The Small Carry-on Impactor (SCI) operation will take place between April 3 – 6. This is an impact experiment to create an artificial crater in a designated area. Please see the table and figure below for information regarding the operation schedule.
SCI operation main schedule
| Date & Time UTC ( ) is the ground confirmation time |
Date & Time JST ( ) is the ground confirmation time |
Spacecraft line-of-sight velocity (cm/s) |
Altitude (m) | Event |
|---|---|---|---|---|
| 04/02 21:30 → 05:30 |
04/03 06:30 → 14:30 |
Communication via Usuda Deep Space Center begins | ||
| 04/02 22:40 → 05:30 |
04/03 07:40 → 14:30 |
0 | 20,000 | Shift 0-A [Preparation for descent #1] UDSC |
| 04/03 04:10 → 12:40 |
04/03 13:10 → 21:40 |
Shift 0-B [Monitor] MAD | ||
| 04/03 05:10 → 13:15 |
04/03 14:10 → 22:15 |
Communication via Madrid DSN begins | ||
| 04/03 12:10 → 20:05 |
04/03 21:10 → 05:05 |
Shift 0-C [Monitor] GDS | ||
| 04/03 13:10 → 20:00 |
04/03 22:10 → 05:00 |
Communication via Goldstone DSN begins | ||
| 04/03 19:35 → 02:30 |
04/04 04:35 → 11:30 |
Shift 0-D [Monitor] UDSC | ||
| 04/03 19:55 → 05:30 |
04/04 04:55 → 14:30 |
Communication via Usuda begins | ||
| 04/04 02:00 → 08:00 |
04/04 11:00 → 17:00 |
Shift 1 [Start of descent] Gate1 | ||
| 04/04 03:00 | 04/04 12:00 | Gate1: Begin verification（Confirmation before the start of descent） | ||
| 04/04 04:00 (04/04 04:17) |
04/04 13:00 (04/04 13:17) |
-40 | 20,000 | Begin descent |
| 04/04 05:10 → 13:00 |
04/04 14:10 → 22:00 |
Communication via Madrid DSN begins | ||
| 04/04 07:30 → 13:30 |
04/04 16:30 → 22:30 |
Shift 2 [Auto. OFF] | ||
| 04/04 08:49 (04/04 09:07) |
04/04 17:49 (04/04 18:07) |
13,000 | ||
| 04/04 12:55 → 19:55 |
04/04 21:55 → 04:55 |
Communication via Goldstone DSN begins | ||
| 04/04 13:00 → 22:30 |
04/04 22:00 → 07:30 |
Shift 3 [Descent deceleration] Gate2 | ||
| 04/04 14:20 (04/04 14:37) |
04/04 23:20 (04/04 23:37) |
-10 | 5,000 | Descent deceleration ΔV |
| 04/04 14:37 | 04/04 23:37 | Gate2: Begin verification（confirm descent decelerationΔV） | ||
| 04/04 18:26 (04/04 18:43) |
04/05 03/26 (04/05 03:43) |
3,000 | ||
| 04/04 19:50 → 05:30 |
04/05 04:50 → 14:30 |
Communication via Usuda begins | ||
| 04/04 21:36 (04/04 21:53) |
04/05 06:36 (04/05 06:53) |
2,000 | ||
| 04/04 22:00 → 07:00 |
04/05 07:00 → 16:00 |
Shift 4 [Go/NoGo] Gate3-6 | ||
| 04/04 22:52 | 04/05 07:52 | 1,500 | ||
| 04/05 00:44 | 04/05 09:44 | Gate3: Begin verification（GO/NOGO judgement） | ||
| 04/05 01:44 | 04/05 10:44 | 0 | 500 | Estimated target altitude arrival time |
| 04/05 01:56 (04/05 02:13) |
04/05 10:56 (04/05 11:13) |
----- | ----- | SCI separated |
| 04/05 02:14 (04/05 02:31) |
04/05 11:14 (04/05 11:31) |
----- | ----- | DCAM3 separated |
| 04/05 02:36 (04/05 02:53) |
04/05 11:36 (04/05 11:53) |
----- | ----- | SCI explosion |
| 04/05 04:32 | 04/05 13:32 | ----- | ----- | Gate5: Begin verification（confirm stop evacuationΔV） |
| 04/05 05:10 → 12:55 |
04/05 14:10 → 21:55 |
----- | ----- | Communication via Madrid DSN begins |
| 04/05 05:52 | 04/05 14:52 | ----- | ----- | Gate6: Begin verification |
| 04/05 06:30 → 15:00 |
04/05 15:30 → 00:00 |
----- | ----- | Shift 5 [evacuation] |
| 04/05 06:44 (04/05 07:02) |
04/05 15:44 (04/05 16:02) |
----- | ----- | Begin return to HP ΔV（+XΔV） |
| 04/05 08:14 (04/05 08:32) |
04/05 17:14 (04/05 17:32) |
----- | ----- | HP return rise ΔV（+ZΔV） |
| 04/05 12:50 → 19:55 |
04/05 21:50 → 04:55 |
----- | ----- | Communication via Goldstone begins |
| 04/05 12:52 | 04/05 21:52 | ----- | ----- | Begin cancellation of descent configuration mode |
| 04/05 21:35 → 05:30 |
04/06 06:35 → 14:30 |
----- | ----- | Communication via Usuda begins |
| 04/06 05:10 → 13:15 |
04/06 14:10 → 22:15 |
----- | ----- | Communication via Madrid DSN begins |
- Time: Approximate scheduled time. UTC is Universal Time, JST is Japan standard time. There is a possibility that this may change during operation.
- Spacecraft line-of-sight velocity: This is the speed along the line-of-sight relative to the asteroid (minus is towards the asteroid, positive is away). Numerical value is displayed only when speed control is performed. After a speed control operation, the speed changes due to the gravitational force of Ryugu and other celestial bodies.
- Altitude: Approximate distance from the surface of Ryugu
- Since the spacecraft line-of-sight velocity and altitude become complicated after the SCI separation, they were omitted here.
Schematic of the SCI operation
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Figure 1: Schematic diagram of the SCI operation part #1. The operation from the home position to SCI separation is shown here. The graph on the left shows the change in the spacecraft position with time. On the right, the spacecraft position is shown in the x-z coordinate system (home position coordinate system). The times listed are the scheduled time and may differ from actual operations. (Image credit: JAXA.)
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[Open in a separate window]
Figure 2: Schematic diagram of the SCI operation part #2. The operation from SCI separation to the return to the home position is shown. In this figure, the position of the spacecraft in the x-z coordinate system is shown schematically. The time is the scheduled time and may differ from actual operations. (Image credit: JAXA.)
Crater generation area
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Figure 3: Area selected for creating the artificial crater during the SCI operation. The yellow ellipse in the left figure described as the “CRA1 operation observation area” roughly corresponds to the crater generation area (blue circle in the right figure). (Image credit: JAXA, University of Tokyo, Kochi University, Rikkyo University, Nagoya University, Chiba Institute of Technology, Meiji University, University of Aizu, AIST.)
Hayabusa2 project
2019.04.03 (Translated 2019.04.04)
