Queqiao - Chinese Lunar Communication Relay Satellite

[Flyaway]

China preparing to launch Chang’e-4 relay satellite May 21

HELSINKI, Finland – China is set to launch a relay satellite to the second Earth-moon Lagrange point May 21, in a necessary precursor to the planned Chang’e-4 soft-landing on the lunar far side late in the year.

Chang’e-4 is the backup to the Chang’e-3 mission which put a lander and rover on Mare Imbrium in late 2013. Following that success, the lunar craft have been repurposed for a pioneering landing on the moon’s far side.

The lunar far side does not face the Earth as the moon’s orbital period matches its rotational period, thus requiring a relay satellite to facilitate communications.

Ian Crawford, professor of planetary science and astrobiology at Birkbeck, University of London, told SpaceNews the mission would be a “tremendous undertaking, as it would be the first time any spacecraft has successfully landed on the far side of the moon.”

The landing is currently expected to target the Von Kármán crater within the South Pole-Aitken Basin, though a decision on the final site has not been announced by Chinese scientists.

The South Pole-Aitken Basin is, Crawford notes, a high priority scientific objective for exploration, potentially offering unique insights into the formation of the moon and history of the solar system.

http://spacenews.com/china-preparing-to-launch-change-4-relay-satellite-may-21/

 

[Flyaway]

China launches Queqiao relay satellite to support Chang'e-4 lunar far side landing mission

China has successfully launched a lunar communications relay satellite designed to support an unprecedented mission to put a lander and rover on the far side of the Moon in late 2018, as well as carry out pioneering astronomy.

The Chang’e-4 relay satellite, accompanied by two microsatellites, lifted off atop a Long March 4C rocket from the Xichang Satellite Launch Centre at 21:28 UTC on Sunday (05:28 Beijing time, May 21).

The spacecraft was successfully inserted into a lunar transfer orbit and separated from the rocket’s upper stage, the China Aerospace Science and Technology Corporation (CASC) – the main contractor for the space programme – confirmed just under an hour after launch.

Named ‘Queqiao’ – referencing a ‘Magpie Bridge’ from a Chinese folklore of lovers crossing the Milky Way – the relay satellite is now on an 8-to-9 day journey to the second Earth-Moon Lagrange point (E-M L2) some 60-80,000 kilometres beyond the Moon and nearly half a million kilometres from Earth.

https://gbtimes.com/china-launches-queqiao-relay-satellite-to-support-change-4-lunar-far-side-landing-mission

 

[Flyaway]

Queqiao Chang'e-4 satellite performs Moon flyby, makes successful braking manoeuvre

The Queqiao Chang'e-4 relay satellite has passed the Moon and successfully performed a propulsive manoeuvre to slow itself and send it towards its intended destination beyond the Moon.

The Beijing Aerospace Control Centre (BACC) issued the command at 21:32 Beijing time (13:32 UTC), and by 21:46 confirmed through telemetry that Queqiao had performed the burn and entered a transfer orbit towards the second Earth-Moon Lagrange point, People's Liberation Army Daily reported.

The spacecraft passed the Moon at 100 km above the surface at closest approach. Failure to perform the braking manoeuvre would have seen the spacecraft head back towards the Earth.

https://gbtimes.com/queqiao-change-4-satellite-performs-moon-flyby-makes-successful-braking-manoeuvre

 

[Michel Van]

https://www.youtube.com/watch?v=25KKyIrnxoo

 

[Archibald]

I wish Bob Farquhar could have seen that: his pet idea of 1970 coming true.

 

[blackstar]

I wish Bob Farquhar could have seen that: his pet idea of 1970 coming true.

I know what you're talking about, but perhaps you could elaborate?

 

[Archibald]

He was the first (AFAIK) to propose a relay satellite at EML-2 for farside landings. Perhaps some mixed feelings to see the Chinese doing it instead of America - but whatever...

 

[Flyaway]

https://twitter.com/planet4589/status/1000831214603898880?s=20

So it looks like Longjiang-2 (DSLWP-B) is in a 350 x 13800 km x 21 deg lunar orbit. Longjiang-1 seems to have failed on May 21 and presumably remains in distant Earth orbit following its lunar flyby

 

[Michel Van]

Longjiang 1 and 2 are two identical Chinese lunar microsatellites mission
to perform ultra long-wave astronomical observations developped at the Harbin Institute of Technology (HIT).

also known under name "Discovering the Sky at Longest Wavelengths Pathfinder" (DSLWP A1 and A2)

The two 45 kg micro-satellites are three-axis stabilized and carry a radio-astronomy payload
and carry a micro-optical camera and a amateur radio communications system.
They insert them by themselves into a 200 km × 9000 km lunar orbits and uses the moon as a shield to avoid radio emmanations from earth.
and will use Queqiao as Relay satellite

 

[Flyaway]

Good job they sent two identical microsatellites as it now looks confirmed one is lost.

Chang'e-4: Lunar microsatellite may be lost, Queqiao continues toward Lagrange point beyond Moon

Contact has been lost with one of two microsatellites launched along with the Queqiao Chang'e-4 lunar relay satellite following a standard trajectory correction manoeuvre on the way to the Moon.

While DSLWP-B/Longjiang-2 successfully entered lunar orbit, there has been apparently no communication between the ground and Longjiang-1 following a trajectory correction manoeuvre after trans-lunar injection.

https://gbtimes.com/change-4-lunar-microsatellite-may-be-lost-queqiao-continues-toward-lagrange-point-beyond-moon

 

[Flyaway]

Queqiao update: Chang'e-4 lunar relay satellite establishing halo orbit after approaching Lagrange point

https://gbtimes.com/queqiao-update-change-4-lunar-relay-satellite-establishing-halo-orbit-after-approaching-lagrange-point

 

[Flyaway]

First photos from Longjiang-2 published here:

https://twitter.com/AJ_FI/status/1007211169768144897

This is kind of incredible. Images of the Earth and Moon, taken by a small Saudi camera on a small 45 kg Chinese satellite in lunar orbit (Longjiang-2/DSLWP-B), as part of the Chang'e-4 relay satellite launch.

Relay satellite for Chang'e 4 lunar probe enters orbit

BEIJING -- The relay satellite for the planned Chang'e 4 lunar probe, which is expected to land on the far side of the Moon at the end of the year, has entered orbit, the China National Space Administration (CNSA) announced Thursday.

The satellite named Queqiao (Magpie Bridge) launched on May 21 and entered the Halo orbit around the second Lagrangian (L2) point of the Earth-Moon system, about 65,000 km from the Moon, at 11:06 am Thursday after a journey of more than 20 days.

"The satellite is the world's first communication satellite operating in that orbit, and will lay the foundation for the Chang'e 4, which is expected to become the world's first soft-landing, roving probe on the far side of the Moon," said Zhang Hongtai, president of the China Academy of Space Technology.

http://europe.chinadaily.com.cn/a/201806/14/WS5b221389a31001b8257222e6.html