The Stratospheric Aerosol and Gas Experiment (SAGE) is a series of remote sensing satellite instruments used to study the chemical composition of Earth’s atmosphere. Specifically, SAGE has been used to study the Earth’s ozone layer and aerosols at the troposphere through the stratosphere. The SAGE instruments use solar occultation measurement technique to determine chemical concentrations in the atmosphere. Solar occultation measurement technique measures sunlight through the atmosphere and ratios that measurement with a sunlight measurement without atmospheric attenuation. This is achieved by observing sunrises and sunsets during a satellite orbit. Physically, the SAGE instruments measure ultraviolet/visible energy and this is converted via algorithms to determine chemical concentrations. SAGE data has been used to study the atmospheres aerosols, ozone, water vapor, and other trace gases.
Rehearsals will be performed before the sampling event, during which the solar arrays will be raised into a Y-shaped configuration to minimize the chance of dust accumulation during contact and provide more ground clearance in case the spacecraft tips over (up to 45°) during contact. The descent will be very slow to minimize thruster firings prior to contact in order to reduce the likelihood of asteroid surface contamination by unreacted hydrazine propellant. Contact with the surface of Bennu will be detected using accelerometers, and the impact force will be dissipated by a spring in the TAGSAM arm.
Upon surface contact by the TAGSAM instrument, a burst of nitrogen gas will be released, which will blow regolith particles smaller than 2 centimetres (0.8 in) into the sampler head at the end of the robotic arm. A five-second timer will limit collection time to mitigate the chance of a collision. After the timer expires, the back-away maneuver will initiate a safe departure from the asteroid.
OSIRIS-REx will then halt the drift away from the asteroid in case it is necessary to return for another sampling attempt. The spacecraft will use images and spinning maneuvers to verify the sample has been acquired as well as determine its mass and verify it is in excess of the required 60 grams (2.1 oz). In the event of a failed sampling attempt, the spacecraft will return for another try. There is enough nitrogen gas for three attempts.
In addition to the bulk sampling mechanism, contact pads on the end of the sampling head will passively collect dust grains smaller than 1 mm, upon contact with the asteroid. These pads are made from tiny loops of stainless steel.
After the sampling attempt, the Sample-Return Capsule (SRC) lid will be opened to allow the sampler head to be stowed. The arm will then be retracted into its launch configuration, and the SRC lid will be closed and latched preparing to return to Earth.
The SpaceX Starship system is a fully-reusable, two-stage-to-orbit, super heavy-lift launch vehicle under development by SpaceX since 2012, as a self-funded private spaceflight project.
The second stage—which is also referred to as “Starship”—is being designed as a long-duration cargo, and eventually, passenger-carrying spacecraft. It is being used initially without any booster stage at all, as part of an extensive development program to prove out launch-and-landing and iterate on a variety of design details, particularly with respect to the vehicle’s atmospheric reentry. While the spacecraft is currently being tested on its own at suborbital altitudes during 2019–20, it will later be used on orbital launches with an additional booster stage, the Super Heavy, where the spacecraft will serve as both the second stage on the two-stage-to-orbit launch vehicle and the in-space long-duration orbital spaceship.
Integrated system testing of a proof of concept for Starship began in March 2019, with the addition of a single Raptor rocket engine to a reduced-height prototype, nicknamed Starhopper – similar to Grasshopper, an equivalent prototype of the Falcon 9 reusable booster. Starhopper was used from April through August 2019 for static testing and low-altitude, low-velocity flight testing of vertical launches and landings in July and August 2019. More prototype Starships have been built and more are under construction as the iterative design goes through several iterations. All test articles have a 9-meter (30 ft)-diameter stainless steel hull.
SpaceX is planning to launch commercial payloads using Starship no earlier than 2021. In April 2020, NASA selected a modified human-rated Starship system as one of three potential lunar landing system design concepts to receive funding for a 10-month long initial design phase for the NASA Artemis program.
Technicians at NASA’s Kennedy Space Center in Florida work to safely return the Artemis I Orion spacecraft to the FAST cell after completing the installation of the spacecraft adapter (SA) cone inside the Neil Armstrong Operations and Checkout Building on Aug. 20, 2020. This is one of the final major hardware operations the spacecraft will undergo during closeout processing prior to being integrated with the Space Launch System (SLS) rocket in preparation for the first Artemis mission.
This video shows how NASA’s James Webb Space Telescope is designed to fold to a much smaller size in order to fit inside the Ariane V rocket for launch to space. The largest, most complex space observatory ever built, must fold itself to fit within a 17.8-foot (5.4-meter) payload fairing, and survive the rigors of a rocket ride to orbit. After liftoff, the entire observatory will unfold in a carefully choreographed series of steps before beginning to make groundbreaking observations of the cosmos.
ICESat-2 (Ice, Cloud, and land Elevation Satellite 2), part of NASA’s Earth Observing System, is a satellite mission for measuring ice sheet elevation and sea ice thickness, as well as land topography, vegetation characteristics, and clouds. ICESat-2, a follow-on to the ICESat mission, was launched on 15 September 2018 from Vandenberg Air Force Base in California, into a near-circular, near-polar orbit with an altitude of approximately 496 km (308 mi). It was designed to operate for three years and carry enough propellant for seven years. The satellite orbits Earth at a speed of 6.9 kilometers per second (4.3 mi/s).
The ICESat-2 mission is designed to provide elevation data needed to determine ice sheet mass balance as well as vegetation canopy information. It will provide topography measurements of cities, lakes and reservoirs, oceans and land surfaces around the globe, in addition to the polar-specific coverage. ICESat-2 also has the ability to detect seafloor topography up to 100 feet (30m) below the surface in clear watered coastal areas. Because the great changes of polar ice cover in global warming are not quantified, one of the main purposes of ICESat-2 is measuring the changing of the elevation of ice sheets by its laser system and lidar to quantify the influence of melting ice sheet in sea-level raising. Additionally, the high accuracy of multiple pulses allows collecting measurement of the heights of sea ice to analyze its change rate during the time.
The ICESat-2 spacecraft was built and tested by Northrop Grumman Innovation Systems in Gilbert, Arizona, while the on board instrument, ATLAS, was built and managed by Goddard Space Flight Center in Greenbelt, Maryland. The ATLAS instrument was designed and built by the center, and the bus was built by and integrated with the instrument by Orbital Sciences (later Orbital ATK). Orbital ATK, which was a global leader in aerospace and defense technologies, was acquired by the Northrop Grumman Corporation on June 6, 2018. The satellite was launched on a Delta II rocket provided by United Launch Alliance. This was the last launch of the Delta II rocket.
Video credit: Credit: NASA’s Scientific Visualization Studio/Kel Elkins (USRA): Lead Visualizer/Ryan Fitzgibbons (USRA): Lead Producer/Alek A. Petty (University of Maryland): Scientist/Thomas A. Neumann Ph.D. (NASA/GSFC): Scientist/Nathan T. Kurtz (NASA/GSFC): Scientist
Subscribe to blog posts using RSS
