James Garry

An ultraviolet simulator for the incident Martian surface radiation and its applications

Ultraviolet (UV) radiation can act on putative organic/biological matter at the Martian surface in several ways. Only absorbed, but not transmitted or reflected, radiation energy can be photo-chemically effective. The most important biological UV effects are due to photochemical reactions in nucleic acids, DNA or RNA, which constitute the genetic material of all cellular organisms and viruses. Protein or lipid effects generally play a minor role, but they are also relevant in some cases. UV radiation can induce wavelengths-specific types of DNA damage. At the same time it can also induce the photo-reversion reaction of a UV induced DNA photoproduct of nucleic acid bases, the pyrimidine dimers. Intense UVB and UVC radiation, experienced on early Earth and present-day Mars, has been revealed to be harmful to all organisms, including extremophile bacteria and spores. Moreover, the formation of oxidants, catalytically produced in the Martian environment through UV irradiation, may be responsible for the destruction of organic matter on Mars. Following this, more laboratory simulations are vital in order to investigate and understand UV effects on organic matter in the case of Mars. We have designed a radiation apparatus that simulates the anticipated Martian UV surface spectrum between 200 and 400 nm (UVC-UVA). The system comprises a UV enhanced xenon arc lamp, special filter-sets and mirrors to simulate the effects of the Martian atmospheric column and dust loading. We describe the technical setup and performance of the system and discuss its uses for different applications. The design is focused on portability, therefore, the Mars-UV simulator represents a device for several different Mars simulation facilities with specific emphasis on Mars research topics.

The Huygens Surface Science Package sound speed measurements and the methane content of Titan's atmosphere

The Huygens probe descended through Titans atmosphere in January 2005. On board was the Surface Science Package (SSP), a set of nine sensors, which included a speed-of-sound sensor. We present a detailed description of the SSP speed of sound measurements and report constraints on the methane content in Titans lower atmosphere based on these measurements. After extensive instrument calibration and subsequent Bayesian analysis of the data, the most likely result derived from our measurements in Titans lower atmosphere is a methane fraction of approximately 2% at 10 km, increasing to 3.5% at lower altitudes. These estimates are based on a binary composition. Our data show that any large scale variation of methane within the lower 11 km of Titans atmosphere is unlikely. Within experimental and theoretical uncertainties, our estimates are lower than, but compatible with earlier estimates obtained from the mass spectrometry experiment.

Planetary Landers and Entry Probes: Contents

This book provides a concise but broad overview of the engineering, science and flight history of planetary landers and atmospheric entry probes – vehicles designed to explore the atmospheres and surfaces of other worlds. It covers engineering aspects specific to such vehicles, such as landing systems, parachutes, planetary protection and entry shields, which are not usually treated in traditional spacecraft engineering texts. Examples are drawn from over thirty different lander and entry probe designs that have been used for lunar and planetary missions since the early 1960s. The authors provide detailed illustrations of many vehicle designs from space programmes worldwide, and give basic information on their missions and payloads, irrespective of the mission’s success or failure. Several missions are discussed in more detail, in order to demonstrate the broad range of the challenges involved and the solutions implemented. Planetary Landers and Entry Probes will form an important reference for professionals, academic researchers and graduate students involved in planetary science, aerospace engineering and space mission development.

Planetary Landers and Entry Probes by Andrew Ball

This book provides a concise but broad overview of the engineering, science and flight history of planetary landers and atmospheric entry probes – vehicles designed to explore the atmospheres and surfaces of other worlds. It covers engineering aspects specific to such vehicles, such as landing systems, parachutes, planetary protection and entry shields, which are not usually treated in traditional spacecraft engineering texts. Examples are drawn from over thirty different lander and entry probe designs that have been used for lunar and planetary missions since the early 1960s. The authors provide detailed illustrations of many vehicle designs from space programmes worldwide, and give basic information on their missions and payloads, irrespective of the mission’s success or failure. Several missions are discussed in more detail, in order to demonstrate the broad range of the challenges involved and the solutions implemented. Planetary Landers and Entry Probes will form an important reference for professionals, academic researchers and graduate students involved in planetary science, aerospace engineering and space mission development.

Planetary Landers and Entry Probes: Index

This book provides a concise but broad overview of the engineering, science and flight history of planetary landers and atmospheric entry probes – vehicles designed to explore the atmospheres and surfaces of other worlds. It covers engineering aspects specific to such vehicles, such as landing systems, parachutes, planetary protection and entry shields, which are not usually treated in traditional spacecraft engineering texts. Examples are drawn from over thirty different lander and entry probe designs that have been used for lunar and planetary missions since the early 1960s. The authors provide detailed illustrations of many vehicle designs from space programmes worldwide, and give basic information on their missions and payloads, irrespective of the mission’s success or failure. Several missions are discussed in more detail, in order to demonstrate the broad range of the challenges involved and the solutions implemented. Planetary Landers and Entry Probes will form an important reference for professionals, academic researchers and graduate students involved in planetary science, aerospace engineering and space mission development.

Planetary Landers and Entry Probes: List of acronyms and abbreviations

This book provides a concise but broad overview of the engineering, science and flight history of planetary landers and atmospheric entry probes – vehicles designed to explore the atmospheres and surfaces of other worlds. It covers engineering aspects specific to such vehicles, such as landing systems, parachutes, planetary protection and entry shields, which are not usually treated in traditional spacecraft engineering texts. Examples are drawn from over thirty different lander and entry probe designs that have been used for lunar and planetary missions since the early 1960s. The authors provide detailed illustrations of many vehicle designs from space programmes worldwide, and give basic information on their missions and payloads, irrespective of the mission’s success or failure. Several missions are discussed in more detail, in order to demonstrate the broad range of the challenges involved and the solutions implemented. Planetary Landers and Entry Probes will form an important reference for professionals, academic researchers and graduate students involved in planetary science, aerospace engineering and space mission development.

Planetary Landers and Entry Probes: Planetary Landers and Entry Probes

This book provides a concise but broad overview of the engineering, science and flight history of planetary landers and atmospheric entry probes – vehicles designed to explore the atmospheres and surfaces of other worlds. It covers engineering aspects specific to such vehicles, such as landing systems, parachutes, planetary protection and entry shields, which are not usually treated in traditional spacecraft engineering texts. Examples are drawn from over thirty different lander and entry probe designs that have been used for lunar and planetary missions since the early 1960s. The authors provide detailed illustrations of many vehicle designs from space programmes worldwide, and give basic information on their missions and payloads, irrespective of the mission’s success or failure. Several missions are discussed in more detail, in order to demonstrate the broad range of the challenges involved and the solutions implemented. Planetary Landers and Entry Probes will form an important reference for professionals, academic researchers and graduate students involved in planetary science, aerospace engineering and space mission development.