Commercial Crew Transportation Capability (CCtCap) SpaceX and Boeing developments

[MyJoule]

After a successful launch, Starliner fails to make proper orbit. This really sucks for manned space flight

Starliner suffers "off-nominal" orbital insertion after launch - SpaceNews.com

 

[mongo]

Per Scott Manley, Tweet has video link.

Starliner was pointed at 90 degrees to prograde while they were trying to perform insertion.

Twitter

 

[mongo]

Update

Twitter

Jim Bridenstine
@JimBridenstine
·
18m
Update: #Starliner had a Mission Elapsed Time (MET) anomaly causing the spacecraft to believe that it was in an orbital insertion burn, when it was not. More information at 9am ET:

NASA Live
nasa.gov

Jim Bridenstine
@JimBridenstine
Because #Starliner believed it was in an orbital insertion burn (or that the burn was complete), the dead bands were reduced and the spacecraft burned more fuel than anticipated to maintain precise control. This precluded
@Space_Station
rendezvous.

 

[Solarguy]

I think Elon should offer to send a Dragon up and offer a tow to the ISS

 

[ecarfan]

Per Scott Manley, Tweet has video link.

Twitter

Reading through that it sounds like this mission is a failure. It won’t be able to achieve ISS rendezvous. Is that right?

If so, this is a disaster for Boeing.

 

[mongo]

Reading through that it sounds like this mission is a failure. It won’t be able to achieve ISS rendezvous. Is that right?

If so, this is a disaster for Boeing.

No ISS rendezvous, used up to much fuel due to running tight tolerance position control.

They already tracked down the problem*, but this will require review and an additional flight (I expect).

* EDIT: They know the Mission Elapsed Timer was wrong, but they don't know why.

 

[Cosmacelf]

Brindenstein talking right now. Interesting that they had a communications blackout for a critical period when the second stage had to do their run. The craft was on auto, between satellites, and they couldn’t manually override the craft. SpaceX doesn’t seem to have that problem as they seem to have telemetry continuously?

 

[mongo]

Brindenstein talking right now. Interesting that they had a communications blackout for a critical period when the second stage had to do their run. The craft was on auto, between satellites, and they couldn’t manually override the craft. SpaceX doesn’t seem to have that problem as they seem to have telemetry continuously?

May be due to orbit. SpaceX 2nd stage puts the Capsule in the final orbit. Boeing was a shallower initial orbit to allow abort, followed by a Capsule burn to the ISS orbit.

 

[Cosmacelf]

May be due to orbit. SpaceX 2nd stage puts the Capsule in the final orbit. Boeing was a shallower initial orbit to allow abort, followed by a Capsule burn to the ISS orbit.

As may be but giving up continuous telemetry strikes me as a bad idea.

 

[Nikxice]

Another difficult day for Boeing. No one harmed, only a test. If the problem turns out to be a software issue we know where the comparisons will go.
A couple of months ago when Elon did his Boca Chica Starship presentation I got interested in comparing the differences between Dragon 2 versus Starliner. I was struck by the total number of rocket thrusters used by each spacecraft. The Crew Dragon has a total of 26. It has 8 SuperDraco engines for aborts and 18 Draco for attitude control, orbital maneuvering, and deorbiting.

Starliner is equipped with 4 for potential launch aborts, 20 to support orbital maneuvers, 28 for on-orbit maneuvering and ISS reboost, and finally 12 for atmospheric re-entry. A total of 64. Amazing number, necessary or just added complexity?

To quote Elon during his September TX presentation, "The thing I’m most impressed with when I have design meetings at SpaceX is, ‘What did you undesign?’ Undesigning is the best thing. Just delete it, that’s the best thing."

 

[RubberToe]

Some poor software developer and their associated test team is having a real bad day today. Someone is going to find the bad code in question and realize they cost someone a 9 figure problem.

And they have to figure it out before reentry so a similar clock change doesn't happen again.

RT

 

[ecarfan]

No ISS rendezvous, used up to much fuel due to running tight tolerance position control.

They already tracked down the problem*, but this will require review and an additional flight (I expect).

I wonder how many Starliner capsules Boeing has available.

Assuming the problem can be identified and fixed and NASA signs off on it within 3-4 months, Boeing will then need to repeat the mission with the capsule that they planned to use for their first manned mission, right? That repeat mission might occur mid-202 at earliest? And then their will be a review of that mission before their crewed mission.

This is a huge setback for Boeing.

If the Crew Dragon in-flight abort test next month is successful, SpaceX could launch their first manned mission 6 to 12 months before Boeing does.

 

[ecarfan]

I was struck by the total number of rocket thrusters used by each spacecraft. The Crew Dragon has a total of 26. It has 8 SuperDraco engines for aborts and 18 Draco for attitude control, orbital maneuvering, and deorbiting.

Starliner is equipped with 4 for potential launch aborts, 20 to support orbital maneuvers, 28 for on-orbit maneuvering and ISS reboost, and finally 12 for atmospheric re-entry. A total of 64. Amazing number, necessary or just added complexity?

Wow. I did not know that. That seems like a crazy high number of thrusters.

 

[mongo]

My highlights from the Q&A:
NASA saying too early to determine if it will require additional launch.
Could have commanded burn to reach ISS, if there had been satellite comms.
Had astronauts been on board, they could have also.

My general comment (echos of Elon)
Space is hard
This is why we test

 

[e-FTW]

Well, crap.

 

[mongo]

Further Q&A indicate they are not positive it was lack of coverage (TDRS) that caused Starliner to not respond to the ground initiated burn command.
Atlas V N22 - Starliner OFT (uncrewed) - 20 Dec 2019 (11:36 UTC) - UPDATES

 

[e-FTW]

Ars piece:
Starliner’s timer was off—capsule thought engines were firing when they weren’t — Ars Technica

Being in IT, the system clock is so often the cause of problems that I can relate...

 

[bxr140]

I was struck by the total number of rocket thrusters used by each spacecraft. The Crew Dragon has a total of 26. It has 8 SuperDraco engines for aborts and 18 Draco for attitude control, orbital maneuvering, and deorbiting.

That's not actually that unbelievable. Typically a boring 3 axis stabilized communications satellite will have 12 control thrusters on redundant systems, with nominal operations pretty much using combinations of all of them. I can imagine the superdraco's being redundant systems of 4 each, and I suspect that the finer and more time sensitive control maneuvers of a crewed capsule combined with the lack of other control actuators that the comms satellite has (like reaction wheels) are the reason there are quite a few Dracos.

 

[Nikxice]

That's not actually that unbelievable. Typically a boring 3 axis stabilized communications satellite will have 12 control thrusters on redundant systems, with nominal operations pretty much using combinations of all of them. I can imagine the superdraco's being redundant systems of 4 each, and I suspect that the finer and more time sensitive control maneuvers of a crewed capsule combined with the lack of other control actuators that the comms satellite has (like reaction wheels) are the reason there are quite a few Dracos.

No doubt SpaceX designed Dragon 2 with an optimum number of thrusters. The 64 thousand dollar question I have is why are there more than twice as many thrusters on Starliner? To meet the design requirements, added redundancy, or (not trying to be too cynical) Boeing had 1.8 billion $$$$$ more on development to spend than SpaceX.

 

[Bobfitz1]

Ars piece:
Starliner’s timer was off—capsule thought engines were firing when they weren’t — Ars Technica

Being in IT, the system clock is so often the cause of problems that I can relate...

Given how critical system clock is, do Starliner and Dragon have triple redundancy that would allow
two backups to over rule the main clock if it does not check out against the others?