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Trace Gas Orbiter

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ExoMars Trace Gas Orbiter
ExoMars Trace Gas Orbiter with Schiaparelli lander
Mission typeMars orbiter & lander
OperatorESA, RKA
COSPAR ID2016-017A Edit this at Wikidata
SATCAT no.41388
Websiteexploration.esa.int/mars
Mission duration7 years (planned)[1][2]
Spacecraft properties
ManufacturerThales Alenia Space
Launch massTGO: 3,732 kg (8,228 lb)[3]
EDM: 600 kg (1,300 lb)
Dry massTGO: 1,432 kg (3,157 lb)
Payload massTGO: 116 kg (256 lb)
EDM: 5 kg (11 lb)
Power~2000 W
Start of mission
Launch date14 March 2016 (2016-03-14)
09:31 UTC[4]
RocketProton-M/Briz-M
Launch siteBaikonur 200/39
ContractorKhrunichev
Orbital parameters
Reference systemAreocentric
RegimeCircular
Eccentricity0
Periareion altitude400 km (250 mi)
Apoareion altitude400 km (250 mi)
Inclination74 degrees
Period120 minutes
Epochplanned
Mars orbiter
Spacecraft componentTGO
Orbital insertion19 October 2016 (2016-10-19) (planned)
Mars lander
Spacecraft componentEDM
Landing date19 October 2016 (2016-10-19) (planned)
Landing siteMeridiani Planum
Main telescope
NameCaSSIS
TypeThree-mirror anastigmat
Diameter13.5 cm (5.3 in)
Focal length88 cm (35 in)
Wavelengthsfrom 0.475 µm (blue)
to 0.95 µm (near-infrared)
Instruments
NOMAD Nadir and Occultation for MArs Discovery
ACS Atmospheric Chemistry Suite
CaSSIS Colour and Stereo Surface Imaging System
FREND Fine Resolution Epithermal Neutron Detector

The ExoMars Trace Gas Orbiter (TGO) is a collaborative project between the European Space Agency (ESA) and the Russian Federal Space Agency (Roscosmos) to send an atmosphere research orbiter and the Schiaparelli demonstration lander to Mars in 2016 as part of the European-led ExoMars mission.[5][6] The mission will follow with the ExoMars rover in 2018,[7] in which the 2016 launched TGO spacecraft will also operate as a communication link with Earth and the rover.

The Trace Gas Orbiter will deliver the ExoMars Schiaparelli EDM lander and then proceed with atmospheric mapping. A key goal of this mission is to gain a better understanding of methane (CH4) and other atmospheric gases present in the Martian atmosphere that could be evidence for possible biological or geological activity. This research will also help select the landing site for the 2018 ExoMars rover which will search for biomolecules and biosignatures. The TGO and lander combine to make the heaviest spacecraft ever sent to Mars.[8]

History

Investigations with space and Earth-based observatories have demonstrated the presence of small amounts of methane on the atmosphere of Mars that seems to vary with location and time.[9][10][11] This may indicate the presence of microbial life on Mars, or a geochemical process such as volcanism or hydrothermal activity.[12][13][14][15]

The challenge to discern the source of methane in the atmosphere of Mars prompted the independent planning by ESA and NASA of one orbiter each that would carry instruments in order to determine if its formation is of biological or geological origin,[16][17] as well as its decomposition products such as formaldehyde and methanol.

Attempted collaboration with NASA

NASA's Mars Science Orbiter (MSO) was originally envisioned in 2008 as an all NASA endeavor aiming for a late 2013 launch.[18][19] NASA and ESA officials agreed to pool resources and technical expertise and collaborate to launch only one orbiter.[20] The agreement, called Mars Joint Exploration Initiative, was signed on July 2009 and proposed to utilize an Atlas rocket launcher instead of a Soyuz rocket, which significantly altered the technical and financial setting of the European ExoMars mission. Since the ExoMars rover was originally planned to be launched along the TGO, a prospective agreement would require that the rover lose enough weight to fit aboard the Atlas launch vehicle with NASA's orbiter.[21] Instead of reducing the rover's mass, it was nearly doubled when the mission was combined with other projects to a multi-spacecraft programme divided over two Atlas V-launches:[20][22][23] the ExoMars Trace Gas Orbiter (TGO) was merged into the project, carrying a meteorological lander slated for launch in 2016. The European orbiter would carry several instruments originally meant for NASA's MSO, so NASA scaled down the objectives and focused on atmospheric trace gases detection instruments for their incorporation in ESA's ExoMars Trace Gas Orbiter.[6][19][24]

Under the FY2013 budget President Obama released on 13 February 2012, NASA terminated its participation in ExoMars due to budgetary cuts in order to pay for the cost overruns of the James Webb Space Telescope.[25] With NASA's funding for this project cancelled, most of ExoMars' plans had to be restructured.[26]

Collaboration with Russia

On 15 March 2012, the ESA's ruling council announced it will press ahead with its ExoMars program in partnership with the Russian space agency (Roscosmos), which plans to contribute two heavy-lift Proton launch vehicles and an additional entry, descent and landing system to the 2018 rover mission.[27][28][29][30][31]

Under the collaboration proposal with Roscosmos, the ExoMars mission is split into two parts: the orbiter/lander mission in March 2016 that includes the TGO and a 2.4 m (7.9 ft) diameter stationary lander build by ESA named Schiaparelli;[32] this will be followed by the ExoMars rover mission in 2018[7] —also to be launched with a Russian Proton rocket.

Status

The 600 kg descent module Schiaparelli and orbiter completed testing and were integrated to a Proton rocket at the Baikonur cosmodrome in Kazakhstan.[33] The launch occurred at 09.31 GMT on 14 March 2016.[34] Four rocket burns occurred in the following 10 hours before the descent module and orbiter were released.[8] A signal from the orbiter was received at 21:29 GMT that day, which confirmed that the launch was completely successful and the spacecraft is functioning properly.[35]

The Schiaparelli lander will separate from the orbiter on 16 October 2016, three days before it arrives at Mars, and enter the atmosphere at 21,000 kilometres per hour (13,000 mph).[36] After Mars orbit injection in late 2016, the orbiter will undergo several months of aerobraking to adjust its speed and manoeuver into a 400 km-high circular orbit above the planet, with actual science activities beginning in late 2017.[36]

Specifications

Size of the Trace Gas Orbiter compared to the Mars Express and an average human

The specifications are:[37]

Dimensions
  • Central bus is 3.5m × 2m × 2m [38]
Propulsion
  • 424 N bi-propellant main engine to be used to enter Mars orbit and maneuver
Power
  • 20m2 solar arrays entirely covered with cells and capable of rotating one degree, generating about 2000 W of power at Mars
Batteries
Communication
Thermal control
  • Spacecraft yaw axis control to ensure the three faces containing the science payload remain cold
Mass
  • 3,732 kg (8,228 lb) – mass of the TGO
  • 4,332 kg (9,550 lb) – launch mass including the Schiaparelli lander[8]
Payload
  • Up to 135.6 kg (299 lb) of scientific instruments

Science

Scale model of ExoMars Trace Gas Orbiter displayed during Paris Air Show 2015

The TGO will separate from the ExoMars Schiaparelli demonstration lander and will provide it with telecommunication relay for 8 sols after landing. Then the TGO will gradualy aerobrake for seven months into a more circular orbit for science observations and will provide communications relay for the ExoMars rover to be launched in 2018, and will continue serving as a relay satellite for future landed missions until 2022.[2]

The mission will map hydrogen levels just beneath the Martian surface.[39] Locations where hydrogen is found may indicate water-ice deposits, which could be useful for future crewed missions.

Particularly, the mission will characterise spatial, temporal variation, and localization of sources for a broad list of atmospheric trace gases. If methane (CH
4) is found in the presence of propane (C
3H
8) or ethane (C
2H
6), that will be a strong indication that biological processes are involved.[40] However, if methane is found in the presence of gases such as sulfur dioxide (SO
2), that would be an indication that the methane is a by-product of geological processes.[41]

Detection

Nature of the methane source requires measurements of a suite of trace gases in order to characterize potential biochemical and geochemical processes at work. The orbiter has very high sensitivity to (at least) the following molecules and their isotopomers: water (H
2O), hydroperoxyl (HO
2), nitrogen dioxide (NO
2), nitrous oxide (N
2O), methane (CH
4), acetylene (C
2H
2), ethylene (C
2H
4), ethane (C
2H
6), propane (C
3H
8),[citation needed] formaldehyde (H
2CO), hydrogen cyanide (HCN), hydrogen sulfide (H
2S), carbonyl sulfide (OCS), sulfur dioxide (SO
2), hydrogen chloride (HCl), carbon monoxide (CO) and ozone (O
3). Detection sensitivities are at levels of 100 parts per trillion, improved to 10 parts per trillion or better by averaging spectra which could be taken at several spectra per second.[42]

Characterization
  • Spatial and temporal variability: Latitude-longitude coverage multiple times in a Mars year to determine regional sources and seasonal variations (reported to be large, but still controversial with present understanding of Mars gas-phase photochemistry.)
  • Correlation of concentration observations with environmental parameters of temperature, dust and ice aerosols (potential sites for heterogeneous chemistry.)
Localization
  • Mapping of multiple tracers (e.g., aerosols, water vapor, CO, CH
    4    ) with different photochemical lifetimes and correlations helps constrain model simulations and points to source/sink regions.
  • To achieve the spatial resolution required to localize sources might require tracing molecules at the ~1 part per billion concentration.

Payload

Like the Mars Reconnaissance Orbiter, the Trace Gas Orbiter is a hybrid science-telecom orbiter.[43] Its science payload mass is about 115 kg and consist of:[44][45]

  • Nadir and Occultation for Mars Discovery (NOMAD) has two infrared and one ultraviolet spectrometer channels. Developed by Belgium.
  • Atmospheric Chemistry Suite (ACS) has three infrared spectrometer channels [46][47] Developed by Russia.
NOMAD and ACS will provide the most extensive spectral coverage of Martian atmospheric processes so far.[43][48] Twice per orbit, at local sunrise and sunset, they will be able to observe the Sun as it shines through the atmosphere. Detection of atmospheric trace species at parts-per-billion (ppb) level will be possible.
  • Color and Stereo Surface Imaging System (CaSSIS) is a high-resolution (4.5 m/pixel), colour stereo camera for building accurate digital elevation models of the Martian surface. It will also be an important tool for characterizing candidate landing site locations for future missions. Developed by Switzerland.
  • Fine Resolution Epithermal Neutron Detector (FREND) is a neutron detector that can provide information on the presence of hydrogen, in the form of water or hydrated minerals, in the top metre layer of the Martian surface.[47] Developed by Russia.

Relay telecommunications

Due to the challenges of entry, descent, and landing, Mars landers are highly constrained in mass, volume, and power. For landed missions, this places severe constraints on antenna size and transmission power, which in turn greatly reduce direct-to-Earth communication capability in comparison to orbital spacecraft. As an example, the capability downlinks on Spirit and Opportunity rovers have only 1/600th the capability of the Mars Reconnaissance Orbiter downlink. Relay communication addresses this problem by allowing Mars surface spacecraft to communicate using higher data rates over short-range links to nearby Mars orbiters, while the orbiter takes on the task of communicating over the long-distance link back to Earth. This relay strategy offers a variety of key benefits to Mars landers: increased data return volume, reduced energy requirements, reduced communications system mass, increased communications opportunities, robust critical event communications and in situ navigation aide.[49] NASA provided an Electra telecommunications relay and navigation instrument to assure communications between probes and rovers on the surface of Mars and controllers on Earth.[50] The TGO will provide the Schiaparelli demonstration lander and ExoMars rover with telecommunication relay; it will also serve as a relay satellite for future landed missions until 2022.[2]

See also

References

  1. ^ "ExoMars Orbiter and EDM Mission (2016)". ESA. 13 March 2014. Retrieved 4 September 2015.
  2. ^ a b c Allen, Mark; Witasse, Olivier (16 June 2011), "2016 ESA/NASA ExoMars Trace Gas Orbiter", MEPAG June 2011, Jet Propulsion Laboratory (PDF)
  3. ^ "Mission Story:2016 EXOMARS Mission- Trace Gas Orbiter and EDM". Planex News. 30 June 2015. Retrieved 4 September 2015.
  4. ^ "Russian, EU Space Agencies Propose to Delay Joint Mission to Mars". Sputnik News. Moskow. 18 September 2015. Retrieved 19 September 2015.
  5. ^ J. L. Vago (10 September 2009), "Mars Panel Meeting" (PDF), Planetary Science Decadal Survey, Arizona State University, Tempe (USA): ESA {{citation}}: |format= requires |url= (help)
  6. ^ a b MEPAG Report to the Planetary Science Subcommittee Author: Jack Mustard, MEPAG Chair. 9 July 2009 (pp. 3)
  7. ^ a b "Money Troubles May Delay Europe-Russia Mars Mission". Agence France-Presse. Industry Week. 15 January 2016. Retrieved 16 January 2016.
  8. ^ a b c Elizabeth Gibney (11 March 2016). "Mars launch to test collaboration between Europe and Russia". Nature. doi:10.1038/nature.2016.19547. Retrieved 14 March 2016.
  9. ^ Mars Trace Gas Mission (10 September 2009)
  10. ^ Mumma, Michael J.; Villanueva, Geronimo L.; Novak, Robert E.; Hewagama, Tilak; Bonev, Boncho P.; Disanti, Michael A.; Mandell, Avi M.; Smith, Michael D. (20 February 2009). "Strong Release of Methane on Mars in Northern Summer 2003" (PDF). Science. 323 (5917): 1041–1045. Bibcode:2009Sci...323.1041M. doi:10.1126/science.1165243. PMID 19150811.
  11. ^ Hand, Eric (21 October 2008). "Plumes of methane identified on Mars" (PDF). Nature News. Retrieved 2 August 2009.
  12. ^ Making Sense of Mars Methane (June 2008)
  13. ^ Steigerwald, Bill (15 January 2009). "Martian Methane Reveals the Red Planet is not a Dead Planet". NASA's Goddard Space Flight Center. NASA. Retrieved 24 January 2009.
  14. ^ Howe,, K. L.; Gavin, P.; Goodhart, T. and Kral, T. A. Methane Production by Methanogens in Perchlorate-Supplemented Media (PDF). 40th Lunar and Planetary Science Conference (2009).{{cite conference}}: CS1 maint: extra punctuation (link) CS1 maint: multiple names: authors list (link)
  15. ^ Levin, Gilbert V. Levin; Patricia Ann Straat (3 September 2009). "Methane and life on Mars". Proc. SPIE. Proceedings of SPIE. 7441 (74410D): 74410D. doi:10.1117/12.829183.
  16. ^ Rincon, Paul (9 July 2009). "Agencies outline Mars initiative". BBC News. Retrieved 26 July 2009.
  17. ^ "NASA orbiter to hunt for source of Martian methane in 2016". Thaindian News. 6 March 2009. Retrieved 26 July 2009.
  18. ^ Mars Trace Gas Mission – Science Rationale & Concept (10 September 2009)
  19. ^ a b "Report to MEPAG on the ESA-NASA Joint Instrument Definition Team (JIDT) for the Proposed 2016 Orbiter-Carrier" (PDF). NASA. 29 July 2009. Retrieved 4 September 2015.
  20. ^ a b "ESA Proposes Two ExoMars Missions". Michael A. Taverna. Aviation Week. 19 October 2009. Retrieved 30 October 2009.
  21. ^ NASA Could Take Role in European ExoMars Mission 19 June 2009
  22. ^ Amos, Jonathan (12 October 2009). "Europe's Mars plans move forward". BBC News. Retrieved 12 October 2009.
  23. ^ "ESA Proposes Two ExoMars Missions". Michael A. Taverna. Aviation Week. 19 October 2009. Retrieved 23 October 2009.
  24. ^ "ExoMars Trace Gas Orbiter (TGO)". European Space Agency. 6 January 2012. Retrieved 19 March 2012.
  25. ^ "Experts React to Obama Slash to NASA's Mars and Planetary Science Exploration". Ken Kremr. Universe Today. 1 February 2012. Retrieved 18 February 2012.
  26. ^ "Have Europe's Martian exploration plans been derailed by America?". Megan Whewell. MSN News. 15 February 2012. Retrieved 15 February 2012.
  27. ^ "Europe Joins Russia on Robotic ExoMars". Amy Svitak. Aviation Week. 16 March 2012. Retrieved 16 March 2012.
  28. ^ "ESA Ruling Council OKs ExoMars Funding". Peter B. de Selding. Space News. 15 March 2012. Retrieved 16 March 2012.
  29. ^ "NASA drops ExoMars missions in 2013 budget". Optics. 15 February 2012. Retrieved 15 February 2012.
  30. ^ Spacewatch: Uncertainties for ExoMars
  31. ^ "Europe still keen on Mars missions". Jonathan Amos. BBC News. 15 March 2012. Retrieved 16 March 2012.
  32. ^ "ExoMars". Russian Space Web. Retrieved 22 October 2013.
  33. ^ "ExoMars 2016 Schiaparelli Module in Baikonur". ESA. SpaceRef. 6 January 2016. Retrieved 6 January 2016.
  34. ^ Jonathan Amos (14 March 2016). "Mars methane mission lifts off". BBC. Retrieved 14 March 2016.
  35. ^ "ExoMars on its way to solve the Red Planet's mysteries". ESA. 14 March 2016. Retrieved 15 March 2016.
  36. ^ a b Aron, Aron (7 March 2016). "ExoMars probe set to sniff out signs of life on the Red Planet". New Scientist. Retrieved 7 March 2016.
  37. ^ "ExoMars Trace Gas Orbiter (TGO)". European Space Agency (ESA). 12 July 2012. Retrieved 8 March 2014.
  38. ^ Evolution of the Trace Gas Orbiter specifications, according to ESA. Russian Space Web. Anatoly Zak. 3 March 2016.
  39. ^ Grayzeck, Ed (2015). "ExoMars 2016 - NSSDCA ID: EXOMARS16". NASA News. Retrieved 15 March 2016.
  40. ^ Montmessin, F. "Atmospheric Chemistry Suite: Science Overview" (PDF). LATMOS CNRS, France. Retrieved 14 March 2016. Determining the origin of methane on Mars can only be addressed by looking at methane isotopologues and at higher alkanes (ethane, propane) - page 44.
  41. ^ McKie, Robin (20 February 2016). "'Giant nose in the sky' ready for lift-off in mission to sniff out traces of life on Mars". The Guardian. Retrieved 21 February 2016.
  42. ^ Vandaele, A. C.; et al., NOMAD, a spectrometer suite for nadir and solar occultation observations on the ExoMars Trace Gas Orbiter (PDF), Institut des NanoSciences de Paris, retrieved 4 September 2015
  43. ^ a b J Vago et al., "ExoMars, ESA’s next step in Mars exploration", ESA Bulletin magazine, number 155, August 2013, pages 12–23
  44. ^ "ExoMars Trace Gas Orbiter Instruments". ESA. 20 February 2014. Retrieved 8 March 2014.
  45. ^ Zak, Anatoly (25 February 2016). "Trace Gas Orbiter might help unlock mysteries of Mars". Russian Space Web. Retrieved 26 February 2016.
  46. ^ Europe to invest 12 bln euros in a new space Odyssey, by Olga Zakutnyaya. Space Daily, 25 November 2012.
  47. ^ a b "Russia to Construct Landing Pad for Russian-European "ExoMars-2018" Space Mission". RIA Novosti. Russia. 4 August 2014. Retrieved 5 August 2014.
  48. ^ "Europe". Jonathan Amos. BBC News. 18 June 2013. Retrieved 18 June 2013.
  49. ^ Relay Orbiters for Enhancing and Enabling Mars In Situ Exploration (15 September 2009)
  50. ^ "U.S., Europe Won't Go It Alone in Mars Exploration". Peter B. de Selding. Spacew News. 26 September 2012. Retrieved 27 September 2012.

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