Developing Responsive and Agile Space Systems - Space-Library

week in July 2001. Aerospace supported
the launch site activities for all three of the
STP-sponsored spacecraft, and provided
on-console support to the Air Force mission
manager during launch operations. After
a series of terrestrial and space weather
delays, and travel limitations imposed in
the aftermath of September 11, launch of
the Kodiak Star mission occurred on September
29, 2001, with the launch vehicle
achieving the desired parameters for both
targeted orbits.
Nanosat-2
The Air Force Space and Missile Systems
Center (SMC) tasked STP in June 2003 to
investigate the feasibility of flying an auxiliary
payload on the EELV Delta IV heavy
demonstration, scheduled to launch in June
2004. Nanosat-2 was ultimately selected.
Nanosat-2 had originally been planned
to launch aboard the space shuttle in the
Shuttle Hitchhiker Experimental Launch
System, but after significant delays in the
shuttle manifest, Nanosat-2 was put into
storage to await other flight opportunities.
Nanosat-2, actually a stack of three space
vehicles, was developed under the University
Nanosatellite Program, a joint program
of the Air Force Research Laboratory, the
Air Force Office of Scientific Research,
and the American Institute of Aeronautics
and Astronautics. Constructed by student
teams at the University of Colorado, New
Mexico State University, and Arizona
State University, Nanosat-2 was designed
to demonstrate two different low-shock
separation systems for small satellites and
perform collaborative formation flying. All
three spacecraft and the associated interface
hardware had been assembled
and tested when selected for
the demonstration.
After call-up on January
23, 2004, the satellite had
four months until it had to be
mated to the DemoSat, the
main payload of the mission.
After an initial kickoff meeting
with the mission team,
including the government
agencies and contractors
representing both the satellite
and launch vehicles, the
Nanosat-2 stack was reduced
from three spacecraft to two.
Satellite and launch-vehicle
work began immediately.
The satellite was refurbished
and cleaned February 2–25
and reassembled February
26–27; electrical checks were
PCSat-1 (Prototype Communications Satellite) was built at the U. S. Naval Academy with
student participation throughout its development. The mission demonstrated a low-cost
approach to satellite design. PCSat-1 completed its eighth year in orbit in Sept. 2009.
completed March 8–12. Meanwhile, the
launch vehicle team was developing a oneof-a-kind
adapter to mount the satellite to
the DemoSat, designing unique mechanical,
electrical, and environmental interfaces.
On March 29, the launch vehicle interface
requirements were completed, and the
satellite began testing to the new requirements.
Random vibration and sine tests
were conducted April 5–9, electromagnetic
interference testing April 14–23, and shock
testing May 3–7. Nanosat-2 was mated to
DemoSat May 3–7, and on June 28 encapsulation
inside the fairing was completed.
The Nanosat-2 team managed to go from
storage to mate in 115 days, with approximately
half that time spent waiting for the
definition of the interface for the launch
vehicle.
During this four-month effort, Aerospace
served as the systems engineering liaison
between the Air Force Research Laboratory
and the launch vehicle contractor,
with personnel from what is now the Space
Innovation Directorate supporting STP
and personnel from the Launch Operations
Division supporting the Air Force Launch
and Range Systems Wing.
After the physical integration was
completed, the Aerospace focus shifted to
mission assurance, with an emphasis on
ensuring that the presence of the nanosat
payloads would not adversely affect the
primary goal of the Delta IV heavy-lift
demonstration mission. Particular emphasis
was placed on the qualification of the satellite
and the robustness of the separation
system, including a new separation-signal
timer box. After a thorough Aerospace
review, including the requirement for additional
separation system ground testing,
Aerospace deemed the nanosat system low
risk for launch.
The Delta IV heavy demonstration was
launched December 21, 2004. During
launch, sensors in the Delta IV common
booster cores incorrectly registered depletion
of propellant, resulting in a premature
shutdown of all three stage-one engines
and a significant performance shortfall.
Nanosat-2 was successfully separated
from Demo Sat, but in a lower orbit than
expected, and was unable to complete its
remaining science goals.
Responsive Launch Vehicles
Minotaur
Orbital Sciences Corporation, under the
U.S. Air Force Orbital/Suborbital Program
contract, develops and provides launch
services for government-sponsored payloads
using a combination of governmentsupplied
Minuteman and Peacekeeper
rocket motors and commercial launch
technologies. The use of surplus ICBM assets
significantly reduces launch costs while
leveraging the heritage of proven systems.
Orbital’s Minotaur I is a four-stage
launch vehicle using surplus Minuteman
solid rocket motors for the first and second
stages, combined with the upper-stage
structures and motors originally developed
for Orbital’s Pegasus XL vehicle. Minotaur
I can launch payloads up to 580 kilograms
into low Earth orbit, and has had 100-percent
success after eight missions.
Minotaur IV uses the three solid rocket
motor stages from the Peacekeeper ICBM
and a commercial solid rocket upper stage
to place payloads up to 1730
kilograms into low Earth
orbit. The first flight of Minotaur
IV is scheduled for
2009. Minotaur V is a fivestage
derivative of Minotaur
IV using two commercial
upper stages to launch small
spacecraft into high-energy
trajectories.
The Minotaur launch
vehicles have a standard
Courtesy of U.S. Naval Academy
18-month procurement
cycle. Studies show this
cycle could be reduced to
12 months without any new
processes or hardware; however,
this is still a 52-week
cycle, as opposed to the
one-week ORS target. Additional
reductions in schedule
are being investigated,
Crosslink Summer 2009 • 21