Reception of the Moon lander BGM-1

On 2 March, the Moon lander ‘Blue Ghost Mission 1’ (BGM-1) landed on the Moon. With the Dwingeloo telescope, we received its signals during landing. We did not decode these signals, but by measuring their Doppler shift we could measure the (radial) velocity of the spacecraft.

During the landing, we shared our reception through a livestream. Also Firefly Aerospace, the company that made BGM-1, hosted a livestream. We could see in our telescope’s reception that the maneuvers announced in their stream had actually taken place.

The above spectrum features a narrow carrier wave and a more fuzzy signal. The fuzzy signal is the reflection of the carrier wave on the lunar surface. After some time, the reflection coincides with the carrier, when the spacecraft approaches the lunar surface and thus has the same Doppler.

This is the fifth Moon landing we tracked with the restored Dwingeloo radio telescope: in 2019 we saw the landings of Beresheet and Chandrayaan-2 fail, in 2024 we saw SLIM and IM-1 tip over. BGM-1’s landing appears to be the first to have gone by the book.

Our raw data is available on data.camras.nl/bgm1-landing. We are further analyzing it.