Gaia Ground Segment Development and Operations Concept

Milligan, David; Rudolph, A.; Whitehead, Gary; Loureiro, Tiago

doi:10.2514/6.2010-2162

Cited by 3 publications

(6 citation statements)

References 2 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…from diffracted sunlight or particular bright stellar/solar system objects), so it was decided to run two dedicated in-flight tests. In these tests the 4 A subsequent failure of the equivalent A branch thruster would mean the spacecraft would be unable to perform attitude control with the chemical propulsion subsystem. 5 The extended development and validation time is mandatory due to the critical nature of the changes.…”

Section: Telescope Straylightmentioning

confidence: 99%

“…The onboard Failure Detection Isolation and Recovery (FDIR) was configured to replace thruster 3B usage with 3A, though this left a potential single failure within the spacecraft. 4 At this point it was decided to investigate implementation of a new Safe Mode software that would recover this lost redundancy. A feasibility study performed by Airbus Defense and Space concluded that two of the thrusters that had been fitted only to perform ΔV actually had sufficient residual torque authority to be used in place of the failed attitude control thruster.…”

Section: Chemical Propulsion Thruster Loss and Redesigned Safe Modementioning

confidence: 99%

“…The ground segment design and development is covered in detail in [4], and a summary is given below. The main components of the ground segment are shown in Fig.…”

Section: Ground Segment Overviewmentioning

confidence: 99%

“…The spacecraft was designed for a mission lifetime of 5.5 years comprising all mission phases and an optional mission extension of 1 year[3,4].…”

mentioning

confidence: 99%

See 3 more Smart Citations

ESA's billion star surveyor – Flight operations experience from Gaia's first 1.5 Years

et al. 2016

View full text Add to dashboard Cite

Section: Telescope Straylightmentioning

confidence: 99%

Section: Chemical Propulsion Thruster Loss and Redesigned Safe Modementioning

confidence: 99%

“…The ground segment design and development is covered in detail in [4], and a summary is given below. The main components of the ground segment are shown in Fig.…”

Section: Ground Segment Overviewmentioning

confidence: 99%

“…The spacecraft was designed for a mission lifetime of 5.5 years comprising all mission phases and an optional mission extension of 1 year[3,4].…”

mentioning

confidence: 99%

See 2 more Smart Citations

ESA's billion star surveyor – Flight operations experience from Gaia's first 1.5 Years

et al. 2016

View full text Add to dashboard Cite

“…The ground segment design and development is covered in detail in [5] , and a summary is given below. The main components of the ground segment are shown in figure 3: 1) The Mission Operations Centre (MOC), located in ESOC, Darmstadt, in charge of all mission operations planning, execution, monitoring and control of the spacecraft and operations ground segment.…”

Section: B Ground Segment Overviewmentioning

confidence: 99%

In Flight Evolution of Onboard Automation on ESA’s Gaia Mission

Milligan¹,

Collins²

2018

2018 SpaceOps Conference

View full text Add to dashboard Cite

This paper details the progressive steps taken in enhancing the onboard automation of ESA's Gaia mission in response to in-flight experience. Tasked with mapping 1 billion stars to unprecedented precision (to the micro-arc-second level, comparable to the width of a smart phone on the Moon as viewed from Earth). ESA's Science cornerstone mission is expected to also discover and chart 100,000's of new objects including near Earth asteroids, exoplanets, brown dwarfs and quasars. After a flawless launch 19 Dec 2013, Gaia was brought the circa 1.5 million kms into L2 via a sequence of orbit transfer manoeuvres. Starting in parallel to this, and lasting 6 months, the full spacecraft was commissioned and brought gradually up to full performance. Since Q3 2014, Gaia has been in the routine operations phase, gathering the enormous Astronomical data set for the multiple map releases planned throughout the mission lifetime and beyond. During commissioning, and later routine operations, ground responded to a number of challenges with the aim of efficiently maximizing mission performance. Measures were taken to increase onboard autonomy in a number of areas. These have been of two main types; one being efficient increase of mission data return (e.g. due to onboard performance in some areas being higher than expected), and the second responding to repeatable anomalies (i.e. autonomously recovering and thereby limiting their impact). Such repeatable anomalies have no permanent impact on the performance of the mission and can have their origin in various subsystems in the space and/or ground segment. This paper details various examples of onboard autonomy enhancements that have been implemented since launch. Their design, validation and implementation are described, along with an assessment of some of the onboard PUS services used (e.g. OBCPs, event-action, TC sequences) with respect to their usefulness to ground operations teams. The trade-offs and logic used when deciding firstly what to automate (and what to leave to manual operations), and also where to automate (onboard or on ground using the closed loop MATIS system), is also presented. Specific examples in the paper will include: dealing with a significant increase of data volume (circa 45%) to be downlinked to ground; automatically coping with local bad weather events at the ground stations; dealing with repeatable onboard anomalies ranging from the relatively benign (those temporarily impacting the precise thermal balance) to the more severe (those that can trigger Safe Mode and produce data losses in the range of weeks).

show abstract

Progress in Automated Ground Control of ESA’s Gaia Mission

Collins¹,

Qedar²,

Brach³

et al. 2018

2018 SpaceOps Conference

Self Cite

View full text Add to dashboard Cite

Tasked with mapping one billion stars to unprecedented precision (to the tens of microarc-second level, comparable to the width of a coin on the Moon as viewed from Earth), ESA's Science cornerstone mission Gaia was launched on 19 December 2013. Mission operations are performed from ESA's Operations Centre (ESOC) in Germany, and after insertion into its operational Lissajous orbit around the Sun-Earth system Lagrange point two, plus completion of approximately six months of commissioning, Gaia has been operating in its routine science phase since July 2014. Following the first full sky survey it was observed that Gaia's Science return was larger than predicted and consequently there was a significant increase of data volume (circa 45%) to be downlinked. This was due to various factors, mainly Gaia's ability to observe stars fainter than the original magnitude 20 limit. In order to downlink this data in an efficient manner a stepwise approach was implemented involving taking unmanned ground station passes to downlink this extra science data. A simple solution using open loop automation was quickly implemented and gradually improved upon over time, adding robustness and closed loop functionality using ESA's automation software Matis. In addition, the desire to improve efficiency has been combined with the capabilities of Matis to allow daily tasks to be automated that would otherwise require the need of a dedicated person to be present on-console in the control room. This includes not only ground-based tasks such as checking for data archive completeness and requesting offline data retrievals to fill gaps, but also commanding of the on-board spacecraft subsystems to dump stored telemetry to ground and request reports of on-board anomalies. Matis is also used in combination with telemetry arriving from the ground station network using another piece of ESA software named LMS. Together they will be used to, amongst other things, monitor the power level from the spacecraft transponder and automatically stop the downlink of science data on-board to avoid science data loss. This paper describes the experience of the Gaia operations team in evolving from an almost exclusively manual operations environment to the large amount of automation in use today. The introduction of further automation tasks to improve efficiency, and their implications for system monitoring of multiple spacecraft covering the entire Astronomy division within ESOC, will also be discussed. Finally, the future extensions of automation concepts for Gaia and other flying and not-yet-flying ESA missions will be explored.

show abstract

Gaia Ground Segment Development and Operations Concept

Cited by 3 publications

References 2 publications

ESA's billion star surveyor – Flight operations experience from Gaia's first 1.5 Years

ESA's billion star surveyor – Flight operations experience from Gaia's first 1.5 Years

In Flight Evolution of Onboard Automation on ESA’s Gaia Mission

Progress in Automated Ground Control of ESA’s Gaia Mission

Contact Info

Product

Resources

About