source Concept,
like the New Horizons Space Probe
This design keeps the core of the spacecraft cool.

13. A traveling space probe benefits
from an external energy core.
However,
a star-sized battleship is left too open to attacks.
KABOOM

14. 1 2 3 4 5Minimal Minor Moderate Signif cant Severe
5
4
3
2
1
Near Certainty
(~90%)
Highly Likely
(~70%)
Likely
(~50%)
Low Likelihood
(~30%)
Not Likely
(~10%)
Likelihood
Consequences
Death Star External Power Source
Risk Report Matrix
With an external power
source, there is severe
risk of leaving the Death
Star either powerless or
destroyed. If the New
Horizons space probe
were built for war
(happily, it wasn’t), the
external energy core
would almost certainly
be exploited.

16. • Could this
have saved
the Death
Star?
• Radiator
• #StarWarsSci
ence
We think
so!
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