Author Topic: ESA-Roscosmos: ExoMars 2016 updates and discussion  (Read 220663 times)

Offline bolun

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Re: ESA-Roscosmos: ExoMars 2016 updates and discussion
« Reply #960 on: 03/08/2017 07:32 PM »
Literally a week away from Europe's first attempt at aerobraking now?
Yep after ME SC bus was determined to not be strong enough for traditional aerobraking and the fact the ME was a quickly built to re fly the Mars-96 instruments.

Venus Express was the first european probe that performed aerobraking manoeuvres.

http://forum.nasaspaceflight.com/index.php?topic=2181.msg1213672#msg1213672
« Last Edit: 03/09/2017 07:56 AM by bolun »

Offline Svetoslav

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Re: ESA-Roscosmos: ExoMars 2016 updates and discussion
« Reply #961 on: 03/11/2017 11:02 AM »
UPDATE: An interesting event:

http://www.ph.ed.ac.uk/events/2017/73525-the-exomars-trace-gas-orbiter-mission-to-mars-and-the-search-for-signs-of-life

 The ExoMars Trace Gas Orbiter mission to Mars and the search for signs of life

    Event time: 1:30pm until 3:00pm
    Event date: 14th March 2017
    Speaker: Dr. Manish Patel (The Open University)

Searching for signs of life beyond the Earth is a one of the primary aims of space exploration.  The ExoMars Trace Gas Orbiter (TGO) is a mission to Mars, which seeks to answer this question.

TGO is a joint European-Russian mission to explore the atmosphere of Mars from orbit, and demonstrate Europe’s ability to land a spacecraft on Mars for the first time.  The mission launched in March 2016, with Mars arrival and ‘landing’ on 19th October 2016.  Investigating trace gases in the atmosphere is the primary purpose of the mission – gases such as methane, and ozone.  Methane is a particularly interesting gas, in that its variable presence in the atmosphere of Mars is not expected; on Earth, the majority of the methane in the terrestrial atmosphere is produced by life.  Hence, its presence on Mars opens up a tantalising possibility that this trace gas may be a sign of the presence of (past or present) life on Mars.

The Open University co-leads one of the methane hunting instruments (called NOMAD).  Here, I will present the mission and its background to you, and update you on the latest status of the mission and the results to date from the orbiter and the fate of the lander.

Offline Svetoslav

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Re: ESA-Roscosmos: ExoMars 2016 updates and discussion
« Reply #962 on: 03/14/2017 09:01 AM »
Happy birthday, ExoMars! Today we mark one year since launch!

Offline Star One

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Re: ESA-Roscosmos: ExoMars 2016 updates and discussion
« Reply #963 on: 03/14/2017 09:24 AM »
UPDATE: An interesting event:

http://www.ph.ed.ac.uk/events/2017/73525-the-exomars-trace-gas-orbiter-mission-to-mars-and-the-search-for-signs-of-life

 The ExoMars Trace Gas Orbiter mission to Mars and the search for signs of life

    Event time: 1:30pm until 3:00pm
    Event date: 14th March 2017
    Speaker: Dr. Manish Patel (The Open University)

Searching for signs of life beyond the Earth is a one of the primary aims of space exploration.  The ExoMars Trace Gas Orbiter (TGO) is a mission to Mars, which seeks to answer this question.

TGO is a joint European-Russian mission to explore the atmosphere of Mars from orbit, and demonstrate Europe’s ability to land a spacecraft on Mars for the first time.  The mission launched in March 2016, with Mars arrival and ‘landing’ on 19th October 2016.  Investigating trace gases in the atmosphere is the primary purpose of the mission – gases such as methane, and ozone.  Methane is a particularly interesting gas, in that its variable presence in the atmosphere of Mars is not expected; on Earth, the majority of the methane in the terrestrial atmosphere is produced by life.  Hence, its presence on Mars opens up a tantalising possibility that this trace gas may be a sign of the presence of (past or present) life on Mars.

The Open University co-leads one of the methane hunting instruments (called NOMAD).  Here, I will present the mission and its background to you, and update you on the latest status of the mission and the results to date from the orbiter and the fate of the lander.

Are there many results given that it isn't in its science orbit yet?

Offline Svetoslav

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Re: ESA-Roscosmos: ExoMars 2016 updates and discussion
« Reply #964 on: 03/14/2017 09:31 AM »
I suppose today they may show us some new pics, some few graphics just to demonstrate the power of their instruments - but nothing more.

Offline Svetoslav

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Re: ESA-Roscosmos: ExoMars 2016 updates and discussion
« Reply #965 on: 03/15/2017 06:00 AM »
http://www.elecnor-deimos.com/exomars-edl-post-flight-analysis/

Deimos Space Planetary Entry Toolbox (PETBox) for Mission Engineering and the related design methodology for Atmospheric Flight are now Flight Qualified in both Earth and Mars

Schiaparelli separated from the Trace Gas Orbiter (TGO) on October 16th 2016 and reached Mars three days later. It performed a nominal hypersonic entry with a pre-defined flight path angle, decreasing its velocity until reaching subsonic regime under the parachute. During the descent phase an anomaly occurred, and the demonstrator module separated from the backshell earlier than expected, compromising the landing phase. During the whole EDL mission, Schiaparelli was able to communicate with the TGO and with the Mars Reconnaissance Orbiter, transmitting its real time on-board telemetry. The data collected is extremely valuable for the preparation of the 2020 mission.

The post-flight results have contributed to the validation of key technologies and design tools, including the Deimos Space Planetary Entry Toolbox (PETBox) for Mission Engineering and the related design methodology for Atmospheric Flight. As a result, these self-developed technologies  are now Flight Qualified for missions in Earth (through the successful ESA IXV mission) and Mars.

Deimos Space has been involved in ExoMars since 2004, carrying out technical activities in the Mission Engineering and Guidance, Navigation and Control domains for more than 12 years. This high commitment to the ExoMars programme has allowed the company to be the first organisation to submit a paper about ExoMars 2016 Post-Flight analyses to international conferences. The results of these studies will be showcased in detail at the upcoming 14th International Planetary Probe Workshop (The Hague, The Netherlands) and International Astronautical Congress 2017 (Adelaide, Australia).

Offline Svetoslav

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Offline Svetoslav

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Re: ESA-Roscosmos: ExoMars 2016 updates and discussion
« Reply #967 on: 03/27/2017 01:07 PM »
This is the first manuscript I've seen about Schiaparelli's AMELIA instrument:

http://oro.open.ac.uk/48861/1/Ferri_MAMOGranada2017.pdf


A quick summary of the article:

-- Meeting the goals of the AMELIA scientific objectives depends on the radio signal and the telemetry data set, but these data are still under embargo due to crash investigations

--Prior to Schiaparelli mission, seven profiles of Mars atmosphere density have been reported by the missions Viking 1, 2, Mars Pathfinder, Spirit and Oppy, Phoenix, Curiosity

--Schiaparelli has sent new in situ measurements during the latest martian dust season, they will enrich the knowledge

--Data from AMELIA will be compared to independent remotely sensed data like Mars Climate Sounder

Offline bolun

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Offline Svetoslav

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Online FutureSpaceTourist

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Online Flying Beaver

Re: ESA-Roscosmos: ExoMars 2016 updates and discussion
« Reply #971 on: 05/24/2017 07:12 PM »
The really interesting excerpt from the report.

Quote
THE CIRCUMSTANCES OF THE ANOMALY

The sequence (timeline) of the events is reported below with respect to UTC time.

a) Separation from TGO on 16/10/2016 at 14:42:00.

b) Awakening from hibernation on 19/10/2016 at 13:29:48.

c) Entry in the Mars atmosphere (EIP) detected at 14:42:22 through accelerometers.

d) Between EIP and Parachute Deployment triggering, an unexpected evolution in the spin rate of
the EDM was noticed.

e) At 14:45:23 the parachute deployment was triggered (trigger is the g-level).
- The dynamic conditions at the moment of parachute deployment derived from telemetry
showed a total angle of attack (AOA) estimated of about 6.5 deg and a lateral angular rate <
3 deg/s

f) Parachute deployment time (time from mortar firing to peak load factor) was circa 1 sec (in line
with the predictions).
- The parachute was deployed, and the parachute inflation triggered some oscillations of
Schiaparelli at a frequency of approximately 2.5 Hz.
- About 0.2 sec after the peak load of the parachute inflation, the IMU measured a pitch angular
rate (angular rate around Z-EDM axis) larger than expected.
- The IMU raised a saturation flag,.
- During the period the IMU saturation flag was set, the GNC Software integrated an angular
rate assumed to be equal to the saturation threshold rate. The integration of this constant
angular rate, during which the EDM was in reality oscillating, led to an error in the GNC
estimated attitude of the EDM of about 165 degrees. This would correspond to an EDM nearly
turned downside up with the front shield side pointing to quasi-zenith.
- After the parachute inflation, the oscillatory motion of Schiaparelli under its parachute was
mostly damped and Schiaparelli was descending at a nominal descent rate, with very small
oscillations (< 3 deg) around pitch and yaw axis.
- After parachute inflation the angular acceleration around the spin axis changed again

g) The Front Shield was jettisoned as planned 40s after parachute deployment (timer based
command) at 14:46:03

h) The RDA was switched on at 14:46:19 (15s after Front Shield separation acknowledgment) and
provided coherent slant ranges, without any indication of anomalies;
- Once the RDA is on, RIL mode, “consistency checks” between IMU and RDA measurements are
performed. The parameters checked are: delta velocity and delta altitude. The altitude is
obtained using the GNC estimated attitude to project the RDA slant ranges on the vertical.
- Because of the error in the estimated attitude that occurred at parachute inflation, the GNC
Software projected the RDA range measurements with an erroneous off-vertical angle and
deduced a negative altitude (cosinus of angles > 90 degrees are negative). There was no check
on board of the plausibility of this altitude calculation

i) Consequently the “consistency check” failed for more than 5 sec. after which the RDA was forced
anyway into the loop based on the logic that landing was impossible without the RDA. The
correctness of the other contributor to the altitude estimation, i.e. the attitude estimate, was not
put in question. The RDA was put in the loop (event signalled by RIL time-out flag at 14:46:46).
- The GNC mode entered was TERMINAL DESCENT where the altitude is scrutinized to release
the Back-Shell and parachute if the altitude is below an on board calculated limit.
EXOMARS 2016 - Schiaparelli Anomaly Inquiry
Reference: DG-I/2017/546/TTN
Date 18/05/2017 Issue 1 Rev 0
Page 13
- Because of the incorrect attitude estimation leading to an estimated negative altitude, the
GNC Software validated the conditions for separating the back-shell and parachute

j) Back-shell separation at 14:46:49.

k) Switch-on of the Reaction Control System (RCS).
- First RCS thruster operation was at 14:46:51 (no backshell avoidance manoeuvre)

l) Switch-off of the RCS 3 seconds later at 14:46:54.
- The criterion for the RCS switch-off was based on the estimation of the EDM energy (as
combination of the altitude and vertical velocity) being lower than a pre-set threshold. Since
the estimation of the altitude was negative and very big, the negative potential energy was
much higher than the positive kinetic energy (square of the velocity) and this criterion was
immediately satisfied the RCS was commanded off as soon as allowed by the thruster
modulation logic. This occurred just 3 seconds after the RCS switch on command when the
capsule was at an altitude of about 3.7 km, leading to a free fall of Schiaparelli and to the
impact on Mars surface about 34 seconds later.
m) The Touch Down occurred at 14:47:28 corresponding to the crash of the surface platform on the
surface of Mars at an estimated velocity of ≈150 m/s. The expected landing time was 14:48:05
(some 37s later).


« Last Edit: 05/24/2017 07:12 PM by Flying Beaver »
Saw OG-2 Booster Land in person 21/12/2015.

Offline baldusi

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Re: ESA-Roscosmos: ExoMars 2016 updates and discussion
« Reply #972 on: 05/24/2017 07:38 PM »
Well, go figure, a saturation on a gyro during parachute deployment meant that they integrated everything else assuming that the capsule was upside down, and thus everything was negative. But that happened many seconds later. Quite interesting. It is exactly the sort of error that normally could be expected, but for this level of requirement shouldn't. Always check saturation conditions!

Offline vjkane

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Re: ESA-Roscosmos: ExoMars 2016 updates and discussion
« Reply #973 on: 05/24/2017 10:01 PM »
Well, go figure, a saturation on a gyro during parachute deployment meant that they integrated everything else assuming that the capsule was upside down, and thus everything was negative. But that happened many seconds later. Quite interesting. It is exactly the sort of error that normally could be expected, but for this level of requirement shouldn't. Always check saturation conditions!
And we learned from the '98 Polar Lander to always fully test debounce routines.

My take on the ESA lander report: they weren't anal enough about the simulations and testing.

Online redliox

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Re: ESA-Roscosmos: ExoMars 2016 updates and discussion
« Reply #974 on: 05/24/2017 11:02 PM »
Well, go figure, a saturation on a gyro during parachute deployment meant that they integrated everything else assuming that the capsule was upside down, and thus everything was negative. But that happened many seconds later. Quite interesting. It is exactly the sort of error that normally could be expected, but for this level of requirement shouldn't. Always check saturation conditions!
And we learned from the '98 Polar Lander to always fully test debounce routines.

My take on the ESA lander report: they weren't anal enough about the simulations and testing.

Agreed, and apparently that was a similar problem with Beagle 2.  All 3 missions suffered from not having enough of a budget for testing; virtually all of their problems could have been avoided.  At least ESA seems to have nailed down getting into orbit around Mars which poor JAXA still has yet to achieve.  Let's hope the ExoMars orbiter aerobrakes without incident while we're on the subject of testing hardware.
"Let the trails lead where they may, I will follow."
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Offline Kosmos2001

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Re: ESA-Roscosmos: ExoMars 2016 updates and discussion
« Reply #975 on: 05/25/2017 03:48 PM »
[...]All 3 missions suffered from not having enough of a budget for testing; virtually all of their problems could have been avoided. [...]

I can't understand why they have to risk a mission because of that. It makes no sense.

Offline Blackstar

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Re: ESA-Roscosmos: ExoMars 2016 updates and discussion
« Reply #976 on: 05/25/2017 06:06 PM »
[...]All 3 missions suffered from not having enough of a budget for testing; virtually all of their problems could have been avoided. [...]

I can't understand why they have to risk a mission because of that. It makes no sense.

Actually, I think there is a (bad) logic to it:

You are on a restricted budget. When you start to run tight on money, you cannot cut things off of the spacecraft to save money because it just does not work that way. Plus, you only run short of money once you have started to build things. So that means that testing is doubly vulnerable to cutting, both because it can be cut, and because it comes at the end of a program development, when the money is tightest.

The only way to get around this is with strong program management and program management rules. For instance, rules about how you manage budget reserves. I don't know how all of that works, but one solution is that some of the budget reserves are controlled NOT by the program itself, but above the program, by the oversight managers. That means that the program cannot eat up its budget reserves on its own, but has to ask for permission. (And if they keep coming in asking for permission to use up their reserves, they will get replaced.) There are also ways to hold some of the reserves for different phases of development at different levels--some of it held within the program, some reserves (for specific phases) held outside of the program.


Offline Blackstar

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Re: ESA-Roscosmos: ExoMars 2016 updates and discussion
« Reply #977 on: 05/25/2017 06:21 PM »
Just for reference, here are the recommendations from the Beagle 2 failure investigation, as well as the full report, and a "lessons learned" document.

RECOMMENDATIONS
These are the recommendations of the Commission for future missions which can be found in the
report; referenced to the section in which they occur.

Recommendation 1 (sec. 4.2.2.)
Future lander missions should be under the responsibility of an Agency with appropriate
capability and resources to manage it. The lander/orbiter mission should be managed as an
integrated whole. Nationally-funded science instruments should be included in the lander
on the same basis as on the orbiter.

Recommendation 2 (sec. 4.2.2.)
For future science payloads which are critical to overall mission success or have a very high
public profile, the ESA Executive should make a formal, comprehensive assessment of all
aspects of proposals including technical, management and finance, and advise SPC
accordingly before acceptance. If the assessme nt is not positive, ESA should advise the SPC
not to accept the proposal.

Recommendation 3 (sec. 4.3.2.)
Sponsoring Agencies of nationally-funded contributions to ESA projects should ensure that
the required financing is committed at the outset to meet the estimated Cost at Completion
and require that a structured development programme is established.

Recommendation 4 (sec. 4.3.2.)
In addition to the ESA-led reviews of interfaces, formal Project Reviews of nationally funded
contributions to ESA missions should be undertaken by the sponsoring Agency to a
standard agreed with ESA and should cover the entire project.

Recommendation 5 (sec. 4.4.2.)
When an independent review of a nationally-funded project, such as the Casani review of
Beagle 2, is commissioned, it is essential that ESA and the Sponsoring Agency ensure that
its recommendations are properly dispositioned and those which are agreed are actioned
and followed up through a formal process.

Recommendation 6 (sec. 4.5.2.)
For future projects, Heads of Agreement or similar formal arrangements between
cooperating entities, ESA, and national sponsors, should be put in place at the outset of
projects and should include formal consultations at key stages of the project to jointly
consider its status.

Recommendation 7 (sec. 4.5.2.)
Fixed price contracting should be avoided solely as a mechanism for controlling costs, and
used only where the sponsor and contractor are in alignment on the requirements and
scope of the work and the sharing of risks between the m. Both parties should be confident
that the contractor has sufficient margins to manage his uncertainties and risks.

Recommendation 8 (sec. 4.6.2.)
For future high-profile/high-risk projects, ESA and any Sponsoring Agency should manage
the expectations of the outcome of the project in a balanced and objective way to prepare
for both success and failure.

Recommendation 9 (sec. 5.1.1.)
At the start of a programme, the funding authority(ies) should require that there is
system-level documentation. This is necessary to provide all partners with the technical
requirements for the project and sufficient design description and justification such that
the margins and risks being taken in each partner's area of responsibility are visible.

Recommendation 10 (sec. 5.2.1.)
Future planetary missions should be designed with robust margins to cope with the
inherent uncertainties, and they should not be initiated without adequate and timely
resources to achieve that.

Recommendation 11 (sec. 5.2.2.)
Future planetary entry missions should include a minimum telemetry of critical
performance measurements and spacecraft health status during mission critical phases
such as entry and descent.

Recommendation 12 (sec. 5.2.3.)
For future planetary entry missions, a more robust communications system should be used,
allowing direct commanding of the lander for essential actuations and resets without
software involvement - enabling recoveries in catastrophic situations.

Recommendation 13 (sec. 5.3.1.)
Planetary probe missions involving high-level shocks from pyros and other events should
undergo representative shock environmental testing at system level.

Recommendation 14 (sec. 5.3.2.)
Adequate and realistic deployment tests should be performed, and sufficient time and
resources must be available in the development of a new planetary mission.

Recommendation 15 (sec. 5.4.1.2.)
Elimination of internal connectors for mass saving should be avoided if at all possible. But
if unavoidable, a stringent system of check and independent cross-check should be followed
during the final wiring operation.

Recommendation 16 (sec. 5.4.3.)
A back-up for the entry detection event (T0) must be included in the design of planetary
entry probes.

Recommendation 17 (sec. 5.4.4.)
Future planetary entry missions should include a release of the back cover and front shield
which is aerodynamically stable and analytically predictable to avoid uncontrolled re -
contact of front shield with the lander.

Recommendation 18 (sec. 5.4.4.)
Sufficient difference between ballistic coefficients of all separated items, eg. back cover
assembly and the main parachute, or other positive means, must be ensured to exclude
collision after separation.

Recommendation 19 (sec. 5.4.7.)
Adequate competencies in air-bag and parachute technology must be available for future
European planetary missions, making best use of existing expertise e.g. in USA and Russia.

Offline woods170

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Re: ESA-Roscosmos: ExoMars 2016 updates and discussion
« Reply #978 on: 05/25/2017 07:14 PM »
[...]All 3 missions suffered from not having enough of a budget for testing; virtually all of their problems could have been avoided. [...]

I can't understand why they have to risk a mission because of that. It makes no sense.
ESA has made this basic error (not thoroughly testing border cases) before. Remember how Ariane 501 got lost?

Oh btw: Beagle 2 was NOT a purely ESA mission. It was a UK mission that just managed to hitch a ride on Mars Express.
« Last Edit: 05/25/2017 07:21 PM by woods170 »

Offline vjkane

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Re: ESA-Roscosmos: ExoMars 2016 updates and discussion
« Reply #979 on: 05/25/2017 09:30 PM »
[...]All 3 missions suffered from not having enough of a budget for testing; virtually all of their problems could have been avoided. [...]

I can't understand why they have to risk a mission because of that. It makes no sense.
ESA has made this basic error (not thoroughly testing border cases) before. Remember how Ariane 501 got lost?

Oh btw: Beagle 2 was NOT a purely ESA mission. It was a UK mission that just managed to hitch a ride on Mars Express.
Every space agency has made this error.  One of the reasons they do such thorough investigations is to learn from them.  I don't know that the same error has been made twice.

Tags: Mars Exomars