Author Topic: SNC Dream Chaser DISCUSSION Thread  (Read 523859 times)

Offline envy887

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Re: SNC Dream Chaser DISCUSSION Thread
« Reply #1800 on: 04/20/2017 12:56 AM »
Please remember that DreamChaser is expected to use a 552 Atlas V. It should be able to do around 21 tonnes to LEO. Which is around what SpaceX claims Falcon 9 to do in expendable mode (22 tonnes). So it would either need a fully expendable Falcon 9 or a RTLS Falcon Heavy. An Atlas V 552 should cost quite a penny, probably in the 110~120M range. How much would SpaceX charge for a Falcon Heavy? Which would be the expected reliability and schedule margins? I wouldn't count Atlas V nor Vulcan out, yet.

Gunter says DreamChaser is expected to launch on Atlas V 412
http://space.skyrocket.de/img_lau/atlas-5-412__dream-chaser__1.jpg

Is the dual-engined Centaur required for redundancy? It certainly doesn't seem to be for payload capability.

Offline LastStarFighter

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Re: SNC Dream Chaser DISCUSSION Thread
« Reply #1801 on: 04/20/2017 01:27 AM »
Please remember that DreamChaser is expected to use a 552 Atlas V. It should be able to do around 21 tonnes to LEO. Which is around what SpaceX claims Falcon 9 to do in expendable mode (22 tonnes). So it would either need a fully expendable Falcon 9 or a RTLS Falcon Heavy. An Atlas V 552 should cost quite a penny, probably in the 110~120M range. How much would SpaceX charge for a Falcon Heavy? Which would be the expected reliability and schedule margins? I wouldn't count Atlas V nor Vulcan out, yet.

Gunter says DreamChaser is expected to launch on Atlas V 412
http://space.skyrocket.de/img_lau/atlas-5-412__dream-chaser__1.jpg

Is the dual-engined Centaur required for redundancy? It certainly doesn't seem to be for payload capability.

552 is for Dream Chaser cargo version. 412 is for Dream Chaser crew version. The lack of crew, cargo container and payload fairing allow for the increase in solids to maximize payload. Dual engine is just for performance increase by minimizing gravity loses.

Offline yg1968

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Re: SNC Dream Chaser DISCUSSION Thread
« Reply #1802 on: 04/23/2017 05:50 PM »
At 14m30s, Vern Thorp from ULA said that they were making modifications, this year, to the White Room for other customers in the future.

It's not clear what he meant by other customers. Presumably, he meant modifications for space tourist flights but he may have meant for other companies such as SNC:



See above.
« Last Edit: 04/23/2017 06:23 PM by yg1968 »

Offline JAFO

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Re: SNC Dream Chaser DISCUSSION Thread
« Reply #1803 on: 05/26/2017 02:08 AM »
Quote from: NASA
from
CCP Status report
http://www.nasa.gov/directorates/heo/nac-heoc

Approach & Landing Test 2 (ALT-2) is CCiCap Milestone 4B and CRS2
Integration Milestone 5
– Full scale Dream Chaser® engineering test article (ETA) unpowered approach & landing
test (ALT-2)
- Ship to AFRC Q1 2017 for Range and Taxi Testing then Approach & Landing Test 2
- Primary Objectives:
o Collect subsonic aerodynamic data to validate wind tunnel and CFD aero results
o Validation of spacecraft low-speed aerodynamic flying qualities – stability and control
o Validate subsonic orbital vehicle flight software and GN&C functionality.

Key Dream Chaser test vehicle Activities, Q3-Q4 2016
– Successfully executed a large number of offline, on-vehicle and integrated tests in
Louisville, CO facility to verify system design requirements and validate system function.
– Landing Gear tests identified nose/main landing gear (NLG/MLG) deploy sequence issue
– Remaining work planned in Colorado before Jan 2017 ship to AFRC/EAFB
- Complete Landing Gear hydraulic system modifications and acceptance testing
  Avionics Checkout with Flight Fault Tolerant Flight Computers using Flight Software ver. 3.0 (flight load)
   Polarity Test, Multi-Actuator Test, pre-Ship Day-In-The-Life Test, Radar Altimeter installs,
  Flush Air Data System Checkout, Rollout Ground Resonance Test
  Prep ETA for ship before Christmas, Ship to AFRC/EAFB 1st week January 2017

"Execute Free Flight Test (ALT2) March 2017, complete milestone NLT Aug
2017 (current CCiCap 5-year period of performance).

You'll hardly find a bigger DC fanboy than myself, but (WADR to the Mods), when she was delivered to Dryden/Armstrong I predicted that there was no way SNC would make a March free flight, they would take the time to make sure everything was A-OK, were most likely looking at September-October, and my post was deleted.

I don't mind that my post was moderated. I'm just glad SNC is not rushing and is taking the time to make sure she's ready to go. Getting near time to dig my "I heart DC" t-shirt out.
 

https://twitter.com/sierranevcorp/status/867833578528284673

Dream Chaser® spacecraft at dawn.


« Last Edit: 05/26/2017 02:13 AM by JAFO »
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Offline GWH

Re: SNC Dream Chaser DISCUSSION Thread
« Reply #1804 on: 05/26/2017 03:15 AM »
Please remember that DreamChaser is expected to use a 552 Atlas V. It should be able to do around 21 tonnes to LEO. Which is around what SpaceX claims Falcon 9 to do in expendable mode (22 tonnes). So it would either need a fully expendable Falcon 9 or a RTLS Falcon Heavy. An Atlas V 552 should cost quite a penny, probably in the 110~120M range. How much would SpaceX charge for a Falcon Heavy? Which would be the expected reliability and schedule margins? I wouldn't count Atlas V nor Vulcan out, yet.

Gunter says DreamChaser is expected to launch on Atlas V 412
http://space.skyrocket.de/img_lau/atlas-5-412__dream-chaser__1.jpg

Is the dual-engined Centaur required for redundancy? It certainly doesn't seem to be for payload capability.

552 is for Dream Chaser cargo version. 412 is for Dream Chaser crew version. The lack of crew, cargo container and payload fairing allow for the increase in solids to maximize payload. Dual engine is just for performance increase by minimizing gravity loses.
To answer baldusi an Atlas 551 starts at $163 according to ULA's rocketbuilder.com. Add the cost of a second RL-10 to that.

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Offline Rocket Science

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Re: SNC Dream Chaser DISCUSSION Thread
« Reply #1805 on: 05/31/2017 01:44 AM »
Quote from: NASA
from
CCP Status report
http://www.nasa.gov/directorates/heo/nac-heoc

Approach & Landing Test 2 (ALT-2) is CCiCap Milestone 4B and CRS2
Integration Milestone 5
– Full scale Dream Chaser® engineering test article (ETA) unpowered approach & landing
test (ALT-2)
- Ship to AFRC Q1 2017 for Range and Taxi Testing then Approach & Landing Test 2
- Primary Objectives:
o Collect subsonic aerodynamic data to validate wind tunnel and CFD aero results
o Validation of spacecraft low-speed aerodynamic flying qualities – stability and control
o Validate subsonic orbital vehicle flight software and GN&C functionality.

Key Dream Chaser test vehicle Activities, Q3-Q4 2016
– Successfully executed a large number of offline, on-vehicle and integrated tests in
Louisville, CO facility to verify system design requirements and validate system function.
– Landing Gear tests identified nose/main landing gear (NLG/MLG) deploy sequence issue
– Remaining work planned in Colorado before Jan 2017 ship to AFRC/EAFB
- Complete Landing Gear hydraulic system modifications and acceptance testing
  Avionics Checkout with Flight Fault Tolerant Flight Computers using Flight Software ver. 3.0 (flight load)
   Polarity Test, Multi-Actuator Test, pre-Ship Day-In-The-Life Test, Radar Altimeter installs,
  Flush Air Data System Checkout, Rollout Ground Resonance Test
  Prep ETA for ship before Christmas, Ship to AFRC/EAFB 1st week January 2017

"Execute Free Flight Test (ALT2) March 2017, complete milestone NLT Aug
2017 (current CCiCap 5-year period of performance).

You'll hardly find a bigger DC fanboy than myself, but (WADR to the Mods), when she was delivered to Dryden/Armstrong I predicted that there was no way SNC would make a March free flight, they would take the time to make sure everything was A-OK, were most likely looking at September-October, and my post was deleted.

I don't mind that my post was moderated. I'm just glad SNC is not rushing and is taking the time to make sure she's ready to go. Getting near time to dig my "I heart DC" t-shirt out.
 

https://twitter.com/sierranevcorp/status/867833578528284673

Dream Chaser® spacecraft at dawn.
Thanks for my new desktop background! 8)
"The laws of physics are unforgiving"
~Rob, Physics instructor, aviator, vintage auto racer

Offline jgoldader

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Re: SNC Dream Chaser DISCUSSION Thread
« Reply #1806 on: 06/04/2017 03:38 PM »
Has SNC released any more info on the cargo module?  I'm trying to model it, and dimensions would be hugely helpful.  I can get close scaling from the renderings, but real numbers would be great.  Thanks!
Recovering astronomer

Offline hans_ober

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Re: SNC Dream Chaser DISCUSSION Thread
« Reply #1807 on: 07/19/2017 02:38 PM »
Wrt them announcing Atlas 552: Pricey. They could have a lot by switching over the F9.

Offline Jim

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Re: SNC Dream Chaser DISCUSSION Thread
« Reply #1808 on: 07/19/2017 02:46 PM »
Wrt them announcing Atlas 552: Pricey. They could have a lot by switching over the F9.

No, F9 is a competitor

Offline gongora

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Re: SNC Dream Chaser DISCUSSION Thread
« Reply #1809 on: 07/19/2017 03:30 PM »
Wrt them announcing Atlas 552: Pricey. They could have a lot by switching over the F9.

If it needs an Atlas 552 then it probably couldn't launch on F9, would need to be FH.

Offline Rebel44

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Re: SNC Dream Chaser DISCUSSION Thread
« Reply #1810 on: 07/19/2017 03:46 PM »
Wrt them announcing Atlas 552: Pricey. They could have a lot by switching over the F9.

If it needs an Atlas 552 then it probably couldn't launch on F9, would need to be FH.
Bases on published info, Atlas 552 has slightly lower performance to LEO than expendable performance listed for  Falcon 9  (block 5)
Atlas V 552 : 20 520kg to LEO
Falcon 9: 22 800kg to LEO
« Last Edit: 07/19/2017 03:58 PM by Rebel44 »

Offline GWH

Re: SNC Dream Chaser DISCUSSION Thread
« Reply #1811 on: 07/19/2017 04:00 PM »
Is a Dream Chaser Cargo even able to fit in the F9/FH fairing?  It looks to be pretty long.

In comparing values, Dream Chaser Cargo capacity is 5500kg, Dragon is 6000kg BUT is seemingly volume limited at 14m3 pressurized, and it's heaviest load was ~3100kg.
What is the volumetric capacity of Dream Chaser cargo?  Tried pretty hard to find this but came up pretty empty, there may be 16m3 in DC + extra in service module but the source was pretty patchy.

Offline Rebel44

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Re: SNC Dream Chaser DISCUSSION Thread
« Reply #1812 on: 07/19/2017 04:37 PM »
Is a Dream Chaser Cargo even able to fit in the F9/FH fairing?  It looks to be pretty long.

In comparing values, Dream Chaser Cargo capacity is 5500kg, Dragon is 6000kg BUT is seemingly volume limited at 14m3 pressurized, and it's heaviest load was ~3100kg.
What is the volumetric capacity of Dream Chaser cargo?  Tried pretty hard to find this but came up pretty empty, there may be 16m3 in DC + extra in service module but the source was pretty patchy.

Yeah, F9/FH would need a longer fairing

Not sure about cargo volume of Dream Chaser

Offline TrevorMonty

Re: SNC Dream Chaser DISCUSSION Thread
« Reply #1813 on: 07/19/2017 05:03 PM »
NG would be good option once flying, got be lot cheaper than Atlas V552.

Offline Lars-J

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Re: SNC Dream Chaser DISCUSSION Thread
« Reply #1814 on: 07/20/2017 01:23 AM »
I am a bit surprised by the weight of the cargo DC... An Atlas V 552 won't be cheap. This so it requires three more SRBs compared to what the crew DC was baselined for, right?

I also (for some reason) expected them to be ready before 2020. But they have been forced to a slower development process since losing the commercial crew down-select.

Offline russianhalo117

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Re: SNC Dream Chaser DISCUSSION Thread
« Reply #1815 on: 07/20/2017 03:08 AM »
I am a bit surprised by the weight of the cargo DC... An Atlas V 552 won't be cheap. This so it requires three more SRBs compared to what the crew DC was baselined for, right?

I also (for some reason) expected them to be ready before 2020. But they have been forced to a slower development process since losing the commercial crew down-select.
the expendable module and the fact that DC is now carrying cargo that can be heavier than humans  is the reason for the choice of AV-552.

Offline envy887

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Re: SNC Dream Chaser DISCUSSION Thread
« Reply #1816 on: 07/20/2017 05:41 PM »
What's the performance difference to ISS between 552 and 551?

Offline GWH

Re: SNC Dream Chaser DISCUSSION Thread
« Reply #1817 on: 07/20/2017 08:11 PM »
551 with the longest fairing is 18,813 kg according to RocketBuilder.com
$167M for "Signature Service" to LEO

According to this link here if you can open it (page 14) 552 is 20,520 kg to LEO
https://web.archive.org/web/20120921011608/http://www.faa.gov/about/office_org/headquarters_offices/ast/media/ast_developments_concepts_2010.pdf
*Credit to link from Twitter https://twitter.com/ethan829/status/888031620489515013
Also see Altas V Wikipedia entry
« Last Edit: 07/20/2017 08:12 PM by GWH »

Offline russianhalo117

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Re: SNC Dream Chaser DISCUSSION Thread
« Reply #1818 on: 07/20/2017 09:09 PM »
551 with the longest fairing is 18,813 kg according to RocketBuilder.com
$167M for "Signature Service" to LEO

According to this link here if you can open it (page 14) 552 is 20,520 kg to LEO
https://web.archive.org/web/20120921011608/http://www.faa.gov/about/office_org/headquarters_offices/ast/media/ast_developments_concepts_2010.pdf
*Credit to link from Twitter https://twitter.com/ethan829/status/888031620489515013
Also see Atlas V Wikipedia entry
That is for LEO-Reference (200 km circular at 28.7 deg) not LEO-ISS (407 km circular at 51.6 deg).
Source (AV info last Updated in 2013): http://www.ulalaunch.com/uploads/docs/Launch_Vehicles/AV_DIV_product_card.pdf

Offline yg1968

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Re: SNC Dream Chaser DISCUSSION Thread
« Reply #1819 on: 07/27/2017 05:13 PM »
This has probably been discussed before but is there any reasons that DC could not fly to cislunar space?

I remember that SNC's original plans was that DC could fly to BLEO but some time after that, they changed their mind and said that DC was LEO only.

But my question is more whether it would be difficult to adapt DC for BLEO since NASA said that it will need cargo services to the DSG.
« Last Edit: 07/27/2017 05:15 PM by yg1968 »

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