Using the Satellite Lifetime Tool versus HPOP for Re-Entry Prediction
- Jun 20, 2016
- Article
- Space Situational Awareness
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SatPro
I recently had a customer ask about the differences he was seeing in a satellite’s predicted decay time when using the Satellite Lifetime Tool versus propagating the satellite using HPOP. This particular customer was seeing a variance of about two months. I helped him realize the large time gap in this instance was due to inconsistent setup of the Lifetime Tool and HPOP Force Models. This customer inquiry led me to realize we should create a “best practices” article for using these tools for comparison. I’ve laid these practices out in an FAQ here.
decay time estimate, while HPOP and Astrogator can be used for decay time and location prediction. HPOP and Astrogator will need to fully propagate the satellite forward until it reaches its decay altitude. This can become time consuming if your satellite doesn’t decay for a few months or even years. What I’d recommend is to define your satellite using either HPOP or Astrogator using the default scenario time period (~24 hours). Then use the Satellite Lifetime Tool to obtain an initial estimate of the satellite decay time and be sure to use my best practices. If you’d like to explore the decay time and location more precisely with HPOP or Astrogator, then you’ll know an estimated analysis period needed and can change that accordingly to allow STK to propagate the satellite forward to that time.