Using a 17-foot-long helium-filled blimp, four
propellers and sophisticated electronics, three Johns
Hopkins undergraduates have built a model airship that will
aid professional engineers who are designing a military
craft to conduct surveillance at the outer edge of the
The similar but much larger unmanned airship is being
developed by engineers at the university's
Laboratory to provide visual and communications support
from an altitude of about 100,000 feet above sea level. To
help test and refine the guidance, navigation and control
system for such a craft, APL engineers asked students in
School's Engineering Design Project class to devise a
smaller version of the airship.
During the two-semester course, offered by the
Department of Mechanical
Engineering, the student team built a model airship
that can fly autonomously, following computer commands to
move itself to a predetermined location. The craft can also
be steered manually through a wireless remote controller.
The onboard equipment includes a video camera that can
transmit real-time images from about 50 feet above the
"We're trying to see how these systems would work,
using commercial off-the-shelf equipment," Vincent F.
Neradka, an APL engineer who worked with the
undergraduates, said. "The model aircraft works very well.
The students met almost all of our objectives. We're
delighted with what they did."
One of the goals was to keep costs down because the
full-size system is envisioned as a relatively inexpensive
disposable airship that would hover high over a military
location for two to four weeks, sending pictures of
activity on the ground and relaying communications. Then
the airship would either disintegrate or be destroyed.
As envisioned by APL, the airship, dubbed High
Altitude Reconnaissance Vehicle, or HARVe, would be stuffed
inside a missile or reusable rocket, which would carry it
to a near space altitude. After emerging from its carrier,
a mammoth balloon would self-inflate and carry a gondola
equipped with sensors and propellers. Unlike most
conventional satellites, HARVe could be directed to stay in
place above a single ground location for weeks at a
The smaller model, built by the students for about
$12,500, will help APL determine whether existing low-cost
technology might work in a full-size version. The student
model utilizes a commercial blimp capable of carrying a
10-pound aluminum gondola. The gondola is equipped with two
propellers facing forward and two reversible propellers
facing up and down, a video camera and the electronic
navigation, control and guidance system. Just before the
end of the school year, the students conducted test flights
with the model, then turned it over to APL engineers.
The student inventors were Ben Jackson, a
double-degree major in mechanical engineering and trumpet
performance from Wilmette, Ill.; Nicholas Keim, a
mechanical engineering major from Ellicott City, Md.; and
Michael K. Chin, a mechanical engineering major from
The undergraduates had to overcome several hurdles
while completing the project. "Being mechanical engineers,
a lot of the circuitry was beyond our training," Keim said.
"We had to get some outside help."
In addition, the motors that the students' computers
had predicted would be powerful enough to run the vertical
propellers turned out to be not powerful enough and had to
be replaced. "One of the things we learned was that theory
doesn't always work out," Keim said. "Sometimes, things
break and you have to deal with it."
Added Jackson, "There were frustrating times when
things didn't work, and we didn't know why. But overall, it
was a great experience to be able to complete the design of
something new and then see the whole invention come to
fruition. That was very satisfying."
The model airship was one of nine Johns Hopkins
projects completed this year by undergraduates in the
engineering design course taught by Andrew F. Conn, a Johns
Hopkins graduate with more than 30 years of experience in
public and private research and development. Each team of
three or four students, usually working within budgets of
up to $10,000, had to design a device, purchase or
fabricate the parts and assemble the final product.
Corporations, government agencies and nonprofit groups
provided the assignments and funding.