Author Topic: Dawn Aerospace  (Read 32906 times)

Offline FutureSpaceTourist

  • Global Moderator
  • Senior Member
  • *****
  • Posts: 48138
  • UK
    • Plan 28
  • Liked: 81622
  • Likes Given: 36928
Dawn Aerospace
« on: 09/01/2021 07:47 am »
Couldn’t find a thread for: https://www.dawnaerospace.com/

They are working on reusable spaceplanes. The Mk II Aurora is suborbital and has begun flight (not yet rocket flight) test. The planned Mk III is a small sat launcher.
Media report on current testing:

https://newatlas.com/space/dawn-aerospace-aurora-reusable-spaceplane-demonstrator-test-flights/

Quote
Reusable spaceplane demonstrator completes 5 test flights in 3 days

By David Szondy
August 31, 2021

Dawn Aerospace has successfully completed five test flights of its uncrewed Mk-II Aurora suborbital spaceplane in the skies over Glentanner Aerodrome on New Zealand’s South Island. The flights were conducted by the New Zealand-Dutch space transportation company from July 28 to 30, 2021 at altitudes of up to 3,400 feet (1,036 m), with the prototype airframe fitted with surrogate jet engines.

P.S. First 2 attachments are fine when opened, don’t know why they’re black in preview :(
« Last Edit: 09/01/2021 07:48 am by FutureSpaceTourist »

Offline FutureSpaceTourist

  • Global Moderator
  • Senior Member
  • *****
  • Posts: 48138
  • UK
    • Plan 28
  • Liked: 81622
  • Likes Given: 36928
Re: Dawn Aerospace
« Reply #1 on: 09/01/2021 07:51 am »
Some YT videos






Offline jdon759

  • Full Member
  • *
  • Posts: 117
  • Liked: 105
  • Likes Given: 108
Re: Dawn Aerospace
« Reply #2 on: 09/01/2021 09:21 am »
I'm not sure this thread should be in commercial crew vehicles...

Yay!  I quite like Dawn.  They used to have a pretty unique plan for their rockets: selling orbital downmass rather than upmass.  Unfortunately, it looks like in the last ~11 months since I checked their progress, they've done away with that plan  :'( .  But that does nothing to reduce the elegant appearance of their suborbital rocket & (now 2-stage) launcher.
« Last Edit: 09/01/2021 09:22 am by jdon759 »

Offline FutureSpaceTourist

  • Global Moderator
  • Senior Member
  • *****
  • Posts: 48138
  • UK
    • Plan 28
  • Liked: 81622
  • Likes Given: 36928
Re: Dawn Aerospace
« Reply #3 on: 09/06/2021 08:45 am »

Offline TrevorMonty

Re: Dawn Aerospace
« Reply #4 on: 09/06/2021 09:49 am »

Mark 2 engine test.

Sent from my SM-G570Y using Tapatalk


Offline TrevorMonty

Re: Dawn Aerospace
« Reply #5 on: 08/16/2022 09:47 am »
Dawn have been busy landing Rocket Powered space planes and sell small in space thrusters.

https://twitter.com/DawnAerospace?t=hf5SNfl0U2kgXgbAXpnK1g&s=09
« Last Edit: 08/17/2022 08:31 am by zubenelgenubi »

Offline Rik ISS-fan

  • Full Member
  • ****
  • Posts: 1519
  • the Netherlands
  • Liked: 617
  • Likes Given: 211
Re: Dawn Aerospace
« Reply #6 on: 08/20/2022 01:57 pm »
Finally some other NSF member got aware of Dawn Aerospace and started a topic.
I think they are progressing very well on several developments. Possibly I'll share more info on request.

Offline john smith 19

  • Senior Member
  • *****
  • Posts: 10350
  • Everyplaceelse
  • Liked: 2430
  • Likes Given: 13605
Re: Dawn Aerospace
« Reply #7 on: 08/20/2022 03:14 pm »
Finally some other NSF member got aware of Dawn Aerospace and started a topic.
I think they are progressing very well on several developments. Possibly I'll share more info on request.
Information is always appreciated.

However whenever I see one of these my first question is "So how you handling the Centre-of-Pressure/Centre-of-Mass shifting that's going on as you go from M0 to Mupper-stage-seperation" ?

Hint. Nothing has the operating Mach range of a launcher spaceplane. 

They don't look much different that Radian. I'm not seeing anything very substantial here either.  :(

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.

Re: Dawn Aerospace
« Reply #8 on: 08/21/2022 02:13 am »
They don't look much different that Radian. I'm not seeing anything very substantial here either.  :(

???
Radian has no hardware, while Dawn has small scale prototypes. Radian is trying to build a crewed vehicle, while Dawn's goal is an uncrewed smallsat launcher. Radian wants to build an SSTO, and Dawn is only trying for a two-stage design. They aren't really comparable at all.
Wait, ∆V? This site will accept the ∆ symbol? How many times have I written out the word "delta" for no reason?

Offline john smith 19

  • Senior Member
  • *****
  • Posts: 10350
  • Everyplaceelse
  • Liked: 2430
  • Likes Given: 13605
Re: Dawn Aerospace
« Reply #9 on: 08/21/2022 10:51 am »

???
Radian has no hardware, while Dawn has small scale prototypes. Radian is trying to build a crewed vehicle, while Dawn's goal is an uncrewed smallsat launcher. Radian wants to build an SSTO, and Dawn is only trying for a two-stage design. They aren't really comparable at all.
I'll admit that was a little harsh. They have complete flight hardware
Radian has been conducting test firings at Brereton airport for some time, but that's about all.

I'm just very weary of a company that shows videos with no humans in shot (for scale) and a flight time of less than 2 minutes.  :( There website says it's 4.8m long (IE just shy of 16 feet) and HTP/Kero. With an empty weight of 75Kg and GTOW of 280Kg thats a structural fraction of 26.7% and a stated goal of M3 to give microgravity of 180secs at above 100Km IE space.

That potentially opens up the market for academic institutions and businesses that want sounding rocket type access with on-demand availablility.  If they sell this as a turn-key package that will be a paradign shift in the industry from solid fuel expendable sounding rockets.

Beyond that  the Cp/Cm shift over the Mach range will be tough with an engine in the tail.

The Mark III is supposed to be 18000Kg and a 250Kg to LEO. That's a payload fraction of 1.38%. Not what you'd expect from a TSTO with an expendable US.  This suggests either
a) It'll be a TSTO and the US will be 1)Cost optimised IE Heavy, expendable or 2)Recoverable and reusable.
or
b) They are going to extend the Mark II into a full SSTO.

a) suggests the funders will take the payload hit, having been convinced the market is there to support it at the price Dawn say they can offer. 2) would be very clever, very bold and very implausible.
b) They are esssentially in Radian territory. Needing either a radical improvement in materials or structural architecture to cut the structural fraction a lot, or some super-duper engine tech to seriously raise the Isp (from 100s to 1000s of seconds).

As with Radian time will tell if they really have something special or if they are playing the Silicon Valley strategy of "Do the easy(ish) bits first and hope/pray some highly-caffinated-engineer/glory hungry intern has an astonishing-deep-insights-giving-a-viable-but-unexpected-solution/one-night-stand with Tony Stark/something- else" happens which solves the problem.

Their plan, as sketched out so far, does not appear capable of delivering the stated end result. The numbers just don't work out.  :( Exactly like Radian.

I will admit the scenery around the airport is pretty spectacular. Something about it said "Colorado" to me :)

More than 3 decades since REL laid out in Spaceflight why Skylon had the engine positions it did and what happens if you try to operate with rear-mounted engines over a large Mach range and it seems that yet another spaceplane startup is going to ignore them.  :(

I will wish them luck and look forward to seeing what progress they make.
« Last Edit: 08/21/2022 10:59 am by john smith 19 »
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 TrevorMonty

Re: Dawn Aerospace
« Reply #10 on: 08/21/2022 11:13 am »



???
Radian has no hardware, while Dawn has small scale prototypes. Radian is trying to build a crewed vehicle, while Dawn's goal is an uncrewed smallsat launcher. Radian wants to build an SSTO, and Dawn is only trying for a two-stage design. They aren't really comparable at all.
I'll admit that was a little harsh. They have complete flight hardware
Radian has been conducting test firings at Brereton airport for some time, but that's about all.

I'm just very weary of a company that shows videos with no humans in shot (for scale) and a flight time of less than 2 minutes.  :( There website says it's 4.8m long (IE just shy of 16 feet) and HTP/Kero. With an empty weight of 75Kg and GTOW of 280Kg thats a structural fraction of 26.7% and a stated goal of M3 to give microgravity of 180secs at above 100Km IE space.

That potentially opens up the market for academic institutions and businesses that want sounding rocket type access with on-demand availablility.  If they sell this as a turn-key package that will be a paradign shift in the industry from solid fuel expendable sounding rockets.

Beyond that  the Cp/Cm shift over the Mach range will be tough with an engine in the tail.

The Mark III is supposed to be 18000Kg and a 250Kg to LEO. That's a payload fraction of 1.38%. Not what you'd expect from a TSTO with an expendable US.  This suggests either
a) It'll be a TSTO and the US will be 1)Cost optimised IE Heavy, expendable or 2)Recoverable and reusable.
or
b) They are going to extend the Mark II into a full SSTO.



MK2 is suborbital only vehicle.

MK3 will be expendable 2nd stage with HTOHL booster ie rocket spaceplane. Mass fractions are about right for this RLV, given boosters extra dry mass due to wings and need to RTLS.

Electron is 2.3% as ELV.

Video is first rocket powered flight of MK2 which is quite an achievement especially as its an automous rocket plane built on shoestring budget. Over next few months they should slowly increase altitude.


Offline john smith 19

  • Senior Member
  • *****
  • Posts: 10350
  • Everyplaceelse
  • Liked: 2430
  • Likes Given: 13605
Re: Dawn Aerospace
« Reply #11 on: 08/21/2022 02:00 pm »

MK2 is suborbital only vehicle.
Saw that on their website.
Quote from: TrevorMonty
MK3 will be expendable 2nd stage with HTOHL booster ie rocket spaceplane. Mass fractions are about right for this RLV, given boosters extra dry mass due to wings and need to RTLS.
It will be noted that Musk is claiming a 2% payload fraction for Starship, with full reusability.
Quote from: TrevorMonty
Electron is 2.3% as ELV.
Which may be a fairer comparison. The question of course will be how big a payload hit will RL take for booster recovery? If <0.9% they still come out ahead.
Quote from: TrevorMonty
Video is first rocket powered flight of MK2 which is quite an achievement especially as its an automous rocket plane built on shoestring budget. Over next few months they should slowly increase altitude.
[/i]
Let's hope so.
That's sort of the point. Electron can do 2.3% of take off mass.
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.

Re: Dawn Aerospace
« Reply #12 on: 08/22/2022 04:29 am »
Radian has been conducting test firings at Brereton airport for some time, but that's about all.

I didn't know that. Awesome

More than 3 decades since REL laid out in Spaceflight why Skylon had the engine positions it did and what happens if you try to operate with rear-mounted engines over a large Mach range and it seems that yet another spaceplane startup is going to ignore them.  :(

The website says that the Mk-II's max speed is "Mach 3+". That's SR-71 territory. Difficult, but plenty achievable, particularly when using a rocket rather than an advanced jet engine. A rear engine will be just fine for the Mk-II.

Mk-III is trickier, since first stage typically go much faster (Mach 10 for F9, Mach 16 for Atlas V). I guess it's possible that they intend for the Mk-III to be more of a pop-up rocket, like the crazy and inefficient proposals that have been discussed for making New Shepard a smallsat launcher. In the end I'm not too worried about it, because the Mk-III isn't what they're working on right now. Perhaps when they start actually working on it, they will discover that they have to redesign it to have centrally mounted engines, but that is a problem for later.
Wait, ∆V? This site will accept the ∆ symbol? How many times have I written out the word "delta" for no reason?

Offline john smith 19

  • Senior Member
  • *****
  • Posts: 10350
  • Everyplaceelse
  • Liked: 2430
  • Likes Given: 13605
Re: Dawn Aerospace
« Reply #13 on: 08/22/2022 12:39 pm »
I didn't know that. Awesome
Yes. They are not entirely powerpoint engineering.
Quote from: JEF_300
The website says that the Mk-II's max speed is "Mach 3+". That's SR-71 territory. Difficult, but plenty achievable, particularly when using a rocket rather than an advanced jet engine. A rear engine will be just fine for the Mk-II.

Mk-III is trickier, since first stage typically go much faster (Mach 10 for F9, Mach 16 for Atlas V). I guess it's possible that they intend for the Mk-III to be more of a pop-up rocket, like the crazy and inefficient proposals that have been discussed for making New Shepard a smallsat launcher. In the end I'm not too worried about it, because the Mk-III isn't what they're working on right now. Perhaps when they start actually working on it, they will discover that they have to redesign it to have centrally mounted engines, but that is a problem for later.
Yes that's pretty much what I expect them to do.  It puts them back at square one in design terms however.  :( What Mark II teaches them about the flying characteristics of the vehicle is unlikely to transfer to their new Mark III design

I'm not sure what it's made of. If it's CFRC then without serious TPS their operating limits will not be far above M3 anyway.
« Last Edit: 08/22/2022 12:40 pm by john smith 19 »
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 TrevorMonty

Re: Dawn Aerospace
« Reply #14 on: 08/22/2022 01:27 pm »
I didn't know that. Awesome
Yes. They are not entirely powerpoint engineering.
Quote from: JEF_300
The website says that the Mk-II's max speed is "Mach 3+". That's SR-71 territory. Difficult, but plenty achievable, particularly when using a rocket rather than an advanced jet engine. A rear engine will be just fine for the Mk-II.

Mk-III is trickier, since first stage typically go much faster (Mach 10 for F9, Mach 16 for Atlas V). I guess it's possible that they intend for the Mk-III to be more of a pop-up rocket, like the crazy and inefficient proposals that have been discussed for making New Shepard a smallsat launcher. In the end I'm not too worried about it, because the Mk-III isn't what they're working on right now. Perhaps when they start actually working on it, they will discover that they have to redesign it to have centrally mounted engines, but that is a problem for later.
Yes that's pretty much what I expect them to do.  It puts them back at square one in design terms however.  :( What Mark II teaches them about the flying characteristics of the vehicle is unlikely to transfer to their new Mark III design

I'm not sure what it's made of. If it's CFRC then without serious TPS their operating limits will not be far above M3 anyway.
The heat loads for suborbital plane shouldn't be that high, see Virgin SpaceShip2.

Offline john smith 19

  • Senior Member
  • *****
  • Posts: 10350
  • Everyplaceelse
  • Liked: 2430
  • Likes Given: 13605
Re: Dawn Aerospace
« Reply #15 on: 08/22/2022 05:36 pm »
The heat loads for suborbital plane shouldn't be that high, see Virgin SpaceShip2.
Except Mark III is not designed to be a sub-orbital plane.

It's designed as the booster stage for a full up orbital launch vehicle.

Staying with a maximum speed of M3 leaves the upper stage needing to make 19-20Machs to get to orbit.

Historically the rule of thumb has been to split the delta 50/50 booster to US, but F9 its more 1/4-3/4s, so at least M6.

So I think it's safe to say Mark III will need to at least double the top speed of Mark II.

Time will tell how that works out for them.
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 CameronD

  • Senior Member
  • *****
  • Posts: 2374
  • Melbourne, Australia
    • Norton Consultants
  • Liked: 868
  • Likes Given: 548
Re: Dawn Aerospace
« Reply #16 on: 08/22/2022 11:36 pm »
James Powell on LinkedIn:
Quote
Pushing toward 40 flights, averaging just under 1 a week now.
With sufficient thrust, pigs fly just fine - however, this is not necessarily a good idea. It is hard to be sure where they are
going to land, and it could be dangerous sitting under them as they fly overhead.

Offline FutureSpaceTourist

  • Global Moderator
  • Senior Member
  • *****
  • Posts: 48138
  • UK
    • Plan 28
  • Liked: 81622
  • Likes Given: 36928
Re: Dawn Aerospace
« Reply #17 on: 09/21/2022 10:39 am »

Offline john smith 19

  • Senior Member
  • *****
  • Posts: 10350
  • Everyplaceelse
  • Liked: 2430
  • Likes Given: 13605
Re: Dawn Aerospace
« Reply #18 on: 09/21/2022 01:02 pm »

OMG I knew it was small but it's actually tiny

It's teeny tiny.  :)

That moment at the end surrounding the vehicle was a real LOL moment.  :)

I thought it was an airport, but actually, I think it's a road.

This has put a real smile on my face. Both very serious and utterly hilarious at the same time.

That said GNC and flight dynamics issues dont really scale (except when they get worse), so there's a lot to be said to solving issues with them at the smallest possible scale, before you scale up, so the control systems are rock solid. If they couldn't get it flying well at this scale they'd be doomed when they scale up.

I'll wish them well with their test plan.
« Last Edit: 09/21/2022 01:07 pm by john smith 19 »
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 TrevorMonty

Re: Dawn Aerospace
« Reply #19 on: 09/21/2022 05:52 pm »

OMG I knew it was small but it's actually tiny

It's teeny tiny.  :)

That moment at the end surrounding the vehicle was a real LOL moment.  :)

I thought it was an airport, but actually, I think it's a road.

This has put a real smile on my face. Both very serious and utterly hilarious at the same time.

That said GNC and flight dynamics issues dont really scale (except when they get worse), so there's a lot to be said to solving issues with them at the smallest possible scale, before you scale up, so the control systems are rock solid. If they couldn't get it flying well at this scale they'd be doomed when they scale up.

I'll wish them well with their test plan.
They operate out of strip near Mt Cook. COVID would of reduced tourist scenic flight air traffic considerably as borders have been closed for two years.

Offline john smith 19

  • Senior Member
  • *****
  • Posts: 10350
  • Everyplaceelse
  • Liked: 2430
  • Likes Given: 13605
Re: Dawn Aerospace
« Reply #20 on: 09/22/2022 07:59 pm »
They operate out of strip near Mt Cook. COVID would of reduced tourist scenic flight air traffic considerably as borders have been closed for two years.
That would explaine the total absence of people in shot.

There is something about the scenery that puts me in mind of the Colorado Rockies, but I'm not really sure why?

I wish them luck with the rest of the test programme and their future plans.
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: Dawn Aerospace
« Reply #21 on: 09/23/2022 02:56 pm »
The heat loads for suborbital plane shouldn't be that high, see Virgin SpaceShip2.
Except Mark III is not designed to be a sub-orbital plane.

It's designed as the booster stage for a full up orbital launch vehicle.

Staying with a maximum speed of M3 leaves the upper stage needing to make 19-20Machs to get to orbit.

Historically the rule of thumb has been to split the delta 50/50 booster to US, but F9 its more 1/4-3/4s, so at least M6.

So I think it's safe to say Mark III will need to at least double the top speed of Mark II.

Time will tell how that works out for them.
Just getting to vacuum and above the atmosphere with an initial push helps a lot. ~20% higher Isp and thrust (if optimized), no need for a fairing, no drag, and you can start out with a much lower thrust to weight ratio.

A single stage to orbit stage on the ground is hard because you need 9.3km/s or whatever. But with 15-20% higher Isp and thrust and without needing to worry about aero loads and ability to have a T/W ratio lower than 1? Easy. And 7-8km/s is probably all you need. Piece of cake.

A “pop-up” stage is an appropriate approach to solving these problems.

The spaceplane doesn’t need to operate for long periods at hypersonic speeds in the atmosphere. High supersonic is fine. The aero thermal problem is much easier than an airbreathing hypersonic bomber or whatever.

This is more comparable to XCOR’s Lynx than to SpaceShipOne. Lynx Mk3 was going to do a similar mission to Dawn’s Mark III, just that Dawn is doing it uncrewed.
« Last Edit: 09/23/2022 03:07 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 TrevorMonty

Re: Dawn Aerospace
« Reply #22 on: 09/26/2022 08:51 am »
From miltary point of view Dawn's spaceplane has significant advantage over pad based LVs. In a war launch pads would be high value targets and take out in short order if possible. Dawn's plane can operate from any airfield making them lot more resilent to attack. Being able to replaced down satellites quickly from remote airfields is big plus.

Offline john smith 19

  • Senior Member
  • *****
  • Posts: 10350
  • Everyplaceelse
  • Liked: 2430
  • Likes Given: 13605
Re: Dawn Aerospace
« Reply #23 on: 10/12/2022 07:08 am »
From miltary point of view Dawn's spaceplane has significant advantage over pad based LVs. In a war launch pads would be high value targets and take out in short order if possible. Dawn's plane can operate from any airfield making them lot more resilent to attack. Being able to replaced down satellites quickly from remote airfields is big plus.
If things have gotten to the stage where launch pads are being targetted so will airfields.  :(

OTOH it does offer the practical benefit of simpler (not simple) operations, provided the S2 is designed for straightforward loading and preparation. That means no solids, no NTO/UDMH type storables.
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 trimeta

  • Full Member
  • ****
  • Posts: 1685
  • Kansas City, MO
  • Liked: 2146
  • Likes Given: 57
Re: Dawn Aerospace
« Reply #24 on: 10/12/2022 03:46 pm »
If things have gotten to the stage where launch pads are being targetted so will airfields.  :(
There are far more airfields than launch pads.

Of course, no air-launch vehicle can really launch from just any airfield; specific ground support equipment is needed, and could be targeted. But if that equipment is also mobile, perhaps finding it is harder.

Offline Zed_Noir

  • Senior Member
  • *****
  • Posts: 5490
  • Canada
  • Liked: 1809
  • Likes Given: 1302
Re: Dawn Aerospace
« Reply #25 on: 10/13/2022 11:38 pm »
If things have gotten to the stage where launch pads are being targetted so will airfields.  :(
There are far more airfields than launch pads.

Of course, no air-launch vehicle can really launch from just any airfield; specific ground support equipment is needed, and could be targeted. But if that equipment is also mobile, perhaps finding it is harder.
In theory and field exercises airfield can be replaced by a stretch of roadway and wheeled GSE vehicles (off road capable military trucks). However keeping the aircraft in service and generating sorties will be much harder.

Offline john smith 19

  • Senior Member
  • *****
  • Posts: 10350
  • Everyplaceelse
  • Liked: 2430
  • Likes Given: 13605
Re: Dawn Aerospace
« Reply #26 on: 10/14/2022 03:30 pm »
In theory and field exercises airfield can be replaced by a stretch of roadway and wheeled GSE vehicles (off road capable military trucks). However keeping the aircraft in service and generating sorties will be much harder.
True, as has been SOP for Sweden for decades.

OTOH it depends what you want from an airfield.  A 1Km/3280 ft runaway. Plenty.
Apparently the range of common commercial airline runways runs roughly 2438-3962m/8-13000ft according to this guy (https://www.stantec.com/en/ideas/topic/mobility/how-long-is-an-airport-s-runway )

Keep in mind if you want to operate out of an airport you'll need one or more support aircraft. They could well be siderably bigger.

Also consider the recent Skyrora launch. Basically 4 shipping containers (admittedly the one carrying the sounding rocket looks like a special design) in more-or-less an empty field. Going back further you have the V2 on its copper "milking stool" blast deflector with a couple of APC's for the control room.

Anyone asking "How small can you make an ELV" should look at the Black Arrow. 13m long and 2m in diameter to put 135Kg in a 220Km orbit, although a significant part of the delta V was from the Waxwing solid S3.

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.

Online edzieba

  • Virtual Realist
  • Senior Member
  • *****
  • Posts: 6104
  • United Kingdom
  • Liked: 9325
  • Likes Given: 39
Re: Dawn Aerospace
« Reply #27 on: 10/15/2022 07:26 pm »
Sweden also has roads designed specifically to double as runways (straight, level, widened, specialised markings added, either cleared of obstructions like signage and lighting or with signage and lighting designed to be very rapidly removed to flush ground level, etc), and aircraft designed to launch from roads (more tolerant wheels, short take-off distance, etc), and pre-placed hardened bunkers near roads to store aircraft and ground handling kit. You can't just pick some random roads and aircraft and expect things to work. Many countries that implemented Highway Strips have since ceased the practice, including Sweden.

Launch-site-in-a-box (or the good old TEL) is much more viable than trying to shoehorn a rocket-carrier aircraft into a size and performance that allows it to take off from converted roadways whilst also acting as a launch platform.

Offline john smith 19

  • Senior Member
  • *****
  • Posts: 10350
  • Everyplaceelse
  • Liked: 2430
  • Likes Given: 13605
Re: Dawn Aerospace
« Reply #28 on: 10/16/2022 09:20 am »
Launch-site-in-a-box (or the good old TEL) is much more viable than trying to shoehorn a rocket-carrier aircraft into a size and performance that allows it to take off from converted roadways whilst also acting as a launch platform.
On that basis Skyrora is a more credible candidate for this sort of scenario. Those picturse of the Iclandic launch site show essentially an empty field with 4 shipping containers in it.
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 su27k

  • Senior Member
  • *****
  • Posts: 6414
  • Liked: 9100
  • Likes Given: 885
Re: Dawn Aerospace
« Reply #30 on: 12/07/2022 01:58 am »
https://twitter.com/DawnAerospace/status/1600219483985293312

Quote
$20 million for spaceplanes and green satellite propulsion! 🎉🛰️🌱

We are proud to announce Dawn Aerospace has secured #funding from Kiwi investors -
@IcehouseVenture, @gd1_vc and @movac_vc 👏

#spacetech #vc #capitalraise

Offline TrevorMonty

Re: Dawn Aerospace
« Reply #31 on: 12/23/2022 04:40 am »
Aurora II now has a rocket engine, not enough for 100km suborbital flights but enough to do some high altitude flight testing. I think the two tests in one day were engine not flight tests.

https://twitter.com/DawnAerospace/status/1605702819301842944?t=Uhig3a8YgyShH59_xDhEvw&amp;s=19

Offline FutureSpaceTourist

  • Global Moderator
  • Senior Member
  • *****
  • Posts: 48138
  • UK
    • Plan 28
  • Liked: 81622
  • Likes Given: 36928
Re: Dawn Aerospace
« Reply #32 on: 02/01/2023 07:16 am »
https://twitter.com/dawnaerospace/status/1620697153336401921

Quote
A milestone for hydrazine replacement: we now have 50 Dawn #satellite thrusters in orbit, all powered by non-toxic propellants! 🛰️

To celebrate, @Stefan__Powell has written an update on #nitrous - why people love it, its drawbacks, and the road ahead👇

https://www.dawnaerospace.com/latest-news/prevalence-of-nitrous-based-in-space-propellants

Offline FutureSpaceTourist

  • Global Moderator
  • Senior Member
  • *****
  • Posts: 48138
  • UK
    • Plan 28
  • Liked: 81622
  • Likes Given: 36928
Re: Dawn Aerospace
« Reply #33 on: 03/01/2023 02:47 pm »
https://twitter.com/jeff_foust/status/1630957313837113346

Quote
Khaki Rodway of Dawn Aerospace says at #NSRC2023 this morning that the company plans to start rocket-powered test flights of its Mk II Aurora spaceplane this month in New Zealand; subscale prototype of its Mk III vehicle, capable of going up to 100 km.

Offline FutureSpaceTourist

  • Global Moderator
  • Senior Member
  • *****
  • Posts: 48138
  • UK
    • Plan 28
  • Liked: 81622
  • Likes Given: 36928
Re: Dawn Aerospace
« Reply #34 on: 03/01/2023 02:50 pm »
More context:

https://twitter.com/spacecom/status/1630955318669893636

Quote
Khaki Rodway, Dawn Aerospace: Building a two-stage to orbit spaceplane. Started with subscale jet powered version to test out systems and air frame, flew 47 times. Concluded flights in September. #nsrc2023

Jet engine replaced with rocket engine, did a tie down test. Will fly a rocket powered flight test later this month. #nsrc2023

Rodway: Phase II of the flight system is suborbital flights above 100 km (Karman line) with payload. Dawn Mk-II Aurora and Mk-III are remotely piloted. Hope to have Phase II completed by the end of the year. Mk-III wouldbe capable of deploying satellites to orbit.

Rodway: Development and testing being done in New Zealand. Will be brought to the USA. If Phase II is completed this year, will be in operation on suborbital flights by this time in 2024. #nsrc2023

Rodway: Would like to have a vehicle in every spaceport. #nsrc2023

Offline Robotbeat

  • Senior Member
  • *****
  • Posts: 39270
  • Minnesota
  • Liked: 25240
  • Likes Given: 12115
Re: Dawn Aerospace
« Reply #35 on: 03/01/2023 03:05 pm »
I actually like this concept a lot. Like XCOR’s Lynx but uncrewed (which honestly makes more sense nowadays, although ironically makes it harder to get approval in the US! …hence New Zealand flight testing…).

It’s a pretty straightforward path to HTHL reusable space launch, starting at low performance reusable first stage but with rockets, which are scalable smoothly all the way (potentially) to orbit as performance improvements are done.

HTHL does have advantages in terms of launch sites, which are getting crowded now.
« Last Edit: 03/01/2023 03:25 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 TrevorMonty

Re: Dawn Aerospace
« Reply #36 on: 03/01/2023 06:44 pm »
There is potential for Aurora MK2 to generate a good revenue stream for Dawn.

Offline john smith 19

  • Senior Member
  • *****
  • Posts: 10350
  • Everyplaceelse
  • Liked: 2430
  • Likes Given: 13605
Re: Dawn Aerospace
« Reply #37 on: 03/03/2023 05:25 pm »
It’s a pretty straightforward path to HTHL reusable space launch, starting at low performance reusable first stage but with rockets, which are scalable smoothly all the way (potentially) to orbit as performance improvements are done.
AFAIK there are two 2 stage HTO aircraft systems that were actually built. Both in the 1930's and both designed to carry passengers at slower speed and the second stage to carry mail, across the Atlantic IIRC. Look up Mercury Maia.

IOW the experience for this sort of systems is both a)Very small b)Very old.

IIRC Len Cornier, ex-North American Aviation was one of the strongetst advocates of this concept but when you compare the 300+secs of any rocket that's not burnging H2 and the 3 000+ secs of an air breather your design has to deliver something very special to justify an all-rocket system.  :(
HTHL does have advantages in terms of launch sites, which are getting crowded now.
That's less a matter of the takeoff site as the 1000s of Km of down-range due to their history of ICBMs :(

[EDIT. It comes down to this. Does their cunning plan eliminate a stage? Two stages is the minimum number for an orbital launcher in common usage. If they can't match that then you're looking at two unique vehicles  because of sizing (unless they  plan to implement a horizontal biemese concept, which would be quite bold) and some kind of upper stage to get the final yard up the hill.
 If they are really going TSTO then they are going to need some orbit-grade TPS to survive re-entry. We know that's possible because Shuttle did it. The question is wheather it's commercially affordable  :( ]



But we'll see. It's a bit more plausible than Radian.
« Last Edit: 03/04/2023 10:05 am by john smith 19 »
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 Action

  • Member
  • Posts: 90
  • Massachusetts
  • Liked: 76
  • Likes Given: 9
Re: Dawn Aerospace
« Reply #38 on: 03/04/2023 06:55 pm »
IIRC Len Cornier, ex-North American Aviation

I think it's Len Cormier.

Offline john smith 19

  • Senior Member
  • *****
  • Posts: 10350
  • Everyplaceelse
  • Liked: 2430
  • Likes Given: 13605
Re: Dawn Aerospace
« Reply #39 on: 03/04/2023 11:15 pm »
IIRC Len Cornier, ex-North American Aviation

I think it's Len Cormier.
You're right.  It's been a long time since I met him.
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 Gliderflyer

Re: Dawn Aerospace
« Reply #40 on: 03/04/2023 11:47 pm »
I actually like this concept a lot. Like XCOR’s Lynx but uncrewed (which honestly makes more sense nowadays, although ironically makes it harder to get approval in the US! …hence New Zealand flight testing…).

It’s a pretty straightforward path to HTHL reusable space launch, starting at low performance reusable first stage but with rockets, which are scalable smoothly all the way (potentially) to orbit as performance improvements are done.

HTHL does have advantages in terms of launch sites, which are getting crowded now.
They are very much like XCOR (they even use CSJ engines). I wonder if they will realize why tip rudders are nice once they start expanding the flight envelope; I wouldn't be surprised if it gets more Lynx-like in the future.

I also wonder if they will eventually evolve to something similar to XCOR's orbital concept.
I tried it at home

Offline john smith 19

  • Senior Member
  • *****
  • Posts: 10350
  • Everyplaceelse
  • Liked: 2430
  • Likes Given: 13605
Re: Dawn Aerospace
« Reply #41 on: 03/06/2023 04:59 pm »
They are very much like XCOR (they even use CSJ engines). I wonder if they will realize why tip rudders are nice once they start expanding the flight envelope; I wouldn't be surprised if it gets more Lynx-like in the future.

I also wonder if they will eventually evolve to something similar to XCOR's orbital concept.
Sounds plausible.

But the more I dig into TSTO HTOL concepts the more doubts I have.  :(

My little design game for Radian made it very tough to see how it was possible to make orbit. You have to pack so much into such a small structural fraction because a rocket Isp is about 1/6 what an air breather can give you (while it can breath air of course).

I had great respect for the XCOR crew and I really wanted them to succeed but I still can't figure out how they were going to get to orbit, even with a two stage Lynx. Next to Reaction Engines they were the "last men standing" (I think Masten was formed after them and Armadillo shut down before them) from that wave of space startups.  :(
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 FutureSpaceTourist

  • Global Moderator
  • Senior Member
  • *****
  • Posts: 48138
  • UK
    • Plan 28
  • Liked: 81622
  • Likes Given: 36928
Re: Dawn Aerospace
« Reply #42 on: 03/23/2023 11:27 pm »
https://twitter.com/dawnaerospace/status/1639060304264056832

Quote
✅Dawn's Mk-II Aurora spaceplane has been certified for rocket-powered flight! 🚀An update from our CEO, @Stefan__Powell:

https://www.dawnaerospace.com/latest-news/certified-and-ready-for-rocket-powered-flight

Quote
Certified and Ready for Rocket-Powered Flight
Mar 24

Mk-II Aurora Integrated Ground Test

By Stefan Powell, CEO

I am excited to announce we have received certification from the Civil Aviation Authority of New Zealand (CAA) for the imminent rocket-powered flight campaign of our Mk-II Aurora spaceplane. The mission of the Mk-II Aurora is to fly to space twice in a day and, in doing so, demonstrate that rocket-powered systems can be as reusable as commercial aircraft. This marks the first time a remotely piloted, rocket-powered vehicle has been certified for flight out of a civil airport.

Certification as an aircraft is a crucial step towards our mission, as it allows us to operate without excluding other airspace users. This enables us to integrate with existing airspace and fly as frequently as the vehicle permits, rather than as often as we can clear the airspace.

In the past, utilising surrogate jet engines, we have achieved two flights within hours and four flights in a day. Rapid reusability is a key property that enables both swift iteration in development and unparalleled utility of the end product.

Aside from being a key technology demonstrator, the Mk-II holds significant commercial promise as a suborbital vehicle, spanning a wide range of applications such as earth monitoring, microgravity research, disaster management, and in-situ atmospheric measurements - providing unprecedented enhancements to weather and climate models.

Our team has been diligently designing and building the Mk-II Aurora spaceplane since 2018. We have completed 48 test flights using jet engines, validating all non-rocket systems.

We have now also concluded static integrated testing of the Mk-II Aurora engine. During the rocket engine's development, it was fired 112 times, including seven instances where it was integrated with the vehicle.

With vehicle certification and integration testing completed, we are thrilled to announce that rocket-powered flights are set to begin within the next month. 

Initial flights will continue to follow a build-up approach, as we have done in the past. The first flights will reach modest speeds and altitudes while aiming to maintain the rapid test cadence we have previously demonstrated using surrogate jet engines.

Exciting times ahead!

Offline Lampyridae

  • Veteran
  • Senior Member
  • *****
  • Posts: 2641
  • South Africa
  • Liked: 949
  • Likes Given: 2056
Re: Dawn Aerospace
« Reply #43 on: 03/24/2023 11:05 am »
Small note: it's hard to see in their pic but the Mk-III has two pods for what appear to be air-breathing engines. Likely for self-ferry, loiter and return to launch (takeoff?) site.

Offline TrevorMonty

Re: Dawn Aerospace
« Reply #44 on: 03/24/2023 05:16 pm »
Small note: it's hard to see in their pic but the Mk-III has two pods for what appear to be air-breathing engines. Likely for self-ferry, loiter and return to launch (takeoff?) site.
Think I can see them, easy to mistake for rocket engines.

Offline Steven Pietrobon

  • Member
  • Senior Member
  • *****
  • Posts: 39214
  • Adelaide, Australia
    • Steven Pietrobon's Space Archive
  • Liked: 32734
  • Likes Given: 8178
Re: Dawn Aerospace
« Reply #45 on: 03/25/2023 05:11 am »
Image of the ground test.
Akin's Laws of Spacecraft Design #1:  Engineering is done with numbers.  Analysis without numbers is only an opinion.

Offline john smith 19

  • Senior Member
  • *****
  • Posts: 10350
  • Everyplaceelse
  • Liked: 2430
  • Likes Given: 13605
Re: Dawn Aerospace
« Reply #46 on: 03/25/2023 09:14 am »
Image of the ground test.
Looks like it could be narrow enough to fit in that shipping container.
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 Yiosie

  • Full Member
  • ****
  • Posts: 456
  • Liked: 635
  • Likes Given: 97
Re: Dawn Aerospace
« Reply #47 on: 04/05/2023 06:17 pm »
Dawn flies rocket-powered spaceplane [dated Apr. 5]

Quote from: SpaceNews
Dawn Aerospace completed its first series of rocket-powered flights last week.

Mk-II Aurora, a scaled down version of the spaceplane Dawn is developing for commercial operations, took to the skies March 29, 30 and 31 from New Zealand’s Gentanner Aerodrome.

The initial test campaign validated key flight systems and demonstrated the benefit of rapid reusability, Dawn CEO Stefan Powell told SpaceNews.

During the first flight, the Mk-II Aurora consumed more fuel than anticipated due to a leak in the propellant system. The next day, Dawn engineers removed the Mk-II Aurora engine, took out the oxidizer tank and found the leak.

“It was reasonably trivial to fix that, put it back together and fly again,” Powell said. “That speaks to just how different this concept is than a regular rocket. Not only would you have not gotten the vehicle back, but you wouldn’t have been able to execute a repair and show that it works in the same day.”

<snip>

The Mk-II is designed to reach an altitude of 20 kilometers. During initial flight tests, the vehicle flew to roughly 2,000 meters and traveled at a maximum speed of 315 kilometers per hour.

Offline TrevorMonty

Re: Dawn Aerospace
« Reply #48 on: 04/05/2023 06:45 pm »
Max altitude of 20km seems bit low for suborbital vehicle. If it can still provide a few minutes of zeroG then they should have viable business.

Offline russianhalo117

  • Global Moderator
  • Senior Member
  • *****
  • Posts: 8755
  • Liked: 4671
  • Likes Given: 768
Re: Dawn Aerospace
« Reply #49 on: 04/05/2023 07:12 pm »
Max altitude of 20km seems bit low for suborbital vehicle. If it can still provide a few minutes of zeroG then they should have viable business.
That is not a typo  for MK-II. Mk-III will be much higher and carry an expendable second stage to reach orbit.
« Last Edit: 04/05/2023 07:16 pm by russianhalo117 »

Offline whitelancer64

Re: Dawn Aerospace
« Reply #50 on: 04/05/2023 07:25 pm »
Max altitude of 20km seems bit low for suborbital vehicle. If it can still provide a few minutes of zeroG then they should have viable business.

They've said for a while that Phase II tests will end up sending the Mk-II plane to 100 km.

20 km may be the upper limit for Phase I testing.
"One bit of advice: it is important to view knowledge as sort of a semantic tree -- make sure you understand the fundamental principles, ie the trunk and big branches, before you get into the leaves/details or there is nothing for them to hang on to." - Elon Musk
"There are lies, damned lies, and launch schedules." - Larry J

Offline trimeta

  • Full Member
  • ****
  • Posts: 1685
  • Kansas City, MO
  • Liked: 2146
  • Likes Given: 57
Re: Dawn Aerospace
« Reply #51 on: 04/05/2023 08:29 pm »
This article from Eric Berger about the company clears up the confusion here:

Quote
The test campaign, which is taking place from the Glentanner Aerodrome in New Zealand, will eventually see this vehicle top out at about 20 kilometers. The lessons learned from this plane will be put into a second version of the Mk-II Aurora, which could take flight before the end of this year or early in 2024.

In an interview, Dawn Aerospace chief executive Stefan Powell said this second vehicle would have a far lighter structure, a more powerful engine, and other features that would allow it to climb far higher. The goal is to fly the spaceplane to an altitude of 100 km, above the internationally recognized boundary of space.

In other words, there are two Mk-II rocket planes, the one they're currently flying (which is capped at 20km), and the one they'll build using lessons learned from the current flight campaign (which will get to over 100km).

Offline FutureSpaceTourist

  • Global Moderator
  • Senior Member
  • *****
  • Posts: 48138
  • UK
    • Plan 28
  • Liked: 81622
  • Likes Given: 36928
Re: Dawn Aerospace
« Reply #52 on: 04/05/2023 10:39 pm »

Offline FutureSpaceTourist

  • Global Moderator
  • Senior Member
  • *****
  • Posts: 48138
  • UK
    • Plan 28
  • Liked: 81622
  • Likes Given: 36928
Re: Dawn Aerospace
« Reply #53 on: 04/06/2023 12:17 am »
https://twitter.com/wehavemeco/status/1643685079745536010

Quote
🎙️ Today on the show, I’m joined by Stefan Powell, CEO of @DawnAerospace, to talk about their big news: they flew their rocket-powered spaceplane 3 times in 3 days last week!

We chat about the company, their plans for the future, and their flights.

https://mainenginecutoff.com/podcast/244

Offline Robotbeat

  • Senior Member
  • *****
  • Posts: 39270
  • Minnesota
  • Liked: 25240
  • Likes Given: 12115
Re: Dawn Aerospace
« Reply #54 on: 04/06/2023 12:45 am »
I love it. I actually do think that at the very small scale, HTOL isn't totally nuts. And if it's in a place with rational air space regulations like New Zealand (not the US, obv), then you can make it a drone instead of crewed.

(This thing is tiny, right? Like 4.5 meters long? This is the same scale as one of those big hobby R/C 1:4 scale fighter jets.)

At this scale, you can be a garage startup and maybe hope to get to the Karman Line. Reusably. Then scale up and do maybe microlaunch or something with an HTOL first stage, ala Xcor's Lynx MkIII.
« Last Edit: 04/06/2023 12:50 am 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 russianhalo117

  • Global Moderator
  • Senior Member
  • *****
  • Posts: 8755
  • Liked: 4671
  • Likes Given: 768
Re: Dawn Aerospace
« Reply #55 on: 04/06/2023 12:55 am »
I love it. I actually do think that at the very small scale, HTOL isn't totally nuts. And if it's in a place with rational air space regulations like New Zealand (not the US, obv), then you can make it a drone instead of crewed.

(This thing is tiny, right? Like 4.5 meters long? This is the same scale as one of those big hobby R/C 1:4 scale fighter jets.)

At this scale, you can be a garage startup and maybe hope to get to the Karman Line. Reusably. Then scale up and do maybe microlaunch or something with an HTOL first stage, ala Xcor's Lynx MkIII.
Statement): Then scale up and do maybe microlaunch or something with an HTOL first stage, ala Xcor's Lynx MkIII.

Reply): That is the exact goal of the large full size Mk-III which will be a reusable hypersonic HTOL flyback/glide booster stage with an initially expendable second stage and PLF. Mk-II also functions as an upper stage testbed concept.
« Last Edit: 04/06/2023 01:00 am by russianhalo117 »

Offline Vahe231991

  • Full Member
  • ****
  • Posts: 1689
  • 11 Canyon Terrace
  • Liked: 462
  • Likes Given: 199
Re: Dawn Aerospace
« Reply #56 on: 04/07/2023 03:52 am »
Max altitude of 20km seems bit low for suborbital vehicle. If it can still provide a few minutes of zeroG then they should have viable business.
That is not a typo  for MK-II. Mk-III will be much higher and carry an expendable second stage to reach orbit.
Even if the Mk-III design carries an expendable second stage to reach orbit, it could in some ways behave more like a single-stage-to-orbit spaceplane than a TSTO spaceplane because it is not designed to be launched from a mother aircraft or atop a large rocket stage.

Offline russianhalo117

  • Global Moderator
  • Senior Member
  • *****
  • Posts: 8755
  • Liked: 4671
  • Likes Given: 768
Re: Dawn Aerospace
« Reply #57 on: 04/07/2023 04:40 am »
Max altitude of 20km seems bit low for suborbital vehicle. If it can still provide a few minutes of zeroG then they should have viable business.
That is not a typo  for MK-II. Mk-III will be much higher and carry an expendable second stage to reach orbit.
Even if the Mk-III design carries an expendable second stage to reach orbit, it could in some ways behave more like a single-stage-to-orbit spaceplane than a TSTO spaceplane because it is not designed to be launched from a mother aircraft or atop a large rocket stage.
That is a flat out no for SSTO. There are no sustainer engines on any stage burning from horizontal take-off all the way to the inital orbital insertion during the burn of the flight to even be called an SSTO. A carrier aircraft is classed as Stage-0.
« Last Edit: 04/07/2023 04:47 am by russianhalo117 »

Offline trimeta

  • Full Member
  • ****
  • Posts: 1685
  • Kansas City, MO
  • Liked: 2146
  • Likes Given: 57
Re: Dawn Aerospace
« Reply #58 on: 04/07/2023 02:34 pm »
That is a flat out no for SSTO. There are no sustainer engines on any stage burning from horizontal take-off all the way to the inital orbital insertion during the burn of the flight to even be called an SSTO. A carrier aircraft is classed as Stage-0.
If you're counting the carrier aircraft as Stage 0, then the rocket itself (which has only one stage) would be an SSTO, no? Although if you wanted to call the plane Stage 1 and the rocket Stage 2 (thus making it a TSTO), I wouldn't argue.

Offline russianhalo117

  • Global Moderator
  • Senior Member
  • *****
  • Posts: 8755
  • Liked: 4671
  • Likes Given: 768
Re: Dawn Aerospace
« Reply #59 on: 04/07/2023 05:11 pm »
That is a flat out no for SSTO. There are no sustainer engines on any stage burning from horizontal take-off all the way to the inital orbital insertion during the burn of the flight to even be called an SSTO. A carrier aircraft is classed as Stage-0.
If you're counting the carrier aircraft as Stage 0, then the rocket itself (which has only one stage) would be an SSTO, no? Although if you wanted to call the plane Stage 1 and the rocket Stage 2 (thus making it a TSTO), I wouldn't argue.
The previous poster was referring to the Mk-III version which is flying the second stage therefore it is TSTO. It is not being released from a carrier aircraft. Dawn Aerospace is classing their system as a TSTO system.
« Last Edit: 04/07/2023 05:12 pm by russianhalo117 »

Offline trimeta

  • Full Member
  • ****
  • Posts: 1685
  • Kansas City, MO
  • Liked: 2146
  • Likes Given: 57
Re: Dawn Aerospace
« Reply #60 on: 04/07/2023 06:56 pm »
That is a flat out no for SSTO. There are no sustainer engines on any stage burning from horizontal take-off all the way to the inital orbital insertion during the burn of the flight to even be called an SSTO. A carrier aircraft is classed as Stage-0.
If you're counting the carrier aircraft as Stage 0, then the rocket itself (which has only one stage) would be an SSTO, no? Although if you wanted to call the plane Stage 1 and the rocket Stage 2 (thus making it a TSTO), I wouldn't argue.
The previous poster was referring to the Mk-III version which is flying the second stage therefore it is TSTO. It is not being released from a carrier aircraft. Dawn Aerospace is classing their system as a TSTO system.
Sure, the Mk-III version has two components: the rocket plane that takes off from the surface and reaches at least 100km (before returning back to the runway and being reused), and the expendable single-stage rocket dropped from the rocket plane (which reaches orbit). One could maybe argue that the rocket plane is a "carrier aircraft," and thus is a Stage 0; from that perspective, since the rocket has just one stage, it's an SSTO. But it's certainly not single stage from the ground to orbit. The fact that the rocket itself only needs one stage to get to orbit is perhaps prima facie evidence that the rocket plane is doing enough work to qualify as an actual stage, not just a carrier aircraft.

Offline TrevorMonty

Re: Dawn Aerospace
« Reply #61 on: 04/07/2023 08:11 pm »


Dawn flies rocket-powered spaceplane [dated Apr. 5]

Quote from: SpaceNews
Dawn Aerospace completed its first series of rocket-powered flights last week.

Mk-II Aurora, a scaled down version of the spaceplane Dawn is developing for commercial operations, took to the skies March 29, 30 and 31 from New Zealand’s Gentanner Aerodrome.

The initial test campaign validated key flight systems and demonstrated the benefit of rapid reusability, Dawn CEO Stefan Powell told SpaceNews.

During the first flight, the Mk-II Aurora consumed more fuel than anticipated due to a leak in the propellant system. The next day, Dawn engineers removed the Mk-II Aurora engine, took out the oxidizer tank and found the leak.

“It was reasonably trivial to fix that, put it back together and fly again,” Powell said. “That speaks to just how different this concept is than a regular rocket. Not only would you have not gotten the vehicle back, but you wouldn’t have been able to execute a repair and show that it works in the same day.”

&lt;snip&gt;

The Mk-II is designed to reach an altitude of 20 kilometers. During initial flight tests, the vehicle flew to roughly 2,000 meters and traveled at a maximum speed of 315 kilometers per hour.

That 20km altitude comment is bit misleading sounds like it is max.
Specifications on webpage is 110km with upto 180seconds of microgravity.

https://www.dawnaerospace.com/spacelaunch

Offline russianhalo117

  • Global Moderator
  • Senior Member
  • *****
  • Posts: 8755
  • Liked: 4671
  • Likes Given: 768
Re: Dawn Aerospace
« Reply #62 on: 04/07/2023 09:52 pm »


Dawn flies rocket-powered spaceplane [dated Apr. 5]

Quote from: SpaceNews
Dawn Aerospace completed its first series of rocket-powered flights last week.

Mk-II Aurora, a scaled down version of the spaceplane Dawn is developing for commercial operations, took to the skies March 29, 30 and 31 from New Zealand’s Gentanner Aerodrome.

The initial test campaign validated key flight systems and demonstrated the benefit of rapid reusability, Dawn CEO Stefan Powell told SpaceNews.

During the first flight, the Mk-II Aurora consumed more fuel than anticipated due to a leak in the propellant system. The next day, Dawn engineers removed the Mk-II Aurora engine, took out the oxidizer tank and found the leak.

“It was reasonably trivial to fix that, put it back together and fly again,” Powell said. “That speaks to just how different this concept is than a regular rocket. Not only would you have not gotten the vehicle back, but you wouldn’t have been able to execute a repair and show that it works in the same day.”

&lt;snip&gt;

The Mk-II is designed to reach an altitude of 20 kilometers. During initial flight tests, the vehicle flew to roughly 2,000 meters and traveled at a maximum speed of 315 kilometers per hour.

That 20km altitude comment is bit misleading sounds like it is max.
Specifications on webpage is 110km with upto 180seconds of microgravity.

https://www.dawnaerospace.com/spacelaunch
Depends on the flight test article number and mk number.

Offline Rik ISS-fan

  • Full Member
  • ****
  • Posts: 1519
  • the Netherlands
  • Liked: 617
  • Likes Given: 211
Re: Dawn Aerospace
« Reply #63 on: 04/08/2023 10:37 am »
AFAIK Dawn Aerospace is currently only developing the Mk.II Aurora. The Mk.III is a plan for the future.
This first version of Mk.II Aurora was equipped with structure to mount micro jet engines,
the second version will not have this structure. Thus saving weight.
Dawn Aerospace also found other hardware to save weight on. And they increase propellent tank size.
The reduced structure mass, increased propallent capacity and increased thrust of the engine will enable the second iteration to reach above the Karman Line (~110km) instead of only 20km altitude, the final target they try to reach with the first iteration of mk. II Aurora.

Early this year NASA launched the two MesOrion rockets. The Dawn Mk. II could also launch the payloads flown by these two imp. Orion rockets. (3U <5kg) Dawn could launch these payloads multiple times daily with Mk.II Aurora vehicles. With the purpose to measure atmospheric parameters between 40 and 100km. This can be feed into weather and climate models to improve their accuracy. 

The Mk.III is a much larger version of the same vehicle concept. With 1000kg instead of 3kg payload capability on a suborbital mission. (That's to space and back; not orbital) A payload of <250kg can be launched into (L)LEO orbit, when an expandable second stage is used.
For this second stage I think Dawn might be able to use a vacume optimized version of the engine used on Mk.II Aurora. I think this engine would also be very nice for an (in orbit) kick-stage.

Personally I think there might also be a market for a intermediate size. This would be closer to Mk.II than to Mk.III. I'm thinking about a 50 to 100kg payload to up to 300km altitude.

The spaceplanes from Dawn Aerospace take off and land horizontally. I think the system could be smaller/ or  heavier payloads can be launched when the vehicle launches vertically. Dawn Aerospace is trying to operate Mk.II like an aircraft. But I'm not sure this can fully materialize. I think it's likely (aero)nautical closures remain required. If this is the case; I think vertical launch don't hamper potential launch locations. Possibly landing down range from the launch site increase launch location options, because the launch aerospace closure can be located a distance from the landing airport. The glide-back landing can take place at the airport while it is in operation. The Mk.II is small enough to load it in a van or truck. So moving is from the landing site to the launch site wouldn't be that hard.

Re: Dawn Aerospace
« Reply #64 on: 04/08/2023 11:12 pm »
Guys, please please please listen to the latest MECO podcast episode before you keep talking about this. It's a fantastic episode, which goes into detail about not just the MkII and it's test campaign, but also the broader business case of the company and of the spaceplanes. The CEO had great answers, which were perfectly logical and reasonable; I'm way more confident in and hopeful for the company as a whole after listening to it.

EDIT: Whoops, forgot the link: https://mainenginecutoff.com/podcast/244
« Last Edit: 04/08/2023 11:20 pm by JEF_300 »
Wait, ∆V? This site will accept the ∆ symbol? How many times have I written out the word "delta" for no reason?

Offline TrevorMonty

Re: Dawn Aerospace
« Reply #65 on: 04/10/2023 08:55 am »


Dawn flies rocket-powered spaceplane [dated Apr. 5]

Quote from: SpaceNews
Dawn Aerospace completed its first series of rocket-powered flights last week.

Mk-II Aurora, a scaled down version of the spaceplane Dawn is developing for commercial operations, took to the skies March 29, 30 and 31 from New Zealand’s Gentanner Aerodrome.

The initial test campaign validated key flight systems and demonstrated the benefit of rapid reusability, Dawn CEO Stefan Powell told SpaceNews.

During the first flight, the Mk-II Aurora consumed more fuel than anticipated due to a leak in the propellant system. The next day, Dawn engineers removed the Mk-II Aurora engine, took out the oxidizer tank and found the leak.

“It was reasonably trivial to fix that, put it back together and fly again,” Powell said. “That speaks to just how different this concept is than a regular rocket. Not only would you have not gotten the vehicle back, but you wouldn’t have been able to execute a repair and show that it works in the same day.”

&lt;snip&gt;

The Mk-II is designed to reach an altitude of 20 kilometers. During initial flight tests, the vehicle flew to roughly 2,000 meters and traveled at a maximum speed of 315 kilometers per hour.

That 20km altitude comment is bit misleading sounds like it is max.
Specifications on webpage is 110km with upto 180seconds of microgravity.

https://www.dawnaerospace.com/spacelaunch
After listening to MECO podcast this 20km ceiling makes sense as it applies to current Mk2A test vehicle.  MK2B being built now has more fuel and thrust plus RCS to allow it to reach 100km. Should be ready fly by end of 2023.

At this stage suborbital market is bit unknown but Dawn hope access to spaceplane that could fly multiple low cost missions a day could create its own market. In space manufacturing is a possibility assuming 5 minutes of micro G is enough time for some products. They really are hoping MK2 is profitable in its own right and not just an expensive tech demostrator for larger MK3.




Offline FutureSpaceTourist

  • Global Moderator
  • Senior Member
  • *****
  • Posts: 48138
  • UK
    • Plan 28
  • Liked: 81622
  • Likes Given: 36928
Re: Dawn Aerospace
« Reply #66 on: 04/10/2023 07:14 pm »

Offline Rik ISS-fan

  • Full Member
  • ****
  • Posts: 1519
  • the Netherlands
  • Liked: 617
  • Likes Given: 211
Re: Dawn Aerospace
« Reply #67 on: 04/11/2023 09:55 pm »
Where is the dislike button?
An image says more than a thousand words. thus ...

Edit: Dawn Aerospace started in The Netherlands and New Zealand.
I think because of the market succes of the N2O Propylene (C3H6) satellite propulsion they setup a sales office in the USA.
Thus this isn't a Kiwi space plane; it's international; also Dutch (and a little bit American).

The flag in the middle is: The International Flag of Planet Earth.

« Last Edit: 04/12/2023 05:58 pm by Rik ISS-fan »

Offline whitelancer64

Re: Dawn Aerospace
« Reply #68 on: 04/11/2023 10:05 pm »
Where is the dislike button?
An image says more than a thousand words. thus ...

What you're looking at are three flags, including the New Zealand and Netherlands flags, I'm not sure what the blue one in the center is as it's very blurry. It kind of looks like the "international world flag." However: 

"Dawn Aerospace is a space company based in the United States of America, the Netherlands and New Zealand."

Literally the first sentence in the Wikipedia page.  Dawn Aerospace has offices in all three nations.

What's to dislike about that?
"One bit of advice: it is important to view knowledge as sort of a semantic tree -- make sure you understand the fundamental principles, ie the trunk and big branches, before you get into the leaves/details or there is nothing for them to hang on to." - Elon Musk
"There are lies, damned lies, and launch schedules." - Larry J

Offline FutureSpaceTourist

  • Global Moderator
  • Senior Member
  • *****
  • Posts: 48138
  • UK
    • Plan 28
  • Liked: 81622
  • Likes Given: 36928
Re: Dawn Aerospace
« Reply #69 on: 04/27/2023 05:51 am »

Offline TrevorMonty

Re: Dawn Aerospace
« Reply #70 on: 05/12/2023 05:38 am »
Good article on why Dawn use nitrous oxide and propylene (aka propene) to fuel their satellite thrusters.
Auroa II rocket plane uses H202 as oxidizer not sure of propellant. Engine has monopropellant mode which is H202, for low thrust. See the latest youtube video from them and comments.

https://twitter.com/Firefly_Space/status/1653863708727050242?t=rzvtkGPmtNKO6jGvnDyBJw&s=19

Offline Steven Pietrobon

  • Member
  • Senior Member
  • *****
  • Posts: 39214
  • Adelaide, Australia
    • Steven Pietrobon's Space Archive
  • Liked: 32734
  • Likes Given: 8178
Re: Dawn Aerospace
« Reply #71 on: 05/13/2023 03:45 am »
Our first ever composite common dome structure is on the test stand as we undergo development testing for our Medium Launch Vehicle. This configuration allows us to cut out the entire intertank, significantly reducing vehicle weight with fewer parts. pic.twitter.com/hltMeP6qnE

Wrong tweet!
Akin's Laws of Spacecraft Design #1:  Engineering is done with numbers.  Analysis without numbers is only an opinion.

Offline Rik ISS-fan

  • Full Member
  • ****
  • Posts: 1519
  • the Netherlands
  • Liked: 617
  • Likes Given: 211
Re: Dawn Aerospace
« Reply #72 on: 05/13/2023 04:02 pm »
Good article on why Dawn use nitrous oxide and propylene (aka propene) to fuel their satellite thrusters.
Auroa II rocket plane uses H202 as oxidizer not sure of propellant. Engine has monopropellant mode which is H202, for low thrust. See the latest youtube video from them and comments.

The Dawn Aerospace Mk. II rocket engine catalytically decomposes 90% H2O2; optionally adds kerosine is also injected into the nozzle for bi-propellent burn. This info is on their website.
https://www.dawnaerospace.com/spacelaunch

 :D ?
I'm all for it.
« Last Edit: 05/13/2023 04:09 pm by Rik ISS-fan »

Offline FutureSpaceTourist

  • Global Moderator
  • Senior Member
  • *****
  • Posts: 48138
  • UK
    • Plan 28
  • Liked: 81622
  • Likes Given: 36928
Re: Dawn Aerospace
« Reply #73 on: 05/30/2023 06:40 am »
twitter.com/astro_rayyanah/status/1663289138831867904

Quote
These are the faces of a happy team holding the 100th B20 thruster off the production line! A milestone we hit last week!🎉🚀
#greenpropulsion

https://twitter.com/dawnaerospace/status/1663405547939590145

Quote
The first B20 was produced in 2020. Since then, we have scaled up production significantly and are now producing them at rate of 2 per week. This year alone, we’ll produce and ship 100 of these to customers around the globe 🛰

Offline TrevorMonty

Re: Dawn Aerospace
« Reply #74 on: 05/30/2023 07:28 pm »
Excellent video on their spaceplane. Didn't know it was electric pump rocket engine, kind of makes sense given they are a NZ+Dutch company.


« Last Edit: 06/01/2023 04:24 pm by zubenelgenubi »

Offline Steven Pietrobon

  • Member
  • Senior Member
  • *****
  • Posts: 39214
  • Adelaide, Australia
    • Steven Pietrobon's Space Archive
  • Liked: 32734
  • Likes Given: 8178
Re: Dawn Aerospace
« Reply #75 on: 06/01/2023 08:46 am »
Excellent video on their spaceplane. Didn't know it was electric pump rocket engine, kind of makes sense given they are a NZ+Dutch company.

They forgot the Chinese X-37 clone and Dream Chaser hasn't flown yet.
Akin's Laws of Spacecraft Design #1:  Engineering is done with numbers.  Analysis without numbers is only an opinion.

Offline TrevorMonty

Re: Dawn Aerospace
« Reply #76 on: 06/01/2023 04:07 pm »
Could've also included XCOR but video was about Dawn not history of spaceplanes.

Offline john smith 19

  • Senior Member
  • *****
  • Posts: 10350
  • Everyplaceelse
  • Liked: 2430
  • Likes Given: 13605
Re: Dawn Aerospace
« Reply #77 on: 06/03/2023 08:20 am »
twitter.com/astro_rayyanah/status/1663289138831867904

Quote
The first B20 was produced in 2020. Since then, we have scaled up production significantly and are now producing them at rate of 2 per week. This year alone, we’ll produce and ship 100 of these to customers around the globe 🛰

Which also means they have a regular cash flow and are not entirely investor dependent.

Doesn't guarantee success, but it does improve their odds a bit.  :)
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 TrevorMonty

Re: Dawn Aerospace
« Reply #78 on: 06/03/2023 08:52 pm »
twitter.com/astro_rayyanah/status/1663289138831867904

Quote
The first B20 was produced in 2020. Since then, we have scaled up production significantly and are now producing them at rate of 2 per week. This year alone, we’ll produce and ship 100 of these to customers around the globe

Which also means they have a regular cash flow and are not entirely investor dependent.

Doesn't guarantee success, but it does improve their odds a bit.  :)

Auroa 2 was designed as subscale demostrator for considerable more expensive to develop Auroa 3.
Dawn is hoping Auroa 2 unlocks a successful suborbital business which would help pay its way and boost their profits. This market is big unknown and has never had rapidly reuseable vehicle serving it. Being able to fly payload days apart or ideally hours is nice selling point. Besides flight price, customer has to pay for their staff's travel costs. If they can get few flights over a few days that is significant saving per flight.

Build Auroa 3 is going need large cash injection from investors or loans. Besides building the spaceplane need to design and build upperstage which will need production line. Using runway only eliminates vertical pad still need all the other facilities that launch sites have to support an orbital launch.

My guess is around $100M.
« Last Edit: 06/03/2023 08:52 pm by TrevorMonty »

Offline john smith 19

  • Senior Member
  • *****
  • Posts: 10350
  • Everyplaceelse
  • Liked: 2430
  • Likes Given: 13605
Re: Dawn Aerospace
« Reply #79 on: 06/03/2023 09:20 pm »
Could've also included XCOR but video was about Dawn not history of spaceplanes.
Well...
Reaction were included (with a logo that's decades out of date  :(  ) presumably because they are still in business.

OTOH XCOR did not succeed in flying a vehicle and is out of business, hence no mention.
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 FutureSpaceTourist

  • Global Moderator
  • Senior Member
  • *****
  • Posts: 48138
  • UK
    • Plan 28
  • Liked: 81622
  • Likes Given: 36928
Re: Dawn Aerospace
« Reply #80 on: 06/13/2023 07:19 am »
https://twitter.com/dawnaerospace/status/1668429947927670785

Quote
Go Falcon, go D-Orbit, go Dawn! 🚀
Congratulations to D-Orbit on a successful launch aboard @SpaceX's Transporter8. We’re proud to supply the propulsion which will now take D-Orbit’s customers on to their operational orbit.
The number of Dawn thrusters in space is now 63!✨🛰

Offline FutureSpaceTourist

  • Global Moderator
  • Senior Member
  • *****
  • Posts: 48138
  • UK
    • Plan 28
  • Liked: 81622
  • Likes Given: 36928
Re: Dawn Aerospace
« Reply #81 on: 07/03/2023 05:57 am »
https://www.dawnaerospace.com/latest-news/dawn-aerospace-has-promoted-johann-joubert-to-the-role-of-head-of-in-space-propulsion

Quote
Dawn Aerospace has promoted Johann Joubert to the role of Head of In-Space Propulsion.

Dawn Aerospace has promoted Johann Joubert to the role of Head of In-Space Propulsion.

Dawn Aerospace, a space transportation company based in NZ, the Netherlands, and the United States, is on a mission to provide sustainable and scalable ways to access and move around in space. The company is the fastest growing supplier of green propulsion for satellites in the world and has an ever-growing amount of hardware in space having flown on Falcon 9, Soyuz and Vega rockets. Dawn is also building a spaceplane – a launch vehicle that combines the performance of a rocket with the rapid reusability and fleet economics of an aircraft.

Joubert joined Dawn with an impressive background in engineering and space. After several design engineer roles developing hardware and embedded systems in the mining & military industries in South Africa, he got his start in the space industry with Space Advisory Company as a technical advisor to companies building satellites. He went on to become the first South African employee of New Space Systems where he oversaw engineering and led the company’s growth for seven years.

Joubert joined Dawn in August last year as a Project Manager role but was recently promoted to the Head of In-Space Propulsion, a 50-person team that was, until recently, led by CEO, Stefan Powell.

Joubert said, “It’s great to be in a company that has a massive vision. We’re doing revolutionary things.  I’m excited to be leading a team that is disrupting the hydrazine space industry and enabling our clients to offer a complete solution rather than just saying here are the parts, away you go. I think it’s a massive game changer.”

Dawns’ systems use readily available fuels, nitrous oxide and propylene, which provide safer handling and huge cost savings compared to traditional hydrazine propulsion.

CEO, Stefan Powell said, “I’m super excited to have someone as experienced and capable as Johann to hand the reins to. It’s a key role. In-space propulsion is currently the financial backbone of Dawn. Johan impressed us with not only his technical knowledge but also his leadership skills.”

Dawn Aerospace also made headlines earlier this year when they flew their spaceplane technology demonstrator, the Mk-II Aurora, under rocket-power for the first time. 

Read more about Johann’s career journey here.

Offline FutureSpaceTourist

  • Global Moderator
  • Senior Member
  • *****
  • Posts: 48138
  • UK
    • Plan 28
  • Liked: 81622
  • Likes Given: 36928
Re: Dawn Aerospace
« Reply #82 on: 07/24/2023 05:56 am »
https://twitter.com/dawnaerospace/status/1683334332805681153

Quote
Mk-II Aurora looking fine on the cover of @BIS_spaceflight magazine ✨
Pick up a copy of the August issue to read @Stefan__Powell's interview on the iterative process we’re taking to turn the long-held dream of a spaceplane into a reality 🚀

Offline TrevorMonty

Re: Dawn Aerospace
« Reply #83 on: 09/20/2023 06:12 pm »
Dawn aren't the only startup developing spaceplanes.


Polaris from Germany are using similar development program to Dawn. Start with subscale technology demostrators before scaling up, adding rocket engine and  expanding flight envelope.

https://www.polaris-raumflugzeuge.de/Technology


https://www.space.com/polaris-spaceplanes-mira-light-flight-test-campaign-complete
« Last Edit: 09/20/2023 06:13 pm by TrevorMonty »

Online catdlr

  • Member
  • Senior Member
  • *****
  • Posts: 11169
  • Enthusiast since the Redstones
  • Marina del Rey, California, USA
  • Liked: 8784
  • Likes Given: 7815
Re: Dawn Aerospace
« Reply #84 on: 10/19/2023 03:18 am »


Quote

Oct 18, 2023
Dawn's manufacturing team welcomed a new 5-axis mill to the workshop in July!  This was another step in scaling up our production to meet growing customer demand for our in-space propulsion systems.
« Last Edit: 10/19/2023 03:18 am by catdlr »
Tony De La Rosa, ...I'm no Feline Dealer!! I move mountains.  but I'm better known for "I think it's highly sexual." Japanese to English Translation.

Offline john smith 19

  • Senior Member
  • *****
  • Posts: 10350
  • Everyplaceelse
  • Liked: 2430
  • Likes Given: 13605
Re: Dawn Aerospace
« Reply #85 on: 11/03/2023 05:41 pm »
Dawn aren't the only startup developing spaceplanes.

Polaris from Germany are using similar development program to Dawn. Start with subscale technology demostrators before scaling up, adding rocket engine and  expanding flight envelope.

https://www.polaris-raumflugzeuge.de/Technology

https://www.space.com/polaris-spaceplanes-mira-light-flight-test-campaign-complete
It'll be interesting to see how they cope with the Cp/Cg mismatch, just as Dawn and Venus will. If any of them get that far.

30 years after HOTOL people are still raising money for these sorts of designs and still not thinking that this is going to be a problem.  :(

I don't think I've seen a thread for Polaris. They do look nice. I'm reminded of the film "The Flight of the Phoenix"
[EDIT Ooops.  :) Didn't realise they are going for a pure rocket HTOL SSTO spaceplane without launch assist of some kind (what Boeing expected to make RASV viable, along with an uprated SSME of course).

That puts them in Radian territory, only worse.  :(

It'd be interesting to see how much thinking they have done about the structural mass and TPS they are going to need to slow from 7900m/s.

My guess is "not much." ]
« Last Edit: 11/03/2023 05:57 pm by john smith 19 »
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 FutureSpaceTourist

  • Global Moderator
  • Senior Member
  • *****
  • Posts: 48138
  • UK
    • Plan 28
  • Liked: 81622
  • Likes Given: 36928
Re: Dawn Aerospace
« Reply #86 on: 12/12/2023 03:31 am »


https://www.dawnaerospace.com/latest-news/dawn-aerospace-achieves-key-rocket-engine-milestonenbspnbsp

Quote
Dawn Aerospace achieves key rocket engine milestone

Dawn Aerospace has successfully completed a full-duration, bi-propellant test of the Mk-II Aurora spaceplane’s rocket engine. The Mk-IIA engine was fired for 112 seconds at their test facility in Christchurch, New Zealand. 

This engine will be fitted to the Mk-II Aurora, a subscale technology demonstrator for the Mk-III – Dawn’s two-stage to orbit solution for scalable and sustainable space access.   

The Mk-II Aurora has already completed 50 test flights, 47 with jet engines and 3 under rocket power in March 2023. Dawn’s propulsion team have been working on improvements in preparation for the next set of flight tests, set to take the vehicle to supersonic speeds and above 20km altitude in early 2024 to complete the test campaign of the Mk-IIA.   

The rocket engine utilizes HTP and kerosene as propellants, rather than the more commonly used liquid oxygen, due to their storability and deep throttling capabilities. These are crucial factors as Dawn builds towards having a global fleet of spaceplanes with aircraft-like operations. 

Ralph Huijsman, Lead Propulsion Engineer, commented: “While HTP is the right long-term choice for the spaceplane, it led to some interesting challenges in the development of the engine. The available information is extremely limited and is often outdated or walled off. This meant we ran into some fundamental challenges along the way that were difficult to engineer our way out of. That makes this achievement even more special. It is exciting to see everything come together and work flawlessly.” 

CEO of Dawn Aerospace, Stefan Powell said: “The team has put in significant work to reach this milestone. We're excited about our future flights where we’ll fly MUCH higher and faster than ever before.”

The next phase in the development roadmap for the Mk-IIA is to test critical aspects of operating the vehicle such as high-altitude operations and BVLOS flights (beyond visual line of sight). 

The Mk-IIB will incorporate all the learnings from the Mk-IIA to achieve an optimised vehicle for flights to 100 km. In doing so, it will be the first vehicle to fly to space twice in a day. 

The Mk-IIB will be a uniquely capable vehicle with commercial applications in atmospheric, microgravity, and high-speed flight research as well as earth observation.
« Last Edit: 12/12/2023 03:32 am by FutureSpaceTourist »

Offline john smith 19

  • Senior Member
  • *****
  • Posts: 10350
  • Everyplaceelse
  • Liked: 2430
  • Likes Given: 13605
Re: Dawn Aerospace
« Reply #87 on: 12/13/2023 02:58 pm »
Ralph Huijsman, Lead Propulsion Engineer, commented: “While HTP is the right long-term choice for the spaceplane, it led to some interesting challenges in the development of the engine. The available information is extremely limited and is often outdated or walled off. This meant we ran into some fundamental challenges along the way that were difficult to engineer our way out of. That makes this achievement even more special. It is exciting to see everything come together and work flawlessly.” 
True.

Not the least of which will be the low Isp they'll have to work with in order to 2nd stage launch altitude and velocity.

This will make the structural mass available for vehicle (and the 2nd stage it's going to be carrying) even more challenging than with kerolox.  :(

Obviously not going for actual SSTO (even the assisted kind Radian are aiming for) helps but that low Isp (a poor jet is looking at Isp of 3000s, 450secs is the vac Isp of the SSME) really hurts structural fraction.

I'll wish them good luck.

And Merry Christmas to all.  :)
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 TrevorMonty

Re: Dawn Aerospace
« Reply #88 on: 12/13/2023 05:15 pm »
Ralph Huijsman, Lead Propulsion Engineer, commented: “While HTP is the right long-term choice for the spaceplane, it led to some interesting challenges in the development of the engine. The available information is extremely limited and is often outdated or walled off. This meant we ran into some fundamental challenges along the way that were difficult to engineer our way out of. That makes this achievement even more special. It is exciting to see everything come together and work flawlessly.” 
True.

Not the least of which will be the low Isp they'll have to work with in order to 2nd stage launch altitude and velocity.

This will make the structural mass available for vehicle (and the 2nd stage it's going to be carrying) even more challenging than with kerolox.  :(

Obviously not going for actual SSTO (even the assisted kind Radian are aiming for) helps but that low Isp (a poor jet is looking at Isp of 3000s, 450secs is the vac Isp of the SSME) really hurts structural fraction.

I'll wish them good luck.

And Merry Christmas to all.  :)

ISP isn't everything other wise everbody would be using hydrolox. There are operational considerations. Fuel delivery, storage and handling at remote airfields, not cheap or easy with LOX. HTP allows engine to run in lower thrust monopropellant mode, they use this for taxiing and inflight maneuvers, with bipropellant mode used for climb to space, watch the videos.
« Last Edit: 12/13/2023 05:17 pm by TrevorMonty »

Offline Emmettvonbrown

  • Full Member
  • **
  • Posts: 257
  • Liked: 135
  • Likes Given: 641
Re: Dawn Aerospace
« Reply #89 on: 12/13/2023 05:29 pm »
Their initial target is sounding rockets science payloads, except recoverable and with the inner flexibility of an aircraft - "drone" might be the correct word. XCOR, Virgin, Blue Origin all chased the same payloads except - obviously - the P.I could fly along the payload.
And then - small satellites with an expendable upper stage. Admittedly, Rocketlab probably killed that market - well SpaceX F9 rideshares probably killed it for real.

Re: Dawn Aerospace
« Reply #90 on: 12/14/2023 06:31 pm »
And then - small satellites with an expendable upper stage. Admittedly, Rocketlab probably killed that market - well SpaceX F9 rideshares probably killed it for real.

If that market is dead (and I'm not convinced it is), an LV with a rapidly reusable first stage would be just the sort of thing that might be able to reopen it.
Wait, ∆V? This site will accept the ∆ symbol? How many times have I written out the word "delta" for no reason?

Offline Steven Pietrobon

  • Member
  • Senior Member
  • *****
  • Posts: 39214
  • Adelaide, Australia
    • Steven Pietrobon's Space Archive
  • Liked: 32734
  • Likes Given: 8178
Re: Dawn Aerospace
« Reply #91 on: 12/15/2023 04:53 am »
Part of the engine gets red hot!

The other advantage of HTP is its high density. 1.4424 kg/L compared to LOX at 1.149 kg/L. It also has a high oxidiser to fuel ratio, typically over 7! At delta-Vs below 7 km/s, this results in smaller tank sizes compared to kerolox for the same performance. Another advantage is that no ignition source is required. Decomposed HTP will ignite spontaneously with kerosene due to its high decomposed temperature.
« Last Edit: 12/15/2023 04:54 am by Steven Pietrobon »
Akin's Laws of Spacecraft Design #1:  Engineering is done with numbers.  Analysis without numbers is only an opinion.

Online catdlr

  • Member
  • Senior Member
  • *****
  • Posts: 11169
  • Enthusiast since the Redstones
  • Marina del Rey, California, USA
  • Liked: 8784
  • Likes Given: 7815
Re: Dawn Aerospace
« Reply #92 on: 12/15/2023 05:13 am »
Part of the engine gets red hot!



I re-edit the video and zoomed into the upper right-hand corner of the area you pointed out

Video Credit: Dawn Aerospace.

Tony De La Rosa, ...I'm no Feline Dealer!! I move mountains.  but I'm better known for "I think it's highly sexual." Japanese to English Translation.

Offline Rik ISS-fan

  • Full Member
  • ****
  • Posts: 1519
  • the Netherlands
  • Liked: 617
  • Likes Given: 211
Re: Dawn Aerospace
« Reply #93 on: 12/15/2023 11:09 pm »
I think what you see is ~900deg C, afaik that's roughly the upperlimit of temperature reached when hydrogenperoxide decomposes. I think you look at the chamber wall of the H2O2 decomposing cathalitic pack.
I thing the method of decomposition is a combination of chamical (cathalizer) and thermal decomposition.
Most likely the red colour is the method to radiate the heat away.

Could this be a good starting point for an kick stage development? 

Offline Rik ISS-fan

  • Full Member
  • ****
  • Posts: 1519
  • the Netherlands
  • Liked: 617
  • Likes Given: 211
Re: Dawn Aerospace
« Reply #94 on: 12/15/2023 11:14 pm »
And then - small satellites with an expendable upper stage. Admittedly, Rocketlab probably killed that market - well SpaceX F9 rideshares probably killed it for real.

If that market is dead (and I'm not convinced it is), an LV with a rapidly reusable first stage would be just the sort of thing that might be able to reopen it.

I think the beter discription of the purpose for Dawn Aerospace mkII Aurora is :
Atmosphere probing vehicle.

Offline TrevorMonty

Re: Dawn Aerospace
« Reply #95 on: 12/15/2023 11:35 pm »

I think the beter discription of the purpose for Dawn Aerospace mkII Aurora is :
Atmosphere probing vehicle.

Great way to sample upper atmosphere especially near edge of space. At present it high altitude balloons and they only go so high.

Would need to operate out of US is NASA wanted to sample upper atmosphere in northern hemisphere. Could be used to take samples straight after launch to see if LVs damage atmosphere.
« Last Edit: 12/15/2023 11:42 pm by TrevorMonty »

Offline Robotbeat

  • Senior Member
  • *****
  • Posts: 39270
  • Minnesota
  • Liked: 25240
  • Likes Given: 12115
Re: Dawn Aerospace
« Reply #96 on: 12/16/2023 07:40 pm »
Ralph Huijsman, Lead Propulsion Engineer, commented: “While HTP is the right long-term choice for the spaceplane, it led to some interesting challenges in the development of the engine. The available information is extremely limited and is often outdated or walled off. This meant we ran into some fundamental challenges along the way that were difficult to engineer our way out of. That makes this achievement even more special. It is exciting to see everything come together and work flawlessly.” 
True.

Not the least of which will be the low Isp they'll have to work with in order to 2nd stage launch altitude and velocity.

This will make the structural mass available for vehicle (and the 2nd stage it's going to be carrying) even more challenging than with kerolox.  :(

Obviously not going for actual SSTO (even the assisted kind Radian are aiming for) helps but that low Isp (a poor jet is looking at Isp of 3000s, 450secs is the vac Isp of the SSME) really hurts structural fraction.

I'll wish them good luck.

And Merry Christmas to all.  :)

ISP isn't everything other wise everbody would be using hydrolox. There are operational considerations. Fuel delivery, storage and handling at remote airfields, not cheap or easy with LOX. HTP allows engine to run in lower thrust monopropellant mode, they use this for taxiing and inflight maneuvers, with bipropellant mode used for climb to space, watch the videos.
Yeah, density is sometimes even more important than Isp, ESPECIALLY for an SSTO rocket.

HTP is very dense, too. 1.45 times water, vs 1.14 for LOx. Additionally, the lower effective energy density of HTP/fuel might mean you can operate closer to stoichiometric, thus reducing the actual real life Isp hit from not using LOx. Plus the O:F mixture ratio would be even higher than for oxygen (higher mix ratios help bulk density as the oxidizer is usually denser than the fuel), so you could get excellent bulk density.

In fact, all things being equal, typically you'll get higher SSTO performance with kerolox than hydrolox, and the HTP/RP-1 performance is nearly equal to that of hydrolox for SSTO with the benefit of having room temperature storable propellants:
https://web.archive.org/web/20120206022209/http://www.dunnspace.com/alternate_ssto_propellants.htm
(Looks like Steven Pietrobon already said this.)

And for a first stage, it's just about perfect. (Although at large scale, LOx--besides being high performance--is also the cheapest oxidizer other than straight air itself, which doesn't store very well on a rocket.)
« Last Edit: 12/16/2023 07:41 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 john smith 19

  • Senior Member
  • *****
  • Posts: 10350
  • Everyplaceelse
  • Liked: 2430
  • Likes Given: 13605
Re: Dawn Aerospace
« Reply #97 on: 12/18/2023 12:59 pm »
Part of the engine gets red hot!

The other advantage of HTP is its high density. 1.4424 kg/L compared to LOX at 1.149 kg/L. It also has a high oxidiser to fuel ratio, typically over 7! At delta-Vs below 7 km/s, this results in smaller tank sizes compared to kerolox for the same performance. Another advantage is that no ignition source is required. Decomposed HTP will ignite spontaneously with kerosene due to its high decomposed temperature.
All good points. I'll also note that (IIRC) all engines that have use it have also used it as the coolant something (despite NASA work on a 40klb pressure fed stand engine in the 90's and Rotary Rocket's work) is still viewed as virtually opening the doors of Hell itself  :).

LOX is also capable of simple densification down to maybe 79-80k just with LN2 (based on the temperature loss through the X33 sub-cooling HX). I think that would get you up to about 1.2Kg/L.

The joker in the pack is always insulation with cryogens, although others have pointed out that at LOX (or even LN2) temps that could be literally a thick coat of paint.
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 john smith 19

  • Senior Member
  • *****
  • Posts: 10350
  • Everyplaceelse
  • Liked: 2430
  • Likes Given: 13605
Re: Dawn Aerospace
« Reply #98 on: 12/18/2023 01:02 pm »
Yeah, density is sometimes even more important than Isp, ESPECIALLY for an SSTO rocket.
True.

For a vertical takeoff SSTO rocket.

But this is a HTO TSTO aircraft.  :(

Different architecture. Different rules.
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 Steven Pietrobon

  • Member
  • Senior Member
  • *****
  • Posts: 39214
  • Adelaide, Australia
    • Steven Pietrobon's Space Archive
  • Liked: 32734
  • Likes Given: 8178
Re: Dawn Aerospace
« Reply #99 on: 12/25/2023 05:36 am »
LOX is also capable of simple densification down to maybe 79-80k just with LN2 (based on the temperature loss through the X33 sub-cooling HX). I think that would get you up to about 1.2Kg/L.

You can get 1.2539 kg/L at -206.7 C (66.5 K), 11.6 K above the freezing point of -218.3 C (54.9 K).
Akin's Laws of Spacecraft Design #1:  Engineering is done with numbers.  Analysis without numbers is only an opinion.

Offline john smith 19

  • Senior Member
  • *****
  • Posts: 10350
  • Everyplaceelse
  • Liked: 2430
  • Likes Given: 13605
Re: Dawn Aerospace
« Reply #100 on: 12/27/2023 05:07 pm »
You can get 1.2539 kg/L at -206.7 C (66.5 K), 11.6 K above the freezing point of -218.3 C (54.9 K).
Oh sure, but note my use of the word "simple"  :(

For that kind of performance you're either looking at a supply of LH2 (or D2 or Ne) on the other side of the HX or sub-atmospheric boiling of the coolant like the LH2 sub-cooling system on the X33.

While  a straight HX with H2, D2 or Ne is basically as simple as with N2 the prices of any of those are going to be considerably higher, (I think Xe is more expensive, and He even more so, but I don't think that make Ne "cheap") while the mechanical complexity of the sub-atmospheric design is going to be challenging

I've become very weary of pushing for "bleeding edge" performance (maybe I've just read too many development reports?)
Not impossible (I'd say sub-cooling on the X33 programme was one of the more successful parts of the project) but quite tough. OTOH getting a   cryogenic HX with a 2K temperature loss is well within the SoA.
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 FutureSpaceTourist

  • Global Moderator
  • Senior Member
  • *****
  • Posts: 48138
  • UK
    • Plan 28
  • Liked: 81622
  • Likes Given: 36928
Re: Dawn Aerospace
« Reply #101 on: 02/07/2024 11:10 pm »
https://twitter.com/dawnaerospace/status/1755383357838336010

Quote
Fire 'em up!🔥

Check out this sneak peek of a long(er) duration burn of our next-gen B20thrusters – now steady state capable for those more demanding maneuvers🌌

Watch this space 👀✨

Online catdlr

  • Member
  • Senior Member
  • *****
  • Posts: 11169
  • Enthusiast since the Redstones
  • Marina del Rey, California, USA
  • Liked: 8784
  • Likes Given: 7815
Re: Dawn Aerospace
« Reply #102 on: 03/07/2024 07:44 am »
https://twitter.com/DawnAerospace/status/1765562076351832079

Quote
How big is a satellite?🛰

People are often surprised that many satellites are the size of a loaf of bread🍞

These small sats need small engines for mobility🌌

Enter the CubeDrive, a rocket engine for CubeSats ✨
(and Dawn’s first system launched to orbit, way back in 2020).
Tony De La Rosa, ...I'm no Feline Dealer!! I move mountains.  but I'm better known for "I think it's highly sexual." Japanese to English Translation.

 

Advertisement NovaTech
Advertisement Northrop Grumman
Advertisement
Advertisement Margaritaville Beach Resort South Padre Island
Advertisement Brady Kenniston
Advertisement NextSpaceflight
Advertisement Nathan Barker Photography
1