Author Topic: Impulse Space  (Read 34029 times)

Offline RDMM2081

  • Full Member
  • **
  • Posts: 295
  • Liked: 287
  • Likes Given: 595
Re: Impulse Space
« Reply #80 on: 01/18/2024 04:55 am »
One of his interviews today he said Deneb is staged combustion

Offline TrevorMonty

Re: Impulse Space
« Reply #81 on: 01/18/2024 07:08 am »
What do we think the Deneb engine is likely to be like? I'm assuming an expander cycle would be a great fit, but electric pumped might work too.
Knowing Tom Mueller's background, what do we think is the most likely?
For electric pump 5klbs is about limit before turbopump engines are better option. Deneb is 15klbs.

Offline Zed_Noir

  • Senior Member
  • *****
  • Posts: 5490
  • Canada
  • Liked: 1811
  • Likes Given: 1302
Re: Impulse Space
« Reply #82 on: 01/18/2024 07:28 am »
One of his interviews today he said Deneb is staged combustion

Unlikely to be FFSC or ORSC, that leaves FRSC as the mostly likely engine type.

AIUI. FFSC is much harder with a small engine. ORSC engines requires exotic materials and complicated manufacturing processes.

List of Acronyms:
FFSC = full flow stage combustion
FRSC = fuel rich stage combustion
ORSC = oxidizer rich stage combustion
« Last Edit: 01/28/2024 10:15 pm by Zed_Noir »

Offline Kaputnik

  • Extreme Veteran
  • Senior Member
  • *****
  • Posts: 3079
  • Liked: 722
  • Likes Given: 822
Re: Impulse Space
« Reply #83 on: 01/18/2024 05:00 pm »
One of his interviews today he said Deneb is staged combustion

Interesting. Expander works really well at small scales and is simple and reliable.

What's the advantage of staged? Higher T:W maybe? Or does expander not really work well with CH4?
"I don't care what anything was DESIGNED to do, I care about what it CAN do"- Gene Kranz

Offline Asteroza

  • Senior Member
  • *****
  • Posts: 2872
  • Liked: 1099
  • Likes Given: 33
Re: Impulse Space
« Reply #84 on: 01/18/2024 11:05 pm »
I get the feeling Helios is targeting the Artemis TLI crowd and not so much HEO/GEO, at least for "commercial" space...

Offline sdsds

  • Senior Member
  • *****
  • Posts: 7221
  • “With peace and hope for all mankind.”
  • Seattle
  • Liked: 2072
  • Likes Given: 1978
Re: Impulse Space
« Reply #85 on: 01/19/2024 12:05 am »
Regarding Deneb:
Methalox Staged Combustion Cycle
— 𝐬𝐝𝐒𝐝𝐬 —

Offline ZachF

  • Full Member
  • ****
  • Posts: 1624
  • Immensely complex & high risk
  • NH, USA, Earth
  • Liked: 2635
  • Likes Given: 532
Re: Impulse Space
« Reply #86 on: 01/19/2024 12:06 am »
One of his interviews today he said Deneb is staged combustion

Interesting. Expander works really well at small scales and is simple and reliable.

What's the advantage of staged? Higher T:W maybe? Or does expander not really work well with CH4?

Staged combustion could let you get stupid high expansion ratios for the same engine bell size… like >500:1 if they wanted. Higher ER = higher ISP.
« Last Edit: 01/19/2024 12:10 am by ZachF »
artist, so take opinions expressed above with a well-rendered grain of salt...
https://www.instagram.com/artzf/

Offline ZachF

  • Full Member
  • ****
  • Posts: 1624
  • Immensely complex & high risk
  • NH, USA, Earth
  • Liked: 2635
  • Likes Given: 532
Re: Impulse Space
« Reply #87 on: 01/19/2024 12:18 am »
Because ultimately you can get power and cooling and perhaps globally accessible data via lasers for cheaper than terrestrial.

LOL, ok. At this point let's just agree to disagree because we aren't even in the same solar system in terms of world view.
Have you updated your worldview on this? Just run some numbers. Starlink gen2s may cost around $100/kg. Starlink v1 was $1000/kg.

They’re using commodity solar cells probably costing about 20-30¢/Watt, and using a German built stringer (used for making commodity terrestrial utility scale solar modules for 30-40¢/Watt) to solder them up into spacecraft arrays. They’re not manufacturing the satellites by 3D printing or expensive CNC machining, but by mass manufacturing stamped metal or molding, like how you mass-manufacture automobiles. We ARE in a different solar system already…

I think I made a thread about this years ago and most people called me crazy lol.

What’s the cost of in-space solar power with <$0.30 watt solar PV and <$100/kg to LEO? Probably almost laughably cheap…
artist, so take opinions expressed above with a well-rendered grain of salt...
https://www.instagram.com/artzf/

Offline ParabolicSnark

  • Full Member
  • *
  • Posts: 150
  • CA
  • Liked: 189
  • Likes Given: 124
Re: Impulse Space
« Reply #88 on: 01/19/2024 12:38 am »
What do we think the Deneb engine is likely to be like? I'm assuming an expander cycle would be a great fit, but electric pumped might work too.
Knowing Tom Mueller's background, what do we think is the most likely?
For electric pump 5klbs is about limit before turbopump engines are better option. Deneb is 15klbs.

I remember that being the case around 2015, but is that still the case? Has battery and controller technology advanced enough in the past decade (that hurts to say) where maybe it would now trade favorably at the 10-15k lb range? EV's have given us a lot in that sector.

Offline TrevorMonty

Re: Impulse Space
« Reply #89 on: 01/19/2024 02:18 am »
10-15k might be upper limit now. Give Toms background a turbopump engine is better path.

Offline Tywin

Re: Impulse Space
« Reply #90 on: 01/19/2024 03:09 am »
Because ultimately you can get power and cooling and perhaps globally accessible data via lasers for cheaper than terrestrial.

LOL, ok. At this point let's just agree to disagree because we aren't even in the same solar system in terms of world view.
Have you updated your worldview on this? Just run some numbers. Starlink gen2s may cost around $100/kg. Starlink v1 was $1000/kg.

They’re using commodity solar cells probably costing about 20-30¢/Watt, and using a German built stringer (used for making commodity terrestrial utility scale solar modules for 30-40¢/Watt) to solder them up into spacecraft arrays. They’re not manufacturing the satellites by 3D printing or expensive CNC machining, but by mass manufacturing stamped metal or molding, like how you mass-manufacture automobiles. We ARE in a different solar system already…

I think I made a thread about this years ago and most people called me crazy lol.

What’s the cost of in-space solar power with <$0.30 watt solar PV and <$100/kg to LEO? Probably almost laughably cheap…

And sorry I don't follow this conversation, can you explain your point?
The knowledge is power...Everything is connected...
The Turtle continues at a steady pace ...

Offline deltaV

  • Senior Member
  • *****
  • Posts: 2259
  • Change in velocity
  • Liked: 673
  • Likes Given: 2388
Re: Impulse Space
« Reply #91 on: 01/19/2024 03:17 am »
If you have a super-cheap two-stage fully reusable superheavy that can put (say) 200 tonne into LEO, then its payload can be a 100-tonne expendable kick stage with a 100-tonne actual payload. I think this beats Vulcan Centaur, except for the minor fact that it does not exist. Think of it as a one-off "tug".

From the rocket equation in a spreadsheet and a bunch of wild guesses at parameters I'd guess Starship plus Helios could get around 19 tonnes direct GEO, 37 tonnes to TLI, or 22 tonnes to low lunar orbit. That TLI figure is more than any current rocket other than SLS with EUS can do. A 100 tonne class kick stage or propellant transfer would of course make Starship even more capable (100+ tonnes to GEO, TLI or LLO) but Starship + Helios is already quite capable.

(https://www.impulsespace.com/updates/impulse-space-unveils-design-specifications-for-helios has one very important fact about Helios: it has up to 14 tonnes of propellant.)

Offline sdsds

  • Senior Member
  • *****
  • Posts: 7221
  • “With peace and hope for all mankind.”
  • Seattle
  • Liked: 2072
  • Likes Given: 1978
Re: Impulse Space
« Reply #92 on: 01/19/2024 04:14 am »
From the rocket equation in a spreadsheet and a bunch of wild guesses at parameters I'd guess Starship plus Helios could get around 19 tonnes direct GEO, 37 tonnes to TLI, or 22 tonnes to low lunar orbit.

Out of curiousity, for LLO what assumptions did you make about methalox boil-off rates? The Impulse website makes no mention of LLO as a destination orbit....
— 𝐬𝐝𝐒𝐝𝐬 —

Offline deltaV

  • Senior Member
  • *****
  • Posts: 2259
  • Change in velocity
  • Liked: 673
  • Likes Given: 2388
Re: Impulse Space
« Reply #93 on: 01/19/2024 05:37 am »
Out of curiousity, for LLO what assumptions did you make about methalox boil-off rates? The Impulse website makes no mention of LLO as a destination orbit....

I didn't account for boil-off or the mass of anti-boil-off hardware such as sun shields.

Now that you mention it I wonder if boil-off is why their stated GEO performance isn't as good as I expected.

Offline illectro

Re: Impulse Space
« Reply #94 on: 01/19/2024 05:39 am »
Plenty of numbers from Tom himself - 13.5T of propellent
Adds 3.9km/sec dv for a 6065kg payload
& 5.25 km/sec for 3241kg payload

Specific impulse is close to 378s

https://x.com/lrocket/status/1747742865424535565?s=20

https://x.com/lrocket/status/1747801633881485536?s=20

https://x.com/Phrankensteyn/status/1748115917395874108?s=20

Offline Robotbeat

  • Senior Member
  • *****
  • Posts: 39283
  • Minnesota
  • Liked: 25275
  • Likes Given: 12124
Re: Impulse Space
« Reply #95 on: 01/20/2024 12:45 am »
Plenty of numbers from Tom himself - 13.5T of propellent
Adds 3.9km/sec dv for a 6065kg payload
& 5.25 km/sec for 3241kg payload

Specific impulse is close to 378s

https://x.com/lrocket/status/1747742865424535565?s=20

https://x.com/lrocket/status/1747801633881485536?s=20

https://x.com/Phrankensteyn/status/1748115917395874108?s=20
notbadface.jpg
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 sdsds

  • Senior Member
  • *****
  • Posts: 7221
  • “With peace and hope for all mankind.”
  • Seattle
  • Liked: 2072
  • Likes Given: 1978
Re: Impulse Space
« Reply #96 on: 01/20/2024 11:53 pm »
Referencing here a comment on the Griffin Plan thread:

If Helios had long-duration capability, it could serve as a service module for Dragon launched on Falcon Heavy.

This certainly renews my interest in Helios as a potential candidate to provide propulsion for lunar orbit insertion. In that context, long-duration means only about 4 days, with acceptable boil-off rates. Have Mueller or Impulse Space provided any hints at all on that?
« Last Edit: 01/20/2024 11:54 pm by sdsds »
— 𝐬𝐝𝐒𝐝𝐬 —

Offline Robotbeat

  • Senior Member
  • *****
  • Posts: 39283
  • Minnesota
  • Liked: 25275
  • Likes Given: 12124
Re: Impulse Space
« Reply #97 on: 01/21/2024 12:20 am »
10-15k might be upper limit now. Give Toms background a turbopump engine is better path.
It's a staged combustion engine.
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 deltaV

  • Senior Member
  • *****
  • Posts: 2259
  • Change in velocity
  • Liked: 673
  • Likes Given: 2388
Re: Impulse Space
« Reply #98 on: 01/21/2024 03:49 pm »
Referencing here a comment on the Griffin Plan thread:

If Helios had long-duration capability, it could serve as a service module for Dragon launched on Falcon Heavy.

This certainly renews my interest in Helios as a potential candidate to provide propulsion for lunar orbit insertion. In that context, long-duration means only about 4 days, with acceptable boil-off rates. Have Mueller or Impulse Space provided any hints at all on that?

It seems sub-optimal to have all the cost and complexity of a low-boil-off pump-fed cryogenic stage but use it for only the ~1 km/s of delta vee that it takes to enter low lunar orbit. (Dr. Griffin's plan has the same issue.) It's more usual to use fewer and bigger cryogenic stages each providing 3+ km/s of delta vee. Bigger stages like Centaur V and the Falcon 9 upper stage seem better for crewed lunar missions since you can get more delta vee out of them. If you want to use Impulse Space hardware in a crewed lunar mission it may be better to make a new larger stage or lander using several of Helios's 15 klbf Deneb engines.

Offline deltaV

  • Senior Member
  • *****
  • Posts: 2259
  • Change in velocity
  • Liked: 673
  • Likes Given: 2388
Re: Impulse Space
« Reply #99 on: 01/28/2024 06:33 pm »
From the video section:

https://twitter.com/bccarcounters/status/1750912993607459012

Quote
Very happy to announce that this week @NASASpaceflight live will feature Impulse Space CEO Tom Mueller (@lrocket).

The show will start on Sunday at 3 p.m. Eastern time.

Link:



This is starting in half an hour.

Edit: that live interview happened. The same YouTube link can be used to watch the replay.
« Last Edit: 01/29/2024 12:05 am by deltaV »

Tags:
 

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