SSA Activities at JAXA 28 Feb 2019

Director Shinji OGAWA

Space Tracking and Communications Center Aerospace Exploration Agency

Logo Contents of This Presentation

(1) Overview of Current SSA activities in Space Tracking and Communications Center (STCC)

(2) Newly developing SSA system

2 Satellites & Ground Systems Operated/Managed by STCC

◼ About STCC ➢ In charge of satellite tracking, operations, and R&D. ➢ Operates satellites using our ground stations around the world. ➢ Does research on space debris.

Astronomy Planetary Science

SPRINT-A SOLAR-B ASTRO-E2 ERG SpaceBepiColombo debrisPLANET-C are a Communications, and Engineering Test major threat for

WINDS SDS-4 SLATS EGS operationalIKAROS satellites. Earth Observation

ALOS-2 GCOM-W1 GOSAT GCOM-C GOSAT-2 INDEX 3 Overview of JAXA SSA Activities

Observation CSpOC Optical & Radar Bisei Space Ephemeris, Observation Data Guard Center (BSGC)

Orbit Determination

Kamisaibara JAXA Space Guard Conjunction Assessment Satellites Center (KSGC) JAXA Satellite Tracking Station （CA）for JAXA satellites Network CA, DAM, Deorbit Debris Avoidance Maneuver Planning, Re-entry （DAM） planning

CSpOC JAXA HQs (Combined Space Operation Center) Re-entry Analysis Risk Management 4 JAXA SSA System

Kamisaibara Space Guard Center （Radar 2004～） Bisei Space Guard Center （Optical telescope 2002～)

Okayama Pref. Ibaraki Pref.

Map of Okayama Pref. JAXA・Tsukuba Space Center （Analysis system）

➢ Radar Observes the low orbit ➢ Optical telescopes Observe the high orbit (36,000km range) ➢ Analysis system Performs orbit determination using observation data, CA for JAXA satellites, and re-entry analysis 5 Conjunction Assessment Process

CSpOC JAXA ② Screening ① Provide Ephemeris ・Do screening with a debris ・Provide the latest ephemeris catalogue observed by Space of JAXA satellites Surveillance Network ④ Conjunction Analysis ・Analyze a probability of collision (Pc), trends of conjunction data, etc. ・Check whether a Pc and the days to TCA (Time of Closest Approach) ③ Provide CDMs exceed our risk criteria ・Report the screening results ⑤ Collision Avoidance Operation in Conjunction Data Message (CDM) format ・Have meetings with Satellite Operation Team ・Plan maneuver and execute DAM 6 Conjunction Assessment

・The figure below shows the number of CDMs we received and the measures we took last year.（1 Apr 2017 ～ 31 Mar 2018） ・We executed 3 DAMs to mitigate the threat of conjunctions in this time frame. ・Conjunctions that exceed our criteria consisting of two factors, Pc and the days to TCA, are categorized as high risk.

Statistics for conjunction No Collisions ! assessment towards JAXA Execute DAM satellites 3 We held technical meetings the number of satellites: 14 Prepare for DAM for DAM 8 per 45 days. CDMs (high risk) A high risk conjunction 146 occurred once per 2.5 days.

CDMs We received CDMs everyday. 7 Example of a Debris Avoidance Maneuver

180°

Maneuver

8 Re-Entry Observation and Analysis

• Re-entry observation by KSGC radar - JAXA observes re-entry objects using KSGC radar in Okayama pref. - We calculate when & where (Lat./Lon.) the object re-enters the atmosphere. • Example of re-entry analysis - The following figure shows the re-entry prediction results of Tiangong-1 which we calculated using the data observed at KSGC. - As our prediction and the final Tracking and Impact Prediction (TIP) are almost the same, we assume that our predictions are precise.

9 Observation of Close Approach

This movie is a combination of images taken when INSAT 2 A approached ETS – 8 (Engineering Test Satellite-8).

• TCA ：December 10, 2012 at 23:06 (UTC) • Observations were carried out while

tracking INSAT-2A INSAT using the 1-