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Mars missions complete first course corrections on journey to Red Planet – Spaceflight Now

This illustration from NASA’s “Eyes on the Solar System” app shows the Mars 2020 spacecraft outbound from planet Earth. Credit: NASA/JPL-Caltech

Three robotic Mars missions launched from Earth last month have begun fine-tuning their trajectories through the solar system with the first in a series mid-course corrections to take aim on the Red Planet for arrival next February.

NASA’s Mars 2020 Perseverance rover launched from Cape Canaveral on July 30, following successful launchings with the United Arab Emirates’ Hope orbiter July 19 and China’s Tianwen 1 Mars mission July 23.

The missions launched during a period of several weeks when Earth and Mars were in the right positions in their orbits around the sun to permit a direct route between the planets. All three spacecraft are due to arrive at Mars in February 2021.

NASA said Aug. 14 that the Mars 2020 mission’s first trajectory correction maneuver, or TCM, was a success. The spacecraft fired eight thrusters to adjust its course toward Mars, beginning to shift the probe’s initial post-launch aim point on to the Red Planet.

The mission’s Atlas 5 launcher intentionally released the Mars 2020 spacecraft on a course that would miss Mars, ensuring the rocket’s upper stage would not crash into the Red Planet.

As of Wednesday, the Perseverance rover cocooned inside the Mars 2020 spacecraft’s aeroshell had logged more than 35 million miles, or 56 million kilometers, since blasting off from Florida’s Space Coast on July 30.

Mars 2020 mission planners have set aside time and propellant for five trajectory correction maneuvers to refine the spacecraft’s path toward Mars and set up the rover to target a precise landing at Jezero Crater, an impact basin that once harbored a lake of liquid water with a river flowing into it.

The nuclear-powered Perseverance rover will explore the crater, seeking signs of ancient life while collecting rock core samples for return to Earth by a future mission.

In addition to the five planned course correction burns, Mars 2020 mission managers have opportunities to command the spacecraft to perform backup or contingency maneuvers if required.

The next trajectory correction burns for Mars 2020 are scheduled for Sept. 30, Dec. 18, Feb. 10, and Feb. 16. That will set the stage for the Perseverance rover’s landing on Mars on Feb. 18.

This illustration shows China’s Tianwen 1 Mars mission as it appears during the cruise to the Red Planet. Credit: Xinhua

China’s Tianwen 1 mission completed its first post-launch course correction Aug. 1 (GMT), according to the state-run Chinese Xinhua news agency.

The spacecraft fired its main engine for 20 seconds in the first of several maneuvers planned during the trip to Mars. The maneuver also served as a test of the probe’s main engine, which performed well during the burn, Chinese officials said.

Tianwen 1 launched July 23 aboard a heavy-lift Long March 5 rocket. The ambitious mission will become China’s first to reach Mars, and includes an orbiter, lander and rover.

The spacecraft is scheduled to swing into orbit around Mars in February — using a lengthy engine burn — and the orbiter will survey candidate landing sites for two-to-three months before releasing the lander and rover to enter the Martian atmosphere.

If China pulls off those feats according to plan, they will make China the third country to perform a soft landing on Mars — after the Soviet Union and the United States — and the second country to drive a robotic rover on the Red Planet.

NASA has landed the only successful rovers on Mars to date.

The UAE’s Hope Mars orbiter has also successfully executed its first interplanetary course correction maneuver, mission officials announced Aug. 17.

In a tweet, officials described the event as a “major milestone” on the journey to Mars. It was the first firing of the probe’s six largest thrusters since the orbiter’s launch July 19 on top of a Japanese H-2A rocket.

Credit: Mohammed Bin Rashid Space Center / UAE Space Agency

Like NASA’s Mars 2020 mission and China’s Tianwen 1 spacecraft, the UAE’s Hope orbiter will arrive at Mars in February.

Funded and led by the United Arab Emirates — and developed in partnership with U.S. scientists — the Hope Mars probe carries a digital camera to image the Martian surface, dust storms and ice clouds, and spectrometers to measure constituents at multiple levels of the planet’s atmosphere.

The Hope mission is the Arab world’s first interplanetary probe.

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Follow Stephen Clark on Twitter: @StephenClark1.

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complete Spacewalkers

Spacewalkers complete penultimate set of battery upgrades for space station – Space.com

Two NASA astronauts have completed the second-to-last set of battery replacements outside of the International Space Station, advancing a multi-year project to upgrade the power system for the orbiting laboratory.

Expedition 63 commander Chris Cassidy and Bob Behnken, who launched on SpaceX’s Crew Dragon spacecraft in late May, conducted their second spacewalk together on Wednesday (July 1), five days after beginning the battery swap work for one of two power channels on the station’s far starboard (S6) truss still needing to be upgraded. 

The spacewalk began at 7:13 a.m. EDT (1113 GMT) as Cassidy and Behnken switched their spacesuits to internal power. 

Video: NASA spacewalkers work outside space station to swap batteries


In photos: The Expedition 63 mission to the International Space Station

NASA astronauts Chris Cassidy and Bob Behnken conduct a spacewalk to replace batteries outside of the International Space Station on Wednesday, July 1, 2src2src.

NASA astronauts Chris Cassidy and Bob Behnken conduct a spacewalk to replace batteries outside of the International Space Station on Wednesday, July 1, 2020.  (Image credit: NASA TV)

Working alongside a pallet supported by the station’s Canadarm2 robotic arm, the astronauts retrieved and installed one more lithium-ion battery and one more adapter plate, adding to the two new batteries and two adapter plates they put into place on June 26. The spacewalkers also removed the sixth and last, older nickel-hydrogen battery, stowing it on the pallet for its disposal.

Each new battery measures about half the size of a refrigerator, or 40 inches long by 37 inches wide by 19 inches high (101 by 94 by 48 centimeters). The old nickel-hydrogen batteries weigh 365 lbs. (165 kilograms) each. The lithium-ion replacements weigh 428 lbs. (194 kg).

As the new batteries have more capacity, one lithium-ion battery (and one adapter plate) can replace two nickel-hydrogen batteries. Since January 2017, astronauts have been working to upgrade each of the station’s eight power channels with three lithium-ion batteries in place of their original six nickel-hydrogen batteries.

Related: Spacewalk photos: International Space Station gets a power upgrade

The new batteries have been delivered to and disposed by Japan’s H-II Transfer Vehicles (HTV), the latest and last of which arrived at the space station in May.

Cassidy and Behnken’s work on Wednesday completed the battery upgrade to the station’s IB power channel, leaving only the 3B channel for a future set of two spacewalks. Flight controllers at NASA’s Mission Control Center in Houston verified that the new battery was operational.

Having achieved the primary task of the extravehicular activity (EVA), the astronauts then turned to accomplishing several “get-aheads.” First, they loosened the bolts holding down the final set of nickel-hydrogen batteries and relocated footholds to prepare for the next pair of spacewalks planned for later this month.

The duo then split up, heading to separate parts of the space station. Cassidy routed new power and ethernet cables on the S3 truss to prepare for the installation of a new external wireless communications system. The power and data running through the cables will support an enhanced high-definition (HD) camera and increase coverage area for future spacewalkers’ helmet-mounted wireless cameras.

Behnken, meanwhile, headed to the end of the starboard truss to remove a no longer needed device called an “H-Fixture” from the base of one of the solar array masts, which was installed before the array was launched. The removal, though, did not go as planned.

View from NASA astronaut Bob Behnken's spacesuit helmet camera showing him working, unsuccessfully, to remove the

View from NASA astronaut Bob Behnken’s spacesuit helmet camera showing him working, unsuccessfully, to remove the “H-Fixture” from a solar array mast outside of the International Space Station, Wednesday, July 1, 2020. (Image credit: NASA TV)

“I’ve been putting about as much force as I can into it to try to pull it off, but it is not interested in coming off,” Behnken reported to Mission Control after trying to use several tools to pry the fixture from the mast. “I think the best answer may be a longer tool inserted into the tether point — although that might break the tether point off. I can pull on it pretty good, but it is really not moving at all.”

“We don’t think there is anything else we can do to get it off, so we will have to reassess for future EVAs,” replied astronaut-capcom Jasmin Moghbeli, calling off the removal attempt from the ground.

Giving up on the H-Fixture’s removal, Behnken then reunited with Cassidy on the S3 truss to help in routing the new ethernet cable before they both headed back to the Quest airlock to head inside the space station. The spacewalk came to an end at 1:14 p.m. EDT (1714 GMT) after 6 hours and 1 minute.

Related: The International Space Station: inside and out (infographic)

NASA astronauts Chris Cassidy and Bob Behnken wrap up their six-hour spacewalk to replace batteries outside of the International Space Station on Wednesday, July 1, 2src2src.

NASA astronauts Chris Cassidy and Bob Behnken wrap up their six-hour spacewalk to replace batteries outside of the International Space Station on Wednesday, July 1, 2020. (Image credit: NASA TV)

Wednesday’s spacewalk was the 229th in support of space station assembly and maintenance. It was the eighth spacewalk for both astronauts.

Cassidy now has spent a total of 43 hours and 22 minutes and Behnken has spent a total of 49 hours and 41 minutes spacewalking.

Robert Pearlman is a Space.com contributing writer and the editor of collectSPACE.com, a Space.com partner site and the leading space history news publication. Follow collectSPACE on Facebook and on Twitter at @collectSPACE. Follow us on Twitter @Spacedotcom and on Facebook.

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