The Pod Bay

XKCD

05:23

Seventh year: Perfectly coherent words, but in the pet's language, not mine.

Vedant Chandra

10:40

Test hasn't been scrubbed yet, it's happening on Monday, 7 AM HST.

called2voyage

13:37

@VedantChandra When I last checked, they hadn't released the time yet. I'll update the event now.

Vedant Chandra

Sure :) It's 1 PM EDT @called2voyage

I'll post links myself 15 minutes prior.

called2voyage

thanks

Vedant Chandra

15:40

Just our luck, the launch is at the exact same time as WWDC!

Shouldn't be a problem though, the first three hours of the launch are rather dull, just the balloon ascending to the stratosphere.

Stack Exchange

16:07

NASA Image of the Day: Samantha Cristoforetti Prepares For the Journey Home

posted on June 08, 2015

ESA astronaut Samantha Cristoforetti checks her Sokol pressure suit in preparation for the Expedition 43 crew's departure from the International Space Station after 6 1/2 months in space. Cristoforetti now holds the record for the longest single spaceflight for a woman, a record previously held by NASA astronaut Sunita Williiams.

Vedant Chandra

16:43

Live Coverage of the Low Density Supersonic Decelerator Mars Landing Technology Flight Test in 15 minutes. More details on the LDSD: nasa.gov/pdf/737628main_Final_LDSD_Fact_Sheet_3-26-13.pdf

Links to watch the test LIVE at 1 PM EDT:

nasa.gov/multimedia/nasatv

ustream.tv/nasajpl2

youtube.com/watch?v=_Q5SQBC_e64 (preferred)

Tune in now, almost live!

It's begun! Happy viewing :)

duzzy

17:14

Thank you for the links.

geoffc

17:26

Marmac 304, with new wings, is replacing JRTI ASDS, and images recovered via Cruise-Stalker-Cam:

No name painted on it yet, so not sure if JRTI's brain was transplated, or is OCISLY, or a third name.

briligg

So as i understand it, once launched it will take between 2 and 3 hours for the LDSD test equipment to be at the right altitude. It has to get to the right height, and also be far enough out over the ocean, and it could drift in a less than ideal direction at times, making the time to correct position unpredictable.

geoffc

marmac 300 is now retired, wings cut off, and on deck of Marmac 303, expected to traverse the canal sometime soon.

briligg

they replaced the whole main barge? what, did they adjust the positioning equipment?

geoffc

New bow/stern walls. Much less gear on deck. Theory is they moved a lot below deck. And enclosed the wings. More space for stuff.

briligg

what is the term - the motors to keep the deck level

Hennes

17:32

@briligg True. And last years flight pattern was interesting.

geoffc

The thrusters. Thrustmaster brand. (That company must love when they get a call fro mSpaceX. Ya, we burned up one of your units, our rocket crashed into it again).

Hennes

(shown in the NASA briefing about a week ago)

geoffc

You should see the blue drive shafts sticking down, so looks like they are not currently installed. As far as I can see.

Hennes

Oh, speaking about last year. I just beat it a few seconds

geoffc

@briligg Marmac is the 'brand'. 300, 301 (not known where it is), 302, 303, and 304 are specific instances of the brand model.

So Marmac 300 was the original ASDS, with wings added. Those have been clipped off, for use on Marmac 303, which is expected to be towed through the canal to be the Pacific coast ASDS. (Maybe named OCISLY, "Of Course I Still Love You").

Marmac 304 had more work done it, clearly, and after 300 was towed to Louisiana they presumably transferred the equipment that makes sense to 303 and 304, and brought 304 back. 300 is supposedly being retired. It had a long and active career before ASDS duties. There are some great pics of 300 doing its duty over the years.

briligg

17:35

why would they have abandoned the original barge instead of modifying it? It didn't take that much damage, did it?

geoffc

But the cruise cam has departed. Won't be back till next week. Still have 18 days till next attempt to catch a stage.

Vedant Chandra

@briligg Yes, it's about three hours till it reaches it's altitude. I'll ping you guys here when they're nearing that point (if I'm still awake ;))

briligg

ah, okay, old...

geoffc

@briligg The theory is, they had been working on upgrades. Deployed on 304 first. Then will be applied to 303, but they needed the wings from 300.

(Also a theory that the 300 is registered with coast guard as an experimental vehicle, not as a production vehicle, and it was easier to change barges with a new registration. Some debate on this theory though).

Vedant Chandra

Haven't even released the LDSD yet, balloon is not done inflating.

geoffc

17:38

There seems to be no proof that the 2 failed landing attempts damaged 300 sufficient to abandon it. Rather the new stuff was being built to replace it

briligg

@VedantChandra cheers, Vedant. But i'll set an alarm to check in, i starred the link so i can get back to it quickly. You're far from needing to keep yourself looking youthful, but it's never to early to start. :)

Vedant Chandra

@briligg Hahaha thank you! Launching now.

And we're off.

It's just majestic! I wonder where Mark Adler is, I didn't see him during the pre-launch footage.

briligg

wouldn't he have been out at the field?

^yeah, there is a considerable difference between the original JRTI deck and the new one.

LocalFluff

19:09

At what time is this LDSD-thing supposed to be dropped? I'd like to watch it live, but I'm on a low bandwidth diet right now and need to time the stream.

Vedant Chandra

Live broadcasting will resume at 4:15 EDT.
The drop will happen soon after.

Come back after about an hour :)

Don't sit idle though everyone, stay in the mood with this hour-long presentation from Mark Adler at NASA JPL about the development of the LDSD and their rational for its design:

NASA | Low Density Supersonic Decelerator [HD]

►

It's priceless seeing Mark try not to giggle when a lady asks him about "orbaatical decay" ;)

Update for those not watching; the LDSD is more than halfway up, at 80,000 feet.

Rory Alsop

19:47

@VedantChandra damn - I'm going to just miss it then - got to pick up the kids from Air Cadets

Vedant Chandra

@RoryAlsop I'll post links to the recording as soon as it's out, I'll tag you.

Rory Alsop

@VedantChandra you're a star - thanks man

Vedant Chandra

Also, your children go to Air Cadets? I salute you as a wonderful father :)

Rory Alsop

@VedantChandra well - my eyesight was too bad to be a fighter pilot like my dad, and a fighter/helicopter pilot like my brother, so my kids are getting the benefit - keen glider pilots already

I get to live vicariously through them :-)

Vedant Chandra

@RoryAlsop WOW, wish them the very best!

Update 2: LDSD Test Vehicle now at 100,000 feet, only 20,000 feet to go. Going on course as predicted, very mild deviation from the predicted path. Heading 271º at 27 knots. Live broadcast should continue in half-an-hour.

Nick T

19:58

so is the purple line the predicted path?

how are they predicting balloon flight so closely...or does the track keep updating based on current information/position

Vedant Chandra

As far as I know they don't have visual contact with the balloon anymore but they're maintaining telemetry readings of it's position in 2-D space. Combined with an altimeter, it'll give a pretty accurate reading of it's position. @NickT

The prediction is actually based on weather data from last night!

So they're pretty good at what they do ;)

Nick T

The purple line looks like it's moving around, so it seems like prediction/extrapolation from current position

Vedant Chandra

It looked pretty solid to me :/ Either way, the LDSD is very close to the predicted path calculated last night.

Nick T

feed back back back back back back

briligg

:D

looks like we are getting some inside glimpses...

Vedant Chandra

20:11

Hahahaha do they know they're broadcasting this?

briligg

don't think so...

Nick T

why's the balloon descend, the gas cooling off, it being vented, leaking...?

briligg

do you mean after the payload is released and it is just drifting on its own?

Vedant Chandra

@briligg I'm pretty sure the balloon will explode on it's own after a certain altitude.

Pressure outside will get too low.

Nick T

no, someone over the radio is saying "balloon now descending through XXXX feet"

briligg

20:20

i'm going to guess they just misspoke or the radio wasn't clear

Nick T

the readout shows it descending

maybe just bouncing around

Vedant Chandra

Broadcast resume time has been pushed back to 5 PM EDT.

briligg

Over the radio they just estimated drop time as 21:35, in whatever the reference timezone is...

Nick T

and drop time of 21:35 UTC (5:35 P ET, 4:35 P ET, 2:35 P PT)

briligg

ah was it UTC?

Nick T

20:27

yeah

probably can go do an errand before then...hmm

briligg

right - i'm shuffling between screens, sorry for being behind. it's all there in black and white... :P

Vedant Chandra

Hmm data is back, it's at 120,000 feet and descending..

I hope nothing's wrong.

briligg

i'm actually enjoying the chatter

Vedant Chandra

Ah it's rising again.

briligg

maybe there is a delay in the broadcast where i am, or in different places

for me the readout shows it just cleared 120,000 ft

aand yeah, now it's dipped again

Vedant Chandra

20:32

@briligg It's definitely high enough, I think they're keeping it level till drop time.

Just a guess.

briligg

they can do that?

maybe it was designed to be in equilibrium at that altitude

that would make sense.

Nick T

Yeah, it's a pretty simple balloon, passive control

Vedant Chandra

Yes perhaps the balloon was designed to expand to a stable state at that altitude.

briligg

they seem concerned about air temps

Nick T

no use in bothering with balloon-in-balloon if you just need to go up to some altitude

I think stratospheric air temp is pretty stable

briligg

20:35

there was chatter about it

Vedant Chandra

Is there a problem with the test?

Drop in one hour.

briligg

they mentioned two sensors with readings of -20 and -30 degrees, didn't catch units. they mentioned that as an issue, but the guy informing just said he was making them aware. so at least it isn't a good thing, but that doesn't mean it will cause trouble.

Vedant Chandra

Then he said, "Drop T-minus one hour, all systems green"

Seems to be on track (phew)

briligg

break time :D

Vedant Chandra

@briligg It's 2 AM here, I don't want a break time!

Drop time: 2135 UTC (5:35 PM EDT)

briligg

20:58

i hope we hear all the power up routine instead of going back to the more general banter of the hosts or anchors that were on earlier.

Vedant Chandra

@briligg Yeah I much prefer the raw chatter.

The banter is back!

briligg

darn...

Vedant Chandra

Just going through the mission again. Still half an hour to drop right?

briligg

yeah, i didn't hear any change...

Vedant Chandra

Hah

She just said the same thing.

briligg

21:03

frog... hehe

Vedant Chandra

Stop thanking frog you guys, go back to the banter.

Thank you frog, btw ;)

Rory Alsop

21:17

Yay - I'm back and I haven't missed it

is the youtube link the best one to use

briligg

i'm getting good results with ustream

with the spacex launch, the youtube stream had a delay of close to 10 seconds

Rory Alsop

youtube is 4 seconds ahead right now - just done a side by side

:-)

Vedant Chandra

I'm using YouTube, best for me.

briligg

oh heck

Vedant Chandra

@briligg @NickT @RoryAlsop @LocalFluff @geoffc @Hennes @duzzy @BrianTompsett-汤莱恩 @DavidFreitag PING!!! Tune in now, coverage has resumed on the LDSD Test Launch. Drop is imminent! 15 minutes to go.

Rory Alsop

21:22

:-)

briligg

hehe, had that prepared did you?

duzzy

:)

It would be so cool to be there.

briligg

you'd want to be up on the roof of the hangar with 'Frog'. He's got the big camera tracking the balloon.

Rory Alsop

@briligg I think I just missed the frog chat

briligg

He was thanked when the hosts came back on for managing to track the balloon from the ground and maintaining a video feed of it.

LocalFluff

21:26

"We're about 11 minutes out now", a voice just said on the NASA stream.

Vedant Chandra

@LocalFluff Bang on time. Shame Tildal isn't here.

Would've been AMAZING if Mark was here ;)

briligg

heehee

Vedant Chandra

Noo the banter.....

LocalFluff

Tidal and Mark are probably sitting on top of that inflatable dropped thingy. R.I.P.

Vedant Chandra

@LocalFluff HAH front row seats!

duzzy

21:33

lol

geoffc

@LocalFluff I would feel safer inside a Dragon capsule, than on top of the LDSD or balloon.

Vedant Chandra

Drop in 60 seconds.

Nick T

FIRE WORKS GO GO GO PEW PEW

geoffc

Will this be as cool as the Dragono pad abort?

(That one was really hard to top).

briligg

system is armed...

LocalFluff

21:35

@geoffc Of course. But space exploration doesn't care much about what you feel is safe.

Nick T

5..4....3.....2.....1

Star 48 burning

Vedant Chandra

Wooooooo

duzzy

That is so cool.

geoffc

Spinning for stability,.

Vedant Chandra

That's one hell of a rocket..

Nick T

21:36

fairly high acceleration

1010 m/s?

geoffc

V sub T. Terminal velocity, not acceleration.

briligg

i'm surprised by the wobble.

geoffc

@VedantChandra Star seems like the most common Solid booster you can buy in the US as a third/upper stage.

Vedant Chandra

SIAD deployed.

Out comes the balute.

Nick T

asplod

briligg

21:38

the moment of truth

Nick T

shreded

duzzy

awww

LocalFluff

Impressively how easily they stabilize a spin of 50 or so round per seconds.

briligg

ooohhhhhh

Vedant Chandra

Ohhhhhh damn

briligg

21:39

awww, look at them all so silent

Vedant Chandra

At least the new, larger SIAD was successful.

briligg

anomaly 1, moving ships for intercept

Nick T

is this siad larger?

briligg

yeah, i also thought they'd said they wouldn't test that until later.

geoffc

Always amazing how well Soyuz and Dragon parachutes work on deploy. So much depends on it, and they pretty much always work. (One Soyuz failure?)

Nick T

21:40

looks similar to the last, doesn't look like the bigger of the two variants

Vedant Chandra

@NickT I seem to remember Mark saying that it's the larger one.

Could be wrong.

Nick T

@geoffc subsonic parachutes have had a long period of development

Rory Alsop

I had the kids in watching - and there was a simultaneous "Awwww no..." :-(

We were asking why they didn't have a couple of chutes - and the option to jettison and test a second one

briligg

it's going to come in hard. but it handled that fine last time right?

Nick T

yea, same ripped chute last time

Rory Alsop

21:41

@briligg what's expected splashdown velocity?

Vedant Chandra

@RoryAlsop I JUST had that thought! Why not?

briligg

i'm just basing that on it not having a chute now, is all

Vedant Chandra

Why does the SIAD look so loose and wobbly?

briligg

getting the chute to deploy correctly was one of the big challenges

it's moving awfully fast through air denser than it was designed for

Vedant Chandra

It looks deflated

Nick T

21:44

I think the vehicle is pretty light (so some of the acceleration loads are higher for the test than would be expected on an actual vehicle)

briligg

it wasn't supposed to have to sustain these speeds, at this density. it may have still fulfilled mission parameters

geoffc

@NickT And yet every parachuter carries a spare. :) I am always amazed at how well they work. It is great, but so scary to rely on.

briligg

the ballute, the cannon for chute deployment, doing that for two chutes must have been too problematic

Vedant Chandra

Ahh see, the SIAD has deflated.

Back to the drawing board for the chute.. Next launch will be next year this time right? Can they do winter launches?

Nick T

the parachute seems to inflate in an instant; if two were side-by-side it might get all crazy

briligg

21:48

Rory had mentioned the idea of a spare in case the first didn't deploy correctly, that was the thing about two

Rory Alsop

@NickT I was envisioning the same setup a parachutist has. Deploy one - if it fails, jettison and deploy reserve

Vedant Chandra

When is the press conference again?

I heard 1 PM EDT tomorrow.

briligg

3

Q: How far can the supersonic parachute in the LDSD system for Mars be placed from the entry capsule?

In this interview on NASA Edge Ian Clark, principle investigator for the Low Density Supersonic Decelerator, talked about the environment the parachute part of the system has to operate in: Parachutes are very fickle devices, particularly supersonic parachutes. When we have to use them like...

3

Q: Modelling for the LDSD parachute - what are the issues with scale models and software simulations?

The LDSD1 parachute is too large to test in any current wind tunnel, the only test possible on the ground was the rocket sled test. In this NASA Edge episode (starting at 15:12), Ian Clark talked about modelling the SIAD2, saying it is a rigid body and so scale models can be tested. Why aren'...

design parachute ldsd supersonic

^some relevant stuff mentioned in Mark's answers here

duzzy

I want to be on a recovery boat.

Vedant Chandra

Ah well successful or not, that was rather exciting. Now it's well past 3 AM here, I bid you goodnight. Thanks for checking in :)

briligg

21:52

@RoryAlsop in the first one he said the cannon to get the chute 10 vehicle lengths behind the capsule had to be large

duzzy

@VedantChandra good night.

LocalFluff

Was it the parachute that failed? Not the inflatable heat shield which was to be tested? Was it the shield or the test that failed?

briligg

@VedantChandra goodnight V

Rory Alsop

@VedantChandra night

duzzy

The parachute looked like it ripped apart as it deployed.

briligg

21:54

@LocalFluff the inflatable part on the capsule - the SIAD - deflated, but it wasn't supposed to enter the atmosphere at those speeds, the parachute was supposed to slow it. So i wouldn't call that a failure, it may well have been outside design parameters when it deflated.

but it isn't a heat shield, really. It is only supposed to decelerate the vehicle from Mach 4.5 to Mach 2.5 (in the test). Then its job is done. It isn't there for protection from heating.

Nick T

rocket sleds best rockets

:P

cheap, so you can do stupid things with them

briligg

@LocalFluff Actually maybe i didn't get you - the SIAD looked rigid until well after the parachute deployed, it was performing as expected. Later it deflated at high speed in thicker atmosphere.

LocalFluff

Trying to waft spacecrafts through the sky with lines and cloths, is sooo girly! And easily complicated and failed. The obvious solution is to simply land using fiery rocket power. That's why all boys love SpaceX.It's a survival instinct.

briligg

@NickT hehe that was beautiful

@LocalFluff well, maybe we can ask Mark how the system compares to retrorockets according to what is currently known.

or rather, ask on the site... i imagine he is busy now and probably wouldn't get to it for a bit

you've been pretty busy asking questions for a while now, i've noticed.

does that one suit your fancy?

LocalFluff

22:56

@briligg So Mark, here, is entangled in parachutes? That's brave! Valiant. And hard. But the parachute was only used to help test the inflatable heat shield (the last component I could imagine be inflatable). I do think that some retro rocket bursts could've helped out, and that they will soon be a mandatory complement to parachutes.

And yes, I do ask questions like a 4 years old. Is there something wrong with that here?

briligg

23:48

@LocalFluff yep, our own Mark Adler is the head of the project. Both the inflatable and the parachute are being developed for use on a Mars mission.

Mark Adler, Southern California

16.6k 1 28 66

orbital-mechanics mars orbit trajectory nasa probe launch

@LocalFluff no, we need questions. you have managed to ask a bunch of interesting ones. it's appreciated.

Transcript for