Particle Impacts with SEET

STK Premium (Space) or STK Enterprise
You can obtain the necessary licenses for this tutorial by contacting AGI Support at support@agi.com or 1-800-924-7244.

The results of the tutorial may vary depending on the user settings and data enabled (online operations, terrain server, dynamic Earth data, etc.). It is acceptable to have different results.

Capabilities Covered

This lesson covers the following STK Capabilities:

  • STK Pro
  • Space Environment and Effects Tool (SEET)

Problem Statement

For a given vehicle configuration and orbit, you need to determine the degree of exposure to potentially damaging debris and meteoroid impacts over the course of its mission lifetime.

Break It Down

You have some information before you get started:

  • Debris model calculations are based on average satellite altitude and only apply for spacecraft where the average altitude is between 300 and 2250 km.
  • You will analyze a past event from 15 Oct 2010 - 20 Oct 2010.
  • You will analyze the Grace-1 satellite.
  • The cross-sectional area of the satellite surface is 2.5 m2.
  • The material of the satellite surface is Mylar. The impact depth threshold for functional/operational damage is two (2) mm.
  • Particle impact results to be generated include: impact flux and rate over time.

Solution

Use STK Pro and STK's Space Environment and Effects Tool (SEET) to build a scenario that covers the desired time period for the satellite orbit of interest. Specify the environmental and satellite surface properties. Generate a report and graph containing the desired impact information.

Introduction

The SEET Particle Impacts component computes the probabilistic distributions and rates of impact of small meteoroid and orbital debris particles upon a spacecraft of given cross-section and orbit as a function of time or particle mass. It can also determine the portion of these particles that cause damage, for specified surface properties and damage threshold.

Create a Scenario

  1. Create a new scenario by using the New Scenario Wizard. You can also extend the File menu and select New...
  2. Fill in the scenario name and description.
  3. Set the analysis period to the following:
    OptionValue
    Analysis Start Time15 Oct 2010 16:00:00.000 UTCG
    Analysis End Time20 Oct 2010 16:00:00.000 UTCG

Add a Satellite

This tutorial will use the existing Grace-1 satellite.

  1. Insert a new satellite using the following method:
    2. Option Value
    Select an Object to be Inserted: Satellite
    Select a Method From Standard Object Database
  2. Click the Insert button.
  3. Enter Grace-1 as the Name.
  4. Click Search.
  5. Select the Grace-1 satellite with Source = AGIs Standard Object Data Service.
  6. Click Insert.
  7. Close the Satellite Database tool.
  8. Close the Insert STK Objects tool.

Set the Particle Environment and Satellite Surface Properties

  1. Open the satellite's () properties ().
  2. Select the Basic - SEET Particle Flux page.

    3. The properties related to the calculation of impact information are displayed on the Basic - SEET Particle Flux page. The following settings are available:

    • Debris impact calculations require the F10.7 solar flux average from the 13 months prior to the time period of study. A static F10.7 value may be specified, or the value may be calculated automatically from the solar flux data source file.
    • Specify the satellite cross-sectional area for potential impacts.
    • If damaging impact results are desired, select the surface material and specify the associated pit depth threshold. Custom material property values may be specified when the ‘User Defined’ material is selected.
    • Optionally, the contribution of Sporadic Meteors (cosmic dust) to the impact calculations may be excluded.
  3. Set the following properties for the Grace-1 satellite.
    4. Option Value
    Cross-Sectional Area 2.5 m2
    Pit Depth 2 mm
    Material Mylar
  4. Click OK.

Generate a Report Detailing the Damage

Let's use STK's Report & Graph Manager to determine the damage impact on the satellite.

  1. Right-click Grace-1 () in the Object Browser.
  2. Open the Report & Graph Manager ().
  3. Click the New Report () button.
  4. Enter a name for the Report like ParticleFlux.
  5. Expand () the SEET Particle Flux Model Data Provider.
  6. Move () the Definition item to the Report Contents field.
  7. Expand () the SEET Meteor Flux Data Provider.
  8. Expand () the Damaging Impacts group.
  9. Move () the following items to the Report Contents field:
    • Time
    • Impact Flux
    • Impact Rate
  10. Click OK.
  11. Generate the ParticleFlux report.

Generate a Custom Graph

Let's create a custom graph that graphs the report you created.

  1. Click the New Graph Style () button.
  2. Enter a name for the Graph like ParticleFlux.
  3. Expand () the SEET Meteor Flux Data Provider.
  4. Expand () the Damaging Impacts group.
  5. Move () the Impact Rate data provider to the Y-Axis.
  6. Click OK.
  7. Generate the ParticleFlux graph.

Results and Analysis

Note the short up-and-down variation of the damaging meteoroid flux of each orbit. This is due to the satellite passing behind the Earth relative to the respective travel directions of the various meteor showers active during this time period. The overall plot trend, peaking late on 17 Oct, is due to the variation of the Ursids meteor shower activity. The Ursids annual shower is a brief, but intense meteor shower. This trend will vary throughout the year, as it depends on the specific periods of activity of the many showers contained in the meteoroid environment database.