Conjunction Assessment Process

For Lunar Orbiters

Author: 

David Berry, Mission Design and Navigation Section MADCAP Representative

March, 2022

Jet Propulsion Laboratory

California Institute of Technology

© 2022 California Institute of Technology. Government sponsorship acknowledged. 
This document has been reviewed and determined not to contain export controlled technical data. URS309081 ii

DOCUMENT CHANGE LOG

DATE PAGES AFFECTED REASON FOR CHANGE VERSION/

REVISION

3/21/2022 All Initial version Initial
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Table Of Contents

1 Introduction and Brief History 1

2 Driving Requirements 1

3 Procedure 2

4 Monitoring Function (Daily*) 3

5 Response Notifications 4

6 Non-NASA Vehicles Considerations 4

7 Inactive Vehicles Considerations 4

8 Natural Body Considerations 4

9 Sample Response Message (Associated with Next Section) 5

10 Sample Monitor Message: Red Event with 2 Spacecraft 6

11 References 10

12 Acknowledgment 10
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1 Introduction and Brief History

In May 2005, NASA's Mars Odyssey and ESA's Mars Express (MEX) experienced a close approach (<10km 

with orbit crossing <1km). Uncertainties in the MEX trajectory led ESA to perform an avoidance maneuver. 

No formal process for conjunction assessment at Mars was in place at that time. In mid-2006, the MRO 

navigation team developed a collision avoidance (COLA) process that was used initially during aerobraking 

operations. MRO performed 27 aerobraking maneuvers, six of which were executed to avoid possible 

collisions with other spacecraft. In summer 2011, the MADCAP process (MArs Deepspace Collision 

Avoidance Program) was instituted for regular weekly monitoring of Mars Odyssey, Mars Express, and the 

Mars Reconnaissance Orbiter. Non-operating spacecraft such as MGS and the Viking 1 orbiter were also 

included. The process was progressively formalized, and in January 2012, a Lunar run was instituted given 

the presence of several Lunar orbiters concurrently at the Moon (Lunar Reconnaissance Orbiter, ARTEMISP1, ARTEMIS-P2, GRAIL-A, GRAIL-B). In June 2012, the MADCAP process was presented at the 

SpaceOps Conference in Stockholm, Sweden (reference 1). 

In late 2014, a new release of the MADCAP software was produced and re-christened "Multimission 

Automated Deepspace Conjunction Assessment Process" given its use beyond the Mars orbital 

environment. Since that time, daily analysis runs have been instituted. Approximately annual software 

updates have been implemented with bug fixes and improvements to scheduling, processing, reports, and 

report distribution lists. Several conference papers have reported MADCAP progress (see references 2, 3).

This document describes the conjunction assessment process that routinely monitors Lunar-orbiting 

spacecraft trajectories for future orbit crossings and close approaches, as it exists today. In essence it 

follows the same process used for the Mars orbital environment. The process uses the aforementioned

MADCAP automated navigation utility that executes on secure flight network computers at JPL. MADCAP

is built upon JPL's Monte multimission navigation software. Requirements (reference 4) and a technical 

description/user guide (reference 5) for MADCAP are available in the AMMOS documentation in EPDM (do 

a find on "multimission conjunction assessment"). The process takes advantage of and depends upon the 

availability of ephemeris predictions provided to the DSN by flight projects (including non-NASA vehicles) 

for tracking and communications support. Summary Reports are sent to stakeholders by email via tailored 

email lists. As spacecraft (including non-NASA missions) are added to the existing fleet in orbit at the Moon, 

every effort will be made to include them in this process.

The process consists of Monitoring and Response Functions. The Monitoring Function is implemented via 

a daily Summary Report emailed to interested parties. The Response Function is invoked when there is a 

"red event" (i.e., spacecraft are predicted to be "too close") reported in the Summary Report. In these cases, 

a JPL MDNAV MADCAP Representative will work with the navigation team(s) involved to determine a 

course of action. In some cases, collision avoidance maneuvers are negotiated between the affected flight 

project teams. In the event a response plan cannot be agreed upon by the affected flight projects, the JPL 

MDNAV MADCAP Representative will chair a meeting with relevant decision makers to determine the final 

response via a Conflict Resolution Process.

A virtually identical process is also in use for Mars orbiters and objects at Sun/Earth Lagrange Points.

2 Driving Requirements

1. The MADCAP shall perform conjunction assessment analyses routinely for all maneuverable Lunar

orbiting spacecraft.

2. The MADCAP shall identify potentially high risk Lunar orbiter close approaches and communicate any 

to key stakeholders sufficiently in advance to enable an avoidance response.

3. The MADCAP shall maintain (on best efforts basis) estimated locations of non-functioning Lunarorbiting spacecraft.
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3 Procedure

MONITORING FUNCTION

Step Who Action

1

JPL MDNAV (Mission 

Design and Navigation)

MADCAP Rep

Ensure routine daily execution of monitoring software to identify 

predicted close approaches (orbit crossing distances and orbit crossing 

timings). Provide daily summary to “Monitoring” group. (See Section 4.)

2 MDNAV MADCAP Rep

Invoke "Response Function" when the daily summary report shows that 

any close approach (orbit crossing distance AND orbit crossing timing)

within 14 days from run time falls below pre-defined thresholds 

(hereafter called a "red event"). 

RESPONSE FUNCTION

3 MDNAV MADCAP Rep Communicate with affected NAV Team Chiefs within 24 hours to 

confirm that they are aware of the reported red event. 

4

MDNAV MADCAP Rep 

and Flight Project 

Navigation (NAV) Reps

Discuss options and agree to recommended response actions to red 

event, which may include actions by at least one and possibly both 

flight projects. Obtain approvals as necessary. Depending on the timeto-go until the red event, "watch" may be the initial action.

5 MDNAV MADCAP Rep

Within 24 hours of discussing with NAV Team Chiefs, communicate 

reported red event and proposed action outcome to the identified 

“Response” group. (See Section 5.) Invoke "Conflict Resolution 

Function" in the event that agreement on action cannot be obtained.

6 Flight Project(s) Nav Prepare to implement agreed response action(s), e.g., design, build, 

and test of avoidance maneuver (if applicable).

7 All Continue Monitoring Function while response action is prepared.

8 MDNAV MADCAP Rep

If response involves a maneuver, and if requested by flight project(s), 

execute a MADCAP test run (on best effort basis) to confirm planned 

avoidance maneuver (a) mitigates red event risk and (b) no new 

threshold violations result.

9 Flight Project(s) Implement agreed response action(s) if/when desirable or necessary.

Confirm proper execution.

10 All Continue Monitoring Function (end of process).

CONFLICT RESOLUTION FUNCTION

N/A N/A

Next steps are conditional and only exercised if the normal process fails

(e.g., high criticality event, flight projects cannot agree on response 

actions, there is disagreement with proposed response actions, lack of 

response by a flight project involved in red event, etc.)

11 MDNAV MADCAP Rep

Convene a meeting with decision makers of affected flight project 

teams. Discuss issues with candidate response actions. Negotiate and 

iterate until agreement is reached. This may involve concurrence with

the NAV recommendation or an alternate response. This process may 

have to be modified for red events that do not involve NASA satellites.

Determine appropriate escalation if agreement cannot be reached.

12 MDNAV MADCAP Rep Communicate agreed action outcome to the identified “Response” 

group. (See Section 5.)

13 All Go to Step 5 of Response Function.
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4 Monitoring Function (Daily*)

*Frequency of execution used for current Lunar orbiters. Frequency can be increased/decreased if 

conditions render it necessary or desirable. Red event threshold values are based on each Project's threesigma trajectory uncertainty estimates and are provided by the Project to the MADCAP Team.

The MADCAP Summary Report is emailed to interested parties maintained in an email list 

(moon_madcap_monitor@list.jpl.nasa.gov) maintained by the MDNAV MADCAP Representative. The 

report is essentially open to subscription by parties interested in the Lunar orbital environment. It provides 

information about pairwise orbit crossing distances, orbit crossing timing, and closest approaches based 

on flight project determined thresholds. Lander and flyby missions are included in MADCAP analyses during 

final approach. The organizations and personnel represented in this list (as of publication date) include at 

least:

• Lunar Orbiter Flight Projects (modified as missions are added/retired): 

• NASA Lunar Reconnaissance Orbiter (LRO)

• NASA ARTEMIS-P1 

• NASA ARTEMIS-P2

• ISRO Chandrayaan-2 (CH2O)

• ISRO Chandrayaan-1 (CH-1, inactive)

• JAXA Ouna (inactive)

• JPL MDNAV Section Management Team

• MGSS Program Office

• NASA CARA Representative

• MADCAP Representatives
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5 Response Notifications

The Response Report is sent to designated leadership with respect to the missions involved in a MADCAP 

"red event" (i.e., orbit crossing distance AND orbit crossing timing both below mission defined thresholds

within 14 days from run time). A list of designated recipients for each interest group is maintained by the 

MDNAV MADCAP representative. Missions indicate who they would like to receive the red event messages. 

"Response" notifications are tailored for the missions involved in the red event and include a preliminary 

recommendation for addressing the situation (see Section 9). The organizations that are represented in this 

list (as of publication date) include:

• Lunar Orbiter Flight Projects (generally two of the following):

• NASA Lunar Reconnaissance Orbiter (LRO)

• NASA ARTEMIS-P1 

• NASA ARTEMIS-P2

• ISRO Chandrayaan-2 (CH2O)

• JPL MDNAV Section Management Team

• MGSS Program Office

• NASA CARA Representative

• MADCAP Representatives

6 Non-NASA Vehicles Considerations

Non-NASA Lunar spacecraft (e.g., Chandrayaan-2, etc.) will be included in the MADCAP process to the 

extent that accurate trajectory prediction information is available. Use of the DSN for tracking and 

communication services by those missions facilitates but is not required for the Monitoring and Response 

functions.

7 Inactive Vehicles Considerations

Conjunction events for inactive Lunar orbiters are not included in the summary reporting messages. 

However, for ISRO's Chandrayaan-1 and JAXA's Ouna, end-of-mission orbital states are used to produce 

long-term future predictions of orbit crossings and close approach estimates and are available upon 

request. Given the large orbital uncertainties the orbit crossing and close approach data are of marginal 

value. Bands of inclination may be the only useful information.

8 Natural Body Considerations

There are no Lunar natural satellites. However, the use of MADCAP for monitoring close approaches of 

Near Earth asteroids at Lunar distance has been suggested. This would require adding the ephemeris of 

the Near Earth asteroid to relevant MADCAP runs. Ephemerides of Near Earth asteroids are prepared by 

the Solar System Dynamics group in the MDN Section. Conjunctions of a spacecraft and a Near Earth 

asteroid would be included in the summary reporting messages if added to a MADCAP run. Special 

considerations in threshold settings are necessary for the natural satellites given that (a) the ephemeris 

position is predicted with respect to the center of gravity of the body, and (b) the body has significant size 

compared to a spacecraft, and unlike a spacecraft cannot be treated as essentially a point mass.
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9 Sample Response Message (Associated with Next Section)

From: David Berry <david.s.berry@jpl.nasa.gov>

Date: Wednesday, October 13, 2021 at 1:21 PM

To: <<list of recipients based on spacecraft in conjunction>>

Subject: FW: MADCAP -- Moon -- Summary -- 2 Red

All,

In today's MADCAP Summary report (shown below) 2 Red events were triggered 

for LRO and CH2O on 2021-10-20. These red events first manifested in 

yesterday's MADCAP report, however, today's report showed closer approach 

distances after ephemerides for both spacecraft were refreshed.

The recommendation at this time is:

 

To Be Determined. Based on email exchanges with both the LRO team and the 

CH2O team, there is apparent agreement that a collision avoidance activity of 

some nature is necessary. The MADCAP team is currently working to establish a 

meeting with LRO and CH2O to discuss options and determine a course of 

action, including the party that will maneuver.

An updated response message will be distributed when a plan has been agreed.

Justification for Recommendation

================================

ISRO has indicated that "no maneuver is planned for Chandrayaan-2 until 

November 1st week."

LRO has indicated that the spacecraft performed "a small momentum unload on 

10/11 that likely made that pop up. LRO does not have any planned unloads 

between now and that close approach."

Background

========== 

Several years ago, JPL formalized a Conjunction Assessment Process for Orbiters

at Mars and the Moon. In this process a recommended response by the JPL 

MDNAV MADCAP representative and the navigation teams involved is required when 

a close approach is predicted in less than 14 days to be within pre-defined 

threshold values. These events are flagged as "Red" events in the daily monitor 

email. 

Regards,

David Berry

JPL MDNAV MADCAP Representative
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10 Sample Monitor Message: Red Event with 2 Spacecraft

From: JPL MDNAV <jplmdnav@airmail.fltops.jpl.nasa.gov>

Reply-To: JPL MDNAV <jplmdnav@airmail.fltops.jpl.nasa.gov>

Date: Wednesday, October 13, 2021 at 10:07 AM

To: moon_madcap_monitor <moon_madcap_monitor@jpl.nasa.gov>

Subject: MADCAP -- Moon -- Summary -- 2 Red

Analysis Time: 2021-10-13 16:47:19 UTC

RED Threshold Updates: 0

ALL Threshold Updates: 0

Ephemeris Updates: 2

Conjunction Assessment Bodies and Types

Body Name Type

1 LRO Active

1r LRO Active/Reference

2 ARTEMIS-P1 Active

2r ARTEMIS-P1 Active/Reference

3 ARTEMIS-P2 Active

3r ARTEMIS-P2 Active/Reference

4 CH2O Active

5 Ouna Inactive

6 CH1 Inactive

Red (Conjunction Data < 'Red' Thresholds and Event < 14 days from Analysis Time)

Bodies OXD value/limit 

(km)

OXT value/limit 

(sec)

CAD value/limit 

(km)

Collision 

Probability

CA Epoch 

(UTC-SCET)

1-4 -0.0 1.7 4P -0.1 4.5 1P 25.5 ----- -- no request 2021-10-20 

04:47:11

1-4 -0.0 1.7 4P -0.1 4.5 1P 0.1 ----- -- no request 2021-10-20 

05:45:38

All (Conjunction Data < 'All' Thresholds for <= 100 days)

Bodies OXD (km) OXT (sec) CAD (km) CA Epoch (UTC-SCET)

1-4 0.9 375.7 492.9 2021-10-19 07:12:26

1-4 0.9 375.7 495.7 2021-10-19 08:10:50

1-4 0.8 341.0 445.3 2021-10-19 09:10:08

1-4 0.8 341.0 450.3 2021-10-19 10:08:32

1-4 0.6 306.5 397.8 2021-10-19 11:07:50

1-4 0.6 306.5 405.1 2021-10-19 12:06:15

1-4 0.5 272.1 350.4 2021-10-19 13:05:32

1-4 0.5 272.1 359.8 2021-10-19 14:03:57

1-4 0.4 237.7 303.3 2021-10-19 15:03:14

1-4 0.4 237.7 314.5 2021-10-19 16:01:40

1-4 0.3 203.3 256.2 2021-10-19 17:00:56

1-4 0.3 203.3 269.2 2021-10-19 17:59:22

1-4 0.3 169.0 209.2 2021-10-19 18:58:39

1-4 0.3 169.0 223.8 2021-10-19 19:57:05

1-4 0.3 134.7 162.5 2021-10-19 20:56:21

1-4 0.3 134.7 178.6 2021-10-19 21:54:48

1-4 0.3 100.7 116.0 2021-10-19 22:54:03

1-4 0.3 100.7 133.5 2021-10-19 23:52:30

1-4 0.3 66.9 70.2 2021-10-20 00:51:46
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1-4 0.3 66.9 88.7 2021-10-20 01:50:13

1-4 0.2 33.3 25.9 2021-10-20 02:49:28

1-4 0.2 33.3 44.1 2021-10-20 03:47:56

1-4 -0.0 -0.1 25.5 2021-10-20 04:47:11

1-4 -0.0 -0.1 0.1 2021-10-20 05:45:38

1-4 -0.3 -33.2 69.3 2021-10-20 06:44:53

1-4 -0.3 -33.2 44.0 2021-10-20 07:43:21

1-4 -0.7 -66.0 114.6 2021-10-20 08:42:36

1-4 -0.7 -66.0 87.6 2021-10-20 09:41:04

1-4 -1.1 -98.7 159.9 2021-10-20 10:40:18

1-4 -1.1 -98.7 130.9 2021-10-20 11:38:46

1-4 -1.6 -131.2 205.4 2021-10-20 12:38:01

1-4 -1.6 -131.2 174.0 2021-10-20 13:36:29

1-4 -2.2 -163.6 250.7 2021-10-20 14:35:44

1-4 -2.2 -163.6 216.9 2021-10-20 15:34:12

1-4 -2.8 -196.1 296.1 2021-10-20 16:33:27

1-4 -2.8 -196.1 259.8 2021-10-20 17:31:54

1-4 -3.3 -228.5 341.3 2021-10-20 18:31:11

1-4 -3.3 -228.5 302.7 2021-10-20 19:29:37

1-4 -3.9 -261.1 386.3 2021-10-20 20:28:54

1-4 -3.9 -261.1 345.6 2021-10-20 21:27:20

1-4 -4.6 -293.8 431.3 2021-10-20 22:26:37

1-4 -4.6 -293.8 388.7 2021-10-20 23:25:03

1-4 -5.2 -326.6 476.2 2021-10-21 00:24:20

1-4 -5.2 -326.6 432.0 2021-10-21 01:22:45

1-4 -4.9 -426.8 475.4 2021-10-21 03:20:28

1r-4 17.4 446.8 460.2 2021-11-05 06:16:27

1r-4 17.6 410.3 413.2 2021-11-05 08:14:07

1r-4 17.6 373.9 366.3 2021-11-05 10:11:47

1r-4 17.6 373.9 491.0 2021-11-05 11:10:23

1r-4 17.6 337.7 319.4 2021-11-05 12:09:27

1r-4 17.6 337.7 443.9 2021-11-05 13:08:04

1r-4 17.5 301.6 272.5 2021-11-05 14:07:07

1r-4 17.5 301.6 396.8 2021-11-05 15:05:45

1r-4 17.4 265.6 225.8 2021-11-05 16:04:47

1r-4 17.4 265.6 349.8 2021-11-05 17:03:26

1r-4 17.2 229.8 179.2 2021-11-05 18:02:27

1r-4 17.2 229.8 302.9 2021-11-05 19:01:08

1r-4 17.1 194.0 133.2 2021-11-05 20:00:07

1r-4 17.1 194.0 256.0 2021-11-05 20:58:49

1r-4 16.9 158.3 88.1 2021-11-05 21:57:47

1r-4 16.9 158.3 209.3 2021-11-05 22:56:30

1r-4 16.7 122.7 46.7 2021-11-05 23:55:27

1r-4 16.7 122.7 162.6 2021-11-06 00:54:11

1r-4 16.5 87.2 30.3 2021-11-06 01:53:07

1r-4 16.5 87.2 116.2 2021-11-06 02:51:52

1r-4 16.1 51.8 62.8 2021-11-06 03:50:46

1r-4 16.1 51.8 70.2 2021-11-06 04:49:33

1r-4 15.6 16.5 105.7 2021-11-06 05:48:26

1r-4 15.6 16.5 26.7 2021-11-06 06:47:13
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1r-4 14.9 -18.8 150.2 2021-11-06 07:46:06

1r-4 14.9 -18.8 28.9 2021-11-06 08:44:54

1r-4 14.0 -53.9 194.8 2021-11-06 09:43:45

1r-4 14.0 -53.9 72.5 2021-11-06 10:42:35

1r-4 12.9 -88.9 239.4 2021-11-06 11:41:25

1r-4 12.9 -88.9 117.9 2021-11-06 12:40:16

1r-4 11.8 -123.8 283.8 2021-11-06 13:39:05

1r-4 11.8 -123.8 163.5 2021-11-06 14:37:56

1r-4 10.6 -158.4 327.8 2021-11-06 15:36:45

2-3 -34.0 1354.5 467.9 2021-11-09 10:14:37

1r-2r -130.9 7071.1 135.0 2021-11-20 20:34:20

2r-3r -246.7 897.7 363.5 2021-11-22 22:24:54

1r-2r -118.4 7328.2 354.7 2021-11-23 22:53:30

1r-2r -165.1 321.6 417.8 2021-12-03 07:53:37

1r-2r -51.4 377.2 466.0 2021-12-31 08:39:30

1r-3r -490.4 7032.6 490.6 2022-01-05 21:48:03

1r-2r -427.6 -4.1 427.6 2022-01-19 00:33:16

Notes

OXD means "Orbit Crossing Distance". OXT means "Orbit Crossing Timing". CAD means 

"Close Approach Distance". 

Data for active spacecraft and natural bodies are displayed in the tables above. Data 

for inactive spacecraft are not displayed, but they are available in the conjunction 

metric tables and plots, which have been stored in the output directory listed below. 

Data for reference trajectories are not considered for Red events, but are considered 

in the All section for events not covered by the predicts file. Reference trajectories 

use the same thresholds as the nominal trajectories. 

The note after the probability value listed for RED events refers to the source of 

covariance data used for the probability calculation, with the following definitions: 

C - Covariance data provided by the mission in OEM format.

P - A covariance converted from the RED threshold polynomial coefficients listed 

below. 

N - No covariance data, worst case covariance assumed for this body. 

No Data - Probability could not be calculated due to a lack of covariance data from 

both bodies. 

For more information, please see the point of contact listed below. 

Analysis time: 2021-10-13 16:47:19 UTC

Active spacecraft: LRO, ARTEMIS-P1, ARTEMIS-P2, CH2O

Natural bodies: None

Inactive spacecraft: Ouna, CH1

Output directory: /nav/home/jplmdnav/MADCAP/Moon/archive

Point of contact: MADCAP_Moon@jpl.nasa.gov

MADCAP build: 3.1.2

Red Thresholds -- Polynomial Coefficients

Body Name OXD0 

(km)

OXD1 

(km/t)

OXD2 

(km/t^2)

OXT0 

(sec)

OXT1 

(sec/t)

OXT2 

(sec/t^2)

1 LRO 0.1500 0.0125 0.0005 1.8750 0.2671 0.0184

2 ARTEMISP1 0.1370 -0.0024 0.0089 0.0100 2.8154 0.0045

3 ARTEMISP2 0.1370 -0.0024 0.0089 0.0100 2.8154 0.0045

4 CH2O 0.0000 0.2509 0.0000 0.0000 0.1490 0.0005

Red OX Distance Threshold = OXD0 + (OXD1 * t) + (OXD2 * t^2) [km] 

Red OX Timing Threshold = OXT0 + (OXT1 * t) + (OXT2 * t^2) [sec] 

where t = CA Epoch - Ephemeris File Submit Time (in days) 

Red thresholds are based on 3-sigma values. Thresholds listed as "P" are based on a 

quadratic fit of the 3-sigma values as a function of time to the event. The polynomial 
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coefficients used are listed in the table above. Lines for coefficients which have 

been updated since the last run are colored blue, and each line's body is marked with 

an "*". Thresholds listed as "C" are based on 3-sigma covariance data provided by the 

mission. 

All Thresholds -- Constants

Body Name OXD (km) CAD (km)

1 LRO 1 40

2 ARTEMIS-P1 500 500

3 ARTEMIS-P2 500 500

4 CH2O 500 500

All OX Distance Threshold = OXD 

All CA Distance Threshold = CAD 

All thresholds are always constants. The constants used are listed in the table above. 

Lines for constants which have been updated since the last run are colored blue, and 

each line's body is marked with an "*". 

Ephemerides

Body Ephemeris Submitted Begin End

1* 14day_20211013_01.bsp

2021-10-13 

11:50:42 

UTC

13-OCT2021 

00:00:00 

UTC

27-OCT2021 

00:00:00 

UTC

1r 558day_20211012_01.bsp

2021-10-12 

11:55:39 

UTC

12-OCT2021 

00:00:00 

UTC

23-APR2023 

00:00:00 

UTC

2 192.THEMIS_B.SHORT_TERM.2021_285.oem.bsp_V0.1

2021-10-12 

10:35:30 

UTC

12-OCT2021 

00:00:00 

UTC

11-NOV2021 

00:00:00 

UTC

2r 192.THEMIS_B.LONG_TERM.2021_104.oem.bsp_V0.1

2021-04-14 

17:57:45 

UTC

14-APR2021 

00:00:00 

UTC

13-APR2027 

00:00:00 

UTC

3 193.THEMIS_C.SHORT_TERM.2021_285.oem.bsp_V0.1

2021-10-12 

10:36:36 

UTC

12-OCT2021 

00:00:00 

UTC

11-NOV2021 

00:00:00 

UTC

3r 193.THEMIS_C.LONG_TERM.2021_104.oem.bsp_V0.1

2021-04-14 

18:01:40 

UTC

14-APR2021 

00:00:00 

UTC

13-APR2027 

00:00:00 

UTC

4* ISRO-CH2-2021-10-12-OD814-286-v1.xsp.bsp

2021-10-13 

11:30:10 

UTC

12-OCT2021 

07:00:00 

UTC

11-NOV2021 

09:00:00 

UTC

5 ouna_191201_230101_150608_SMM0710031456-jplekl.bsp

Analysis 

Time

01-DEC2019 

00:59:23 

UTC

31-DEC2022 

23:58:23 

UTC

6 traj_ch1_010920-011022.bsp Analysis 

Time

31-AUG2020 

23:58:50 

UTC

30-SEP2022 

23:58:50 

UTC

Ephemeris files for the bodies analyzed are listed in the table above. Lines for files 

which have been updated since the last run are colored blue, and each line's body is 

marked with an "*". 
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11 References

1. Berry, D. et al., "Automated Spacecraft Conjunction Assessment at Mars and the Moon", Paper 

1262983, 12th International Conference on Space Operations, Stockholm, Sweden, 11 June 2012.

2. Tarzi, Z., Berry, D., Roncoli, R., “An Updated Process for Automated Deepspace Conjunction 

Assessment” Paper AAS 14-373, 25th International Symposium on Space Flight Dynamics, Munich, 

Germany, October 2015.

3. Berry, D., Tarzi, Z., Roncoli, R., Wilson, R., “Automated Spacecraft Conjunction Assessment at Mars 

and the Moon-A Five Year Update”, Paper 2810036, 14th International Conference on Space 

Operations, Marseille, France, May 2018

4. Berry, D., Tarzi, Z., "Multimission Automated Deepspace Conjunction Assessment Process 

(MADCAP) Requirements", MGSS DOC-001813, Revision E, February 8, 2022.

5. Tarzi, Z., “Multimission Automated Deepspace Conjunction Assessment Process (MADCAP) 

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Internal Document IOM-343A-13-001.

12 Acknowledgment

This research was carried out at the Jet Propulsion Laboratory, California Institute of Technology, under a 

contract with the National Aeronautics and Space Administration (80NM0018D0004). 

© 2022 California Institute of Technology. Government sponsorship acknowledged.