SpaceX Dragon 2 Updates and Discussion - Thread 3

[QuantumG]

https://twitter.com/elonmusk/status/1181585837869297664

All hardware is at the Cape. Need to do static fire and reconfigure for flight. Launch probably late Nov / early Dec.

edit/gongora:  This is for IFA

[gongora]

Can anyone summarize what SpaceX is working on for Dragon 2? and where?

My understanding is that the in-flight abort hardware is done, sitting at the Cape, awaiting the next test.

The DM-2 hardware is "done" awaiting results from the in-flight abort test - and may be at the Cape already, but it probably in holding at Hawthorne.

Parachute qualification and abort system qualification are the two big ones that we know about publicly.

[QuantumG]

Parachute qualification and abort system qualification are the two big ones that we know about publicly.

https://twitter.com/elonmusk/status/1181584415362707456

[gongora]

Parachute qualification and abort system qualification are the two big ones that we know about publicly.

https://twitter.com/elonmusk/status/1181584415362707456

Which sounds to me like they're switching parachutes, which will need to go through some testing, preferably before IFA.

[eeergo]

The subsequent tweet is worth including as well.

https://twitter.com/elonmusk/status/1181584415362707456

We had to reallocate some resources to speed this up & received great support from Airborne, our parachute supplier. I was at their Irvine factory with the SpaceX team on Sat and Sun. We’re focusing on the advanced Mk3 chute, which provides highest safety factor for astronauts.

Echoes of a year ago, almost to the day: https://spacenews.com/first-spacex-commercial-crew-flight-test-could-slip-to-2019/ (Oct 3rd, 2018)

SpaceX: "'We’re hoping to do a test flight of Dragon 2 in December [2018], and then a crewed flight next year [2019], hopefully in the second quarter of next year', he said"
Boeing: "Ferguson said he expects NASA to make a decision on extending the Starliner crewed test flight by next spring. 'We’re certainly on track to fly mid-next year [2019] if called upon', he said"

[whitelancer64]

Parachute qualification and abort system qualification are the two big ones that we know about publicly.

https://twitter.com/elonmusk/status/1181584415362707456

Which sounds to me like they're switching parachutes, which will need to go through some testing, preferably before IFA.

Some (or maybe even all) of that testing has been done, though. This parachute issue has been going on for a long time now.

[envy887]

How many Draco thrusters (not Super Draco) are on the newest version(s) of Dragon?  There used to be 18 (three banks of six).  I think there are now fewer.

IIRC there are 4 Dracos in each SD thruster pod, for a total of 16 on the vehicle.

[gongora]

How many Draco thrusters (not Super Draco) are on the newest version(s) of Dragon?  There used to be 18 (three banks of six).  I think there are now fewer.

IIRC there are 4 Dracos in each SD thruster pod, for a total of 16 on the vehicle.

Isn't it 3 next to each SD pod, and 4 under the nosecone?

[FutureSpaceTourist]

https://twitter.com/spacecoast_stve/status/1181649637519872000

Looks like some testing/training going on in Port Canaveral with the Crew Dragon test article. Perhaps we’ll see some official photos from up close in the coming days.

[FutureSpaceTourist]

https://twitter.com/erdayastronaut/status/1181584867492077569

What’s the biggest difference between the cargo chutes and crew dragon chutes (besides number)? Seems like the cargo chutes have been plenty reliable!

twitter.com/aero_johng/status/1181585423476219904

I'd assume it's the safety factor, cargo chutes likely have more tolerance of margins. Higher safety rating needed for crewed missions.

https://twitter.com/elonmusk/status/1181781021785653248

Yeah

[FutureSpaceTourist]

https://twitter.com/jeff_foust/status/1181963225081905152

Benji Reed of SpaceX says that, when the company switches to a Crew Dragon variant for CRS2 cargo missions next year, the vehicle will be able to cary 30% more pressurized cargo than current Dragon 1, and be able to stay at the ISS for up to 75 days. #ISPCS2019

https://twitter.com/jeff_foust/status/1181964246642384896

Reed: investigation into April static-fire anomaly involving Crew Dragon “almost compete” and already incorporating changes. Both the spacecraft and F9 for the in-flight abort now in Fla. #ISPCS2019

Edit to add:

https://twitter.com/jeff_foust/status/1181964806363873280

Reed: have done more than 25 parachute tests for Crew Dragon so far, and “continue to do many more.” Learning a lot with NASA and the overall parachute community. #ISPCS2019

[Asteroza]

So the 10 weeks bit I assume applies only to IFA flying in mid December then? Not including DM-2? Or is DM-2 really ready to go, and assuming IFA is good, and the requisite NASA telemetry analysis time lag before they give their OK, DM-2 could be quite soon after?

But with the end of year holidays coming up (range downtime around then too?) there is a simple scheduling risk that IFA might not fly before the end of the year even though all the hardware and certs are in place? Which pushes back DM-2 as well...

[Johnnyhinbos]

I’m perplexed by something I keep hearing in the media, from NASA, and echoed on this forum.

I keep hearing things to the effect that SpaceX can’t fly crew to the ISS until the IFA (successfully) completes. Bridenstine has even mentioned the IFA in such a light.

But I didn’t think conducting an IFA is a requirement for sending crew to the ISS. Boeing isn’t even doing one. SpaceX opted for it on their own. Hypothetically couldn’t SpaceX back out of the IFA altogether and still meet the contractual requirements to fly crew? It seems like the IFA has somehow become baked into the approval for DM2. If that’s the case wouldn’t that requirement then also extend to Boeing?

I must be missing something.

[cebri]

I’m perplexed by something I keep hearing in the media, from NASA, and echoed on this forum.

I keep hearing things to the effect that SpaceX can’t fly crew to the ISS until the IFA (successfully) completes. Bridenstine has even mentioned the IFA in such a light.

But I didn’t think conducting an IFA is a requirement for sending crew to the ISS. Boeing isn’t even doing one. SpaceX opted for it on their own. Hypothetically couldn’t SpaceX back out of the IFA altogether and still meet the contractual requirements to fly crew? It seems like the IFA has somehow become baked into the approval for DM2. If that’s the case wouldn’t that requirement then also extend to Boeing?

I must be missing something.

Keep in mind that SpaceX is doing the IFA test to prove compliance with a NASA requirement. If they ditch the IFA test, they would still need to come up with an alternative way of proving their system meets NASA safety standards.

From the CCP requirements document:

4.3.3.1.4 Ascent Abort

The continuous launch abort capability requirement shall be verified through test and analysis.
Safety Analysis establishes the failure initiators and the time period(s) during ascent for which
they are credible. The tests shall determine the performance of the detection system, abort logic,
and abort flight systems. Analysis shall include verified 6DOF simulations, including
appropriate modeling of all systems affecting vehicle and launch abort dynamics, along with
their uncertainties for all appropriate flight phases. The Monte Carlo will insert the launch
vehicle failures in a random fashion, uniformly through-time, throughout the ascent trajectory.
Note – failure initiators can be selected assuming a uniform probability distribution during the
time periods for which they are credible or based on documented probabilistic analysis. The
Monte Carlo will simulate the spacecraft's entire abort trajectory from abort initiation through
landing location or achievement of a stable orbit (for abort-to-orbit cases). This includes vehicle
rotation rates during launch vehicle loss of control and changes in acceleration due to launch
vehicle loss of thrust. The abort capability shall be considered successful for each analysis if the
aborting spacecraft demonstrates controllability, no near-field re-contact with the launch vehicle,
increasing spacecraft inertial velocity during abort motor burns that initiate during transonic
(max spacecraft drag) and high dynamic pressure conditions, operation within: hardware thermal
constraints, human capability constraints, structural loads limits, and ability to achieve
acceptable landing. The verification shall be successful when a Monte Carlo simulation of the
required abort scenarios with environment, launch vehicle, and spacecraft dispersions, in time
bins no larger than 10s each, achieves a 95% probability of success with at least 90% confidence
for each time bin throughout the ascent profile. This does not cover assessment of catastrophic
conditions assessed by the LOC analysis in requirement 3.2.1.1.

See CCT-STD-1140, "Flight Mechanics and GN&C Technical Assessment" section for technical
verification expectations pertinent to flight mechanics. [V.CTS.058]

[woods170]

I’m perplexed by something I keep hearing in the media, from NASA, and echoed on this forum.

I keep hearing things to the effect that SpaceX can’t fly crew to the ISS until the IFA (successfully) completes. Bridenstine has even mentioned the IFA in such a light.
...

Keep in mind that SpaceX is doing the IFA test to prove compliance with a NASA requirement. If they ditch the IFA test, they would still need to come up with an alternative way of proving their system meets NASA safety standards.

From the CCP requirements document:
...

Correct. If SpaceX ditched the IFA they would have to "prove" it the way Boeing does it: computer modeling.

[Nomadd]

https://twitter.com/jeff_foust/status/1181963225081905152

Benji Reed of SpaceX says that, when the company switches to a Crew Dragon variant for CRS2 cargo missions next year, the vehicle will be able to cary 30% more pressurized cargo than current Dragon 1, and be able to stay at the ISS for up to 75 days. #ISPCS2019

 Would the extra cargo capability be because of extra fuel capacity, or structural reasons? Or is he talking volume?

[mn]

I’m perplexed by something I keep hearing in the media, from NASA, and echoed on this forum.

I keep hearing things to the effect that SpaceX can’t fly crew to the ISS until the IFA (successfully) completes. Bridenstine has even mentioned the IFA in such a light.
...

Keep in mind that SpaceX is doing the IFA test to prove compliance with a NASA requirement. If they ditch the IFA test, they would still need to come up with an alternative way of proving their system meets NASA safety standards.

From the CCP requirements document:
...

Correct. If SpaceX ditched the IFA they would have to "prove" it the way Boeing does it: computer modeling.

And I have no doubt the computer modeling has already been done. (though perhaps not to the extent NASA would require if they weren't doing the IFA)

[whitelancer64]

I’m perplexed by something I keep hearing in the media, from NASA, and echoed on this forum.

I keep hearing things to the effect that SpaceX can’t fly crew to the ISS until the IFA (successfully) completes. Bridenstine has even mentioned the IFA in such a light.

But I didn’t think conducting an IFA is a requirement for sending crew to the ISS. Boeing isn’t even doing one. SpaceX opted for it on their own. Hypothetically couldn’t SpaceX back out of the IFA altogether and still meet the contractual requirements to fly crew? It seems like the IFA has somehow become baked into the approval for DM2. If that’s the case wouldn’t that requirement then also extend to Boeing?

I must be missing something.

It is a requirement, SpaceX cannot just decide to not do it. It is one of the CCiCap milestones proposed by SpaceX, and accepted by NASA, therefore it is a requirement for SpaceX to do it, in the same way that Boeing's pad abort test is a requirement for them.

NASA did not require any abort flight tests (as posted by cebri), but the CC providers have chosen to do them. SpaceX did not have to propose an in-flight abort test, but it did, so now it has to do it. Frankly, if I were the person at NASA in charge of making the requirements I would have made an in-flight abort test a mandatory milestone.

[gongora]

https://twitter.com/jeff_foust/status/1181963225081905152

Benji Reed of SpaceX says that, when the company switches to a Crew Dragon variant for CRS2 cargo missions next year, the vehicle will be able to cary 30% more pressurized cargo than current Dragon 1, and be able to stay at the ISS for up to 75 days. #ISPCS2019

 Would the extra cargo capability be because of extra fuel capacity, or structural reasons? Or is he talking volume?

Volume.

[gongora]

So the 10 weeks bit I assume applies only to IFA flying in mid December then? Not including DM-2? Or is DM-2 really ready to go, and assuming IFA is good, and the requisite NASA telemetry analysis time lag before they give their OK, DM-2 could be quite soon after?

But with the end of year holidays coming up (range downtime around then too?) there is a simple scheduling risk that IFA might not fly before the end of the year even though all the hardware and certs are in place? Which pushes back DM-2 as well...

The 10 weeks wasn't about IFA, it was about delivering DM-2 hardware to the Cape and hopefully finishing up testing on the hardware.  That doesn't mean it's ready to fly in 10 weeks.  After they finish up their testing they still need to finish going through the qualification process with NASA, which is probably at least a couple more months.