Yeah, misunderstanding on my part about what they were talking about early
in the test flight. It was an Interface Control Document for the Atlas and
the Starliner, or coding error, grabbing the wrong variable for Mission
Elapsed Time. So Starliner switched into some later testing mode and
maneuvered to the wrong attitude instead of finishing it's insertion into
Rendezvous Orbit and timeline. But that still doesn't explain the
propellant consumption of Starliners, I think I heard 25% used. Missing the
beginning of the rendezvous sequence, doesn't mean they can't rendezvous,
they were essentially in the proper orbit. If they had reacted faster, they
could have entered a different but longer rendezvous sequence and still met
Boeing's ?Contractual Requirement? to Dock with the ISS to receive this
?milestone payment?.
Post-flight conference, the Washington post guy.
https://youtu.be/dAPgTckPzOM?t=821
Milestone not met, try again Boeing.
My money is on nasa giving Boeing a pass, because this news conference
looked more like NASA's old way of doing business with Boeing than a
commercial endeavor.
On Sat, Dec 21, 2019 at 11:35 AM Ian M. Garcia <ian@xxxxxxxxxxxxx> wrote:
Craig,
What happened to Starliner is (probably) what they claim. The gains were
not wrong. It was the wrong burn mode and used the fuel that was expected
for that mode. This is pretty standard and no this is not a forgotten
lesson.
ian
--
Ian M Garcia
*From: *Craig Fink <webegood@xxxxxxxxx>
*Sent: *Saturday, December 21, 2019 11:40 AM
*To: *arocket@xxxxxxxxxxxxx
*Subject: *[AR] Re: LEO radiation shielding
Speaking of Control Systems, fresh out of College, with my first real job
working GN&C on Space Shuttle I was assigned to help with the On-Orbit post
flight report for STS-1 and STS-2. One of the problems these first few
flights was in attitude control, the gains were wrong resulting in
excessive fuel usage. Essentially, banging back an forth from positive
limit to negative limit, hosing out propellant. Things haven't changed much
in 40 years with Starliner as the NASA administrator is talking about the
problem.
https://youtu.be/NpQlxN4xbKM?t=85
Here he's saying the attitude tried to maintain "to precise" an attitude
window, which isn't the problem, it's the gains were wrong. The precise
tolerance just means it takes much less time to get from the +side to the
-side, so it hosed fuel out faster. But even with a very loose attitude
window, if the gains are wrong, it's going to be banging back and forth
(+-+-+-+-+-+ firings) from one limit to the other.
--
Craig Fink
WeBeGood@xxxxxxxxx