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Q&A - Continued

Q&A - Continued

This page lists answers to questions received up to 1 August 2012 in response to (the pre-announcement of) the Announcement of Opportunity (AO) for Scientific Instrumentation on-board the JUICE spacecraft.

For the additional questions received after 1 August 2012, see the link "Q&A" on the right.

1 Aug 2012 -  Mechanical and thermal analysis - EID-B
Q: About the EID-B: Which level of mechanical and thermal analyses is required for the proposal?
A: The results of a preliminary thermal and mechanical analysis need to be reported in the proposal such that the overall mass and power numbers can be justified. Taking your preliminary design, a first analysis of the power and (if applicable) rejection of heat shall be quantified. Similarly a first indication that the mechanical design of the instrument can sustain the launch vibrations should be performed.
1 Aug 2012 -  Data transfer
Q: How many data can be transferred during the Ganymede elliptical orbit and the 5000km circular orbit (rate and time) and how many during the fly-bys of Callisto and Europa?
A: This information is reported in the Assessment Study Report. As reported in Section, the present baseline for the amount of transmitted data in the Ganymede orbit is 1.4 Gbits per celestial day. As reported in Sections,,, during flybys data are recorded in a flash memory and then transmitted at the same data rate.
1 Aug 2012 -  Minimum bus voltage
Q: The minimum bus voltage to assume is specified in 2 places with 2 different values – perhaps this was intentional, but it appears contradictory. EIDA-R001860: The PI shall ensure that the instruments operate with nominal performance within the following steady state voltage limits provided by the PCDU: Min: 26 V. And from EIDA-R001500: The PI shall ensure that the survival heater lines are sized for a minimum primary bus voltage of 27 V. (TBC). It is not obvious why the minimum bus voltage for Instrument power and Heater power would be different, and therefore we thought there may be a typographical error here.
A: Please assume the 26 V as a minimum primary bus voltage.
1 Aug 2012 -  Payload shielding - Note: answer updated on 9 August 2012
Q: From EID-A I interpreted, (a) 1 mm Al spherical shielding for "internal" payloads only, and (b) assume solid shielding on one hemisphere for "external" payloads. Can you confirm this statement or correct me?
A: The assumption (a) is correct, internally mounted payload can assume a 1 mm Al spherical shielding. For the instruments outside the spacecraft instrument teams shall perform the radiation analyses assuming that no shielding is provided by the spacecraft. The assumption (b) therefore is not valid. After payload selection the industrial contractors will start accommodating the payload and the shielding mass can be redistributed. Regardless of the assumptions, the shielding geometry must be accurately described and justified and the shielding mass specified as a separate item of the mass budgets. The unit radiation tolerance must be specified.
1 Aug 2012 -  Cooling system design
Q: Do we have to design our own cooling system (cryo generator / heater radiator) in case of lack of Cold Finger's benefit?
A: If your instrument needs extreme cooling power (i.e., much more than what was required by the instruments considered in the MPDD) then the instrument team shall propose a design of the required cooling system and take all the related resources (mass, power, thermal shielding, etc.) into account in the instrument resource budget.
1 Aug 2012 -  Temperature of the cold finger provided by the S/C
Q: What is the temperature of the cold finger provided by the S/C (if any). How much power it may dissipate?
A: A radiator for the instruments will be part of the S/C, providing requested resources within the platform capabilities. Please, refer – when possible – to the instrument(s) in the MPDD for the maximum assumed power on the cold finger. The proposing teams need to specify what they require in terms of cooling from the radiator. We will consider the requests and verify whether or not the platform can accommodate them. Iteration with proposing teams might be needed. It is essential that proposing teams provide detailed justification on the power to be rejected and assumptions taken on the contact conductance at interface level. The proposing teams shall identify a single attachment point for the S/C thermal strap as specified in the EID-A. As specified also in the EID-A, all the thermal hardware on the instrument side up to the cold finger thermal interface with the S/C has to be accounted for in the instrument design and mass.
1 Aug 2012 -  List of S/C position of objects
Q: Would it be possible to add Io to the objects relative to which the S/C position is calculated?
A: It is not foreseen to add this information at the present time. We kindly ask you to perform those calculations yourself.
1 Aug 2012 -  Complete trajectory
Q: The CSV file ends during the 5000-km circular phase of Ganymede. Is it possible to have also the trajectory to end of the mission?
A: We have included the complete trajectory in CCSDS format and as a SPICE kernel in the AO package in the zip file
1 Aug 2012 -  RDM requirements
Q: EID-A states that minimum required RDM shall be 1 for TID and TNID. Please provide the exact definition of RDM. That is, when computing RDM, what external environment should be used – the environment with or without the safety factor of two?
A: RDM is considered as the margin at unit/component level on the exposure after radiation transport simulations. RDM is therefore a margin on the required device radiation tolerance. A safety factor of two shall be included for the environment and a RDM =1 may be assumed, if component tolerance is known, else a more suitable RDM factor needs to be used.
1 Aug 2012 -  Radiation transport analysis
Q: The PIP documents released heavily refer to the usage of Geant4 related transport tools as examples. Is it allowed to use other radiation transport tools (which are commonly used within the radiation transport physics community) for shielding and instrument performance analyses?
A: Other radiation transport codes are allowed. However, for each radiation transport analysis we ask the teams to provide details about used tool, version and update and about the assumptions made for the analysis. Please bear in mind that we expect Monte Carlo simulations to be necessary as ray tracing have been proven to yield major deficiencies.
1 Aug 2012 -  CAD models of the MAG boom
Q: Are there CAD models of the MAG boom(s), and if so, can we have access to information to define mechanical interfaces to the MAG boom? Is it possible to propose multiple booms for different sensors, and are those project provided?
A: The design for the MAG boom is not available yet. We assume (if the MAG is selected) to provide the boom as S/C provided item. Proposing teams are expected to indicate the requirements coming from their experiment on the boom(s). Instrument configurations will be analysed during the payload review process and technical complexity will be considered as part of the evaluation. For each selected and confirmed instrument, the project will review appendices also in terms of risks to the S/C. Appendices (and other items) with high potential risk will be put under project control and will be project provided. This is why the MAG-boom, if selected, will be provided by ESA. Independent of who will provide the boom(s), the mass will be charged to the instrument. Please do specify your interface requirements for your instrument in the EID-B appendix.
18 Jul 2012 -  ESA interaction with National Agencies
Q: Lead Funding Agencies (LFA) are supposed to write Letters of Endorsement (LoE). Will ESA interact with National Agencies during proposals evaluation?
A: ESA will maintain continuous interaction with National Agencies.
18 Jul 2012 -  Reference document consistency
Q: There are some discrepancies between properties of instruments (for instance, IPR sounding depth between MPDD, Sci-RD, and the Yellow Book). Which document should be used as reference in proposals?
A: MPDD is a "reference document" about a possible implementation of the JUICE mission science requirements. The Sci-RD should be used as applicable document for instrument science performance.
18 Jul 2012 -  Instrument descoping
Q: Should instrument's descoping options result from the evaluation process, or should they be presented in the proposal?
A: Proposals should better present options for resources optimization, rather than a descoping plan.
18 Jul 2012 -  Proposal documents: review
Q: Will proposals be provided to reviewers in electronic form or in print?
A: Proposals will be provided to reviewers as baseline in electronic form. In any case, since proposals are requested to be submitted in electronic form, proposers shall ensure that the files can be printed out correctly and, in particular, that the Acrobat security setting to "disallow printing" is not set.
18 Jul 2012 -  Proposal documents: embedded links
Q: Can we allow pdf links in the documents? That would be very helpful.
A: Links are allowed within each single pdf file (part of the proposal).
18 Jul 2012 -  Proposal documents: only one EID-B needed
Q: At the time of interfaces freezing (end 2013) there will still be 2 industrial contractors? Will instrumental teams need to present two interface documents?
A: There will be only one set of interfaces (EID-B) used by both contractors. The interfaces towards the s/c will be the same for both industrial Primes.
18 Jul 2012 -  Radiation modelling/analysis (1)
Q: For a realistic radiation analysis one needs a spacecraft model. Is it available?
A: A full radiation model of the spacecraft is not available. Inputs from the instrument teams will be required to optimise the accommodation. For the proposal, instrument teams should assume 1 mm Al (spherical) shielding as per EID-A. For units that are internal to the s/c body, the teams may assume solid shielding on one hemisphere. This is obviously not possible for externally mounted units/instruments.
18 Jul 2012 -  Radiation modelling/analysis (2)
Q: Can we get some assistance from ESA if a radiation modelling tool is not working properly?
A: Yes. Please be specific about the model you use.
18 Jul 2012 -  Radiation modelling/analysis (3)
Q: Which level of radiation modelling is required in the proposal?
A: Full 3D radiation modelling of instruments is required for the proposal. This model must be described in the proposal (EID- B). The software model will be required only shortly after the selection (in Jan/Feb 2013) to assist the industrial Primes in doing overall radiation modelling.
18 Jul 2012 -  Payload shielding mass
Q: What is the amount of payload shielding mass available at S/C level?
A: This was not studied as such so far. Only the radiation shielding mass for all units was estimated.
18 Jul 2012 -  MPDD instrument masses
Q: MPDD is based on existing units. So, should not it be basic masses given in MPDD?
A: No. MPDD instrument masses refer to nominal mass, not basic masses.
18 Jul 2012 -  Model philosophy
Q: Model philosophy: can we split EQM in two models: EM and QM?
A: The model philosophy has to be respected for the deliverable models as per EID-A. Additional non-deliverable models are welcome and give strength to the instrument development approach. It is acceptable to have EM and additional QMs: EM to be delivered and additional models (QM) for own use.
18 Jul 2012 -  Accuracy of posteriori orbit reconstruction
Q: What is the expected accuracy of a posteriori orbit reconstruction?
A: This is currently under study. As an example for the purposes of the radio-science experiment an accuracy of better than 10 m was assumed.
18 Jul 2012 -  JUICE ground segment description
Q: In which documents is the organization of the JUICE ground segment described?
A: This subject is addressed at high level in the SOAD (Science Operations Assumption Document) and SMP (both are part of the PIP). The former provides a top level description, while the latter gives indications of the ground segment structure and responsibilities. Details will be further defined in the coming phase when the SOCD (Science Operations Concept Document) and the SIRD (Science Interface Requirements Document) will be delivered by ESA. Specific SIP (Science Implementation Plan) documents will have to be prepared by the selected PI teams.
18 Jul 2012 -  ESA support for observations planning and visualization
Q: Which support for observations planning and visualization will be provided by ESA?
A: During the definition phase ESA will provide SPICE kernels.
18 Jul 2012 -  Planetary protection
Q: How will ESA address the planetary protection issue?
A: It will be addressed at the system level by spacecraft reliability assessments to ensure that the probability of accidental collision with Europa will be below the required level. For Ganymede, the Planetary Protection panel recently recommended that the likelihood of penetration of organisms into the ocean is very low due to suppressed exchange of materials between surface and sub-surface of Ganymede. A paper in a refereed journal proving this would remove "+" from the 2+ category of Ganymede.
18 Jul 2012 -  Maintenance of expertise in instrument teams
Q: Is there any requirement on maintenance of expertise in the teams?
A: There is no specific requirement on this. However, SMP (sec 4.1.2 (3)) states that "continuity of human and institutional resources" would be considered as one of the selection criteria.
18 Jul 2012 -  Letters of Endorsement
Q1: Shall a proposal include a Letter of Endorsement from LFA, or from the other involved parties as well?
Q2: I am working with a U.S. industry partner to provide an instrument hardware for an ESA-led instrument that will be proposed by a European-led instrument consortium for JUICE. NASA's SALMON instructions are pretty clear that since this would not be a U.S. P.I.-led instrument then it should not be proposed to the SALMON call. Instead, we are to include our "category 2" subsystem contribution within the ESA proposal that responds to the JUICE AO and that will be submitted to ESA by our consortium PI. However, the instructions in ESA's JUICE AO are extremely vague about how NASA (or other foreign) contributions are to be organized, accommodated, and costed in the proposals submitted to ESA. The instructions are also vague about what details/information/commitments (if any) need to be described or provided in the Letter of Endorsement from NASA that would need to be included as part of our foreign component contribution to the ESA AO. How can we get additional details as well as specific instructions on what is required of us for our U.S.-provided instrument component contribution for a European-led instrument? Also, any public information that you are able to share (or point us to) describing how (and on what timescale) the NASA parts of European-led proposals will be assessed by NASA would also be appreciated.
A: Only a letter from LFA with commitment for the Definition phase and a pre-commitment for the following phases (see SMP and AO document) is required. Letters of endorsement from the other participating agencies are not required since LFA takes full responsibility. However, letters from other participating agencies can be submitted as a proof of status of the multi-agency agreement. See also Answers in the presentation given during the Briefing meeting (JUI-EST-SYS-HO-002_i1-0_Programmatic_Q&A-LC.pdf), on pages 5, 15 and 17. This presentation is available here and from the right-hand menu as "Briefing meeting Q&A presentation (L. Colangeli)".
18 Jul 2012 -  ITAR and information exchange
Q: In some proposals the level of ITAR is so high that no information can be received.
A: US members of a consortium should initiate a Technical Assistance Agreement (TAA) with their European partners. This will accelerate information exchange.
18 Jul 2012 -  Incomplete funding at time of review
Q: What happens when during the review 20% of the funding is lacking?
A: In the proposal the instrument cost should fit within the funding which is provided by the associated Member States. Proposing as a baseline a partly funded instrument will not be acceptable. The LFA takes responsibility for the overall funding of the proposed instrument.
18 Jul 2012 -  Orbit file time resolution
Q: In the orbit file for the Ganymede elliptical phase we would need to increase the time resolution?
A: We suggest interpolation of the data points.
18 Jul 2012 -  Science requirements tracing
Q: How do science requirements need to be traced?
A: All requirements on instrument performances will need to be linked (traced back) to science requirements.
18 Jul 2012 -  Spacecraft pointing properties and stability
Q: What are the properties of Yaw steering and for how long could we assume stable pointing?
A: Please use the appendix of the EID-B to specify your requirements on the spacecraft.
18 Jul 2012 -  Pointing kernels
Q: Are pointing (C) kernels for JUICE imaging/mosaicing available? Are JUICE flight rules known?
A: ESA has not yet generated pointing kernels. This issue will be addressed after the accommodation of selected instruments on the spacecraft becomes known and the Science Activity Plan is developed. The JUICE flight rules are at a very preliminary stage at this point in time. Requirements from instrument teams will need to be reviewed to complete the requirements at platform level.
18 Jul 2012 -  Harness manufacture
Q: The EID-A implies that the instrument providers will be responsible for harness manufacture. How will ESA make the routing information available to allow accurate manufacture of the harness? Will access be provided to a Prime Contractor physical structure for harness manufacture?
A: The instrument providers will be responsible for harness manufacture; see EID-A (e.g., EIDA-R00500 Note 2) for assumptions at this stage. Discussion with the Prime will be needed case by case to define routing for a careful manufacturing of the harness.
5 Jul 2012 -  Clarification on the instrument mass
Q: With respect to EID-A please provide more information about instrument mass allocation and strategy for mass margins allocation. Please clarify the mass indications given in the EID-A with respect to SciRD and PDD.

The following gives clarifications on two aspects linked to the instrument mass:
1. shielding mass to be included in the mass evaluation
2. mass allocation

In the EID-A we have presently (page 35):
  EIDA-R00550: The PI shall calculate and provide the instrument Mass Margin

The instrument Mass Margin (including shielding) is the difference between the total instrument Nominal Mass [i.e. sum of unit(s) Nominal Mass(es)] and the instrument allocated mass.

On page 34, on the description of the unit mass budget we have:

  EIDA-R00500: The PI shall ensure that each unit mass budget include at least the following elements, as applicable:
  1. Structure, mechanisms and optics;
  2. electronics up to the interfaces with the spacecraft power and data systems;
  3. thermal control hardware, including any necessary thermal straps or heaters / thermistors, instrument blankets, cold fingers defined by the instrument
  4. pigtail and interconnecting harness (if instrument consists of more than one unit)
  5. electrical connectors, but not the mating harness connector
  6. attachment hardware including instrument-delivered brackets or struts, but excluding standard fixation bolts to the spacecraft structure and washers
  7. potting compounds used in the units
  8. alignment references, e.g. mirrors, that are not removed before flight
  9. internal balance mass (applicable for periodically operating mechanisms)
  10. electrostatic screens and/or magnetic shielding
  11. in-flight covers, purge ports, purging pigtails
  12. shielding at component level (e.g spot shielding).
    Note1: Shielding at unit level is presently not included in the mass allocation but shall be evaluated and communicated by the PI in the EID-B.
    Note2: for harnesses between units when applicable, a minimum of 2 meters (TBC) shall be assumed at this stage.

=>  point l. corresponds to shielding at component level whereas note1 clearly states that shielding at instrument level is not included.
Therefore on page 34, the statement "including shielding" can be indeed misleading and will be removed in the next version of the EID-A.

EID-A-R00500 defines the elements to be included for each unit mass budget. Using the engineering best estimate of these elements, the basic mass can be derived. When adding contingency to account for uncertainty (see EID-A-R00540 for the contingency factors to be used), the nominal mass is evaluated. The mass margin= (allocation-nominal mass)/allocation *100 shall be as per EID-A-R-00560 during the course of the project.

The masses given in the PDD refer indeed to the engineering best estimate, with a total of 103.9 kg for the total. Adding 25% (as requested at SRR) leads to the total instrument mass allocation which is considered as frozen for the AO review.

We acknowledge the fact that Table 9 of the EID-A is indeed misleading with respect to the PDD since the table refers to mass allocation when the values are in fact best engineering estimate. However, the actual mass allocation is still TBC and will eventually depend on the actual payload complement after the AO review.

We therefore insist on the need by the instrument proposer to:
- Consolidate their current best estimate,
- Apply realistic contingency factor as needed,
- Evaluate the nominal mass.

Based on these nominal masses, the payload complement composition and mass margin philosophy to be applied, the mass allocations will then be determined.

4 Jul 2012 -  Approach for non-European led Consortia
Q: I would like to know how do we handle European contributions to an instrument, which is proposed from an American University to NASA with an American PI? What does ESA need from the European Co-Is and institutions?
A: The approach for contributions to an instrument is the same both for European and for non-European led Consortia, as explained in the JUICE Science Management Plan. At the present time of proposals, ESA does not require any statement/letter from the Funding Agencies supporting CoIs/CoPIs. It is however recommended to start discussions between the PI/LFA (Lead Funding Agency) and the other contributing agencies/CoIs/CoPIs as felt appropriate within the Consortia.
4 Jul 2012 -  Briefing meeting attendance
Q: I would like to ask, whether it is required that American PIs attend the meeting on 13 July at ESTEC.
A: The briefing meeting on the 13th is open to all interested parties.
22 Jun 2012 -  Model Payload Definition Document - mass budgets
Q: Concerning the Model Payload Definition Document for JUICE (iss 3.1 / 31 May 2012) related to the mass: What is exactly taken into account in the mass budgets given in this document in the instrument summary datasheets?
To be more specific are:
 - margin for additional shielding;
 - DPU/harness mass;
 - maturity margin
taken into account?
A: The mass estimate shall include:
  1. Structure, mechanisms and optics;
  2. electronics up to the interfaces with the spacecraft power and data systems;
  3. thermal control hardware, including any necessary thermal straps or heaters / thermistors, instrument blankets, cold fingers defined by the instrument
  4. pigtail and interconnecting harness (if instrument consists of more than one unit)
  5. electrical connectors, but not the mating harness connector
  6. attachment hardware including instrument-delivered brackets or struts, but excluding standard fixation bolts to the spacecraft structure and washers
  7. potting compounds used in the units
  8. alignment references, e.g. mirrors, that are not removed before flight
  9. internal balance mass (applicable for periodically operating mechanisms)
  10. electrostatic screens and/or magnetic shielding
  11. in-flight covers, purge ports, purging pigtails
  12. shielding at component level (e.g spot shielding).
Note1: Shielding at unit level is presently not included in the mass allocation but shall be evaluated and communicated by the PI in the EID-B.
Note2: for harnesses between units when applicable, a minimum of 2 meters (TBC) shall be assumed at this stage.

The mass margin policy with respect to the allocation is defined in the EID-A and is applicable.

22 Jun 2012 -  Assumptions about attitude
Q: It does seem there is no specific attitude information in the trajectory files; what assumptions should we make about the spacecraft attitude in the various phases?
Do you plan to release attitude information, or should we assume some fixed attitude behaviour?
A: Attitude information will not be available at the AO, as this is subject to detailed operations planning and trade-offs at system level. The EID-A will include a tentative specification  with TBC on the pointing performance that could be provided by the spacecraft. So for the purpose of your proposal, you may assume fixed (i.e. desired) attitude, with the performance as per EID-A.
We recommend that you discuss and describe the attitude (including compliance with Yaw steering) that is required for your instrument, including conditions that need to be met and durations, as this provides a necessary input for coordinating with other instruments.
18 Jun 2012 -  Coordination with international partners
Q: Do you have any update on the procedure for involving US partners in the AO proposals for JUICE instruments?
Are the AO and the selection procedure coordinated with NASA or should the US partners ask funds to NASA through a separate channel?
A: Negotiations with international partners, including NASA, about possible minor contributions to JUICE payload procurement are ongoing for a coordinated procedure. Proper details will be provided by the time of the AO Issue. See "Planetary Exploration Newsletter" Volume 6, Number 25, June 3, 2012 for NASA position.
18 Jun 2012 -  Class for Planetary Protection
Q: What is JUICE's class for Planetary Protection?
A: It is Class 3 (see documents TEC-Q/12-7236/KG and ESSB-ST-U-001 provided on these dedicated JUICE web pages). However, it is highlighted that the baseline is that the Planetary Protection requirements will be met by the S/C reliability. Therefore, individual instruments are not expected, for the time being, to embark/prepare for active bio-burden reduction measures.
18 Jun 2012 -  NAC characteristics clarification
(updated 26 Jun 2012)
Q1: After a quick look at the documents published few days ago, I would ask you to clarify an apparent inconsistency related to NAC required characteristics.
In JUI-EST-INST-SP-001_i3.1_MPPD Section 3.1.1 it is stated:
"GO1: ground sampling distance of < 5 m/pixel at 200 km altitude", which is consistent with the summary data sheet in sect. 3.1.11 and also (or at least not in contrast) with the Science Requirements Matrix.
On the other hand in the same sect. 3.1.1 it is also stated:
"JO1: ground sampling distance of 5 km/pixel at 1 Million km distance (identical to GO1)", which implies an IFOV a factor of 5 lower than the upper limit given in GO1 case.
In any case, the number given here is not compatible with the data sheet, nor with the SRM indication for Jupiter atmospheric observations and observations of other satellites.
Q2: Why does the MPDD not reflect the latest science requirements (i.e. IFOV of NAC from 1 arcsec to 5 arcsec)?
A: The MPPD is a reference document, for information on what instrument designs were considered for the payload complement by industry for the design of the spacecraft during the assessment phase.
The JUICE instrument proposals are expected to only consider the Science Requirements Document and the EID-A as source of requirements. Therefore, while the spacecraft resources shall be respected, the actual design of the instrument is matter for the proposal to elaborate.
18 Jun 2012 -  Proposing instruments other than the "Model Payload"
Q: I am writing to ask whether the forthcoming AO for JUICE instrumentation is open only to instruments listed in the model payload, or ESA would look favourably to the submission of proposals for additional instruments and science.
A: The Announcement of Opportunity (AO) will solicit proposals for the provision of the scientific payload on board the JUICE spacecraft. A Model Payload has been considered to demonstrate the achievement of the scientific mission objectives (see Assessment Study Report (Yellow Book) and Model Payload Definition Document [JUI-EST-INST-SP-001] available on these dedicated JUICE web pages). The Announcement of Opportunity will be based on the scientific objectives of the model payload; this means that the AO will call for provision of instruments not necessarily limited to the "Model Payload". Of course, the proposals for the instruments will have to be compatible with the scientific and operational objectives of the JUICE mission and with its design and operational capabilities as they will be defined in the Interface Documents (to be provided with the AO package). Proposed instruments that address the JUICE science goals as described in the Assessment Study Report and the Scientific Requirement document (to be provided with the AO) will be given priority, although proposals addressing other science goals are not excluded a priori.
18 Jun 2012 -  Purpose of simulations for shielding and geometry
Q: What is the purpose of the simulations done for very simple geometries, as are discussed in the reference documentation?
A: The purpose is to illustrate the effect of various shielding materials, and of geometry. This is intended as background information. Obviously radiation transport simulations with such simple geometries cannot be used for design verification, and must be performed on actual design.


Last Update: 1 September 2019
20-Apr-2024 19:39 UT

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