Hyper Gravity-Induced Transients in &amp;lt;i&amp;gt;Phycomyces&amp;lt;/i&amp;gt; as Measured by Single Beam Spectrophotometer on the Sounding Rocket TEXUS 50

Werner Schmidt

doi:10.4236/jmp.2018.92019

Abstract

In the first paper of two referring to the TEXUS 50 campaign using micro dual wavelength spectrometers (MDWS) we kinetically determined the threshold1 for GIACs (gravity-induced absorption changes) in Phycomyces to be lower than 25 × 10−3 g (http://file.scirp.org/pdf/JMP_2015082810060783.pdf). In this second paper, we attended measurement of GIAC-spectra. Unexpectedly, during the upwards movement, i.e. the hypergravity phase up to top acceleration values reaching 11.6 g at 35.4 s after liftoff we observed transient GIAC-spectra ranging from 380 to 750 nm. In addition, during the whole acceleration phase of 68.2 s, another component near 700 nm develops which remains stable during the whole “free fall trajectory parabola” for 381.3 s. The subsequent reentry of the rocket leads to extraordinary deceleration values up 37.8 g, completely destroying Phycomyces sporangiophores excluding their spectral measurement. During the microgravity phase and by centrifuge operation we were unable to detect any GIAC-spectra (in contrast to kinetic MDWS-measurements, first paper).

Highlights

The Micro Dual Wavelength Spectrometer (MDWS) only allows measurements at individual wavelengths of the spectrum defined by selected light emitting diodes (LEDs) [1]
In the first paper of two referring to the TEXUS 50 campaign using micro dual wavelength spectrometers (MDWS) we kinetically determined the threshold1 for GIACs in Phycomyces to be lower than 25 × 10−3 g
We attempted a complementary measurement of the complete spectrum of GIACs in Phycomyces sporangiophores (SPPHs, Figure 1), during the start phase of hypergravity and the subsequent phase of microgravity using a single beam spectrophotometer

Summary

Introduction

The Micro Dual Wavelength Spectrometer (MDWS) only allows measurements at individual wavelengths of the spectrum defined by selected light emitting diodes (LEDs) [1]. We attempted a complementary measurement of the complete spectrum of GIACs in Phycomyces sporangiophores (SPPHs, Figure 1), during the start phase of hypergravity and the subsequent phase of microgravity using a single beam spectrophotometer (diode array spectrophotometer SBS, USB-2000+ by Ocean Optics). Just during the phase of strong hypergravity (0 to 37 s, acceleration up to 11.6 g) we observed pronounced and intermediate GIAC-spectra. Another but smaller peak comes up during the late state of hypergravity, further standing in the subsequent microgravity phase. These GIACs generated under hypergravity conditions appear to be of biological rather than artificial background

Methods

Results

Conclusion