| # |
Burn time |
DV |
Dt |
a |
| M13D | 2019-04-13 16:45:29.000 | 32.5 | 4.434 | 7.32 |
| M13D | 2019-04-13 17:14:31.000 | 32.7 | 4.457 | 7.33 |
| M14D | 2019-04-16 16:45:29.000 | 31.4 | 4.264 | 7.36 |
| M14D | 2019-04-16 17:14:31.000 | 31.4 | 4.264 | 7.37 |
| M15D | 2019-04-20 16:45:29.000 | 27.6 | 3.739 | 7.39 |
| M15D | 2019-04-20 17:14:31.000 | 27.5 | 3.746 | 7.34 |
| M16D | 2019-04-23 16:45:29.000 | 21.7 | 3.013 | 7.21 |
| M16D | 2019-04-23 17:14:31.000 | 21.7 | 3.022 | 7.17 |
| M17D | 2019-04-27 17:00:00.000 | 88.3 | 11.447 | 7.72 |
| M18D | 2019-04-30 17:00:00.000 | 65.3 | 8.539 | 7.64 |
| M19D | 2019-05-04 17:00:00.000 | 79.7 | 10.458 | 7.62 |
| M20D | 2019-05-07 17:00:00.000 | 74.4 | 9.759 | 7.63 |
| M21D | 2019-05-11 17:00:00.000 | 88.6 | 11.469 | 7.72 |
| M22D | 2019-05-14 17:00:00.000 | 83.5 | 10.965 | 7.61 |
| M23D | 2019-05-18 17:00:00.000 | 84.3 | 11.051 | 7.63 |
| M24D | 2019-05-21 17:00:00.000 | 80.0 | 10.505 | 7.62 |
| M25D | 2019-05-25 17:00:00.000 | 76.6 | 10.056 | 7.62 |
| M26D | 2019-05-28 17:00:00.000 | 79.8 | 10.477 | 7.61 |
| M27D | 2019-06-01 17:00:00.000 | 94.5 | 12.253 | 7.72 |
| M28D | 2019-06-04 17:00:00.000 | 94.8 | 12.298 | 7.71 |
The table shows the spacecraft maneuvers executed during this phase.
The first four maneuvers were performed in two steps: one burn varies the trajectory and the other varies the speed (the magnitude of the velocity vector).
Here are the maneuvers from April 10 to June 12 in the Bennu-centric mean ecliptic and mean equinox of J2000 reference frame.
The popup label shows the date, the radius vector (m), the altitude above Bennu (m) and the spacecraft speed (mm/s).
Bennu is shown in the graph as an ellipsoid with equatorial radius of 282.5 m and a polar radius of 254 m, but for the altitude calculation, Bennu is modeled as a triaxial ellipsoid with radii: 282.5, 267.5, 254 m.
The altitude is calculated as the distance between the spacecraft and the point on the surface of Bennu that is nearest to the spacecraft.
Poster (3.6 MiB pdf file) with detailed explanations:
Detailed Survey: Equatorial Stations
The red labels show the seven equatorial stations.
The yellow lines point in the Sun direction; the rightmost line is for the time when the spacecraft is at S1. For example, if we consider S7, it seems that its
LST corresponds to 4 PM shown in the poster, but that's not true, because for the station #7 the Sun direction is represented by the leftmost yellow line.
That said, it's easy to compare the graph with the poster, because all the stations are located exactly at the same LST as shown in the poster.
The graph shows the evolution of the distance between the spacecraft and the asteroid, the altitude and the orbital speed during this phase.
All the seven equatorial stations are clearly shown by the graph. The "equatorial station" is when the periapsis is about 5 km.
The following table shows the station date (obtained from the NAIF's data file; the formal uncertainty is less than 1 s), the spacecraft local solar time, radius vector (m), altitude (m) and speed (mm/s) both in the Bennu fixed (rotating) and inertial reference frames:
| # |
Date |
LST |
r |
h |
Vbfr |
Vine |
| 1 | 2019-04-25 16:59:05 | 15:00 | 5103 | 4821 | 2077 | 42 |
| 2 | 2019-05-02 22:37:24 | 3:19 | 4961 | 4685 | 2016 | 42 |
| 3 | 2019-05-09 19:11:26 | 12:31 | 5008 | 4737 | 2039 | 42 |
| 4 | 2019-05-16 21:01:01 | 10:01 | 4935 | 4653 | 2009 | 43 |
| 5 | 2019-05-23 22:15:41 | 5:58 | 4928 | 4647 | 2004 | 43 |
| 6 | 2019-05-30 18:26:51 | 20:40 | 5059 | 4788 | 2055 | 46 |
| 7 | 2019-06-06 18:27:51 | 18:01 | 5063 | 4786 | 2059 | 51 |