Updates Boeing's CST-100 Starliner

[garyw]

So Starliner read the wrong time from Atlas V.

“Our spacecraft needs to reach down into the Atlas 5 and figure out what time it is.
:facepalm:

What? Why can't it have it's own clock?
It strikes me that Boeing just lost a mission all because they didn't put a clock on board. Damn!

 

[Urwumpe]

What? Why can't it have it's own clock?
It strikes me that Boeing just lost a mission all because they didn't put a clock on board. Damn!

I doubt that is the cause there. Usually the timers onboard a satellite are triggered from signals by the Atlas V, you can find them described in the Atlas V Users Guide (Chapter 5.2).



https://www.ulalaunch.com/docs/default-source/rockets/atlasvusersguide2010.pdf


Unless ULA did heavily modify the Atlas V for this mission, it should be mostly the same hardware in this flight as for satellites.



(Also, having a clock onboard the Centaur alone would be stupid since this clock would no longer be available after separation.)

 

[Kyle]

... so why can't they send a signal to the Starliner capsule to start the countdown clock at a given T-0? I understand why the satellite might not, but for a crewed capsule that would make more sense.

 

[GLS]

What? Why can't it have it's own clock?
It strikes me that Boeing just lost a mission all because they didn't put a clock on board. Damn!

But you still need to know when the vehicle launches, so that reference still needs to be set, either by a "start MET clock" signal or a "launch time signal" to then be able to calculate "at what time should I start the engines". :shrug:

Ouch...
[ame="https://twitter.com/thegrabster/status/1208487317658308609"]https://twitter.com/thegrabster/status/1208487317658308609[/ame]

 

[Notebook]

Boeing's Starliner commercial crew spacecraft is scheduled to land at White Sands, New Mexico, at 7:57 a.m. EST on Sunday, Dec. 22. NASA Television coverage will begin at 6:45 a.m. EST. At 10 a.m. EST (time subject to change) NASA and Boeing will hold a news conference to discuss the landing and the overall flight.

https://www.nasa.gov/

 

[IronRain]

Starliner targets early landing in New Mexico

A day after a timing error caused it to enter the wrong orbit and miss its objective of meeting up with the International Space Station, Boeing’s unpiloted Starliner crew capsule prepared for its next major test Sunday, when it will plunge back into the atmosphere and target a predawn landing at White Sands Space Harbor in New Mexico.

The commercial crew capsule, flying on its first space mission, is scheduled to land under parachutes in a remote corner of the U.S. Army’s White Sands Missile Range in southern New Mexico at 7:57 a.m. MST (5:57 a.m. MST; 1257 GMT) Sunday.

Approaching from the southwest, the 15-foot-wide (nearly 4.6-meter) spacecraft will deploy three main parachutes, jettison its head shield and inflate airbags to cushion its landing in the New Mexican desert.

A backup landing opportunity is available at White Sands at 3:48 p.m. EST (1:48 p.m. MST; 2048 GMT) Sunday.

 

[Thorsten]

If you need to fire lets say 35 seconds before apogee and switch to a finer attitude control mode 45 seconds before apogee, how would you solve this?

You ask Cortana or Siri of course :lol:

Personally, I go with the 'dumb' scheme by the clock rather than the AI-type scheme which tries to be situationally aware by itself - there's far more potential for things to go wrong in the smart computer than in the dumb one.

 

[Urwumpe]

You ask Cortana or Siri of course :lol:

"Siri, perform orbital insertion maneuver."
"I'm sorry, Dave. I'm afraid I can't do that."

 

[Notebook]

NASA TV is doing some run through about what should be happening in 30 minutes or so.

 

[GLS]

...still some RCS activity during the deorbit burn, but less than 2 days ago... :shrug:
Burn complete and SM sep!

---------- Post added at 12:49 PM ---------- Previous post was at 12:26 PM ----------

Maybe half-way thru entry, the vehicle is now tracked from the landing site.

---------- Post added at 12:50 PM ---------- Previous post was at 12:49 PM ----------

IR video of entry from a WB-57!

---------- Post added at 12:52 PM ---------- Previous post was at 12:50 PM ----------

Looks like it's not generating any more plasma, Mach 3.5 now. 6 minutes to landing.

 

[Urwumpe]

And more important, we see only one bright spot of light there, not multiples.

 

[GLS]

Forward heat shield deploy, droges chutes deploy.

---------- Post added at 12:55 PM ---------- Previous post was at 12:53 PM ----------

3 main chutes deployed!

 

[Urwumpe]

The main parachutes look much better now as during the last test

Base heatshield jettisoned

 

[GLS]

Base heat shield deployed (how many heat shields are there?!)

---------- Post added at 12:58 PM ---------- Previous post was at 12:56 PM ----------

Touchdown!

 

[Urwumpe]

The flickering after landing does not look too good. :blink:

 

[GLS]

The flickering after landing does not look too good. :blink:

It was doing that under the chutes, so it's probably a light beacon... :shrug:

---------- Post added at 01:01 PM ---------- Previous post was at 01:00 PM ----------

There was no puff/boom/things flying when it landed, so it "looked safe".

---------- Post added at 01:01 PM ---------- Previous post was at 01:01 PM ----------

Yeah, the guy talking at the landing site says he can see the strobe in the distance.

 

[barrygolden]

I did notice what looked like RCS firings during the 1 stage accent. Did hear where the timer was about 11 hrs off.

 

[Notebook]

https://www.bbc.com/news/science-environment-50855395

 

[4throck]

Well great that it landed "on land" That's not a small thing.

As for the clock, John Glenn comes to mind: "And the Clock has started"

 

[kerlix]

**DISREGARD** I heard that Starliner somehow pulled the wrong time from the computer in the Atlas, which caused the discrepancy.**

I would have thought that the capsules computers would have their own timers/clocks running in parallel with the Atlas and just do a quick comparison to verify reliability and accuracy of on-board systems before separation. Almost the same way the Shuttles GPC's polled each other to make sure everything was in order and, if not, throw a flag and say "Hey, something is wrong here. Please provide me with an update to verify which one of us is correct".


EDIT: Yes, I read it here. Several posts up. My apologies. I feel like a proper idiot now.

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