Tiandu

Tiandu

Mission type	Technology demonstration
Operator	Deep Space Exploration Laboratory CNSA
Mission duration	3 months, 26 days(in progress)
Spacecraft properties
Spacecraft	Tiandu
Manufacturer	Deep Space Exploration Laboratory
Start of mission
Launch date	20 March 2024, 00:31UTC
Rocket	Long March 8
Launch site	Wenchang Space Launch Site LC-2
Orbital parameters
Reference system	Selenocentricelliptic orbit
Lunarorbiter
Orbital insertion	24 March 2024, 17:43UTC

Tiandusatellites are a pair ofChinese Lunar Exploration Program'slunarnavigationandcommunicationstest satellites based onQueqiao-2 relay satellitetechnology.

Design and development

Tiandu satellites will performnavigationandcommunicationstechnologyverificationexperimentswhile flying in formation inlunar orbit.Satellite-to-groundlaser rangingas well as intersatellitemicrowaveranging techniques will also be tested.

The Tiandu satellites' mission is to inform the design of China's proposedQueqiaolunar navigationandcommunicationarray. Supporting services for lunar surface operations would be provided by such system.Line-of-sightcommunications limits affectuncrewedandcrewedoperations on theMoon,especially at thelunar south pole,an area of great interest, or thelunar far side.

The 61 kg (134 lb) Tiandu-1 carries aK_adual-bandintegrated communication payload, a laser retroreflector, a space router and other payloads. The 15 kg (33 lb) Tiandu-2 carries a communication payload and navigation devices.

Mission

The mission was launched together as a single probe withQueqiao 2in 2024 on aLong March 8rocket.

After launch, the two satellites (while being attached to each other) underwent lunar orbit insertion on 24 March 2024 at 17:43UTCand entered a largeelliptical orbitaround the Moon.In that large elliptical orbit around the Moon, they separated on 3 April 2024and later satellite-to-groundlaser rangingareinter-satellite microwave rangingare to be carried out by these satellites via high-precisionlunar orbitdetermination technology.