Thread by @ltelkins

Here's what happens after launch! An epic thread...

@MissionToPsyche is ready to go, soon as weather gives us a break! The attempt on Fri. Oct. 13 (my big brother's bday, along w a great friend at SpaceX on Psyche team, so VERY good luck) is 10:19:43 AM East. time. (1/n)

The "launch phase" began on day L-3 (Oct. 9) w/ launch load of parameters and final spacecraft configuration.
On L-2 we had our formal Launch Readiness Review (500 people!). On L-1 lots of media events, an all-team meeting, & a looong weather discussion 🙄. And a family photo!

Launch Day!
Launch Team will be "On Console" (at their desks in mission ops) at T-8:30 hours (this will be ~2:30 AM local!) for the mission ops team in Florida, and T-4:00 for the mission ops teams in California.
Spacecraft (s/c) power on
Xenon heating begins...

Some things that could cause a launch hold...s/c not on internal power, xenon tank fluid is not above 27C, any of a million warnings or aborts from s/c or rocket.
Battery charging begins
launch day parameter load
T-00:27 – Transition to Internal Power
T-00:00:00 – Lift OFF

Liftoff T=0:00:00
Main Engine Cutoff T + 0:03:54
Core separation T + 0:03:58
Second Stage Engine 1 start T + 0:04:04
Fairing jettison T + 0:04:16
Second Stage Engine 1 Cutoff T + 0:08:24
Second Stage Engine 2 start T + 0:54:03
Second Stage Engine 2 Cutoff T + 0:56:12

Psyche s/c deployment (Separation, or SEP) T + 1:02:24!

Hoping for no rotation for Psyche s/c at tip-off, to make the s/c's next autonomous tasks quicker.

After the Psyche s/c separates from the rocket, the s/c will power up its miniature inertial measurement unit (MIMU) to sense if the s/c is rotating. The MIMU will help the s/c stop any rotation before deploying solar arrays.
Here is 1 of our 10 beautiful solar panels.

The s/c is not pointing intentionally yet, but as soon as SEP+5.5 the DSN might catch a carrier wave signal as our low-gain antennae sweep during s/c rotation. As our launch lead Travis says: "we’re really close to Earth, the spacecraft is yelling, and DSN is sensitive."

S/c then autonomously stops any rotation, begins to warm up comms system, releases and deploys +Y side solar array, stops any new rotation, and then deploys the -Y side solar array.

De-rotation and solar array deployment should be complete by SEP + 21 min. Deployed arrays make the s/c 7.3 x 24.7 m.

Then s/c autonomously starts to spin around s/c long axis to search for Sun. Once Sun is acquired, slew to Sun, start "rotisserie mode" which is spin like a windmill around the axis towards the Sun (+X axis).

This should all be complete at some point between SEP +42 min and SEP +70 min, depending on how much rotation the s/c has to make before its sensors encounter the Sun.

Once the s/c has acquired the Sun, it will enter a planned safe mode to await ground comms intervention.

During this safe mode, Psyche will be spinning in rotisserie mode, and looking for Earth with a low-gain antenna.

It could therefore take up to nearly 3 hours after liftoff (or about 2 hours after SEP) for engineers to acquire the first signal from Psyche...

...because:
- SEP+21 min for solar array deploy;
- longest time to acquire the Sun is SEP+75 min, and then rotisserie starts;
- if at rotisserie start Earth is just past then we wait 30-40 min for the rotisserie to go all the way around & encounter Earth; around SEP +115.

The launch phase ends when the spacecraft is in safe mode. The project then continues with "Countup" (as opposed to Countdown) and transition to Nominal Mode 1 to 2 days after separation from the rocket (L+1 or 2 days)



GO PSYCHE!!jpl.nasa.gov/images/pia2493…