INTERNATIONAL SPACE STATION ZERO-PROPELLANT MANEUVER
DEMONSTRATION (ZPM)
Research Area: Technology Development and Demonstration: Spacecraft and
Orbital Environments
Expedition(s): 14 and 15
Principal Investigator(s): ● Nazareth Bedrossian, PhD, Charles Stark Draper Laboratory,
Incorporated, Houston, Texas
RESEARCH OBJECTIVES
International Space Station Zero-Propellant Maneuver (ZPM) Demonstration introduces new
technology that rotates the station by not expending in-orbit propellant.
EARTH BENEFITS
New knowledge is expected to be the major benefit of this project.
SPACE BENEFITS
The ZPM concept can substantially reduce the International Space Station (ISS) lifetime
propellant use while avoiding thruster plume loads and contamination of solar arrays. A
reduction in propellant use not only saves money, but increases payload capacity for
resupplying vehicles. Even more importantly, ZPM provides the only means of control if ISS
thrusters are unavailable. ZPM will also reduce propellant use for spacecraft maneuvers using
only thrusters. This technology will be even more valuable for future human exploration of the
solar system as the propellant savings will
allow for increased payload or provisions.
RESULTS
The ZPM concept was successfully
demonstrated on the ISS. On November 5,
2006, and March 3, 2007, the ISS was
rotated 90 degrees and 180 degrees,
respectively, without using any propellant.
The 90-degree maneuver of ISS Stage12A
was completed in 2 hours and reached 70%
of CMG momentum capacity (Bedrossian,
2007[a]). The 180-degree maneuver of ISS
Stage 12A.1 was completed in 2 hours and
47 minutes and reached 76% of CMG
momentum capacity (Bedrossian,
2007[b]). The same 180-degree maneuver
was performed with thrusters on January
2, 2007, and consumed 50.8 kilograms or 112 pounds of propellant. At an estimated cost of
$10,000 per pound, the 180-degree maneuver with ZPM saved $1,120,000 (Kang, 2007).
Naval Postgraduate School Professor of Mechanical and Astronautical
Engineering I. Michael Ross briefs NPS Space Systems Academic
Group students on NASA's use of his optimal control software to
maneuver the International Space Station cost-free, without the need
to use thrusters and expend valuable fuel. Photo credit: US Navy, by
Javier Chagoya.