Space mini Passive Hydrogen Maser — A compact Passive Hydrogen Maser for space applications

Abstract

On-board atomic clocks represent the key technology for the success of any satellite navigation system mission and their development has been continuously supported by ESA. The PHM (Passive Hydrogen Maser) has been selected as master clock of the Galileo Navigation Payload and the almost three years of continuous observation on board of GIOVE-B satellite have confirmed the outstanding performance in terms of frequency stability and negligible drift [1]. The results coming from ground life testing have given important feedbacks on the PHM technology capability to comply with the required 12 years of lifetime. The above was the starting point for the development of a Miniaturized PHM (mPHM) carried out in the frame of the ESA European GNSS Evolutions Programme. The main target was to preserve the excellent PHM frequency stability performance with reduction of the overall mass and instrument sensitivity to the environmental conditions (in particular to temperature). This paper presents an overview of the main results achieved by the design, manufacturing and testing of a MPHM elegant breadboard (EBB); the 30% of mass reduction already achieved on the Physic Package gives the concrete possibility to have a complete instrument with a mass of 12Kg.

Review of the development of the hydrogen maser technique and a brief introduction to its space applications

“…The on-board Passive H-MASER of Vremya-CH [22], shown in Figure 12B, for the GLONASS-l had reached a stability performance of 10 −15 / 10,000 s. A Space Mini Passive Hydrogen MASER (mPHM), was carried out in the frame of the ESA European GNSS Evolutions Programme. The design possibly has reduced the mass to only 12 kg, published in 2011 [24].…”

Analysis of single frequency modulation for passive hydrogen maser

“…The physical package of the passive hydrogen maser performs the function of a very narrow-band microwave amplifier and a frequency discriminator, produced by the hydrogen hyperfine transition and microwave cavity [24]. The general idea of absorption and dispersion lock can be applied to the passive hydrogen maser.…”