- WindSAT is a satellite that measures ocean wind speed and direction.
The SED, working in conjunction with NRL's Remote
Sensing Division, successfully launched the WindSat satellite in January, 2003.
WindSat was a demonstration program to evaluate the capability to utilize passive microwave polarimetry
to measure the full ocean surface wind field (wind speed and wind direction) from space. The instrument is
a multi-frequency polarimetric microwave radiometer that passively measures microwave radiation emitted
naturally from the ocean's surface and quantifies these measurements in terms of the brightness temperature.
In microwave measurement systems, the amount of radiation detected depends on the properties of the scene
and the observation frequency. Wind roughening the surface of the ocean causes an increase in the brightness
temperature of the microwave radiation emitted from the water's surface. Recent airborne experiments conducted
jointly by NRL and the Jet Propulsion Laboratory indicate
that by understanding the relationship between wind speed and surface roughness, an observer can determine not
only the speed of winds at the ocean's surface but also their direction. Designed for a 3 year mission, WindSat
is still successfully operating.
The SED was responsible for designing, building, and testing the WindSat instrument, integrating it with the
commercial satellite bus provided by the Air Force Space and Missile Command
Space Test Program (STP), and conducting combined systems testing. WindSat was sponsored by the Operational Navy
(OPNAV) through the Office of Naval Research (ONR), and the National
Polar-orbiting Operational Environmental Satellite System (NPOESS)
- TacSat IV/CommX augments current SATCOM capabilities to advance Operationally Responsive Space systems.
TacSat-4 is a Navy lead Joint project managed by NRL's SED. TacSat-4's mission is to augment current SATCOM capabilities
and to advance Operationally Responsive Space systems. TacSat-4 provides 10 Ultra High Frequency (UHF) communications channels
that can be used for any combination of communications, data exfiltration, or Friendly Force Tracking (FFT).
TacSat-4's HEO (Highly Elliptical Orbit) orbit augments geosynchronous SATCOM by providing near global - but not continuous -
coverage, including the high latitudes. TacSat-4 improves on current SATCOM by providing communications-on-the-move (COTM) for
existing radios without antenna pointing. TacSat-4 provides flexible up- and down-channel assignments, increasing its ability
to operate in some interfered environments. The tasking system, coupled with the orbit, allows dynamic reallocation of communication
channels to different theaters worldwide and within 24 hours, enabling rapid SATCOM augmentation to support unexpected operations
such as when natural events occur.
The purpose of MISSE is to characterize the performance of new and prospective spacecraft materials when subjected
to the combined effects of the space environment. Passive and active experiments are loaded into a Passive
Experiment Carrier (PEC); the PEC is then transported via the Shuttle to the International Space Station (ISS),
where it is attached to the ISS and opened on-orbit to expose the materials to space. At the end of the mission,
the PEC is closed and returned to Earth. The MISSE program has a rich history and benefits from seven (7) previous
on-orbit payloads with substantial legacy hardware and design.
Code 8200 and Code 6800 have collaborated on three (3) MISSE projects currently, including MISSE-5, MISSE7, and MISSE-8.
MISSE-5 was sponsored and built at NRL using a PEC, carried the "Forward Technology Solar Cell Experiment (FTSCE)" and
relayed data to the ground via an on-board transmitter; PCSat2. MISSE-5 was self-powered with an on-board solar panel and
a Li-Ion battery. MISSE-5 also contained its own 2-way communications with an on-board receiver and transmitter box. It
was launched in August 2005 and returned in September 2006; operating successfully for 408 days before returning to Earth.
MISSE-5 on ISS
NASA Astronaut Soichi Noguchi deploying MISSE-5
MISSE7 was sponsored and integrated at NRL. MISSE7 consists of two (2) PECs (PEC7A - NRL and PEC7B - Boeing) and the ExPA
(ExPRESS Payload Adapter) experiments. PEC7A experiments include "Forward Technology Solar Cell Experiment (FTSCE)" II and
other space exposure experiments. The ExPA experiments include the Multi-Core Processor Experiment (MCPE), which was built at NRL;
the Hyper-X; and the SpaceCube. MISSE7 utilizes ISS power from the ELC (ExPRESS Logistic Carrier), sends commands and receives
data from the ELC via the ISS. MISSE7 was launched November 2009 and is currently operating successfully. All experiments are
operating as expected. PEC7A and PEC7B are scheduled to return on STS-134 in February 2011.
MISSE7's location on the ISS
MISSE7 on the ELC
NRL's PEC7A on-orbit
MISSE-8 was sponsored and built at NRL. The MISSE-8 PEC is carrying the "Forward Technology Solar Cell Experiment (FTSCE)" III
amongst other experiments. Some of the additional experiments on MISSE-8 include an evaluation of several advanced technologies for
Xilinx FPGAs, an experiment to characterize arcing effects on solar cells' performance, an experiment to characterize the performance
of components of a reflectarray antenna, reflective materials experiment, optical reflector materials experiment, and advanced space
solar cell technologies. The overall experiment suite represents an extremely wide range of technologies with direct impact and
relevance to several DoD space programs. PEC8 will be replacing PEC7A on the MISSE7 platform, receiving power and data via the ISS.
MISSE-8 is scheduled to fly on STS-134 in February 2011.
On 22 July 2010, five of the six astronauts of the STS-134 crew came to the NRL for the Crew Experiment Interface Test (CEIT) of
the MISSE-8. The test was successful and MISSE-8 was shipped for processing at the Kennedy Space Center on 16 August 2010. On 25
August 2010, the MISSE-8 Sidewall Carrier (SWC) and PEC were installed into the Endeavour payload bay. MISSE7's two (2) SWCs were
also installed and will be used to return MISSE7's PEC7A and PEC7B for examination of all experiments.
MISSE-8 Nadir Side
MISSE-8 Zenith Side
STS-134 Crew with MISSE-8 Team
MISSE-8 Installed in Shuttle Bay
- TEPCE - a tethered spacecraft being developed to demonstrate electrodynamic propulsion in space.
A tethered spacecraft is being developed by the Spacecraft Engineering Department to demonstrate electrodynamic propulsion in space.
Electrodynamic propulsion holds the promise of limitedless propulsion for maneuvering spacecraft without using expendable fuel. Electrodynamic
propulsion can enable missions not previously possible, such as drag makeup for low altitude applications, multiple maneuvers to rendezvous
with and deorbit space junk and repeated traverses through low altitudes to collect science data on the ionosphere. The NRL spacecraft,
TEPCE, will consist of two 1.5U CubeSats attached to each end of one kilometer of electrically conducting tether. The two Cubesats are
virtually identical, housing a processor, memory, command and data handling system, RF system, an elementary attitude control and attitude
determination system. Unique to TEPCE will be the electrodynamic devices for the propulsion consisting of electron emission filaments,
electron collection tapes, electrically conducting tether and the tether deployment subsystem. The experiment will also carry into space
several plasma experiments, the iMesa sensor developed by NRL code 7669 and dual impedence probes developed by NRL, code 6755. The plasma
experiments will take multiple measurements of the electron density and electron temperature as TEPCE orbits the earth.
The development centered around CubeSats provides a low cost approach for development and enables launch opportunities through the Space
Test Program (STP). TEPCE will operate between 500 and 1000 km at inclination above 35 degrees. TEPCE is projected to be completed in June
of 2011 with launch as soon as possible thereafter.