Detection and measurement of micrometeoroids with LISA Pathfinder

Abstract

The Solar System contains a population of dust and small particles originating from asteroids, comets, and other bodies. These particles have been studied using a number of techniques ranging from in-situ satellite detectors to analysis of lunar microcraters to ground-based observations of zodiacal light. In this paper, we describe an approach for using the LISA Pathfinder (LPF) mission as an instrument to detect and characterize the dynamics of dust particles in the vicinity of Earth-Sun L1. Launched on Dec. 3rd, 2015, LPF is a dedicated technology demonstrator mission that will validate several key technologies for a future space-based gravitational-wave observatory. The primary science instrument aboard LPF is a precision accelerometer which we show will be capable of sensing discrete momentum impulses as small as 4 × 10 −8 N s. We then estimate the rate of such impulses resulting from impacts of micrometeoroids based on standard models of the micrometeoroid environment in the inner solar system. We find that LPF may detect dozens to hundreds of individual events corresponding to impacts of particles with masses >10 −9 g during LPF's roughly six-month science operations phase in a 5 × 10 5 km by 8 × 10 5 km Lissajous orbit around L1. In addition, we estimate the ability of LPF to characterize individual impacts by measuring quantities such as total momentum transferred, direction of impact, and location of impact on the spacecraft. Information on flux and direction provided by LPF may provide insight as to the nature and origin of the individual impact and help constrain models of the interplanetary dust complex in general. Additionally, this direct in situ measurement of micrometeoroid impacts will be valuable to designers of future spacecraft targeting the environment around L1.

Light dark matter scattering in gravitational wave detectors

“…where P c ≈ 3.6 × 10 −8 N s [53]. Based on this simple estimation, one can compare the SNR obtained here with the one from the toy model (with the typical KAGRA parameters) discussed in Sect.…”

“…We can nevertheless, give some rough estimate to see, if light DM could be detected in these experiments. We follow the approach in [53] where they looked for micrometeroidal events at LPF which hit the spacecraft. In this reference, the relevant Fourier transform of a force acting on the target mass for a duration much shorter than the time resolution at t = 0 is justF = q R .…”

Review on thermal and mechanical challenges in the development of deployable space optics

“…Another source of jitter is micrometeoroid or orbital debris impact, which causes a transfer of momentum from the impactor to the spacecraft. 40 In general, any release of energy through vibration would fall into this category, but again sources that are specifically due to microdynamics or thermal disturbances will be treated separately in this paper in Secs. 2.4 and 2.8.…”

Micrometeoroid Events in LISA Pathfinder

“…The most substantial difference between the noise level in the various DoFs is in the amplitude of the S 4 term, which is substantially lower for the DoFs sensed by the interferometric system: x, η, and φ. In Thorpe et al (2016) it was shown that SNR of a simple impulse in the presence of this noise shape can be analytically computed as ρ = P i /P c , where P i is the amplitude of the momentum transfer in that DoF and P c is a characteristic threshold momentum given by:…”

“…This control system was designed to counteract disturbances on the spacecraft, including those caused by impacts from micrometeoroids. Shortly before LPF's launch, it was realized that data from the control system, if properly calibrated, could be used to detect and characterize these impacts and infer information about the impacting particles (e.g., Thorpe et al (2016)). Early results from the first few months of LPF operations suggested that such events could indeed be identified and were roughly consistent with the pre-launch predictions of their effect on the control system (e.g., Thorpe et al (2017)).…”