Author Topic: Dream Chaser Q&A (including suggestions and improvements)  (Read 414261 times)

Offline tnphysics

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Re: Dream Chaser Q&A (including suggestions and improvements)
« Reply #20 on: 09/29/2007 10:56 PM »
To carry astronauts to Biglow's space stations.

Offline bad_astra

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Re: Dream Chaser Q&A (including suggestions and improvements)
« Reply #21 on: 09/30/2007 04:25 AM »
Quote
tnphysics - 29/9/2007  5:56 PM

To carry astronauts to Biglow's space stations.

What award are you talking about.
"Contact Light" -Buzz Aldrin

Offline tnphysics

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Re: Dream Chaser Q&A (including suggestions and improvements)
« Reply #22 on: 09/30/2007 04:28 AM »
The contract for crew transportation to Bigelow's habitats will probably go to SpaceX IMO.

Offline A_M_Swallow

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Re: Dream Chaser Q&A (including suggestions and improvements)
« Reply #23 on: 09/30/2007 08:19 AM »
Quote
tnphysics - 30/9/2007  5:28 AM

The contract for crew transportation to Bigelow's habitats will probably go to SpaceX IMO.

Standard advice to a manufacturing company - never have a single source supplier.  Bigelow may want 2 different companies suppling their launches.

Offline antonioe

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Re: Dream Chaser Q&A (including suggestions and improvements)
« Reply #24 on: 09/30/2007 04:41 PM »

Quote
(from several members):

What would happen if Bigelow said in public that Dream Chaser would be the vehicle used to ferry passengers and consummables?

Dragon will probably get that award.

What award?

The contract for crew transportation to Bigelow's habitats will probably go to SpaceX IMO. 

Does Bigelow have an RFP out? Has he stated in public that he is in the market for passenger transportation service to Orbit? How much is he willing to pay? Will he fund the development?

ARS LONGA, VITA BREVIS...

Offline tnphysics

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Re: Dream Chaser Q&A (including suggestions and improvements)
« Reply #25 on: 10/01/2007 10:19 PM »
I don't know, but what I would love to see would be information about Dream Chaser's abort modes.

I don't see an LAS.

Online docmordrid

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Re: Dream Chaser Q&A (including suggestions and improvements)
« Reply #26 on: 10/02/2007 02:47 AM »
I believe it would use the hybrid OMS in abort modes (if steerable), that or some SRM's mounted in the DC-Atlas adapter.  I say that because of this;

Link

Quote
Launch-Pad Abort Capabilities of the HL-20 Lifting Body
( 19940030181_1994030181.pdf )
>
Abstract:

The capability of the HL-20 lifting body to perform an abort maneuver from the launch pad to a horizontal landing was studied. The study involved both, piloted and batch simulation models of the vehicle. A point-mass model of the vehicle was used for trajectory optimisation studies. The piloted simulation was performed in the Langley Visual/Motion Simulator in the fixed-base mode. A candidate maneuver was developed and refined for the worst-case launch-pad-to-landing site geometry with an iterative procedure of off-line maneuver analysis followed by piloted evaluations and heuristic improvements to the candidate maneuver. The resultinq maneuver demonstrates the launchsite abort capability of the HL-2O and dictates requirements for nominal abort-motor performance. The sensitivity of the maneuver to variations in several design parameters was documented.
>
The math model used in the piloted simulation was derived from an existing HL-20 approach-and landing simulation model (refs.5 and6). Modifications included adding a model of the steerable abort motor with thrust and pitch-roll torques specified as a function of time, modeling the orbital maneuvering subsystem (OMS) rocket motors, and increasing the vehicle mass properties appropriately. Modifications to the flight-director and autopilot controll aws, the control-law mode-switch in logic, and simulation initialization logic were required. Head-up and headdown flight displays were modified to assistin pilot orientation during the maneuve.
DM

Online docmordrid

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Re: Dream Chaser Q&A (including suggestions and improvements)
« Reply #27 on: 10/02/2007 03:23 AM »
Continued;

Quote
>
A 6700-1b adapter module will be used to connect the HL-20 to the launch vehicle. (See fig. 2.) This adapter design will include a launch escape system that is intended to thrust the HL-20 away from the booster in case of a malfunction either during the actual launch or on the pad prior to launch (on-pad abort). Acceleration levels on tile order of 8g's (lg = 32.2 ft/sec 2) would be required to propel the vehicle a safe distance away from a malfunctioning booster. After a specified time, the abort-motor thrust would drop to approximately lg for an additional specified amount of time to avoid excessive velocities and associated drag. The adapter module would be jettisoned following abort-motor burnout.
>
DM

Offline tnphysics

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Re: Dream Chaser Q&A (including suggestions and improvements)
« Reply #28 on: 10/02/2007 11:15 PM »
Okay. That makes sense.

Offline clongton

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Re: Dream Chaser Q&A (including suggestions and improvements)
« Reply #29 on: 01/12/2008 11:26 AM »
Bump
Chuck - DIRECT co-founder
I started my career on the Saturn-V F-1A engine

Offline Smoothie

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Re: Dream Chaser Q&A (including suggestions and improvements)
« Reply #30 on: 01/13/2008 05:23 AM »
How does the HL-20 compare to the PlanetSpace FDL-7 based Silver Dart?
http://planetspace.org/lo/silver_dart.htm

Offline marsavian

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Re: Dream Chaser Q&A (including suggestions and improvements)
« Reply #31 on: 01/13/2008 11:34 AM »
Silver Dart is a suborbital tourist vehicle, just a quick rocketplane really. HL-20/Dreamchaser on the other hand is meant to be a mini Space Shuttle.

Offline Smoothie

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Re: Dream Chaser Q&A (including suggestions and improvements)
« Reply #32 on: 01/13/2008 03:17 PM »
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marsavian - 12/1/2008  7:34 PM

Silver Dart is a suborbital tourist vehicle, just a quick rocketplane really. HL-20/Dreamchaser on the other hand is meant to be a mini Space Shuttle.

No.  Its orbital.

To quote their website
"Based on the FDL-7 design which is stable in flight from Mach 22 to 0, the Silver Dart has the glide range of 25,000 miles (one earth circumference) with a cross range of over 4,000 miles. Such a glide performance provides for departure from any LEO and landing in the continental US with no wait time on orbit. An all metal thermal protection system allows for all weather flying. Combined, the thermal protection system and glide range result in a reentry vehicle that cannot be trapped in space and is able to return to base from any orbit around the Earth."

Looks like an OSP to me.  Anyone know the glide range from LEO for the HL-20?

Offline marsavian

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Re: Dream Chaser Q&A (including suggestions and improvements)
« Reply #33 on: 01/13/2008 03:37 PM »
Their CEO doesn't seem to think so

http://cosmiclog.msnbc.msn.com/archive/2007/11/30/490524.aspx
http://www.space.com/news/071130-cots-planetspace.html

Kathuria said the Modular Cargo Carrier is being developed separately from PlanetSpace's planned Silver Dart spacecraft, a reusable space plane based on the U.S. Air Force's Flight Dynamics Laboratory-7 (FDL-7) that is designed to fly cargo or up to eight astronauts through suborbital space for joy rides or point-to-point transportation on Earth.

"We're continuing down that development very strongly in terms of developing the FDL-7 for what we call cargo express or space tourism," Kathuria said. "That's the commercial part of our business."

Offline Smoothie

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Re: Dream Chaser Q&A (including suggestions and improvements)
« Reply #34 on: 01/14/2008 02:57 PM »
Quote
marsavian - 12/1/2008  11:37 PM

Their CEO doesn't seem to think so

http://cosmiclog.msnbc.msn.com/archive/2007/11/30/490524.aspx
http://www.space.com/news/071130-cots-planetspace.html

Kathuria said the Modular Cargo Carrier is being developed separately from PlanetSpace's planned Silver Dart spacecraft, a reusable space plane based on the U.S. Air Force's Flight Dynamics Laboratory-7 (FDL-7) that is designed to fly cargo or up to eight astronauts through suborbital space for joy rides or point-to-point transportation on Earth.

"We're continuing down that development very strongly in terms of developing the FDL-7 for what we call cargo express or space tourism," Kathuria said. "That's the commercial part of our business."

Seeing as how their website talks about FDL-7 being capable of going to orbit I'm sure it would eventually be able to do that as well. I shutter to think about the differences in Sub-orbital and Orbital TPS requirements.  :o

My Guess is the market for Point to Point cargo and people is likely more lucrative then Orbital stuff anyway.  I mean how many packages and people fly internationally every day compared to Orbit?  Imagine flying to europe or Japan in an hour or two.  We may get to see the old "boost glide" concept come to life after all.

The spin offs form COTS should be interesting to watch over the next 10 years.

Offline meiza

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Re: Dream Chaser Q&A (including suggestions and improvements)
« Reply #35 on: 01/14/2008 07:02 PM »
Interesting. X-24B had a hypersonic L/D of about 3
http://history.nasa.gov/SP-4220/ch8.htm
And the FDL-7 and 8 should have had about double so 6. Interesting for Silver Dart.

Offline Sid454

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Re: Dream Chaser Q&A (including suggestions and improvements)
« Reply #36 on: 01/25/2008 04:39 AM »
One suggestions maybe also show a simpler and cheaper vehicle who's primary purpose  would be to get their foot in the door and get contracts to pay for dreamchaser's R&D.
Or try and get the Orion LAS contract too and say experience gained with DC's escape system could be applied to Orion.
Though the real issue here is 175M just is not enough for any of the COTS companies to really fund a vehicle properly more money needs to be given to this program to get good results.

Offline Jim

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Re: Dream Chaser Q&A (including suggestions and improvements)
« Reply #37 on: 01/25/2008 11:43 AM »
Quote
Sid454 - 25/1/2008  12:39 AM


1.  Though the real issue here is 175M just is not enough for any of the COTS companies to really fund a vehicle properly more money needs to be given to this program to get good results.

2.  Or try and get the Orion LAS contract too and say experience gained with DC's escape system could be applied to Orion.

1.  COTS requires that the participant supply part of the funding

2. Lockheed got the Orion contract which included the LAS and they contracted OSC.  please keep up

Offline Sid454

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Re: Dream Chaser Q&A (including suggestions and improvements)
« Reply #38 on: 01/26/2008 01:30 AM »
Yah but LM hasn't been meeting their deadlines though this is not 100% their fault much of it also is due the Ares I's specs being a moving target.

I say just design the capsule to be safe and roomy and then up rate the rocket to fit it vs all this dorking  around.

If the stick can't lift it then don't use the stick use something else you will get a safer spacecraft and it'll fly sooner.

Also  another LAS one Griffin suggested is challenging the tower LAS.
They are not even sure what rocket they want to use on the LAS a solid or liquid or hybrid as each has advantages and disadvantages.

I'd go with a hybrid because an SDV is very unlikely to explode on the pad but it is likely to develop trouble later in flight.

I just can't defend the decisions NASA has making on that project as they are poorly thought out.
 It's not really stupidity but more so the management up at the top are likely just too proud to admit they are wrong or someone below them may have a better idea.

BTW I would not have chosen LM as the prime contractor because they messed up the last big project the X33.

Offline Sid454

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Re: Dream Chaser Q&A (including suggestions and improvements)
« Reply #39 on: 01/26/2008 01:42 AM »
Quote
meiza - 14/1/2008  2:02 PM

Interesting. X-24B had a hypersonic L/D of about 3
http://history.nasa.gov/SP-4220/ch8.htm
And the FDL-7 and 8 should have had about double so 6. Interesting for Silver Dart.

With such a high L/D the dart would be very attractive as a rescue craft because that also means the g loading during reentry is very low .

For a badly injured crew member this could mean the difference between life and death esp if said crew member suffered internal bleeding or blood loss etc.

It also would be attractive in returning science samples that might be on the fragile side such as live vs chemically fixed biological samples.

Also it would offer some interesting options for abort since something with such high lift to drag might be able to flatten what would otherwise be an unpleasant even risky reentry before hitting the lower layers of the atmosphere such as what happened in soyuz 18-1 . http://www.astronautix.com/flights/soyuz181.htm

NASA would consider a reentry and landing like that deep in the black zone since that event almost killed the crew three separate times.

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