According to this TESS tweet:

TESS is on track for a lunar flyby on 17 May at 06:34:35 UTC (2:34 AM EST). At this point, TESS will be 8,253 km from the lunar surface. In the coming days, follow @NASA, @NASAGoddard, @NASAblueshift and @NASA_TESS for more details.

That's 10 20+ hours ago, and there have been no further tweets.

The last TLE I can see is now two weeks old and certainly invalid considering the lunar flyby would modify the trajectory so much.

Also I don't see or at least recognize TESS in the Minor Planet Center's Distant Artificial Satellites Observation page at all, and JPL's Horizons most recent ephemeris was generated on May 14th, several days before the flyby. I can't find any source where the status of TESS' orbit can be verified.

How did it go? Was it successful? Any info on how close the maneuver was to target?

TESS's lunar flyby allows it to make progress toward it's carefully engineered fairly-long-term (decades) stable high Earth orbit which is in 2:1 orbital resonance with the Moon.

Transiting Exoplanet Survey Satellite: 2018-038A and 43435

below x2: Screenshots (06:07, 06:57) from the excellent video Transiting Exoplanet Survey Satellite (TESS).

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1 Answer 1


From NASA_TESS on Twitter:

@NASA_TESS Mission Update: #TESS successfully completed a lunar flyby on May 17. TESS completed scheduled contact with @NASASCaN's Deep Space Network. Post flyby tracking was confirmed. TESS was 8,253.54 km from the surface of the moon at its closest approach.

And an update:

@NASA_TESS Mission Update: Based on great performance from the lunar fly-by, no adjustment burn is required. The next maneuver is the Period Adjust Maneuver (PAM) on May 30th; it will put #TESS into final science orbit. Observatory is in Coarse Pointing Mode operating nominally.

  • $\begingroup$ Wow! That's wonderful! Thank you for the update. $\endgroup$
    – uhoh
    May 20, 2018 at 14:31

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