Space and astronomy news
The first spacecraft to use gravity assist was NASA’s Mariner 10 in 1974. It used a gravity assist from Venus to reach Mercury. Now, the gravity assist maneuver is a crucial part of modern space travel.
The latest spacecraft to use gravity assist is the ESA’s JUICE spacecraft.
Continue reading “After a Boost from Earth and the Moon, Juice is On its Way to Venus and Beyond”
We may take it for granted, but every day we receive picture postcards from the robotic travelers we have sent out to explore our Solar System. Usually, we get to see faraway planets, moons, asteroids, or comets. But sometimes we get to see ourselves.
The Lucy spacecraft took a couple of amazing images of our home planet as the spacecraft was approaching Earth for the first of three slingshot gravity assists on its way out to explore the Trojan asteroids along Jupiter’s orbit.
Continue reading “Lucy Took This Picture of Earth as it was Making its Gravity Assist Maneuver”
KENNEDY SPACE CENTER, FL – NASA’s OSIRIS-REx asteroid mission captured a lovely ‘Blue Marble’ image of our Home Planet during last Fridays (Sept. 22) successful gravity assist swing-by sending the probe hurtling towards asteroid Bennu for a rendezvous next August on a round trip journey to snatch pristine soil samples.
The newly released color composite image of Earth was taken on Sept. 22 by the spacecrafts MapCam camera.
It was taken at a range of approximately 106,000 miles (170,000 kilometers), just a few hours after OSIRIS-REx completed its critical Earth Gravity Assist (EGA) maneuver.
“NASA’s asteroid sample return spacecraft successfully used Earth’s gravity on Friday, Sept. 22 to slingshot itself on a path toward the asteroid Bennu, for a rendezvous next August,” the agency confirmed after receiving the eagerly awaited telemetry.
OSIRIS-Rex, which stands for Origins, Spectral Interpretation, Resource Identification, and Security – Regolith Explorer, is NASA’s first ever asteroid sample return mission.
As it swung by Earth at 12:52 p.m. EDT on Sept. 22, OSIRIS-REx passed only 10,711 miles (17,237 km) above Antarctica, just south of Cape Horn, Chile.
The probe departed Earth by following a flight path that continued north over the Pacific Ocean and has already travelled 600 million miles (1 billion kilometers) since launching on Sept. 8, 2016.
The preplanned EGA maneuver provided the absolutely essential gravity assisted speed boost required for OSIRIS-Rex to gain enough velocity to complete its journey to the carbon rich asteroid Bennu and back.
The mission was only made possible by the slingshot which provided a velocity change to the spacecraft of 8,451 miles per hour (3.778 kilometers per second).
“The encounter with Earth is fundamental to our rendezvous with Bennu,” said Rich Burns, OSIRIS-REx project manager at NASA’s Goddard Space Flight Center in Greenbelt, Maryland, in a statement.
“The total velocity change from Earth’s gravity far exceeds the total fuel load of the OSIRIS-REx propulsion system, so we are really leveraging our Earth flyby to make a massive change to the OSIRIS-REx trajectory, specifically changing the tilt of the orbit to match Bennu.”
The spacecraft conducted a post flyby science campaign by collecting images and science observations of Earth and the Moon that began four hours after closest approach in order to test and calibrate its onboard suite of five science instruments and help prepare them for OSIRIS-REx’s arrival at Bennu in late 2018.
The MapCam camera Blue Marble image is the first one to be released by NASA and the science team.
The image is centered on the Pacific Ocean and shows several familiar landmasses, including Australia in the lower left, and Baja California and the southwestern United States in the upper right.
“The dark vertical streaks at the top of the image are caused by short exposure times (less than three milliseconds),” said the team.
“Short exposure times are required for imaging an object as bright as Earth, but are not anticipated for an object as dark as the asteroid Bennu, which the camera was designed to image.”
The instrument will gather additional data and measurements scanning the Earth and the Moon for three more days over the next two weeks.
“The opportunity to collect science data over the next two weeks provides the OSIRIS-REx mission team with an excellent opportunity to practice for operations at Bennu,” said Dante Lauretta, OSIRIS-REx principal investigator at the University of Arizona, Tucson.
“During the Earth flyby, the science and operations teams are co-located, performing daily activities together as they will during the asteroid encounter.”
The OSIRIS-Rex spacecraft originally departed Earth atop a United Launch Alliance Atlas V rocket under crystal clear skies on September 8, 2016 at 7:05 p.m. EDT from Space Launch Complex 41 at Cape Canaveral Air Force Station, Florida.
Everything with the launch and flyby went exactly according to plan for the daring mission boldly seeking to gather rocks and soil from carbon rich Bennu.
OSIRIS-Rex is equipped with an ingenious robotic arm named TAGSAM designed to collect at least a 60-gram (2.1-ounce) sample and bring it back to Earth in 2023 for study by scientists using the world’s most advanced research instruments.
Watch for Ken’s continuing onsite NASA mission and launch reports direct from the Kennedy Space Center and Cape Canaveral Air Force Station, Florida.
Stay tuned here for Ken’s continuing Earth and Planetary science and human spaceflight news.
Ken Kremer
KENNEDY SPACE CENTER, FL – Barely a year after NASA’s OSIRIS-REx robotic asteroid sampler launched on a trailblazing mission to snatch a soil sample from a pristine asteroid and return it to Earth for research analysis, the probe is speeding back home for a swift slingshot around our home planet on Friday Sept. 22 to gain a gravity assist speed boost required to complete its journey to the carbon rich asteroid Bennu and back.
As it swings by Earth NASA’s first ever asteroid sample return mission, OSIRIS-REx (Origins, Spectral Interpretation, Resource Identification, and Security – Regolith Explorer), will pass only 11,000 miles (17,000 kilometers) above Earth just before 12:52 p.m. EDT on Friday.
And NASA is asking the public to try and ‘Catch It If You Can’ – by waving hello and/or taking snapshots during and after the probes high speed flyby.
Plus you can watch NASA Facebook Live event at Noon Friday: https://www.facebook.com/NASAGoddard/
OSIRIS-REx will be approaching Earth at a velocity of about 19,000 mph on Friday as it begins flying over Australia during the Earth Gravity Assist (EGA) maneuver.
Since blastoff from the Florida Space Coast on Sept. 8, 2016 the probe has already racked up almost 600 million miles on its round trip journey from Earth and back to set up Friday’s critical gravity assist maneuver to Bennu and back.
As OSIRIS-REx continues along its flight path the spacecraft will reach its closest point to Earth over Antarctica, just south of Cape Horn, Chile. It will gain a velocity boost of about 8400 mph.
The spacecraft will also conduct a post flyby science campaign by collecting images and science observations of Earth and the Moon four hours after closest approach to calibrate its five science instruments.
The allure of Bennu is that it is a carbon rich asteroid – thus OSIRIS-REx could potentially bring back samples infused with the organic chemicals like amino acids that are the building blocks of life as we know it.
“We are interested in that material because it is a time capsule from the earliest stages of solar system formation,” OSIRIS-Rex Principal Investigator Dante Lauretta told Universe Today in a prelaunch interview with the spacecraft in the cleanroom at NASA’s Kennedy Space Center.
The do or die gravity assist plunge is absolutely essential to set OSIRIS-REx on course to match the asteroid’s path and speed when it reaches the vicinity of asteroid Bennu a year from now in October 2018.
“The Earth Gravity Assist is a clever way to move the spacecraft onto Bennu’s orbital plane using Earth’s own gravity instead of expending fuel,” says Lauretta, of the University of Arizona, Tucson.
Bennu’s orbit around the Sun is tilted at a six-degree inclination with respect to Earth’s orbital plane.
The asteroid is 1,614-foot (500 m) in diameter and crosses Earth’s orbit around the sun every six years.
Numerous NASA spacecraft – including NASA’s just completed Cassini mission to Saturn – utilize gravity assists around a variety of celestial bodies to gain speed and change course to save vast amounts of propellant and time in order to accomplish science missions and visit additional target objects that would otherwise be impossible.
The flyby will be a nail-biting time for NASA and the science team because right afterwards the refrigerator sized probe will be out of contact with engineers – unable to receive telemetry for about an hour.
“For about an hour, NASA will be out of contact with the spacecraft as it passes over Antarctica,” said Mike Moreau, the flight dynamics system lead at Goddard, in a statement.
“OSIRIS-REx uses the Deep Space Network to communicate with Earth, and the spacecraft will be too low relative to the southern horizon to be in view with either the Deep Space tracking station at Canberra, Australia, or Goldstone, California.”
NASA says the team will regain communication with OSIRIS-REx roughly 50 minutes after closest approach over Antarctica at about 1:40 p.m. EDT.
The post flyby science campaign is set to begin at 4:52 p.m. EDT, Friday, Sept. 22.
The OSIRIS-Rex spacecraft originally departed Earth atop a United Launch Alliance Atlas V rocket under crystal clear skies on September 8, 2016 at 7:05 p.m. EDT from Space Launch Complex 41 at Cape Canaveral Air Force Station, Florida.
Everything with the launch went exactly according to plan for the daring mission boldly seeking to gather rocks and soil from carbon rich Bennu.
OSIRIS-Rex is equipped with an ingenious robotic arm named TAGSAM designed to collect at least a 60-gram (2.1-ounce) sample and bring it back to Earth in 2023 for study by scientists using the world’s most advanced research instruments.
“The primary objective of the OSIRIS-Rex mission is to bring back pristine material from the surface of the carbonaceous asteroid Bennu,” OSIRIS-Rex Principal Investigator Dante Lauretta told me in the prelaunch interview in the KSC cleanroom with the spacecraft as the probe was undergoing final launch preparations.
“We are interested in that material because it is a time capsule from the earliest stages of solar system formation.”
“It records the very first material that formed from the earliest stages of solar system formation. And we are really interested in the evolution of carbon during that phase. Particularly the key prebiotic molecules like amino acids, nucleic acids, phosphates and sugars that build up. These are basically the biomolecules for all of life.”
NASA and the mission team is also inviting the public to get engaged by participating in the Wave to OSIRIS-REx social media campaign.
“Individuals and groups from anywhere in the world are encouraged to take photos of themselves waving to OSIRIS-REx, share them using the hashtag #HelloOSIRISREx and tag the mission account in their posts on Twitter (@OSIRISREx) or Instagram (@OSIRIS_REx).
Participants may begin taking and sharing photos at any time—or wait until the OSIRIS-REx spacecraft makes its closest approach to Earth at 12:52p.m. EDT on Friday, Sept. 22.”
The probe’s flight path during the flyby will pass through the ring of numerous satellites orbiting in geosynchronous orbit, but none are expected to be within close range.
Watch for Ken’s continuing onsite NASA mission and launch reports direct from the Kennedy Space Center and Cape Canaveral Air Force Station, Florida.
Stay tuned here for Ken’s continuing Earth and Planetary science and human spaceflight news.
