Johns Hopkins Gazette: October 10, 1994


Student Spacecraft Design May Prove 'Big Bang' Concept
By Emil enere

Students at Hopkins and Morgan State universities are jointly
designing a spacecraft to search for the mysterious "dark
matter" many theorists believe makes up most of the universe.
    The quest is a bold one, since it involves the nearly
impossible task of detecting ionized hydrogen gas. But if it
succeeds it will be a scientific landmark supporting the Big
Bang concept of cosmic creation. 
    Faculty at the Homewood campus, the Applied Physics
Laboratory and Morgan State joined forces to compete in the
NASA-funded program Student Explorer Demonstration
Initiative, or STEDI. Their conceptual design was among the
top six selected last month out of 66 proposals. But only two
or three of the designs will be chosen for actual
construction.
    The pressure is on to assemble quickly a team of
students to design the spacecraft within a four-month
deadline, a tough assignment even for a staff of professional
engineers, said Vincent Pisacane, assistant director for
research and exploratory development at APL.
    "With inexperienced students it's going to be a
challenge to make the deadline," Dr. Pisacane said.
     Faculty advisers will recruit about 30 undergraduate
and graduate students from Hopkins and six from Morgan State,
said Hopkins astrophysicist Richard C. Henry, director of the
Maryland Space Grant Consortium, a NASA-affiliated
organization that promotes science education and sponsored
the spacecraft proposal.
    Electrical engineering professor Charles Westgate will
lead the spacecraft team on the Homewood campus. Marsha
Allen, an associate research scientist in the Department of
Physics and Astronomy, heads the overall project.
    "We are confident our students can meet the challenge
and produce a successful spacecraft," Dr. Westgate said.
    The satellite, Hydrogen Recombination Radiation
Experiment, was conceived by Dr. Henry. Scientists refer to
the project as Harry, for HRRE. The 3-foot-long, 30-inch-wide
satellite will not see optical light that is visible to the
human eye. It will detect invisible ultraviolet emissions in
an attempt to measure the radiation from hydrogen gas that
scientists believe occupies the vast space between galaxies.
The hydrogen, which has not yet been proven to exist,
represents the ashes left over from the Big Bang that many
cosmologists believe marked the birth of the universe 15
billion to 20 billion years ago.
     Finding the gas would, in effect, be discovering the
sought-after dark matter. But detecting ionized hydrogen is a
remote possibility, since its atoms have been stripped of
their single electrons from bombardment with radiation, so
the hydrogen will not absorb light passing through it and it
leaves no tell-tale signature when viewed through a
spectrograph. However, ionized hydrogen can capture free
electrons, causing a "recombination" of hydrogen atoms. HRRE
will look for the ultraviolet radiation produced when ionized
hydrogen recombines.
    The satellite builders will have to craft a new
spectrograph, based on a design originated by adjunct
research professor William G. Fastie, in the Department of
Physics and Astronomy.
    The existence of dark matter has been inferred for two
decades, according to theories and observations that support
the idea that the universe contains far more matter than has
been directly observed using current technology. Astronomers
think that at least 90 percent of the mass in the universe
has not yet been detected.
    Instruments sensitive to ultraviolet radiation must be
placed above the Earth's atmosphere, which blocks most
ultraviolet light. While some ultraviolet instruments have
found sketchy evidence for the primordial hydrogen, no
instruments now in operation have been designed specifically
for that purpose, Dr. Henry said.
    "The fragmentary observations that exist are very poor
in quality," said Dr. Henry, an expert on "interstellar
medium," the debris found between stars. "We are going to
make the measurements in a definitive way."
    The Hopkins-Morgan State team has received $160,000 from
NASA to design HRRE. Students must be able to demonstrate
that the satellite's cost will not exceed $4 million, a
difficult requirement that can only be met with a detailed
engineering design, said Dr. Pisacane.
    Perhaps the project's most important result will be to
teach students how engineering is done in the real world--by
committee.
    "It's an excellent engineering learning experience that
one rarely gets in undergraduate education, even in graduate
education," Dr. Pisacane said. "When you leave academia you
are rarely working alone. Generally, if you are working on a
small team, it's part of a larger team. You have to design
and build something that satisfies many different criteria.
The learning experience for the students will be in making
compromises to develop a product for a competitive price in a
reasonable amount of time."
    The Hopkins-Morgan State students will have an edge,
with APL on their team. 
    "No other university has built more than 50 spacecraft,"
Dr. Pisacane said. "We are probably the premier builder of
small spacecraft in the world."
    Morgan State also brings some space experience to the
team. Scientists there recently designed an instrument that
tested how the space shuttle reacted to stresses when
thrusters were ignited, said Ernest C. Hammond Jr., an
assistant professor of physics at Morgan State.
    The project will involve about a dozen faculty advisers
from the Department of Physics and Astronomy, the G.W.C.
Whiting School of Engineering and Morgan State. A similar
number of staff members at APL will act as mentors to the
faculty and students.
    Not all students on the team will need engineering
strengths. A variety of skills is necessary to administer
space projects, Dr. Henry said. Those interested in joining
the project may contact Dr. Allen at 516-6561.
    The STEDI program is managed for NASA by the
Universities Space Research Association, a group of
universities that promotes space science and technology. The
five other teams competing for the satellite program are from
the University of Michigan, University of New Hampshire,
Boston University and the University of Colorado, which has
two separate satellite proposals.

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