Members Can Post Anonymously On This Site
Debris from DART impact could reach Earth
-
Similar Topics
-
By NASA
6 min read
Preparations for Next Moonwalk Simulations Underway (and Underwater)
The NISAR mission will help researchers get a better understanding of how Earth’s surface changes over time, including in the lead-up to volcanic eruptions like the one pictured, at Mount Redoubt in southern Alaska in April 2009.R.G. McGimsey/AVO/USGS Data from NISAR will improve our understanding of such phenomena as earthquakes, volcanoes, and landslides, as well as damage to infrastructure.
We don’t always notice it, but much of Earth’s surface is in constant motion. Scientists have used satellites and ground-based instruments to track land movement associated with volcanoes, earthquakes, landslides, and other phenomena. But a new satellite from NASA and the Indian Space Research Organisation (ISRO) aims to improve what we know and, potentially, help us prepare for and recover from natural and human-caused disasters.
The NISAR (NASA-ISRO Synthetic Aperture Radar) mission will measure the motion of nearly all of the planet’s land and ice-covered surfaces twice every 12 days. The pace of NISAR’s data collection will give researchers a fuller picture of how Earth’s surface changes over time. “This kind of regular observation allows us to look at how Earth’s surface moves across nearly the entire planet,” said Cathleen Jones, NISAR applications lead at NASA’s Jet Propulsion Laboratory in Southern California.
Together with complementary measurements from other satellites and instruments, NISAR’s data will provide a more complete picture of how Earth’s surface moves horizontally and vertically. The information will be crucial to better understanding everything from the mechanics of Earth’s crust to which parts of the world are prone to earthquakes and volcanic eruptions. It could even help resolve whether sections of a levee are damaged or if a hillside is starting to move in a landslide.
The NISAR mission will measure the motion of Earth’s surface — data that can be used to monitor critical infrastructure such as airport runways, dams, and levees. NASA/JPL-Caltech What Lies Beneath
Targeting an early 2025 launch from India, the mission will be able to detect surface motions down to fractions of an inch. In addition to monitoring changes to Earth’s surface, the satellite will be able to track the motion of ice sheets, glaciers, and sea ice, and map changes to vegetation.
The source of that remarkable detail is a pair of radar instruments that operate at long wavelengths: an L-band system built by JPL and an S-band system built by ISRO. The NISAR satellite is the first to carry both. Each instrument can collect measurements day and night and see through clouds that can obstruct the view of optical instruments. The L-band instrument will also be able to penetrate dense vegetation to measure ground motion. This capability will be especially useful in areas surrounding volcanoes or faults that are obscured by vegetation.
“The NISAR satellite won’t tell us when earthquakes will happen. Instead, it will help us better understand which areas of the world are most susceptible to significant earthquakes,” said Mark Simons, the U.S. solid Earth science lead for the mission at Caltech in Pasadena, California.
Data from the satellite will give researchers insight into which parts of a fault slowly move without producing earthquakes and which sections are locked together and might suddenly slip. In relatively well-monitored areas like California, researchers can use NISAR to focus on specific regions that could produce an earthquake. But in parts of the world that aren’t as well monitored, NISAR measurements could reveal new earthquake-prone areas. And when earthquakes do occur, data from the satellite will help researchers understand what happened on the faults that ruptured.
“From the ISRO perspective, we are particularly interested in the Himalayan plate boundary,” said Sreejith K M, the ISRO solid Earth science lead for NISAR at the Space Applications Center in Ahmedabad, India. “The area has produced great magnitude earthquakes in the past, and NISAR will give us unprecedented information on the seismic hazards of the Himalaya.”
Surface motion is also important for volcano researchers, who need data collected regularly over time to detect land movements that may be precursors to an eruption. As magma shifts below Earth’s surface, the land can bulge or sink. The NISAR satellite will help provide a fuller picture for why a volcano deforms and whether that movement signals an eruption.
Finding Normal
When it comes to infrastructure such as levees, aqueducts, and dams, NISAR’s ability to provide continuous measurements over years will help to establish the usual state of the structures and surrounding land. Then, if something changes, resource managers may be able to pinpoint specific areas to examine. “Instead of going out and surveying an entire aqueduct every five years, you can target your surveys to problem areas,” said Jones.
The data could be equally valuable for showing that a dam hasn’t changed after a disaster like an earthquake. For instance, if a large earthquake struck San Francisco, liquefaction — where loosely packed or waterlogged sediment loses its stability after severe ground shaking — could pose a problem for dams and levees along the Sacramento-San Joaquin River Delta.
“There’s over a thousand miles of levees,” said Jones. “You’d need an army to go out and look at them all.” The NISAR mission would help authorities survey them from space and identify damaged areas. “Then you can save your time and only go out to inspect areas that have changed. That could save a lot of money on repairs after a disaster.”
More About NISAR
The NISAR mission is an equal collaboration between NASA and ISRO and marks the first time the two agencies have cooperated on hardware development for an Earth-observing mission. Managed for the agency by Caltech, JPL leads the U.S. component of the project and is providing the mission’s L-band SAR. NASA is also providing the radar reflector antenna, the deployable boom, a high-rate communication subsystem for science data, GPS receivers, a solid-state recorder, and payload data subsystem. The U R Rao Satellite Centre in Bengaluru, India, which leads the ISRO component of the mission, is providing the spacecraft bus, the launch vehicle, and associated launch services and satellite mission operations. The ISRO Space Applications Centre in Ahmedabad is providing the S-band SAR electronics.
To learn more about NISAR, visit:
https://nisar.jpl.nasa.gov
News Media Contacts
Jane J. Lee / Andrew Wang
Jet Propulsion Laboratory, Pasadena, Calif.
818-354-0307 / 626-379-6874
jane.j.lee@jpl.nasa.gov / andrew.wang@jpl.nasa.gov
2024-155
Share
Details
Last Updated Nov 08, 2024 Related Terms
NISAR (NASA-ISRO Synthetic Aperture Radar) Earth Science Earthquakes Jet Propulsion Laboratory Natural Disasters Volcanoes Explore More
2 min read Hurricane Helene’s Gravity Waves Revealed by NASA’s AWE
On Sept. 26, 2024, Hurricane Helene slammed into the Gulf Coast of Florida, inducing storm…
Article 22 hours ago 3 min read Integrating Relevant Science Investigations into Migrant Children Education
For three weeks in August, over 100 migrant children (ages 3-15) got to engage in…
Article 2 days ago 5 min read NASA, Bhutan Conclude Five Years of Teamwork on STEM, Sustainability
Article 4 days ago Keep Exploring Discover Related Topics
Missions
Humans in Space
Climate Change
Solar System
View the full article
-
By European Space Agency
This compilation of images, captured by the Copernicus Sentinel-2 mission, showcases the characteristic hues of autumn in different European countries.
View the full article
-
By NASA
NASA/Don Pettit Earth’s city lights streak by in this long-exposure photo taken by NASA astronaut Don Pettit on Oct. 24, 2024. The green glow of Earth’s atmosphere is also visible on the horizon.
Since the station became operational in November 2000, crew members have produced hundreds of thousands of images like this one through Crew Earth Observations. Their photographs of Earth record how the planet changes over time due to human activity and natural events, allowing scientists to monitor disasters and direct response on the ground and study phenomena.
Image credit: NASA/Don Pettit
View the full article
-
By NASA
On Nov. 3, 1994, space shuttle Atlantis took to the skies on its 13th trip into space. During the 11-day mission, the STS-66 crew of Commander Donald R. McMonagle, Pilot Curtis L. Brown, Payload Commander Ellen Ochoa, and Mission Specialists Joseph R. Tanner, Scott E. Parazynski, and French astronaut Jean-François Clervoy representing the European Space Agency (ESA) operated the third Atmospheric Laboratory for Applications and Sciences (ATLAS-3), and deployed and retrieved the U.S.-German Cryogenic Infrared Spectrometers and Telescopes for the Atmosphere-Shuttle Pallet Satellite (CRISTA-SPAS), as part of NASA’s Mission to Planet Earth. The remote sensing instruments studied the Sun’s energy output, the atmosphere’s chemical composition, and how these affect global ozone levels, adding to the knowledge gained during the ATLAS-1 and ATLAS-2 missions.
Left: Official photo of the STS-68 crew of Jean-François Clervoy, left, Scott E. Parazynski, Curtis L. Brown, Joseph R. Tanner, Donald R. McMonagle, and Ellen Ochoa. Middle: The STS-66 crew patch. Right: The ATLAS-3 payload patch.
In August 1993, NASA named Ochoa as the ATLAS-3 payload commander, and in January 1994, named the rest of the STS-66 crew. For McMonagle, selected as an astronaut in 1987, ATLAS-3 marked his third trip into space, having flown on STS-39 and STS-54. Brown, also from the class of 1987, previously flew on STS 47, while Ochoa, selected in 1990, flew as a mission specialist on STS-56, the ATLAS-2 mission. For Tanner, Parazynski, and Clervoy, all from the Class of 1992 – the French space agency CNES previously selected Clervoy as one of its astronauts in 1985 before he joined the ESA astronaut cadre in 1992 – STS-66 marked their first spaceflight.
Left: Schematic illustration of ATLAS-3 and its instruments. Right: Schematic illustration of CRISTA-SPAS retrievable satellite and its instruments.
The ATLAS-3 payload consisted of six instruments on a Spacelab pallet and one mounted on the payload bay sidewall. The pallet mounted instruments included Atmospheric Trace Molecule Spectroscopy (ATMOS), Millimeter-Wave Atmospheric Sounder (MAS), Active Cavity Radiometer Irradiance Monitor (ACRIM), Measurement of the Solar Constant (SOLCON), Solar Spectrum Measurement from 1,800 to 3,200 nanometers (SOLSCAN), and Solar Ultraviolet Spectral Irradiance Monitor (SUSIM).
The Shuttle Solar Backscatter Ultraviolet (SSBUV) instrument constituted the payload bay sidewall mounted experiment. While the instruments previously flew on the ATLAS-1 and ATLAS-2 missions, both those flights took place during the northern hemisphere spring. Data from the ATLAS-3’s mission in the fall complemented results from the earlier missions. The CRISTA-SPAS satellite included two instruments, the CRISTA and the Middle Atmosphere High Resolution Spectrograph Investigation (MAHRSI).
Left: Space shuttle Atlantis at Launch Pad 39B at NASA’s Kennedy Space Center in Florida. Middle: Liftoff of Atlantis on STS-66. Right: Atlantis rises into the sky.
Following its previous flight, STS-46 in August 1992, Atlantis spent one and a half years at the Rockwell plant in Palmdale, California, undergoing major modifications before arriving back at KSC on May 29, 1994. During the modification period, workers installed cables and wiring for a docking system for Atlantis to use during the first Shuttle-Mir docking mission in 1995 and equipment to allow it to fly Extended Duration Orbiter missions of two weeks or longer. Atlantis also underwent structural inspections and systems upgrades including improved nose wheel steering and a new reusable drag chute. Workers in KSC’s Orbiter Processing Facility installed the ATLAS-3 and CRISTA-SPAS payloads and rolled Atlantis over to the Vehicle Assembly Building on Oct. 4 for mating with its External Tank and Solid Rocket Boosters. Atlantis rolled out to Launch Pad 39B six days later. The six-person STS-66 crew traveled to KSC to participate in the Terminal Countdown Demonstration Test, essentially a dress rehearsal for the launch countdown, on Oct. 18.
They returned to KSC on Oct. 31, the same day the final countdown began. Following a smooth countdown leading to a planned 11:56 a.m. EST liftoff on Nov. 3, 1994, Atlantis took off three minutes late, the delay resulting from high winds at one of the Transatlantic Abort sites. The liftoff marked the third shuttle launch in 55 days, missing a record set in 1985 by one day. Eight and a half minutes later, Atlantis delivered its crew and payloads to space. Thirty minutes later, a firing of the shuttle’s Orbiter Maneuvering System (OMS) engines placed them in a 190-mile orbit inclined 57 degrees to the equator. The astronauts opened the payload bay doors, deploying the shuttle’s radiators, and removed their bulky launch and entry suits, stowing them for the remainder of the flight.
Left: Atlantis’ payload bay, showing the ATLAS-3 payload and the CRISTA-SPAS deployable satellite behind it. Middle: European Space Agency astronaut Jean-François Clervoy uses the shuttle’s Remote Manipulator System (RMS) to grapple the CRISTA-SPAS prior to its release. Right: Clervoy about to release CRISTA-SPAS from the RMS.
The astronauts began to convert their vehicle into a science platform, and that included breaking up into two teams to enable 24-hour-a-day operations. McMonagle, Ochoa, and Tanner made up the Red Team while Brown, Parazynski, and Clervoy made up the Blue Team. Within five hours of liftoff, the Blue Team began their sleep period while the Red Team started their first on orbit shift by activating the ATLAS-3 instruments, the CRISTA-SPAS deployable satellite, and the Remote Manipulator System (RMS) or robotic arm in the payload bay and some of the middeck experiments. The next day, Clervoy, operating the RMS, grappled CRISTA-SPAS, lifted it from its cradle in the payload bay, and while Atlantis flew over Germany, deployed it for its eight-day free flight. McMonagle fired Atlantis’ thrusters to separate from the satellite.
Left: Ellen Ochoa and Donald R. McMonagle on the shuttle’s flight deck. Middle: European Space Agency astronaut Jean-François Clervoy in the commander’s seat during the mission. Right: Scott E. Parazynski operates a protein crystallization experiment in the shuttle middeck.
Left: Joseph R. Tanner operates a protein crystallization experiment. Middle: Curtis L. Brown operates a microgravity acceleration measurement system. Right: Ellen Ochoa uses the shuttle’s Remote Manipulator System to grapple CRISTA-SPAS following its eight-day free flight.
For the next eight days, the two teams of astronauts continued work with the ATLAS instruments and several middeck and payload bay experiments such as protein crystal growth, measuring the shuttle microgravity acceleration environment, evaluating heat pipe performance, and a student experiment to study the Sun that complemented the ATLAS instruments. On November 12, the mission’s 10th day, the astronauts prepared to retrieve the CRISTA-SPAS satellite. For the retrieval, McMonagle and Brown used a novel rendezvous profile unlike previous ones used in the shuttle program. Instead of making the final approach from in front of the satellite, called the V-bar approach, Atlantis approached from below in the so-called R-bar approach. This is the profile Atlantis planned to use on its next mission, the first rendezvous and docking with the Mir space station. It not only saved fuel but also prevented contamination of the station’s delicate sensors and solar arrays. Once within 40 feet of CRISTA-SPAS, Ochoa reached out with the RMS, grappled the satellite, and then berthed it back in the payload bay.
A selection from the 6,000 STS-66 crew Earth observation photographs. Left: Deforestation in the Brazilian Amazon. Middle left: Hurricane Florence in the North Atlantic. Middle right: The Ganges River delta. Right: The Sakurajima Volcano in southern Japan.
As a Mission to Planet Earth, the STS-66 astronauts spent considerable time looking out the window, capturing 6,000 images of their home world. Their high inclination orbit enabled views of parts of the planet not seen during typical shuttle missions.
Left: The inflight STS-66 crew photo. Right: Donald R. McMonagle, left, and Curtis R. Brown prepare for Atlantis’ deorbit and reentry.
On flight day 11, with most of the onboard film exposed and consumables running low, the astronauts prepared for their return to Earth the following day. McMonagle and Brown tested Atlantis’ reaction control system thrusters and aerodynamic surfaces in preparation for deorbit and descent through the atmosphere, while the rest of the crew busied themselves with shutting down experiments and stowing away unneeded equipment.
Left: Atlantis makes a perfect touchdown at California’s Edwards Air Force Base. Middle: Atlantis deploys the first reusable space shuttle drag chute. Right: Mounted atop a Shuttle Carrier Aircraft, Atlantis departs Edwards for the cross-country trip to NASA’s Kennedy Space Center in Florida.
On Nov. 14, the astronauts closed Atlantis’ payload bay doors, donned their launch and entry suits, and strapped themselves into their seats for entry and landing. Tropical Storm Gordon near the KSC primary landing site forced a diversion to Edwards Air Force Base (AFB) in California. The crew fired Atlantis’ OMS engines to drop out of orbit. McMonagle piloted Atlantis to a smooth landing at Edwards, ending the 10-day 22-hour 34-minute flight, Atlantis’ longest flight up to that time. The crew had orbited the Earth 174 times. Workers at Edwards safed the vehicle and placed it atop a Shuttle Carrier Aircraft for the ferry flight back to KSC. The duo left Edwards on Nov. 21, and after stops at Kelly Field in San Antonio and Eglin AFB in the Florida panhandle, arrived at KSC the next day. Workers there began preparing Atlantis for its next flight, STS-71 in June 1995, the first Shuttle-Mir docking mission. Meanwhile, a Gulfstream jet flew the astronauts back to Ellington Field in Houston for reunions with their families. As it turned out, STS-66 flew Atlantis’ last solo flight until STS-125 in 2009, the final Hubble Servicing Mission. The 16 intervening flights, and the three that followed, all docked with either Mir or the International Space Station.
“The mission not only met all our expectations, but all our hopes and dreams as well,” said Mission Scientist Timothy L. Miller of NASA’s Marshall Space Flight Center in Huntsville, Alabama. “One of its high points was our ability to receive and process so much data in real time, enhancing our ability to carry out some new and unprecedented cooperative experiments.” McMonagle said of STS-66, “We are very proud of the mission we have just accomplished. If there’s any one thing we all have an interest in, it’s the health of our planet.”
Enjoy the crew narrate a video about the STS-66 mission.
Explore More
3 min read Halloween on the International Space Station
Article 4 days ago 9 min read 60 Years Ago: The First Flight of the Lunar Landing Research Vehicle
Article 5 days ago 11 min read 35 Years Ago: STS-34 Sends Galileo on its Way to Jupiter
Article 2 weeks ago View the full article
-
By NASA
6 min read
Preparations for Next Moonwalk Simulations Underway (and Underwater)
With one of its solar arrays deployed, NASA’s Lunar Trailblazer sits in a clean room at Lockheed Martin Space. The large silver grate attached to the spacecraft is the radiator for HVM³, one of two instruments that the mission will use to better understand the lunar water cycle.Lockheed Martin Space There’s water on the Moon, but scientists only have a general idea of where it is and what form it is in. A trailblazing NASA mission will get some answers.
When NASA’s Lunar Trailblazer begins orbiting the Moon next year, it will help resolve an enduring mystery: Where is the Moon’s water? Scientists have seen signs suggesting it exists even where temperatures soar on the lunar surface, and there’s good reason to believe it can be found as surface ice in permanently shadowed craters, places that have not seen direct sunlight for billions of years. But, so far, there have been few definitive answers, and a full understanding of the nature of the Moon’s water cycle remains stubbornly out of reach.
This is where Lunar Trailblazer comes in. Managed by NASA’s Jet Propulsion Laboratory and led by Caltech in Pasadena, California, the small satellite will map the Moon’s surface water in unprecedented detail to determine the water’s abundance, location, form, and how it changes over time.
“Making high-resolution measurements of the type and amount of lunar water will help us understand the lunar water cycle, and it will provide clues to other questions, like how and when did Earth get its water,” said Bethany Ehlmann, principal investigator for Lunar Trailblazer at Caltech. “But understanding the inventory of lunar water is also important if we are to establish a sustained human and robotic presence on the Moon and beyond.”
Future explorers could process lunar ice to create breathable oxygen or even fuel. And they could also conduct science. Using information from Lunar Trailblazer, future human or robotic scientific investigations could sample the ice for later study to determine where the water came from. For example, the presence of ammonia in ice samples may indicate the water came from comets; sulfur, on the other hand, could show that it was vented to the surface from the lunar interior when the Moon was young and volcanically active.
This artist’s concept depicts NASA’s Lunar Trailblazer in lunar orbit about 60 miles (100 kilometers) from the surface of the Moon. The spacecraft weighs only 440 pounds (200 kilograms) and measures 11.5 feet (3.5 meters) wide when its solar panels are fully deployed.Lockheed Martin Space “In the future, scientists could analyze the ice in the interiors of permanently shadowed craters to learn more about the origins of water on the Moon,” said Rachel Klima, Lunar Trailblazer deputy principal investigator at the Johns Hopkins Applied Physics Laboratory in Laurel, Maryland. “Like an ice core from a glacier on Earth can reveal the ancient history of our planet’s atmospheric composition, this pristine lunar ice could provide clues as to where that water came from and how and when it got there.”
Understanding whether water molecules move freely across the surface of the Moon or are locked inside rock is also scientifically important. Water molecules could move from frosty “cold traps” to other locations throughout the lunar day. Frost heated by the Sun sublimates (turning from solid ice to a gas without going through a liquid phase), allowing the molecules to move as a gas to other cold locations, where they could form new frost as the Sun moves overhead. Knowing how water moves on the Moon could also lead to new insights into the water cycles on other airless bodies, such as asteroids
Two Instruments, One Mission
Two science instruments aboard the spacecraft will help unlock these secrets: the High-resolution Volatiles and Minerals Moon Mapper (HVM3) infrared spectrometer and the Lunar Thermal Mapper (LTM) infrared multispectral imager.
Developed by JPL, HVM3 will detect and map the spectral fingerprints, or wavelengths of reflected sunlight, of minerals and the different forms of water on the lunar surface. The spectrometer can use faint reflected light from the walls of craters to see the floor of even permanently shadowed craters.
The LTM instrument, which was built by the University of Oxford and funded by the UK Space Agency, will map the minerals and thermal properties of the same lunar landscape. Together they will create a picture of the abundance, location, and form of water while also tracking how its distribution changes over time.
“The LTM instrument precisely maps the surface temperature of the Moon while the HVM3 instrument looks for the spectral signature of water molecules,” said Neil Bowles, instrument scientist for LTM at the University of Oxford. “Both instruments will allow us to understand how surface temperature affects water, improving our knowledge of the presence and distribution of these molecules on the Moon.”
Weighing only 440 pounds (200 kilograms) and measuring 11.5 feet (3.5 meters) wide when its solar panels are fully deployed, Lunar Trailblazer will orbit the Moon about 60 miles (100 kilometers) from the surface. The mission was selected by NASA’s SIMPLEx (Small Innovative Missions for Planetary Exploration) program in 2019 and will hitch a ride on the same launch as the Intuitive Machines-2 delivery to the Moon through NASA’s Commercial Lunar Payload Services initiative. Lunar Trailblazer passed a critical operational readiness review in early October at Caltech after completing environmental testing in August at Lockheed Martin Space in Littleton, Colorado, where it was assembled.
The orbiter and its science instruments are now being put through flight system software tests that simulate key aspects of launch, maneuvers, and the science mission while in orbit around the Moon. At the same time, the operations team led by IPAC at Caltech is conducting tests to simulate commanding, communication with NASA’s Deep Space Network, and navigation.
More About Lunar Trailblazer
Lunar Trailblazer is managed by JPL, and its science investigation and mission operations are led by Caltech with the mission operations center at IPAC. Managed for NASA by Caltech, JPL also provides system engineering, mission assurance, the HVM3 instrument, as well as mission design and navigation. Lockheed Martin Space provides the spacecraft, integrates the flight system, and supports operations under contract with Caltech.
SIMPLEx mission investigations are managed by the Planetary Missions Program Office at NASA’s Marshall Space Flight Center in Huntsville, Alabama, as part of the Discovery Program at NASA Headquarters in Washington. The program conducts space science investigations in the Planetary Science Division of NASA’s Science Mission Directorate at NASA Headquarters.
For more information about Lunar Trailblazer, visit:
https://www.jpl.nasa.gov/missions/lunar-trailblazer
News Media Contacts
Karen Fox / Molly Wasser
NASA Headquarters, Washington
202-358-1600
karen.c.fox@nasa.gov / molly.l.wasser@nasa.gov
Ian J. O’Neill
Jet Propulsion Laboratory, Pasadena, Calif.
818-354-2649
ian.j.oneill@jpl.nasa.gov
Gordon Squires
IPAC, Pasadena, Calif.
626-395-3121
squires@ipac.caltech.edu
2024-148
Share
Details
Last Updated Oct 29, 2024 Related Terms
Lunar Trailblazer Earth's Moon Moons Planetary Science Planetary Science Division Science Mission Directorate Explore More
4 min read New NASA Instrument for Studying Snowpack Completes Airborne Testing
Summer heat has significant effects in the mountainous regions of the western United States. Melted…
Article 3 hours ago 3 min read Gateway: Centering Science
Gateway is set to advance science in deep space, bringing groundbreaking research opportunities to lunar…
Article 4 hours ago 6 min read NASA’s Perseverance Rover Looks Back While Climbing Slippery Slope
Article 23 hours ago Keep Exploring Discover Related Topics
Missions
Humans in Space
Climate Change
Solar System
View the full article
-
-
Check out these Videos
Recommended Posts
Join the conversation
You can post now and register later. If you have an account, sign in now to post with your account.
Note: Your post will require moderator approval before it will be visible.