Author Topic: LIVE: JAXA CubeSat deployment from JEM (Read 63518 times)

Space Pete · « **Reply #40 on:** 06/22/2012 06:24 pm »

Quote from: Skyrocket on 06/22/2012 03:31 pm

Cubesats are generally cheap and are also pretty robust.

That may be - but cheap can still be cheaper by being less robust.

FYI, I've seen the lower vibration benefits cited by the project manager of a CubeSat being deployed from the JEM, so I'm not just making it up.

Quote

Competely wrong - there are few flights available to ISS, as the material delivered in the pressurized cargo vehicles to ISS is a limited resource (both in mass and volume). Every cubesat flown is flown at the expence of material, which can be used and is needed on ISS.

On the other side, there are now plenty of flight opportunities on upper stages, where real spare performance can be used without cutting the real payload.

So, let's say you have designed an Earth sensing cubesat that needs to go to 300km at 28 degrees, then get bumped from your ride. It may be a while until another rocket to that altitude and inclination comes round again.

However, by designing a cubesat for 400km at 51.6 degrees (ISS orbit), it won't be long to wait for another flight to that destination if you get bumped off a flight - meaning either less of a delay in event of development taking longer, or eliminating the need for a possible re-design for a different orbit (due to thermal considerations, orbital lifetime, etc).

With regard payload space on ISS flights - CubeSats would be considered science payloads - which have 50% of the space on all ISS flights. Although a CubeSat may take up space that could be used by something else, since science payloads are actually the purpose of the ISS, then the CubeSats would obviously take precedent - else you could say that all science payloads are preventing other science payloads or resupply cargo.

baldusi · « **Reply #41 on:** 06/22/2012 09:11 pm »

Wouldn't this allow for cubesats that carry experiments that are hard to protect from vibrations when assembled, but trivial if separated? Thus, would have astronauts doing some "final assembly"?

Danderman · « **Reply #42 on:** 06/22/2012 09:19 pm »

Quote from: baldusi on 06/22/2012 09:11 pm

Wouldn't this allow for cubesats that carry experiments that are hard to protect from vibrations when assembled, but trivial if separated? Thus, would have astronauts doing some "final assembly"?

I don't know if you want to open up CubeSATs inside the ISS.

Fuji · « **Reply #43 on:** 06/22/2012 11:57 pm »

I can tell you more background information.
- This deployment mechanism can handle more big satellite (other than CubeSat) in the future.
- Deployment operation is basically ground based (minimum crew resources).
- We have other piggy-back payload (Message in a Bottle #2), it isn't deployed and retrieved airlock.

Fuji · « **Reply #44 on:** 06/25/2012 11:51 pm »

Media event at Tsukuba Space Center.
Photos by Koumei Shibata

http://www.sacj.org/openbbs/

thuvt · « **Reply #45 on:** 06/30/2012 01:25 pm »

Here is JAXA's weekly news SPACE@NAVI-Kibo No 166, from 3:12 there are some footage of 5 CubeSats during the media event at Tsukuba Space Center on June 25. Perhaps this is the last time we can see them before they are loaded in the satellite deployer J-SSOD and placed on HTV-3.

jcm · « **Reply #46 on:** 07/20/2012 06:35 am »

So per the question I foolishly asked on the HTV-3 thread instead of here:
The two J-SSOD deployers go up in CTBs on HTV-3. Then they are mounted on the MPEP plate. Is the MPEP also carried up on HTV-3? Or is it already on ISS?

Space Pete · « **Reply #47 on:** 07/20/2012 02:27 pm »

Quote from: jcm on 07/20/2012 06:35 am

So per the question I foolishly asked on the HTV-3 thread instead of here:
The two J-SSOD deployers go up in CTBs on HTV-3. Then they are mounted on the MPEP plate. Is the MPEP also carried up on HTV-3? Or is it already on ISS?

The MPEP is also going up on HTV-3 - you can see it in the two attachments below. The two J-SSODs (the PPOD-like devices) are mounted to the MPEP, which includes a FRGF so that it can be grappled by the JEM RMS. The MPEP will mount directly to the JEM A/L slide table.

Danderman · « **Reply #48 on:** 07/20/2012 02:33 pm »

It's pretty clear that this is a test for a larger later deployment from the JEM airlock, using something like the MPEP. Does the MPEP represent the largest object than pass through the airlock?

AnalogMan · « **Reply #49 on:** 07/20/2012 03:35 pm »

I imagine many folks have already seen this paper - it gives a nice introduction to the concept.

Introduction of the Small Satellite Deployment Opportunity from JEM
3rd Nano-Satellite Symposium 12-14 Dec 2012 6pp

JEM Small Satellite Orbital Deployer (J-SSOD) is the small satellite launcher, which is capable of deploying CubeSats, 30-50cm class satellite, into the space from the ISS. This concept introduces new utilization of the JEM.

http://www.nanosat.jp/images/3rd/pdf/%5BNSS-03-0107%5D_Introduction_of_the_Small_Satellite.pdf

[copy also attached]

jcm · « **Reply #50 on:** 07/20/2012 11:06 pm »

Quote from: Space Pete on 07/20/2012 02:27 pm

Quote from: jcm on 07/20/2012 06:35 am
So per the question I foolishly asked on the HTV-3 thread instead of here:
The two J-SSOD deployers go up in CTBs on HTV-3. Then they are mounted on the MPEP plate. Is the MPEP also carried up on HTV-3? Or is it already on ISS?

The MPEP is also going up on HTV-3 - you can see it in the two attachments below. The two J-SSODs (the PPOD-like devices) are mounted to the MPEP, which includes a FRGF so that it can be grappled by the JEM RMS. The MPEP will mount directly to the JEM A/L slide table.

Yeah, I saw this image, but wasn't sure if this was the flight MPEP or a ground test article (since the MPEP isn't mentioned as a stowage item
in the HTV). The J-SSODs are attached to the MPEP by the crew after unloading of HTV.

Edit: Seems like the MPEP is too big for one of the HRR racks or CTBs but it must
be in the pressurized module somewhere.

Space Pete · « **Reply #51 on:** 07/20/2012 11:10 pm »

Quote from: jcm on 07/20/2012 11:06 pm

Yeah, I saw this image, but wasn't sure if this was the flight MPEP or a ground test article (since the MPEP isn't mentioned as a stowage item
in the HTV). The J-SSODs are attached to the MPEP by the crew after unloading of HTV.

I'm assuming it's a flight article, since the MPEP definitely isn't on ISS already, and the first CubeSat deployment is scheduled for November, so if the MPEP isn't aboard HTV-3, the only other way to get it up there in time would be via SpaceX CRS-1 - and I imagine the Japanese would prefer to fly their hardware on their vehicle.

jcm · « **Reply #52 on:** 07/21/2012 01:27 am »

Quote from: Space Pete on 07/20/2012 11:10 pm

Quote from: jcm on 07/20/2012 11:06 pm
Yeah, I saw this image, but wasn't sure if this was the flight MPEP or a ground test article (since the MPEP isn't mentioned as a stowage item
in the HTV). The J-SSODs are attached to the MPEP by the crew after unloading of HTV.

I'm assuming it's a flight article, since the MPEP definitely isn't on ISS already, and the first CubeSat deployment is scheduled for November, so if the MPEP isn't aboard HTV-3, the only other way to get it up there in time would be via SpaceX CRS-1 - and I imagine the Japanese would prefer to fly their hardware on their vehicle.

Makes sense. It was the 'definitely isn't on ISS already' I wasn't sure about - I was imagining it could have been standard JEM equipment that just wasn't interesting enough to get called out in previous documents.