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Other US Launchers / Re: US Launch Schedule
« Last post by Salo on Today at 04:07 AM »
Just stumbled across the Office of Safety & Mission Assurance's long-term planning schedule for Safety & Mission Success Reviews which shows tentative launch date for GRACE-FO of 2018-03-21.  That date was current based on an ELV milestone schedule from August 2nd.

Link to SMSR .pdf

Hah!  As soon as I say that deruch finds the site for the NASA Office of Safety & Mission Assurance's planning schedules for Safety & Mission Success Reviews.  On the near term schedule it has CRS-14 on January 26. 
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... Since they have 9 engines on the first stage, they could have run 1 (or more?) at the higher thrust and used lower thrust on the remaining to end up with the same overall vehicle thrust.  Doing this would allow them an excellent chance to analyze the performance of the uprated engines in comparison to past engines in a range of performances (i.e. higher, equal, and lower thrust).  Would be especially nice as they get the engines back for hands-on study post flight.

I'm not saying that this was done.  Only that it is a scenario that is also compatible with available data.

Another option is higher throttle after staging, which presents less risk to the primary mission. E.g. For the CRS-11 boostback burn ( http://forum.nasaspaceflight.com/index.php?topic=42389.msg1686855#msg1686855 ) ascent was at 91% of Block 5 thrust, and boostback at 97.5%. CRS-12 however, appears to have used 91% and 90% respectively.
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SpaceX Mars / Re: 9m ITS Development Updates and Discussion Thread
« Last post by TomH on Today at 03:48 AM »
Can do that with just one launch pad.

I presume you are assuming RTLS, landing cradle, and crane for US? What do you see turn around time being between launches?

What about an explosion on the pad? Do you think that risk is low enough to go without a backup pad?
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[SpaceNews] 3-D printing and in-orbit manufacturing promise to transform space missions
Quote
Q: What is the latest on your [Made In Space] optical fiber campaign?

A: Itís going really well. The flight unit is built and we are scheduled to fly on a [SpaceX] Dragon this year. We have produced fiber in our facility on the ground and are looking forward to flying that. We will be flying the payload multiple times on multiple flights because the focus is on making the minimum viable product that is scalable.

This is a fully robotic capability. The astronauts just plug it in. We send the signal for it to go. It pulls the fiber and monitors diameter. When itís done, it can switch over to another free form, thatís the starting material we use, and produce more fiber without any special environment on the ISS, without significant crew involvement other than installation. ...

The article also mentions a failed protest Made In Space filed against a NASA SBIRS award to another company working on manufacturing fiber in space.  The decision said Made In Space didn't have standing to protest the award.  The GAO decision can be found here:
https://www.gao.gov/products/B-414490#mt=e-report
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The document cited below has CRS-15 as 6/6/18:

Just stumbled across the Office of Safety & Mission Assurance's long-term planning schedule for Safety & Mission Success Reviews which shows tentative launch date for GRACE-FO of 2018-03-21.  That date was current based on an ELV milestone schedule from August 2nd.  I won't be too surprised if this date doesn't hold since it's still quite a ways out, especially since then they'd have a bunch of very high profile launches currently scheduled for that month: DM-1, TESS, GRACE-FO.  TESS has a harder deadline for launch and DM-1 is vital for their crew schedules.

Link to SMSR .pdf

You should ignore the CRS dates from those documents, because they are suuuuper fluid.  Since it was published, they have likely shifted right at least 2 months. 
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Is this still the most cost effective way to achieve its aim?

The Cygnus on Atlas 401 typically requires the extra extended 4m fairing on the Atlas. The cost increase is $8-12M to go to 5m depending on length required.
The additional SRBs cost $20-21M.

Even at $31M I don't think a dedicated launch vehicle would be available at that price.

Going through this some more: if this is a CRS2 mission the Cygnus may already require a 5m fairing + a single SRB (Atlas V 511) if it is for a longer 4 segment Cygnus. I've written out the reasons why in this thread: https://forum.nasaspaceflight.com/index.php?topic=42815.0

So in that case the additional hardware to co-manifest peregrine is just 2 SRB's and maybe a longer fairing.
Cost of additional fairing length is $2-4 Million, additional 2 SRB's is $10 Million.

So the total cost of hardware for Peregrine is $12-14 Million which is a lot more reasonable given the pricing posted on Astrobotic's website.

You are forgetting the SYLDA style payload adapter. Which I have no idea of the cost to manufactured and qualified of such an adapter. Will ULA use the Dual Satellite System for this dual manifest payloads?

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SpaceX Mars / Re: Red Dragon Discussion Thread (2)
« Last post by deruch on Today at 03:19 AM »
As an additional consideration, SpaceX now has a pretty good understanding of how much work it is taking them to refurbish and recertify Dragon 1 capsules after they get immersed in salt water.  So, maybe it is turning out to be less problematical (read: costly) than they had originally expected?  In which case, the cost driver for land landings maybe isn't such a big factor for the crewed capsules.  Though this thought does maybe "over-downplay" the difference of having the SuperDraco system get dunked for D2s.
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Just like a cake, the same things have to be done to make and fly one.

For clarification, what exactly needs to be done to fly a cake?  I'm assuming it has to do with correctly balancing the Layers/Decorations (L/D)?
For starters: the cake will fly much better WITHOUT de-icing equipment installed.
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Also, there's only ONE Delta IV Canaveral launch currently scheduled between now and Solar Probe Plus on July 31, 2018--GPS III-1.

SPP is flying before GPS.

I'm guessing this means we shouldn't count on GPS III-2 launching in May  :)
Sat is ready and like its sibling just waiting on Ground segment to be ready to support which is the hold up.
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above 1G forces, and the ITS may not be designed to handle that.

The frame, tanks and engines are likely to be able to handle >1g, what with that whole "launching from Earth" thing.

Launching applies compression forces, not tension. Suspending the ITS from a crane, or attaching two together and spin them, applies tension forces. Literally the bottom of the ITS is trying to separate from the top of the ITS.

And of course when the ITS is on Earth and is being lifted back onto the launch pad it won't be fueled or loaded with cargo & people (i.e. "empty weight"), so any fuel, cargo or crew you add in space would reduce the amount of artificial gravity you could apply.

However I have no doubt that a strong enough cable could be used (I'm a big fan of Dyneema), and I don't think there would be any vibration issues. That said, I think there are better ways to do the testing than spinning up two ITS...
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