Author Topic: Sierra Space Dream Chaser DISCUSSION Thread (was SNC)  (Read 1064527 times)

Offline Robotbeat

  • Senior Member
  • *****
  • Posts: 39270
  • Minnesota
  • Liked: 25240
  • Likes Given: 12115
Re: Sierra Space Dream Chaser DISCUSSION Thread (was SNC)
« Reply #80 on: 08/31/2012 02:27 pm »
What's the angular distribution of MMOD?

Predominantly from behind and the sides.  Stuff coming in from the front is going slower, so has a lower perigee, so has experienced more atmospheric drag and is likely to be scrubbed out of orbit relatively quickly.  That's one reason the ISS orbit is not higher, I believe.

Ditto on things coming in from below.  They have seen more drag.  (However, there was a strike on the Cupola.)
Same altitude orbits in different inclinations approach from the sides.
Stuff in elliptical orbits with higher apogees comes in from behind.

The front of the ISS is probably a relatively safe place, particularly if the VV doesn't stick out like the Shuttle did.

Someone must have quantitative data.  Look online for orbital debris quarterly reports from NASA.
It'd be really nice to see a pretty graph of the angular distribution. My Googlefu isn't strong enough, this is all I've found so far:
http://www.sciencedirect.com/science/article/pii/S0032063301000423
Chris  Whoever loves correction loves knowledge, but he who hates reproof is stupid.

To the maximum extent practicable, the Federal Government shall plan missions to accommodate the space transportation services capabilities of United States commercial providers. US law http://goo.gl/YZYNt0

Offline zerm

  • Hypergolic cartoonist
  • Full Member
  • ****
  • Posts: 1319
    • GWS Books dot com
  • Liked: 34
  • Likes Given: 19
Re: Sierra Space Dream Chaser DISCUSSION Thread (was SNC)
« Reply #81 on: 09/01/2012 03:32 pm »
Runway length is only a small element in this. You can have a 15k Ft. runway waiting for you but if you do not have exact onboard, ground, and visual guidence to take you to the approach end of that runway- in the proper attitude and at the proper airspeed, the length does not mean squat. Thus, there may not be "plenty of choices."

Offline Rocket Science

  • Senior Member
  • *****
  • Posts: 10586
  • NASA Educator Astronaut Candidate Applicant 2002
  • Liked: 4548
  • Likes Given: 13523
Re: Sierra Space Dream Chaser DISCUSSION Thread (was SNC)
« Reply #82 on: 09/01/2012 04:03 pm »
Runway length is only a small element in this. You can have a 15k Ft. runway waiting for you but if you do not have exact onboard, ground, and visual guidence to take you to the approach end of that runway- in the proper attitude and at the proper airspeed, the length does not mean squat. Thus, there may not be "plenty of choices."
Wes, pilot to pilot, I get what you are saying, but this is in an abort or emergency landing. Without knowing what avionics are on board we are pretty much “flying in the dark”, pun intended! ;D  On the other hand the series of X-Planes routinely made landings on dry lakebeds and runways pretty much with only the “sacred six” (plus Q- Ball in the case of the X-15) instruments plus radar data… Energy management is the real item for consideration for a successful landing and a variation of the Terminal Area Energy Management (TAEM) similar to Shuttle will more than likely be utilized…


Edit to add:
« Last Edit: 09/01/2012 07:34 pm by Rocket Science »
"The laws of physics are unforgiving"
~Rob: Physics instructor, Aviator

Offline clongton

  • Expert
  • Senior Member
  • *****
  • Posts: 12053
  • Connecticut
    • Direct Launcher
  • Liked: 7347
  • Likes Given: 3749
Re: Sierra Space Dream Chaser DISCUSSION Thread (was SNC)
« Reply #83 on: 09/01/2012 06:03 pm »
For emergency landing situations all the pilot really needs, with today's avionics, is the gps coordinates of the runway, its altitude above sea level and the radio frequency of the tower. If he's got those he can land safely. It might be a rough ride  to the runway depending on current altitude, direction, rate of descent and airspeed, but a good pilot will know which ones he can make, which ones are iffy and which ones he can't, based on his current position. I can't imagine DC being launched without those 3 data nodes being loaded into the guidance avionics. If the guidance avionics can't compute a flight path to a known runway from current position, altitude, rate of descent and airspeed then throw it out and get another one that's been properly programmed. It's not that hard to compute.
« Last Edit: 09/01/2012 06:05 pm by clongton »
Chuck - DIRECT co-founder
I started my career on the Saturn-V F-1A engine

Offline vulture4

  • Full Member
  • ****
  • Posts: 1099
  • Liked: 431
  • Likes Given: 92
Re: Sierra Space Dream Chaser DISCUSSION Thread (was SNC)
« Reply #84 on: 09/02/2012 05:54 am »
Runways of 3km or more are not common and busy commercial airports are loath to consent to be used for emergency landings of spacecraft. The entire world was surveyed repeatedly for runways for both Shuttle and CERV. The short answer is that they exist, but not in profusion. The Shuttle emergency landing sites around the world are well known; the majority are military fields that could be cleared quickly for an emergency landing. The approach cannot possibly be hand-flown, particularly with something like the DC which has very little aerodynamic reserve; everything from TIG to wheel stop must be autonomous. This was never possible with Shuttle, which predated even GPS. It had an autoland system but it was organizationally infeasible to even test it. In contrast the X-37 has so far made two completely autonomous landings with no significant problems.

Offline Lurker Steve

  • Full Member
  • ****
  • Posts: 1420
  • Liked: 35
  • Likes Given: 9
Re: Sierra Space Dream Chaser DISCUSSION Thread (was SNC)
« Reply #85 on: 09/02/2012 02:06 pm »
Runways of 3km or more are not common and busy commercial airports are loath to consent to be used for emergency landings of spacecraft. The entire world was surveyed repeatedly for runways for both Shuttle and CERV. The short answer is that they exist, but not in profusion. The Shuttle emergency landing sites around the world are well known; the majority are military fields that could be cleared quickly for an emergency landing. The approach cannot possibly be hand-flown, particularly with something like the DC which has very little aerodynamic reserve; everything from TIG to wheel stop must be autonomous. This was never possible with Shuttle, which predated even GPS. It had an autoland system but it was organizationally infeasible to even test it. In contrast the X-37 has so far made two completely autonomous landings with no significant problems.

I assume the problem is that any airport with a suitable runway, is that the airport likes to use them for landing airplanes. For instance, I assume you technically could land the DC at OHare, DFW, Atlanta, LAX, Denver, etc. But that would probably mean shutting down all aircraft operations for hours. And then, losing a major airport for hours means major air traffic delays that ripple across the entire system.

Offline Lee Jay

  • Elite Veteran
  • Global Moderator
  • Senior Member
  • *****
  • Posts: 8566
  • Liked: 3603
  • Likes Given: 327
Re: Sierra Space Dream Chaser DISCUSSION Thread (was SNC)
« Reply #86 on: 09/02/2012 02:57 pm »
Runways of 3km or more are not common and busy commercial airports are loath to consent to be used for emergency landings of spacecraft. The entire world was surveyed repeatedly for runways for both Shuttle and CERV. The short answer is that they exist, but not in profusion. The Shuttle emergency landing sites around the world are well known; the majority are military fields that could be cleared quickly for an emergency landing. The approach cannot possibly be hand-flown, particularly with something like the DC which has very little aerodynamic reserve; everything from TIG to wheel stop must be autonomous. This was never possible with Shuttle, which predated even GPS. It had an autoland system but it was organizationally infeasible to even test it. In contrast the X-37 has so far made two completely autonomous landings with no significant problems.

I assume the problem is that any airport with a suitable runway, is that the airport likes to use them for landing airplanes. For instance, I assume you technically could land the DC at OHare, DFW, Atlanta, LAX, Denver, etc. But that would probably mean shutting down all aircraft operations for hours. And then, losing a major airport for hours means major air traffic delays that ripple across the entire system.

That's just entirely inaccurate.  Any time any aircraft declares an in-flight emergency, the airport in question can get clear and ready for them in seconds or tens of seconds.  This happens all the time right now without causing major ripples throughout the system.  Weather events cause a lot more havoc.  Second, even if DC did have to land quickly at some random airport, that would only close one runway for a short time, not the whole airport for a long time.  It's not a big craft, and it's non-toxic.

Offline clongton

  • Expert
  • Senior Member
  • *****
  • Posts: 12053
  • Connecticut
    • Direct Launcher
  • Liked: 7347
  • Likes Given: 3749
Re: Sierra Space Dream Chaser DISCUSSION Thread (was SNC)
« Reply #87 on: 09/02/2012 03:14 pm »
Runways of 3km or more are not common and busy commercial airports are loath to consent to be used for emergency landings of spacecraft. The entire world was surveyed repeatedly for runways for both Shuttle and CERV. The short answer is that they exist, but not in profusion. The Shuttle emergency landing sites around the world are well known; the majority are military fields that could be cleared quickly for an emergency landing. The approach cannot possibly be hand-flown, particularly with something like the DC which has very little aerodynamic reserve; everything from TIG to wheel stop must be autonomous. This was never possible with Shuttle, which predated even GPS. It had an autoland system but it was organizationally infeasible to even test it. In contrast the X-37 has so far made two completely autonomous landings with no significant problems.

I assume the problem is that any airport with a suitable runway, is that the airport likes to use them for landing airplanes. For instance, I assume you technically could land the DC at OHare, DFW, Atlanta, LAX, Denver, etc. But that would probably mean shutting down all aircraft operations for hours. And then, losing a major airport for hours means major air traffic delays that ripple across the entire system.

That's just entirely inaccurate.  Any time any aircraft declares an in-flight emergency, the airport in question can get clear and ready for them in seconds or tens of seconds.  This happens all the time right now without causing major ripples throughout the system.  Weather events cause a lot more havoc.  Second, even if DC did have to land quickly at some random airport, that would only close one runway for a short time, not the whole airport for a long time.  It's not a big craft, and it's non-toxic.

Thank you. I was about to post nearly exactly the same thing. All DC needs to know is where they are and where the runway is and their flight avionics will take it from there. Once notifying the tower that they are making an emergency landing the runway will be clear and ready for them when they get there. No airport will ever refuse an emergency landing to anybody, aircraft or spacecraft, once an emergency is declared.
Chuck - DIRECT co-founder
I started my career on the Saturn-V F-1A engine

Offline Rocket Science

  • Senior Member
  • *****
  • Posts: 10586
  • NASA Educator Astronaut Candidate Applicant 2002
  • Liked: 4548
  • Likes Given: 13523
Re: Sierra Space Dream Chaser DISCUSSION Thread (was SNC)
« Reply #88 on: 09/02/2012 04:22 pm »
Runways of 3km or more are not common and busy commercial airports are loath to consent to be used for emergency landings of spacecraft. The entire world was surveyed repeatedly for runways for both Shuttle and CERV. The short answer is that they exist, but not in profusion. The Shuttle emergency landing sites around the world are well known; the majority are military fields that could be cleared quickly for an emergency landing. The approach cannot possibly be hand-flown, particularly with something like the DC which has very little aerodynamic reserve; everything from TIG to wheel stop must be autonomous. This was never possible with Shuttle, which predated even GPS. It had an autoland system but it was organizationally infeasible to even test it. In contrast the X-37 has so far made two completely autonomous landings with no significant problems.

I assume the problem is that any airport with a suitable runway, is that the airport likes to use them for landing airplanes. For instance, I assume you technically could land the DC at OHare, DFW, Atlanta, LAX, Denver, etc. But that would probably mean shutting down all aircraft operations for hours. And then, losing a major airport for hours means major air traffic delays that ripple across the entire system.

That's just entirely inaccurate.  Any time any aircraft declares an in-flight emergency, the airport in question can get clear and ready for them in seconds or tens of seconds.  This happens all the time right now without causing major ripples throughout the system.  Weather events cause a lot more havoc.  Second, even if DC did have to land quickly at some random airport, that would only close one runway for a short time, not the whole airport for a long time.  It's not a big craft, and it's non-toxic.

Thank you. I was about to post nearly exactly the same thing. All DC needs to know is where they are and where the runway is and their flight avionics will take it from there. Once notifying the tower that they are making an emergency landing the runway will be clear and ready for them when they get there. No airport will ever refuse an emergency landing to anybody, aircraft or spacecraft, once an emergency is declared.
“In studying several off-nominal conditions, it was
discovered that the HL-20 design is quite robust and forgiving
on approach and consistent on landing. “

http://81.70.242.211/eab1/manual/Magazine/AIAA%20Journal%20of%20Aircraft/1994/3/Preliminary%20piloted%20simulation%20studies%20of%20the%20HL-20%20lifting%20body.pdf

When it comes to aborts or emergency priority landings, Vulture claims to be a pilot and if really true, should know better…
"The laws of physics are unforgiving"
~Rob: Physics instructor, Aviator

Offline belegor

  • Full Member
  • ***
  • Posts: 322
  • Switzerland
  • Liked: 13
  • Likes Given: 67
Re: Sierra Space Dream Chaser DISCUSSION Thread (was SNC)
« Reply #89 on: 09/02/2012 06:22 pm »
That's just entirely inaccurate.  Any time any aircraft declares an in-flight emergency, the airport in question can get clear and ready for them in seconds or tens of seconds.  This happens all the time right now without causing major ripples throughout the system.  Weather events cause a lot more havoc.  Second, even if DC did have to land quickly at some random airport, that would only close one runway for a short time, not the whole airport for a long time.  It's not a big craft, and it's non-toxic.

That's actually not entirely true either: ICAO mandates the fire brigade to be at any point of the airport within two minutes, which means unless the respective airport has a fire brigade big enough to be able to respond to two emergencies simultaneously, the respective airport has to close down entirely, until the fire brigade is ready for a next potential emergency.

Therefore, even minor emergencies can easily cause delays of 20-30 minutes or even more, if the runway remains blocked for a longer time (and thus reducing the capacity of the airport).

Not that it really matters: I don't think airports really care whether it is a normal aircraft or a spacecraft making an emergency landing.. an emergency is an emergency...

Offline Lee Jay

  • Elite Veteran
  • Global Moderator
  • Senior Member
  • *****
  • Posts: 8566
  • Liked: 3603
  • Likes Given: 327
Re: Sierra Space Dream Chaser DISCUSSION Thread (was SNC)
« Reply #90 on: 09/02/2012 06:51 pm »
Not that it really matters: I don't think airports really care whether it is a normal aircraft or a spacecraft making an emergency landing.. an emergency is an emergency...

And there are tons of emergencies declared each year.  DC isn't likely to add to that by any significant amount compared to, say, bird strikes causing engine damage.

Offline Robotbeat

  • Senior Member
  • *****
  • Posts: 39270
  • Minnesota
  • Liked: 25240
  • Likes Given: 12115
Re: Sierra Space Dream Chaser DISCUSSION Thread (was SNC)
« Reply #91 on: 09/05/2012 04:09 pm »
Not that it really matters: I don't think airports really care whether it is a normal aircraft or a spacecraft making an emergency landing.. an emergency is an emergency...

And there are tons of emergencies declared each year.  DC isn't likely to add to that by any significant amount compared to, say, bird strikes causing engine damage.
Except DreamChaser (or any orbital vehicle) is more likely to abort than an airliner is (proportional to number of flights per year per vehicle). This extra burden (more than usual) is borne by the airports. This is called an externality in economics.
Chris  Whoever loves correction loves knowledge, but he who hates reproof is stupid.

To the maximum extent practicable, the Federal Government shall plan missions to accommodate the space transportation services capabilities of United States commercial providers. US law http://goo.gl/YZYNt0

Offline john smith 19

  • Senior Member
  • *****
  • Posts: 10350
  • Everyplaceelse
  • Liked: 2430
  • Likes Given: 13605
Re: Sierra Space Dream Chaser DISCUSSION Thread (was SNC)
« Reply #92 on: 09/05/2012 07:29 pm »
Except DreamChaser (or any orbital vehicle) is more likely to abort than an airliner is (proportional to number of flights per year per vehicle). This extra burden (more than usual) is borne by the airports. This is called an externality in economics.

This seems a fair point *except* that the only orbital vehicle we have seen (the space shuttle) *never* aborted in over 130 flights. It's failure modes were never that benign.

I don't think there's anyway to know if DC will be more "abort prone" than Shuttle. If flown it's LV has no SRB's to leak gases onto cryogenic tanks and it's location should avoid *any* debris from tank insulation shedding on the Atlas (does anyone know if Atlas *does* shed it's insulation?)  that leaves systems failures in the vehicle or on orbit damage.

DC's internal systems *seem* much simpler than Shuttle (well no lethally toxic propellants seem a good start) and it would present a smaller MMOD target so *should* be less likely to suffer surface damage to the TPS.

I've always wondered what happens if (billion billion to one chance I hope) the proverbial lost bolt hits the wind shield and goes through *all* the layers. 

However SNC *might* have to save money and go with lower redundancy or less experienced suppliers whose hardware is not *quite* as reliable as the NASA sourced equipment, leading to more aborts to emergency landing sites. NASA seemed especially worried about TPS damage and SNC having no repair material to fix it (although let's remember that STS flew *most* of its career without carrying such things).

IOW I think it's too finely balanced to call until it's built and operating. If the aerodynamic design is stable it *could* land with all its control surfaces locked in the last position they were powered at. This would downgrade *dozens* of failure types (in the computers, APUs an aerosurface drive system) from LOC or LOV to LOM. Nasty, expensive (if you can't get the landing gear down) but survivable.
MCT ITS BFR SS. The worlds first Methane fueled FFSC engined CFRP SS structure A380 sized aerospaceplane tail sitter capable of Earth & Mars atmospheric flight.First flight to Mars by end of 2022 TBC. T&C apply. Trust nothing. Run your own #s "Extraordinary claims require extraordinary proof" R. Simberg."Competitve" means cheaper ¬cheap SCramjet proposed 1956. First +ve thrust 2004. US R&D spend to date > $10Bn. #deployed designs. Zero.

Offline Robotbeat

  • Senior Member
  • *****
  • Posts: 39270
  • Minnesota
  • Liked: 25240
  • Likes Given: 12115
Re: Sierra Space Dream Chaser DISCUSSION Thread (was SNC)
« Reply #93 on: 09/05/2012 08:47 pm »
...

I've always wondered what happens if (billion billion to one chance I hope) the proverbial lost bolt hits the wind shield and goes through *all* the layers. 
...
Well, you'd get decompression of the cabin, but (unless all the layers shattered) not instantly. The air would be rushing through the hole at a finite velocity, probably sonically choked. mass Flowrate would then be roughly:

mdot=areaofhole*speedofsound*densityofair*someconstantrelatingtoshapeofhole (we'll set the constant=1 for now, to get a rough order of magnitude estimate). Of course, the density of the air would decrease as air was lost.

mdot=-A*c*rho

total mass of air (as a function of time) = m
total volume (constant) of cabin = V
rho = m/V

mdot=-A*c*m/V

dm/dt=-(A*c/V)*m

for convenience, let's set (A*c/V)=w

dm/dt=-w*m

well, we have a differential equation on our hands! And a simple one, at that.

let's do some operations (this step always seemed bogus to me, but it's what you're supposed to do):

dm=-w*m*dt

get all the "m"s on the same side:

dm/m = -w*dt

now integrate both sides:

int((1/m)*dm)=int(-w*dt)+B
("B" is just some integration constant... we'll figure it out later)

which is just:

ln(m)=-w*t+B

To get m by itself:

e^ln(m)=e^(-w*t+B)

m = e^(-w*t)*e^B

yay! Now, we see that m=e^B at time=0, so let's replace e^B with m0:

m=m0*e^(-w*t)

to solve for when the air mass has dropped to a certain level, m1:

m1=m0*e^(-w*t)

t=-ln(m1/m0)/w

if we put the pressure at which consciousness is lost at 1.5 psi (comfortably above the Armstrong limit of ~.9psi), we get a m1/m0=.1
and thus:

for a 1cm^2 square hole (.01*.01m^2=.0001m^2) and Dreamchaser's volume of 16m^3:

t= -ln(.1)/(.0001m^2*343m/s/(16m^3)) = about 18 minutes.


so, barely enough time to do an extreme burn and get low enough in the atmosphere to keep the crew conscious, but not using usual reentry procedures. (If we put the limit at 4.6psi, about Everest pressure, it's just more than 8.5 minutes... probably not enough time.)

If that's not long enough, a small supply of air should be enough to keep the crew conscious for quite a while at 5psi. If you keep a few cabins' worth of air on board, you could do a half hour time between getting hit with the bolt and the crew losing consciousness. You could supply enough air for them to don space suits. Of course, the crew could also try plugging the hole to at least slow the leakrate.

So, air would be lost exponentially (until the pressure difference is low enough that it is no longer sonically choked... but that usually occurs only at very low pressures, which aren't survivable anyway).

If your hole is bigger than 1cm square, then you'll have less time, proportional to the area of the hole (or rather, your length of time would be inversely proportional to the area of the hole).


Is that a good answer?

(this is still just an approximation, but close enough)
« Last Edit: 09/05/2012 08:49 pm by Robotbeat »
Chris  Whoever loves correction loves knowledge, but he who hates reproof is stupid.

To the maximum extent practicable, the Federal Government shall plan missions to accommodate the space transportation services capabilities of United States commercial providers. US law http://goo.gl/YZYNt0

Offline baldusi

  • Senior Member
  • *****
  • Posts: 8356
  • Buenos Aires, Argentina
  • Liked: 2539
  • Likes Given: 8273
Re: Sierra Space Dream Chaser DISCUSSION Thread (was SNC)
« Reply #94 on: 09/05/2012 11:21 pm »
Shuttle did aborted.. to orbit. But still an abort. The big question would be about a pad abort, for example. Or an abort and ditch.

Offline zerm

  • Hypergolic cartoonist
  • Full Member
  • ****
  • Posts: 1319
    • GWS Books dot com
  • Liked: 34
  • Likes Given: 19
Re: Sierra Space Dream Chaser DISCUSSION Thread (was SNC)
« Reply #95 on: 09/17/2012 10:44 pm »
Not that it really matters: I don't think airports really care whether it is a normal aircraft or a spacecraft making an emergency landing.. an emergency is an emergency...

And there are tons of emergencies declared each year.  DC isn't likely to add to that by any significant amount compared to, say, bird strikes causing engine damage.
Except DreamChaser (or any orbital vehicle) is more likely to abort than an airliner is (proportional to number of flights per year per vehicle). This extra burden (more than usual) is borne by the airports. This is called an externality in economics.

This is a good example of why space folks should stick to spaceflight and away from commercial aviation. I've done LOTS of aborts in airliners- yet the comparison is, as Jim would say, apples to oranges.

Frankly- this discussion is really going toward the what if monkeys may fly out of yer butt type of debate.

Here's the deal- EVERY DC mission will be heavily planned- far, far beyond anything in commercial aviation. It is a SPACEFLIGHT, not taking a crowd from JFK to SFO. Although we plan such flights heavily, a spaceflight will use resources and planning way beyond any airliner or corporate jet trip. The DC's cross-range will plotted for every rev. and abort plans will be made for every rev as well- otherwise, the flight will not go. Period.

I love the "bolt through the window" question. Here's what will happen... you'll either make it, or you won't. Simple as that.

Offline JAFO

  • Full Member
  • ****
  • Posts: 1032
    • My hobby
  • Liked: 875
  • Likes Given: 966
Re: Sierra Space Dream Chaser DISCUSSION Thread (was SNC)
« Reply #96 on: 09/18/2012 05:26 am »
Even if they divereted to an out of the way airport, a bigger problem would be clearing the airspace, especially during a heavy departure/arrival push. Would DC carry a transponder? If not, ATC wouldn't know where the vehicle was and where to send aircraft around it. They'd just have to scatter everyone.

(If DC did carry a transponder, would they squawk 1701?)
« Last Edit: 09/18/2012 05:30 am by JAFO »
Anyone can do the job when things are going right. In this business we play for keeps.
— Ernest K. Gann

Offline john smith 19

  • Senior Member
  • *****
  • Posts: 10350
  • Everyplaceelse
  • Liked: 2430
  • Likes Given: 13605
Re: Sierra Space Dream Chaser DISCUSSION Thread (was SNC)
« Reply #97 on: 09/29/2012 05:45 pm »
Shuttle did aborted.. to orbit. But still an abort. The big question would be about a pad abort, for example. Or an abort and ditch.

Interesting data point. That gives what, a 1 in 134 chance of an abort?
Roughly 0.75% of *all* flights ended in an abort. Of course on this basis 1.5% of all flights ended in a LOC

I'm going to stay with my original view that until DC starts flying it's impossible to state *categorically* DC will be more (or less) abort prone than Shuttle.

I *believe* its abort modes will be more benign than Shuttle simply because its stack design is different from Shuttles.

Sticking an ATC transponder (or 2 for redundancy) seems a pretty good idea. I'm not sure it's even *legal* to land at a commercial airport in the US without one and it's definitely the "neighborly" thing to do
MCT ITS BFR SS. The worlds first Methane fueled FFSC engined CFRP SS structure A380 sized aerospaceplane tail sitter capable of Earth & Mars atmospheric flight.First flight to Mars by end of 2022 TBC. T&C apply. Trust nothing. Run your own #s "Extraordinary claims require extraordinary proof" R. Simberg."Competitve" means cheaper ¬cheap SCramjet proposed 1956. First +ve thrust 2004. US R&D spend to date > $10Bn. #deployed designs. Zero.

Offline JAFO

  • Full Member
  • ****
  • Posts: 1032
    • My hobby
  • Liked: 875
  • Likes Given: 966
Re: Sierra Space Dream Chaser DISCUSSION Thread (was SNC)
« Reply #98 on: 09/29/2012 09:20 pm »
I'm not sure it's even *legal* to land at a commercial airport in the US without one and it's definitely the "neighborly" thing to do

It is with prior arrangement. This can be as little as a radio call if it's not busy. If it's Newark at 1700 on Friday, fuggedaboudit.
Anyone can do the job when things are going right. In this business we play for keeps.
— Ernest K. Gann

Offline simonbp

  • Science Guy
  • Senior Member
  • *****
  • Posts: 7138
  • Liked: 314
  • Likes Given: 183
Re: Sierra Space Dream Chaser DISCUSSION Thread (was SNC)
« Reply #99 on: 09/30/2012 06:22 am »
(If DC did carry a transponder, would they squawk 1701?)

Only if it were named after OV-101... ;)

 

Advertisement NovaTech
Advertisement Northrop Grumman
Advertisement
Advertisement Margaritaville Beach Resort South Padre Island
Advertisement Brady Kenniston
Advertisement NextSpaceflight
Advertisement Nathan Barker Photography
0