question: How can the new Chinese object left on the moon send information to earth if its always pointing away from earth?
comment: They launched a relay satellite past the moon that's orbiting a point in space out there that can receive a signal from the dark side and then transmit it to earth once it gets out from the backside
passages: Direct communication with Earth is impossible on the far side of the Moon, since transmissions are blocked by the Moon. Communications must go through a communications relay satellite, which is placed at a location that has a clear view of both the landing site and the Earth. On 20 May 2018, the China National Space Administration (CNSA) launched the Queqiao () relay satellite to a halo orbit around the Earth–Moon L point. The relay satellite is based on the Chang'e 2 design, has a mass of , and it uses a antenna to receive X band signals from the lander and rover, and relay them to Earth control on the S band.
   BULLET::::- Carry out low-frequency radio astronomical observation and research using a radio telescope
  
  BULLET::::- Study of cosmic rays
  
  BULLET::::- Observe the solar corona, investigate its radiation characteristics and mechanism, and to explore the evolution and transport of coronal mass ejections (CME) between the Sun and Earth.
  
  Section::::Components.
  
  Section::::Components.:"Queqiao" relay satellite.
   Section::::Background.
   The probe was remotely controlled from stations at Qingdao and Kashgar, as the first use of the Chinese Deep Space Network. The ESA Maspalomas Tracking Station was also used to transmit signals to and from the probe.
  
  The first pictures of the Moon were relayed on November 26, 2007. The probe was designed to orbit the Moon for one year, but operations were later extended, and it remained in lunar orbit until March 1, 2009.
  
  Section::::End of mission.
   On 8 June 2011, Chang'e 2 completed its extended mission, and left lunar orbit for the Earth–Sun L2 Lagrangian point, to test the Chinese tracking and control network. The probe reached L2 on 25 August 2011 at 23:27 Beijing time (14:27 UTC) after a 77-day cruise, becoming the first object ever to reach the L2 point directly from lunar orbit, and travelling further than any previous Chinese space probe. The probe beamed its first batch of data from L2 in September 2011. Though it was expected to remain at L2 until the end of 2012, it departed on an extended mission in April 2012.
   The spacecraft took 24 days to reach L, using a lunar swing-by to save fuel. On 14 June 2018, "Queqiao" finished its final adjustment burn and entered the L halo mission orbit, which is about from the Moon. This is the first lunar relay satellite at this location.
  
  The name "Queqiao" ("Magpie Bridge") is inspired and came from the Chinese tale "The Cowherd and the Weaver Girl".
  
  Section::::Components.:"Longjiang" microsatellites.
   After completing its primary objective, the probe left lunar orbit for the Earth–Sun L2 Lagrangian point, to test the Chinese tracking and control network, making the China National Space Administration the third space agency after NASA and ESA to have visited this point. It entered orbit around L2 on 25 August 2011, and began transmitting data from its new position in September 2011. In April 2012, Chang'e 2 departed L2 to begin an extended mission to the asteroid 4179 Toutatis, which it successfully flew by in December 2012. This success made China's CNSA the fourth space agency to directly explore asteroids, after NASA, ESA and JAXA. As of 2014, Chang'e 2 has travelled over 100 million km from Earth, and is conducting a long-term mission to verify China's deep-space tracking and control systems.
   An experiment was conducted in 1957 at the U.S. Naval Research Laboratory that used the echo from radar signals to determine the Earth-Moon distance. Radar pulses lasting were broadcast from a diameter radio dish. After the radio waves echoed off the surface of the Moon, the return signal was detected and the delay time measured. From that measurement, the distance could be calculated. In practice, however, the signal-to-noise ratio was so low that an accurate measurement could not be reliably produced.
   The finished system used two sets of transmitters at Annapolis, Maryland and the Opana Radar Site in Hawaii and two sets of receivers at Cheltenham, Maryland and Wahiawa, Hawaii. It was later expanded to accommodate ship-to-shore transmissions to and from the USS "Oxford" (AGTR-1).
  
  Section::::Results.
   Doppler effect at 144 MHz band is 300 Hz at moonrise or moonset. The doppler offset goes to around zero when the Moon is overhead. At other frequencies other doppler offsets will exist. At moonrise, returned signals will be shifted approximately 300 Hz higher in frequency. As the Moon traverses the sky to a point due south the Doppler effect approaches nothing. By Moonset they are shifted 300 Hz lower. Doppler effects cause many problems when tuning into and locking onto signals from the Moon.
   The probe was permanently attached to the third stage of Long March 3C/G2 on 23 October 2014 at 18:00 UTC along with Chang'e 5-T1, making its closest flyby a day after Chang'e 5-T1. The lunar flyby took place during the night of 28 October 2014. After that, the probe entered a highly elliptical geocentric orbit with a period of 14 days and it remains in space. The last transmission from the spacecraft was received on 11 November 2014, 01:35 UTC.
  
  Section::::Honorifics.
   The lunar south pole is a place where scientists may be able to perform unique astronomical observations of radio waves under 30 MHz. The Chinese "Longjiang" microsatellite was launched in May 2018 to orbit the Moon, and as of 2019 it continues to perform astronomical observations in this frequency range. Before "Longjiang", no space observatory had been able to observe astronomical radio waves in this frequency because interference waves from equipment on Earth. The lunar south pole has mountains and basins that are not facing Earth and would be an ideal place to receive such astronomical radio signals from a ground radio observatory. 
   Limited amateur radio operations have occurred, using "moon bounce" or Earth–Moon–Earth communication, in which radio signals aimed at the Moon are reflected back to Earth. The first of these operations was on June 13–14, 1964, using the call KP4BPZ. A dozen or so two-way contacts were made on 144 and 432 MHz. On July 3 and July 24, 1965, KP4BPZ was again activated on 432 MHz, making approximately 30 contacts on 432 MHz during the limited time slots available. For these tests, a very wide-band instrumentation recorder captured a large segment of the receiving bandwidth, enabling later verification of other amateur station callsigns. These were not two-way contacts. From April 16–18, 2010, again, the Arecibo Amateur Radio Club KP4AO conducted moon-bounce activity using the antenna.
   BULLET::::- On April 20, 2019 a Beidou satellite successfully launched. Launch occurred at 10:41 p.m. Beijing time, and the Long March 3B delivered the Beidou navigation payload into an elliptical transfer orbit ranging between 136 miles (220 kilometers) and 22,237 miles (35,787 kilometers), with an inclination of 28.5 degrees to the equator, according to U.S. military tracking data.
  
  Section::::Experimental system (BeiDou-1).
  
  Section::::Experimental system (BeiDou-1).:Description.
   The first high-throughput communications satellite Shijian-13 was launched on April 12, 2017 at 7:04 pm successfully by the Long March 3B (LM-3B/CZ-3B) which is a carrier rocket, from the Xichang Satellite Launch Center in southwest China's Sichuan Province. This flight mission is the 246th launch of the Long March Launch Vehicle. Shijian-13 communication satellite discovered and acquired the target near the equator successfully with Yuan Wang 6 which is thousands of miles away from Xichang, for protecting the rocket flight and made an important contribution to the successful launch of Shijian-13. On January 23, 2018, China's first high-throughput communications satellite Shijian-13 was delivered in-orbit and put into use officially. During the in-orbit test, 11 experimental projects were completed and finished by the Shijian-13. The success of the test on the broadband multimedia satellite communications system of Shijian-13 and its high speed laser communication technology between the first high-speed satellite and the ground. It lays a foundation for the important project of China on the “space-ground integrated information network” project. The design concepts of the “space-ground integrated information network” project can make Shijian-13 communications satellite provide high-speed “Satcom on the Move” (SOTM) which is a new concept for the traditional Multimedia Messaging Service (MMS), it refers to the protection of the satellite communication of the moving carriers such as vehicles, ships and airplanes during the movement. It improves the online experience for passengers on shipping, aviation, railway and other vehicles thoroughly. The higher frequency Ka-band broadband communications makes the satellite can transmit high-definition (HD) videos and the receiving terminal is small which is easy to carry. In addition, Shijian-13 communications satellite can play a pivotal role of emergency communications through without building a network separately, cost-effective and other features.
   The concept is that it will then begin a trajectory toward a multiple lunar, and possibly an Earth swingby transfer; it will be captured into a lunar polar orbit in one or two months after launch, depending on the selected trajectory.
  
  Section::::See also.
  
  BULLET::::- The 13 CubeSats flying in the Artemis 1
  
  BULLET::::- Lunar Flashlight will map exposed water ice on the Moon
  
  BULLET::::- Near-Earth Asteroid Scout by NASA is a solar sail spacecraft that will encounter a near-Earth asteroid
  
  BULLET::::- BioSentinel is an astrobiology mission
  
  BULLET::::- SkyFire by Lockheed Martin
  
  BULLET::::- Lunar IceCube, by the Morehead State University
   Section::::Echo delay and time spread.
  
  Radio waves propagate in vacuum at the speed of light "c", exactly 299,792,458 m/s. Propagation time to the Moon and back ranges from 2.4 to 2.7 seconds, with an average of 2.56 seconds (distance from Earth to the Moon is 384,400 km).
  
  The Moon is nearly spherical, and its radius corresponds to about 5.8 milliseconds of wave travel time. The trailing parts of an echo, reflected from irregular surface features near the edge of the lunar disk, are delayed from the leading edge by as much as twice this value.
   The first picture of the Moon was relayed on 26 November 2007. On 12 November 2008, a map of the entire lunar surface was released, produced from data collected by Chang'e 1 between November 2007 and July 2008.
   Section::::History.:Phase III.
  
  BULLET::::- In November 2014, Beidou became part of the World-Wide Radionavigation System (WWRNS) at the 94th meeting of The International Maritime Organization (IMO) Maritime Safety Committee, which approved the "Navigation Safety Circular" of the Beidou Navigation Satellite System (BDS).
  
  BULLET::::- At Beijing time 21:52, March 30, 2015, the first new-generation BeiDou Navigation satellite (and the 17th overall) was successfully set to orbit by a Long March 3C rocket.
   These initial experiments were intended to be proof-of-concept experiments and only lasted one day. Follow-on experiments lasting one month produced a mean value of , which was the most accurate measurement of the lunar distance at the time.
  
  Section::::History of measurement.:Laser ranging.
  
  An experiment which measured the round-trip time of flight of laser pulses reflected directly off the surface of the Moon was performed in 1962, by a team from Massachusetts Institute of Technology, and a Soviet team at the Crimean Astrophysical Observatory.
   BULLET::::- Data relay satellite (数据中继卫星) Tianlian I (天链一号), specially developed to decrease the communication time between the Shenzhou 7 spaceship and the ground; it will also improve the amount of data that can be transferred. The current orbit coverage of 12 percent will thus be increased to a total of about 60 percent.
  
  BULLET::::- Deep Space Tracking Network composed with radio antennas in Beijing, Shanghai, Kunming and Urumuqi, forming a 3000 km VLBI（甚长基线干涉）.
  
  Section::::Organization.:Monitoring and control centers.:Domestic tracking stations.
   Prior to the Moon Relay project, long distance wireless communication around the curve of the Earth was conducted by skywave ("skip") transmission, in which radio waves are refracted by the Earth's ionosphere, which was sometimes disrupted by solar flares and geomagnetic storms. Before artificial satellites, the Moon provided the only reliable celestial object from which to reflect radio waves to communicate between points on opposite sides of the Earth.
   The mission was scheduled to continue for a year, but was later extended and the spacecraft operated until 1 March 2009, when it was taken out of orbit. It impacted the surface of the Moon at 08:13 UTC. Data gathered by Chang'e 1 was able to create an accurate and high resolution 3-D map of the lunar surface. Chang'e 1 is the first lunar probe to conduct passive, multi-channel, microwave remote sensing of the Moon by using a microwave radiator.
  
  Its sister orbital probe Chang'e 2 was launched on 1 October 2010.
  
  Section::::Overview.
   The Moon-Blink detector has been designed based on the principle that the observer will be immediately drawn to any movement taking place on parts of a large static images. The principle of operation of the detector is described next:
   Section::::Technological innovation.
  
  It was necessary to utilise pre-existing technological systems and components for the first time during the development of Shijian-13. Shijian-13 communications satellite has a variety of the technologies used that China never used on any communications satellites before.
  
  Section::::Technological innovation.:Electric propulsion technology.
  
raw_presuppositions: Object on other side of moon shouldn't be able to communicate with us.
raw_corrections: It communicates with another satelite which then sends the information to us.