Moderators: richierich, ua900, PanAm_DC10, hOMSaR
Francoflier wrote:Welp, that didn't go well... not that anyone is particularly surprised at this stage.
https://spacenews.com/nasa-works-to-tra ... down-test/
After several aborted attempts at a wet dress rehearsal on the pad, the SLS assembly is being rolled back to the VAB to allow the crew to look for and fix a number of issues, mostly relating with leaks it seems, including a hydrogen leak detected during one of the propellant loading attempts.
In SLS' defence, it seems most issues are with the pad and support equipment rather than the rocket itself. The rocket is being rolled back mostly to avoid prolonged environmental stress on it, especially from the wind.
Nomadd wrote:It makes me think someone forgot about the basics in all the years they've been working on this thing.
744SPX wrote:Nomadd wrote:It makes me think someone forgot about the basics in all the years they've been working on this thing.
Wouldn't be surprised. I'm guessing we're probably looking at a month delay at least.
Avatar2go wrote:Just had a NASA teleconference, the rollback decision was taken because the nitrogen vendor asked for time to expand their pipeline capacity, which had been the source of delays on the earlier tests. They are looking at 3 options for completing WDR. Two of them involve double trips back to VAB, the third option is one trip with a combined WDR completion and launch. The first two would make the June 6 launch window challenging, with the next window on June 29th. The third option would preserve the June 6 window.
Eric Berger asked the question about loss of institutional knowledge, they said that they still have people from the shuttle days involved with Artemis. Also said that these problems (check valve and fitting leak) are expected for a first shakedown test. Wayne Hale has said this as well, if anything he thought they were too optimistic about how long WDR would take,
Nomadd wrote:The vendor waited till the stack was on the pad to tell them they were short on capacity?
zanl188 wrote:Artemis 1 is about to reenter the VAB as it rolls back for repairs.
LTEN11 wrote:zanl188 wrote:Artemis 1 is about to reenter the VAB as it rolls back for repairs.
Does it actually need repairs, or is it just the fueling system not being able to cope that's the problem here ?
Avatar2go wrote:LTEN11 wrote:zanl188 wrote:Artemis 1 is about to reenter the VAB as it rolls back for repairs.
Does it actually need repairs, or is it just the fueling system not being able to cope that's the problem here ?
The problem is that LiquidAire must vaporize additional stored LN2 in order to meet the purge demand for Artemis. For smaller vehicles such as Falcon and Atlas, the output of the air separator alone is able to meet the demand.
The vaporizers have been in place since the Shuttle era, so NASA did not expect problems with supply. LiquidAire knew the vaporizers were old so had added new units previously, but had not yet tied them into the pipeline that feeds NASA. So the downtime is to make that switch, from old to new vaporizers.
The issues on the Artemis side are a stuck helium feed check valve, which prevented loading of propellant into the ICPS, and will be replaced. And a small hydrogen leak in the platform mast umbilical plate purge can for the core stage. Both would be safety issues during propellant loading, so NASA decided to repair before next attempt.
Those repairs are probably a week or two at most. So they will try to complete some other launch preparation tasks during this rollback, while waiting for the LiquidAire GN2 upgrade. They have already completed most of the test objectives for WDR, but will repeat them until they complete the process end-to-end.
Avatar2go wrote:NASA will announce the winning vendors for the commercial EVA spacesuit competition, in a media conference on Wednesday June 1 at 2 pm ET. These are needed for the Artemis missions and to replace the aging suits at ISS.
They can't come too soon, as there now has been a second suit with a coolant water leak, and the number of working suits is dwindling. Also the remaining suits are not always the right size for the astronauts.
https://www.nasa.gov/press-release/nasa ... acewalking
FGITD wrote:
Your post led me to some interesting reading. I realize there have been updates but it’s almost hard to believe how long it’s been since there’s been any real change in the suits. Specifically the Russian suits. It really does seem like the Russians decided in the early to mid 70s that their space technology was as perfect as it’ll ever be.
I do think the commercialization of space has created better opportunity for diversification in equipment. Say NASA picks one suit, it doesn’t mean SpaceX won’t continue to develop their own. Would be a nice add on, buy a flight for 4 and get an EVA
Avatar2go wrote:6. Cubesat batteries recharged.
Avatar2go wrote:NASA has decided to preserve the one-suit concept for both ISS and lunar EVA's. This makes the suit essentially a small spacecraft, with 8 to12 hour endurance. The vendors have said they are pursuing modular designs that can be adjusted to the need at hand. Both waist entry and back entry will be available, and the size range will be adjustable from 5% percentile for women, to 95% percentile for men. All suits also will be compatible with a common spacecraft storage and recharge interface, on board the lander and ISS.
Like the xEMU program, those goals seem extremely ambitious, so it will be interesting to follow their progress.
TangoandCash wrote:
Wouldn't it make more sense to have two types of suits, one for ISS spacewalks and one for lunar activities? Seems to me (knowing very little about space suits) that those are two very different design requirements.
Avatar2go wrote:[...]Will be a difficult road ahead to decide on the best course of action and get this platform built. Options are cancellation, split the order between design and build, switch build to fixed-cost, or imposing NASA management accountability & improvements within Bechtel [...]
Tugger wrote:
OK, OK, probably more like 1 billion but still you get the idea.
Tugg
zanl188 wrote:Have we heard what caused the cutout at T minus :29?
Avatar2go wrote:From Artemis media conference today: as expected, target launch dates are August 29, backups on September 2nd and 6th. Rollout on August 18th.
In VAB:
-- Hydrogen leaks repaired, seals replaced.
-- Collet found loose on umbilical, entered engine section and tightened bolts.
-- Batteries replaced with flight versions
-- Flight Termination installation and testing
-- Orion cameras, Helga, Zohar, Moonikin installed
Artemis 1 Flight Objectives:
-- Heat shield test for lunar reentry (skip reentry)
-- Flight mode systems demonstration and testing
-- Radiation shielding & management
-- Recovery of Orion at splashdown
-- Certification of navigation & communication
-- Collection of imagery
-- Deployment of 10 cubesats
-- 42 day mission, lunar flyby and DRO
-- 2 burns for TLI (outbound)
-- 2 burns for TEI (inbound)
aumaverick wrote:I have a silly question...but with last year's SpaceX Dragon missions being (a-hem ) fouled by a malfunctioning space toilet, would an Artemis mission be in jeopardy if the new waste management system onboard could not be fixed? Apollo utilized a much more primitive method to deal with this, so is Artemis equipped for such a back-up situation?
https://www.nytimes.com/2021/11/10/science/spacex-toilet-diapers.html
Avatar2go wrote:aumaverick wrote:I have a silly question...but with last year's SpaceX Dragon missions being (a-hem ) fouled by a malfunctioning space toilet, would an Artemis mission be in jeopardy if the new waste management system onboard could not be fixed? Apollo utilized a much more primitive method to deal with this, so is Artemis equipped for such a back-up situation?
https://www.nytimes.com/2021/11/10/science/spacex-toilet-diapers.html
They have a full range of solutions on board, just like the ISS. They have the toilet, diapers, multiple urination devices (men and women). There is a small privacy area where astronauts can deal with personal needs. Obviously diet plays a large part, so the food is designed to minimize waste problems.
The worst case would be if the Orion crew capsule loses pressurization or atmospheric control, they can survive in their suits for 5 days to return to Earth. But that obviously would not be pretty. That's actually the largest medical risk they face. They would likely go to a liquid diet for that period.
The thing about NASA is that for any given function, there are backups to the backups. So the astronauts are pretty well prepared to deal with problems. The Orion training is much more extensive than commercial crew, where they can abort to earth at any time.
When Gateway comes online, that will provide another emergency option, as it also has all those services. It's interesting that the Orion life support system is designed to handle Gateway if needed, and similarly Gateway can handle a docked Orion. So they have full redundancy if docked. They only need to share consumables, and Gateway will have extra stores of that on board.
bajs11 wrote:Will Artemis 4 still be using the Block 1B SLS?