HELSINKI — China is about to launch its Queqiao-2 communications relay satellite tv for pc to help upcoming moon missions late March 19.
A Lengthy March 8 rocket was vertically transferred to a launch pad at Wenchang Satellite tv for pc Launch Heart early March 17. The rocket will launch Queqiao-2 in the direction of the moon in preparation for the Chang’e-6 lunar far facet pattern return mission in Might.
Queqiao-2 has a mass of 1,200 kilograms and is provided with a 4.2-meter parabolic antenna. Its elliptical orbit will enable it to keep up communication with each Earth and lunar far facet, which by no means faces the Earth.
The satellite tv for pc has a mission lifetime of over eight years. It’s supposed to help not solely Chang’e-6 but in addition the later Chang’e-7 and Chang’e-8 missions to the lunar south pole.
Chinese language authorities haven’t brazenly introduced a time and date for launch, however airspace closure notices reveal two launch home windows. These are 8:21-8:47 p.m. and 9:45-10:16 p.m. Japanese March 19 (0021-0047 and 0145-0216 UTC, March 20).
Queqiao-2 is meant to enter a extremely elliptical, frozen lunar orbit inclined by 55 levels. The satellite tv for pc will make its closest strategy to the moon at roughly 300 kilometers altitude whereas over the northern hemisphere. It should then head out to an apolune, or farthest level from the moon, of 8,600 kilometers.
The moon is tidally locked to the Earth, that means that one hemisphere of the planetary physique at all times faces our planet. Queqiao’s orbit will see it have line of sight to each Chang’e-6—which is focusing on Apollo crater within the southern hemisphere of the far facet—and Earth for a big portion of its orbital interval.
Queqiao-2 will use X and UHF bands to speak with Chang’e spacecraft, and S and Ka-bands for communications with Earth. It options a number of knowledge charges and reconfigurable software program.
China carried out its first lunar pattern return mission, Chang’e-5, in 2020. That mission noticed 1,731 grams of nearside lunar materials delivered to Earth after a fancy, 23-day, four-spacecraft operation.
Chang’e-6 will likewise try to seize as much as 2,000 grams of fabric, this time from the lunar far facet, requiring the help of Queqiao-2. Evaluation of far facet samples may present new insights into why the 2 lunar hemispheres differ. It may additionally reveal clues as to the historical past of the Earth-moon system.
Queqiao-2, or “Magpie Bridge-2”, is a extra succesful follow-up to Queqiao, launched in 2018. That satellite tv for pc facilitated the Chang’e-4 mission—the first-ever lunar far facet touchdown. The growing older, first relay satellite tv for pc stays operational in a halo orbit across the Earth-moon Lagrange level L2. That is located roughly 70,000 kilometers past the moon.
Queqiao-2 additionally carries payloads as a part of the science aims of the 2026 Chang’e-7 mission. These are an excessive ultraviolet digicam, an array impartial atom imager and an Earth-moon size baseline very lengthy baseline interferometry (VLBI) experiment.
Additionally aboard the launch will probably be small, experimental satellites Tiandu-1 and Tiandu-2. These will fly in formation in lunar orbit and conduct assessments for navigation and communications expertise verification. Assessments will embody satellite-to-ground laser ranging and inter-satellite microwave ranging strategies.
The target of the Tiandu satellites is to tell the design of China’s proposed Queqiao lunar navigation and communication constellation.
The launch of Queqiao-2 follows the obvious lack of a pair of satellites supposed to enter lunar distant retrograde orbit. The DRO-A/B satellites launched on a Lengthy March 2C rocket from Xichang spaceport. The mission’s YZ-1S higher stage suffered a malfunction, at the moment thought to have left the satellites in low Earth orbit.
The launch will probably be simply the third for the 50.3-meter-long Lengthy March 8 rocket. It flew for the primary time in 2020, earlier than setting a then-national document for satellites on a single launch in early 2022.
The Lengthy March 8 combines the three.35-meter-diameter new-generation Lengthy March 7 kerosene-liquid oxygen first stage with a 3-meter-diameter liquid hydrogen-liquid oxygen second stage from the older Lengthy March 3A collection. An upgraded model of the rocket is slated to fly for the primary time from a brand new, industrial launch web site close to Wenchang spaceport within the coming months.
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